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HomeMy WebLinkAbout547 49-35 097 03-20-2023 CRRD BLT Initial Response to EPA Notice of Potential Violations From: Burns,Steven <sburns@balch.com> Sent: Monday, March 20, 2023 4:40 PM To: 'red leaf-durbin.joan @epa.gov' <redleaf-durbin.ioan@epa.goy> Cc: 'nakamoto.robert@epa.gov' <nakamoto.robert@epa.eov>;Summers, Robert <Summers.Robert@epa.gov>; Hill, Kyra (she/they) <Hill.Kvra@epa.aov>; LeFleur, Lance R <Ilefleur@adem.alabama.eov>; Kelly, Russell <RAK@adem.alabama.eov>;Cobb, Stephen <SAC@adem.alabama.aov>; SCOMENSK@SOUTHERNCO.COM <SCOMENSK@SOUTHERNCO.COM> Subject: EPA Notice to APC. Initial Response of APC Ms. Durbin, on behalf of Alabama Power Company,please find attached an initial response to EPA's Notice of Potential Violations and Opportunity to Confer,Alabama Power Company, Plant Barry—Bucks,Alabama,which Alabama Power received on January 31, 2023. I have copied Mr. Nakamoto,who is the named recipient of APC's letter per EPA's instructions, as well as your colleagues, Mr. Summers and Ms. Hill. I trust you will handle any further distribution within EPA. Also copied are the ADEM representatives who were copied on EPA's original correspondence. Regarding attachments, as you and I have established separately,we have made arrangements to share files via a website established for that purpose. We anticipate making those documents available to the courtesy copy recipients as well. Also as you and I have discussed, EPA has agreed to a deadline for written responses by April 3, 2023. We also acknowledge EPA's desire to receive documents sooner to the extent possible. In a spirit of cooperation,we are providing this initial response two weeks ahead of the agreed-upon deadline. Thank you for your consideration of this submission. Please feel free to contact me with further comments or questions. In the meantime,we will be in touch with one or more additional responses by April 3, 2023,or sooner. Sincerely, Steven Bums BALCH 4 51-0-Pn ,i Steven A.Burns,Partner,Balch&Bingham LLP 1901 Sixth Avenue North•Suite 1500•Birmingham,AL 352034642 t(205)226-8736 f:(205)488-5638 e:sburnsgbalch.com www.balch.com CONFIDENTIALITY: This email and any attachments may be confidential and/or privileged and are therefore protected against copying, use,disclosure or distribution. If you are not the intended recipient,please notify us immediately by replying to the sender and double deleting this copy and the reply from your system. Alabama Power Susan B.Comensky 600 North 18t'Street Vice President Post Once Box 2W Emtmnmental Moira 12N-0830 Birmingham,Alabama 35291 Tat 205.257.0298 Fez 205.257.A369 scomensk@emithemoo.com March 20, 2023 Via Electronic Mail Mr. Robert Nakamoto U.S. Environmental Protection Agency Region 4 Atlanta Federal Center 61 Forsyth Street Atlanta, Georgia 30303-8960 Re: Notice of Potential Violations(NOPV) and Opportunity to Confer Alabama Power Company, Plant Barry Initial Response of Alabama Power Company Dear Mr.Nakamoto: Alabama Power Company(Alabama Power)received the notice described above from the U.S. Environmental Protection Agency(EPA) on January 31,2023. The notice does not formally allege any violation of EPA's regulations for coal combustion residuals(CCR),but instead identifies"potential violations"and"areas of concern" and provides Alabama Power an opportunity to respond. Subsequent informal communications between counsel have established a deadline for Alabama Power to provide written responses by April 3,2023. EPA also requested that Alabama Power provide information on a rolling basis. In acknowledgement of EPA's desire to receive material as soon as possible,this letter transmits the company's initial response. As an introduction, this letter provides a general overview of Alabama Power's process to develop and execute its strategy to comply with EPA's CCR regulations. The letter then addresses EPA's areas of concern regarding annual inspections,the history of construction, structural stability, documentation for the amended closure plan, and the closure schedule. Alabama Power Has Gone to Great Lengths to Comply with the CCR Regulations,Protect Human Health and the Environment, and Close the Ash Pond at Plant Barry Safely. Alabama Power began the process of developing and implementing plans to comply with EPA's regulations beginning in December 2014,when EPA signed the final rule governing coal combustion residuals codified at 40 C.F.R. Part 257, Subpart D, ahead of publication in the Federal Register on April 17, 2015. Alabama Power necessarily relied on the text of the regulations and any guidance provided by EPA. In doing so,Alabama Power retained teams of experts, including both company employees and independent consulting firms, who worked in good faith to advise the company as to its compliance obligations based on their education and EPA NOPV for Plant Barry: Initial Response of Alabama Power March 20, 2023 Page 2 technical expertise, years of experience—including with the closure and remediation of sites under the Resource Conservation and Recovery Act(RCRA)—and past EPA practice and guidance. The engineers and geologists with responsibility for Alabama Power's plans and obligations maintain licenses issued by the State of Alabama. According to EPA, the use of licensed professional engineers is a foundational element of ensuring compliance under the CCR Rule, and companies were to rely on their professional judgements to determine compliance obligations. As EPA has observed,"professional engineers. . . . being professionals,will uphold the integrity of their profession and only certify documents that meet the prescribed regulatory requirements." 80 Fed. Reg. 21,302, 21,336 (Apr. 17,2015). Alabama Power thus has followed EPA's regulations to obtain certifications from licensed professional engineers for determinations of regulatory compliance with respect to, among other things, the bazard potential, the emergency action plan, structural stability, the safety factor,the groundwater monitoring system, the selection of remedy, and the closure plan. The experts retained by Alabama Power have performed their duties with competence and integrity. According to EPA, "the integrity of both the professional engineer and the professional oversight of boards licensing professional engineers are sufficient to prevent any abuses."Id. This is consistent with the statutory and regulatory obligations of Alabama engineers,whose "first and foremost responsibility is to the public health, safety, and welfare."Ala.Admin. Code r. 330-X-14-0.01(4). With a certification,the engineer represents that engineering services"have been performed . . .based on knowledge and information in accordance with commonly accepted procedures consistent with acceptable standards of practice."Ala. Admin. Code § 330-X-2- .01(7).An engineer is subject to discipline, including the potential revocation of one's license, for"[k]nowingly making any false statements"in a certification,""[e]ngaging in dishonorable . . . or unprofessional conduct,"and perforating services "outside any of the licensee's areas of competence,"among other things. Ala. Code §§ 34-11-11(a)(9), (12), & (15). Area of Concern 1) a.—Annual Inspections (§ 257.83) EPA modeled its annual inspection requirements after federal standards developed for purposes of dam safety. 80 Fed. Reg. at 21,301, 21,315-16 (Apr. 17, 2015). Alabama Power has more than a century of experience building, maintaining, and operating dams, including a longstanding and robust program for dam inspections. The company built Lay Dam to create its fast reservoir in 1913 and began generating electricity there the following year. Today,Alabama Power owns and operates eleven hydropower reservoirs, all with much greater capacity than the Plant Barry Ash Pond. These reservoirs must comply with regulations issued by the Federal Energy Regulatory Commission(FERC), including technical criteria to confirm and document the safety of dams and the reservoirs they create. These criteria are consistent in material respects with those of EPA. Alabama Power has deployed licensed professional engineers with expertise in dam safety to conduct detailed inspections of all of its ash pond dikes since before the inception of EPA's CCR program. Alabama Power has always required those engineers follow the same inspection procedures and criteria as they do for the company's much larger FERC-regulated hydropower reservoirs. EPA NOPV for Plant Barry: Initial Response of Alabama Power March 20, 2023 Page 3 The inspection reports posted to Alabama Power's CCR compliance website have been carefully designed to meet each and every element of§ 257.83(b)(2). EPA's characterization of the reports is that they"consist of a one-page checklist with,in many cases, one-word responses."The rule does not prohibit that practice, nor has EPA provided a template for inspection reports. We me aware of no directive or guidance from EPA to require longer narratives or to suggest any information is required other than that specified in the regulations. We interpret EPA's present observation regarding Alabama Power's compliance documents as a request for more information in support of the conclusions and findings of the company's public inspection reports. Accordingly,we are providing with this letter the internal reports by which Alabama Power's engineers documented annual inspections at Plant Barry from 2016 through 2022. The names of individuals other than the engineers who conducted the inspections and certain details of personally identifiable information have been redacted. Area of Concern 1) b.—History of Construction (§ 257.73(c)) EPA's letter states that"while the report included design drawings for two of the historical dike modifications, the report should also have included design or as-built drawings for the original 1965 construction and a 1972 dike modification."We take this as a reference to § 257.73(c)(vii), which requires the inclusion of"detailed dimensional drawings of the CCR unit" as one of twelve elements of the history of construction. Paragraph(vii) is subordinate to the introductory material of paragraph(c),which requires the compilation of a"history of construction,which shall contain,to the extent feasible,the information specified in paragraphs (c)(1)(i)through(xi) of this section." The drawings subject to potential disclosure under § 257.73(c)(vii)pertain exclusively to the history of construction. Therefore,we have understood the obligations under § 257.73(c) as relating to historical documents. This interpretation is supported by statements EPA made in the context of promulgating the CCR rule. According to EPA,the owner or operator of an existing surface impoundment is required to compile the information related to the history of construction "to the extent available." 80 Fed. Reg. at 21,380. EPA explained further as follows: EPA acknowledges that [for existing units] much of the construction history of the surface impoundment may be unknown or lost. EPA's Assessment Program confirmed that many owners or operators of CCR units did not possess documentation on the construction history or operation of the CCR unit. Information regarding construction materials, expansions or contractions of units,operational history, and history of events was frequently difficult for the owners or operators to obtain. The Assessment Program also confirmed the Agency's initial assumption that this information, in many instances, will be difficult to compile. Therefore, in this rule,EPA is using the phrase "to the extent available" and clarifying that the term requires the owner or operator to provide information on the history of construction only to the extent that such information is reasonably and readily EPA NOPV for Plant Barry: Initial Response of Alabama Power March 20, 2023 Page 4 available. EPA intends facilities to provide relevant design and construction information only if factual documentation exists. EPA does not expect owners or operators to generate new information or provide anecdotal or speculative information regarding the CCR surface impoundment's design and construction history. Id. See also EPA, Comment Summary and Response Document Vol. 6:Design Criteria— Structural Integrity at 32-34(Dec. 2014). Alabama Power searched its archives and was unable to locate contemporaneous design or as- built drawings from 1965 and 1972. Because design or as-built drawings of those vintages do not exist to the best of our knowledge,we determined that those specific documents were not available and it was not feasible to include them. We are aware of no directive or guidance from EPA that would interpret or expand on the regulatory language to require any different response. To the extent EPA's comment may reflect an interest in identifying construction materials and design elements of the dikes in their current conditions,we would refer you to other documentation available on Alabama Power's CCR compliance website, including the"History of Construction—Ash Pond,""Barry Ash Pond Amended Closure Plan Rev 1 April 2020— Updated,"`Barry Ash Pond Amended Closure Plan,""Initial Safety Factor Assessment-Ash Pond," and"PERIODIC STRUCTURAL STABILITY ASSESSMENT-BARRY AP."Please let us know if we can provide any assistance in identifying and reviewing these files. Area of Concern 1) c.—Structural Stability(§ 257.73(d)) Under § 257.73(d),the structural stability assessment"must, at a minimum, document whether the CCR unit has been designed, constructed, operated, and maintained with"various elements, such as stable foundations, slope protections, and spillways meeting certain standards, among others. EPA's letter states that Alabama Power's"two-page report only included general statements and lacked specific details,drawings,historical construction documents, or current photos documenting the status of the unit with respect to items required by 40 C.F.R. § 257.73(d)."However, § 257.73(d) does not include any reference to"specific details, drawings, historical construction documents, or current photos" or require disclosure of those items. In response to EPA's comments,please find attached to this response three documents prepared by Geosyntec: Engineering Calculation Summary Report: CCR Ash Pond Closure,Alabama Power Company,Plant Barry, Bucks,Alabama(2018),North Final Grades Settlement Analysis (2021), and North Final Grades Stability Analysis (2021). These reports provide detailed and exhaustive analytical support for the conclusion that the dikes at the Barry Ash Pond are structurally stable. Additional information about elements that contribute to structural stability is included in other compliance documentation, including especially the History of Construction and the Amended Closure Plan dated April 2020. We trust EPA is familiar with those documents,but we will be pleased to assist EPA in identifying further discussion and documentation of any features of the Ash Pond that may be of interest to the Agency. EPA NOPV for Plant Barry: Initial Response of Alabama Power March 20, 2023 Page 5 Area of Concern 1) d.—Documentation of Amended Closure Plan EPA observed that"the plan that was posted on the Alabama Power Company CCR website included the narrative section but did not include the referenced attachments."Alabama Power's CCR compliance website for the Barry ash pond includes several closure-related documents, including an "Amended Closure Plan"dated July 2019 and an "Amended Closure Plan Rev I" dated April 2020. These documents reflect Alabama Power's submissions to the Alabama Department of Environmental Management(ADEM) in the context of seeking a permit to close the ash pond under ADEM's regulations. The July 2019 document, which included attachments in the same file,reflects revisions to the closure plan as submitted to ADEM at that time. Following subsequent communications with ADEM,Alabama Power submitted a revised document to ADEM,which corresponds to the April 2020 document on our website. The attachments for the April 2020 document were the same as the attachments for the July 2019 document, and Alabama Power did not repeat the inclusion of those same attachments when it uploaded the April 2020 file to the compliance website. In light of EPA's comments,we have now also uploaded an"Updated"copy of the April 2020 document,which brings together the April 2020 content and the attachments into a single file. Area of Concern 2—Construction Details and Schedule The primary factor driving the construction schedule is the total volume of CCR to be moved. The Plant Barry Ash Pond contains approximately 21.7 million cubic yards of CCR. Of that amount,the closure plan requires the handling of approximately 41%,or approximately 9 million cubic yards. This material has to be handled using construction equipment such as excavators and bulldozers and moved one dump truck load at a time. The construction schedule is based on reasonable production rates of approximately 3,500-4,000 cubic yards per day and accounts for bad weather days. In response to EPA's comments,two documents laying out the construction schedule in more detail are included. Thank you for your consideration. We continue to review available information in an effort to prepare one or more additional submissions in response to EPA's letter. This letter does not represent Alabama Power's final word on any topic, including matters discussed herein. In providing this response to EPA, Alabama Power takes no position and makes no concession as to the extent or limits of EPA's authority, including the right to compel the production of information under RCRA or any other source of law. As our respective attorneys are in contact, I will appreciate your directing any informal communications through counsel. Sincerely, 0 Susan B. Comensky EPA NOPV for Plant Barry: Initial Response of Alabama Power March 20, 2023 Page 6 cc: Lance R. LeFlem, ADEM Russell A. Kelly,ADEM Stephen A. Cobb, ADEM Kimberly L. Bingham, EPA Joan Redleaf Durbin,EPA Attachments List of Attachments 1. Barry Steam Plant: Report of Annual Dam Safety Inspection(2016) 2. Barry Steam Plant: Report of Annual Dam Safety Inspection(2017) 3. Barry Steam Plant: Report of Annual Dam Safety Inspection(2018) 4. Barry Steam Plant: Report of Annual Dam Safety Inspection(2019) 5. Barry Steam Plant: Report of Annual Dam Safety Inspection(2020) 6. Barry Steam Plant: Report of Annual Dam Safety Inspection(2021) 7. Barry Steam Plant: Report of Annual Dam Safety Inspection(2022) 8. Engineering Calculation Summary Report: CCR Ash Pond Closure,Alabama Power Company,Plant Barry, Bucks,Alabama(2018) 9. North Final Grades Settlement Analysis(2021) 10. North Final Grades Stability Analysis(2021) 11. Batty Ash Pond Closure—Schedule 1 12. Batty Ash Pond Closure—Schedule 2 BARRY STEAM PLANT REPORT OF ANNUAL DAM SAFETY INSPECTION SEPTEMBER 22, 2016 GENERAL The Barry Steam Plant annual dam safety inspection was conducted on September 22, 2016. The inspection team consisted of Jason Wilson with SCS Environmental Systems & Field Support and Keith Bryant with SCG H dro Services. �� Com liance �S ecialist at Plant Barry, �, Senior Engineer at Plant Barry, and , Assistant Plant Control Operator at Plant Barry accompanied the team during the inspection. At an exit meetin g after the ins ection the ins ection team discussed its findings and conclusions with (Plant Barry Compliance Team Leader),and (Plant Barry Assistant Plant Manager). Weather conditions on the day of the inspection were sunny, hot, and humid, with temperatures in the high 80's rising into the low 90's (degrees Fahrenheit). No rain had been recorded at the plant in the 24 hours preceding the inspection. Overall, the attention to dam safety at Plant Barry is satisfactory, and the inspection team commends the plant staff for their continued commitment to dam safety. The plant staff should continue these practices in the years ahead. Based on observations in this year's inspection, the team has no specific corrective actions or recommendations for plant staff. Minor maintenance-related items were observed, and where noted these are discussed in the observations section below. These items are handled as a part of regular plant maintenance and formal recommendations specific to them were not deemed necessary in this report. The inspection included all sections of the main ash pond dam, the ash pond discharge structure, and the gypsum pond dam. Figure I identifies the areas referenced in the report. Pages 4 and 5 of the attached Inspecting Engineer's Checklist show the approximate photo locations noted in the findings for the ash pond and the gypsum pond dams, respectively. OBSERVATIONS AND RECOMMENDATIONS 1. Main Ash Pond Dam—East Dike First, the team inspected the emergency filter stockpiles located at the north end of the main ash pond. The sand and gravel stockpiles are well supplied, appropriately signed, and are clearly separated from other materials stored in this vicinity(See Photo 1). The inspection team walked the full length of the East Dike, with one inspector walking along the crest and one along the downstream toe. The crest and roadway appeared to be in good condition (see Photos 2 and 3). Vegetation covers the dike slopes well and was being appropriately maintained. The ongoing regular and appropriate maintenance of the dike by plant staff facilitates inspections by plant staff and the Dam Safety team. Plant staff should continue Page 1 of 13 APC Barry_EPA_000001 this regular embankment mowing and maintenance. It is noted that there is no longer a specific CCR rule requirement to maintain vegetation on the embankment to a height of 6-inches and it is recommended that wet conditions be avoided for any routine mowing activities to reduce the potential for rutting. The team observed only one animal burrow along the East Dike (which was flagged for repair) and no feral hog rooting along any of the embankments was noted during the inspection. Several small turtle nesting holes were observed (particularly along the East Dike) which were less than 6-inches in size (See Photo 6). These areas were pointed out to the Plant Staff. It is apparent that the plant staff is adequately monitoring for these activities in their inspections, and when these conditions are observed they are addressed as a part of the plant's regular embankment maintenance. It is also apparent that the Plant's efforts to control burrowing mammals and rooting hogs continue to be effective. Plant staff should continue its current practice of quickly repairing any areas of burrowing or other destructive activity by animals that they may find during their inspections. There are a few minor sloughing areas along the East and West Dikes near the waterline interface(see Photo 5 for an example). On the East and South dikes (from approximately just north of the diversion dike along the East dike to the discharge structure), vegetation at the interface between the pond waterline and the embankment upstream face continues to improve from the previous year's inspection (see Photo 4). The dam safety team appreciates the plant's efforts to control this vegetation. It should be noted that continued efforts to remove vegetation down to the waterline in this area will be required. 2. Main Ash Pond Dam—South Dike and Discharge Structure The team walked the full length of the South Dike—the embankment structure that contains the pond area downstream of the diversion dike. The downstream face of the south dike appears to be in good condition, suitably vegetated, and adequately mowed (see Photos 7 and 8). No other problems or concerns relative to the embankment were observed. The downstream slopes of the embankment appear to be performing well. The team inspected the inlet and outlet of the pond discharge structure. Flows were clear and no problems, e.g., damage to the structures, blockage of flows, erosion at the discharge, etc., were observed (see Photos 9 and 10). The gabion wall installed in 2005 continues to be performing acceptably. Routine debris removal should be performed to remove any woody debris adjacent to the intake structure (an example can be seen in Photo 9). The discharge pipe was visually inspected by a camera mounted rover in October 2015. As a result of that inspection and other relevant discussions, a decision was made to line the corrugated metal pipe. The lining of the pipe was completed during December 2015. 3. Main Ash Pond Dam—West Dike Page 2 of 13 APC Barry_EPA_000002 The team inspected the West Dike by walking its full length. As noted in the East Dike summary,there are some minor sloughing and/or erosion issues near the downstream toe in some locations (See Photo 11). Overall, the West Dike appears to be well vegetated and generally in satisfactory condition (See Photo 12). The roadway along the crest appeared to be in excellent condition(see Photo 13). 4. Gypsum Pond Dam The Barry Steam Plant Gypsum Pond was also inspected by walking along the full length of the exterior dike. The team found no cracks, slides or similar damage on the embankments and crest roads, and no evidence of animal activity affecting the structures. Vegetation covered the dikes adequately and was well maintained(see Photos 14 through 19). As a routine maintenance item, the vegetation and debris should be removed from the perimeter ditch, some portions of the Gypsum Pond,and along the liner of the sedimentation pond. STATUS OF PREVIOUS REcomwNDATIONs There are no open recommendations from the 2015 inspection. CONCLUSION The project structures appear to be performing adequately. There were no conditions that, in the opinion of the inspection team, would immediately affect the continued safe operation of the facilities inspected. Furthermore, the inspection team would like to extend appreciation to the plant compliance staff, in particular, for their cooperation and assistance during our visit to the site. Jason Wilson,P.E. Keith Bryant,. . Page3 ar O APC Barry_EPA_000003 . 1 a 'Fi ti Emergency Filter Izaa6 •W� Stockpiles �P,p C f� • Y- 1 r Q � z Main msQ Ash Pond P ps m Pond '� porn � DIJQ SIpO NORTH South Dike is Discharge Structure w a: Feet 11111' Photo 1: Emergency filter Stockpiles (Note 2015 Photo—Condition Same in 2016) F Photo 2: East Dike—Condition of Crest and Downstream Face, Typical Page 5 of 13 APC Barry_EPA_000005 i� M Photo 3: East Dike—Condition of Upstream Face, Typical x Photo 4: East/South Dike—Condition of Upstream Face Vegetation Page 6 of 13 APC Barry_EPA_000006 ql� l PAY! a' �{'�'d�K y�f• ry' '¢�f.• IFeu . Photo 5: Area of Sloughing at downstream toe—East Dike �y ypp Psi Ili A y ��`R i Photo 6: Turtle Nesting Hole Typical—East Dike Page'/. 13 APC Barry_EPA_00000] i Aa- Photo 7: South Dike—Condition of Downstream Face and Crest,Typical �v Photo 8: South Dike—Condition of Upstream Face and Crest,Typical Page 8 of 13 APC Barry_EPA_000008 If d �I w . ���{`rya p.• , ! N' S L ,{ I 1u' c v t 000009 v' 1 b (,E% Photo 11: Downstream Toe of West Dike,Typical Photo 12: Downstream Toe of West Dike,Typical Page 10 of 13 APC Barry_EPA_000010 Photo 13: Crest of West Dike,Typical Photo 14: Condition of Gypsum Pond Dam, Typical Page 11 of 13 APC Barry_EPA_000011 y d Photo 15: Condition of Gypsum Pond Dam, Typical 4 Photo 16: Condition of Gypsum Pond Dam, Typical Page 12 of 13 APC Barry_EPA_000012 --- 11 Photo 17: Condition of Gypsum Pond,Typical l" eA t \� 1 ! Photo 18: Condition of Gypsum Pond Dam, Typical Page 13 413 APC Barry_EPA_000013 BARRY STEAM PLANT REPORT OF ANNUAL DAM SAFETY INSPECTIONS NOVEMBER 14-15, 2017 GENERAL The Barry Steam Plant annual dam safety inspections were conducted on November 14 and 15, 2017. The Gypsum Pond was inspected on the afternoon of November 14th, while the Ash Pond inspection took place on the morning of November 15". The inspection was conducted by Mr. Jacob Jordan of SCS Fossil Dam Safety.—of Plant Barry Compliance was resent for the inspections. The inspection findings and conclusions were discussed with im upon the completion of each inspection. Weather conditions on the days of the inspection were clear and cool to warm,with temperatures rising from the low 507's in the morning to near 707 in the afternoon. Rainfall less than '/4-inch had been recorded in the week preceding the inspections. Overall, the attention to dam safety at Plant Barry is satisfactory, and the inspection team commends the plant staff for their continued commitment to dam safety. The plant staff should continue these practices in the years ahead. Based on observations in this year's inspection, the team has no specific corrective actions or recommendations for plant staff. Minor maintenance- related items were observed, and where noted these are discussed in the observations section below. These items are handled as a part of regular plant maintenance and formal recommendations specific to them were not deemed necessary in this report. The inspections included all sections of the main ash pond dam, the ash pond discharge structure, and the gypsum pond dam. Figure 1 identifies the areas referenced in the report. Pages 4 and 5 of the attached Inspecting Engineer's Checklist show the approximate photo locations noted in the findings for the ash pond and the gypsum pond dams,respectively. OBSERVATIONS AND RECOMMENDATIONS 1. Main Ash Pond Dam—West Dike The West Dike was inspected by walking from the South Evacuation Bridge toward the South Dike. The inspection alternated between the crest and toe, and also spent time walking along the downstream face of the embankment. The embankment appeared to be in good condition (see Photo 1). The Plant's efforts to curtail burrowing animals were apparent in that very few burrows were observed. A repair of a surficial slough (See Photo 2) was observed and was seen to have a good stand of grass established. Several ant mounds were observed (See Photo 3) on the West Dike and continued to be seen throughout the inspection. —reported that feral hogs had been observed at other areas of the plant, but no evidence of their presence was noted anywhere during the inspection. 2. Main Ash Pond Dam—South Dike and Discharge Structure Page 1 of 11 APC Barry_EPA_000014 The inspection continued full length of the South Dike—the embankment structure that contains the pond area downstream of the diversion dike. Flows were clear and no problems,e.g., damage to the structures,blockage of flows,erosion at the discharge, etc., were observed in the inlet or outfall of the discharge structure (see Photos 4 and 5). The gabion wall installed in 2005 continues to be performing acceptably. The discharge pipe was visually inspected by a camem mounted rover in October 2015. As a result of that inspection and other relevant discussions, a decision was made to line the corrugated metal pipe. The lining of the pipe was completed during December 2015. The downstream face of the south dike appears to be in good condition, suitably vegetated, and adequately mowed (see Photos 6 and 7). No other problems or concerns relative to the embankment were observed. The downstream slopes of the embankment appear to be performing well. 3. Main Ash Pond Dam-East Dike The East Dike was walked from its junction with South Dike until its terminus at the north end of the Ash Pond. The crest, downstream face, and upstream face all appeared to be in satisfactory condition(see Photos 7,8,and 9).Vegetation had good coverage on the slopes,though ant mounds were observed in several areas. The Plants efforts to control vegetation along the waterline appeared to be effective. 4. Emergency Filter Material Stockpiles The stockpiles of emergency filter material were observed(see Photo 10). The stockpiles were in generally good condition;however, grass/weeds were observed on the surface of the stockpiles of the finer gravel and sand. We recommend that the stockpiles be reconditioned and/or refreshed so that they can be used readily if needed. Note: As of 12/22/2017, the vegetation growing on the stockpiles had been removed, and the materials restored to their appropriate condition. 5. Gypsum Pond Dam The Barry Steam Plant Gypsum Pond was also inspected by walking along the full length of the exterior dike (see Photos 11, 12, and 14). The team found no cracks, slides or similar damage on the embankments and crest roads, and no evidence of animal activity affecting the structures though not mounds were observed (see Photo 13). Vegetation covered the dikes adequately and was well maintained. STATUS OF PREVIOUS RECOMMENDATIONS There are no open recommendations from the 2016 inspection. Page]of l l APC Barry_EPA_000015 CONCLUSION The project structures appear to be performing adequately. There were no conditions that, in the opinion of the inspection team, would immediately affect the continued safe operation of the facilities inspected. Furthermore, the inspection team would like to extend appreciation to the plant compliance staff,—in particular,for their cooperation and assistance during our visit to the site. Jfq b A.Jordan,P.E. Page 3 of 11 APC Barry_EPA_000016 qAftergen Filler Stockpiles %y Z7- Main sQ AshPond l ps m Pon Dam Sion z� NORTH South Dike \ . Discharge Structure 1 Photo 1: West Dike, condition of crest and downstream face, typical Photo 2: West Dike,surficial slough repair Page 5 of 11 APC Barry_EPA_000018 y_ a � Y t %,.. a4e1 o .a� 4y7 e�J''e, wtiW d 'a.F:"yyrati'6 a"" x'h C Photo 3: West Dike, ant mound near crest, typical . w e i Photo 4: General condition of discharge outfall Page b of 11 APC Barry_EPA_000019 Photo 5: Discharge inlet structure Lk Photo 6: South Dike, condition of downstream face Page 7 of 11 APC Barry_EPA_000020 Yang A'vY�aD 4J�i3}dd�rt'ei�i.�i' Lt: ' h.(ikl£.df Photo 7: Junction of South Dike and Fast Dike n :y i; Photo S: East Dike—Condition of downstream face,typical Page 8 of l l APC Barry_EPA_000021 Photo 9: East Dike, crest,typical Photo 10: Emergency Material Stockpiles Page 9 of 11 APC Barry_EPA_000022 Photo 11: General condition of Gypsum Pond crest, downstream face, and sluice pipes MENEM", r� Photo 12: General condition of Gypsum Pond Page 10 of 11 APC Barry_EPA_000023 Photo 13: Ant mound at Gypsum Pond,typical c Photo 14: Condition of Gypsum Pond Dam, Typical Page 11 of 11 APC Barry_EPA_000024 BARRY STEAM PLANT ASH & GYPSUM POND ANNUAL DAM SAFETY INSPECTION - 2017 INSPECTING ENGINEER'S CHECKLIST Date of Inspection: November 14-15,2017 he'aien la, Weather/Temp: Clear,cool-low We to upper 60's(de,F) Jacob Jordan,P.E. Rainfall(past 24 hrs): 0 inches Reservoir Elevation: EL 14 f1(lower pond),Normal SUMMARY The 2017 dam safety inspection at Barry SP was performed on November 14,2017(Gyysum Pond)and November 15,2017(Ash Pond). At the time of the inspection,both the ash pond dam and the gypsum pcmd dam was found to be in good condition and were being well-maintained. It was apparent Nat significant continuous effort was being applied to the embankment maintenance,and dam safety is being given a top priority. No recommendations for improvements are proAded as a result of the 2017 Inspection. CURRENT RECOMMENDATIONS(2017 INSPECTION) Description Location Photo No. NONE PREVIOUS RECOMMENDATIONS Location Status OpenlCompleted NONE APC Barry_EPA_000025 e.nvsa-mveswun aory[,5noncnxpin aw.olr�rrv�5.rzmz1 Gage 1 of 5 BARRY STEAM PLANT ASH & GYPSUM POND ANNUAL DAM SAFETY INSPECTION - 2017 OBSERVATIONS Observations-Comments Photograph No. I-ASH POND DIKE 1.Upstream Face a.Sionni or Sliding? Yes() No(X) IS,sell Cracklrp? Yes() No(X) c.Balm an Depressors? Yal No(X) E.Sgnlawm Erosion? Vel No(X) a.Vegetation Iasuea? Yes() No(X) G Mlmel Bon"? Yes(f No(X) g.Am Hills Bepuring Yes(X) No(1 Continue mrdLte sprayinryRmetagent 3 Thistr f 2.Downstream Face and Tea aslumpnga lemg? Yes O No(X) h.Neaamg? Yes O No(X) c sal Content? Yes(J No(X) a.smksarwpleasiman Yes O No(X) e.Significant Er iom Yes O No(X) Repair efforts noted on the West Dike 2 1.Unusual seepage or Wet Yes O No(X) zonea? g.Animal Bundvs or Hung Yes No(X) Acts" b.Vegetation Issues? Yes O No(X) i.Am Idle 6eguinng Yes(X) No(J Continue routine sprayingtheatment 3 Tres road 3.Dam Lreat e.son Drecprlg or laeuea Yes(J No(X) with crest goal b.Signet Seasonal Yes() No(X) c.vegetation Issues? Yes() No(X) a.Significant Froamn? Yes ONo(X) II-ASH POND DISCHARGE STRUCTURE wr Unusu 1. al Cracking or Yes f No`X) 1 Unusu 2.Obstructions to Flow? Yes( Ne(X) III-EMERGENCY FILTER STOCKPILE 1.issues wire Sorro le? Yes(X) No( )Grass should be removed from top of fine gravel and sand stockpiles tit Al Barry_EPA_000026 sayes-mvesyvun rare E non cnxrun de,o lralsrry 11,All Pate 2 Ms BARRY STEAM PLANT ASH $ GYPSUM POND ANNUAL DAM SAFETY INSPECTION - 2017 IV-GYPSUM POND 1.Upstream Face a.slumping or Sliding? YesO No(X) ,sail contend? Ye.O No(X) c,skits«owassians? Yes O No(X) a.slgnirncam Erosion? Yes O No(X) e.Vegetation,I.e.-? Yes() No(X) 1.Impenal Liner lMscee Yes(J No(X) or Damage? d.Am tents Effie d Yes No(X) Treating , 2.Dpernatream Face and T. a.Slumping or Sliding? Yes O No(X) ,.NaTdini Yea(f No(X) c Sol Clucking? Yes O No(x) a,sinks or o.Preval Yes O No(X) e.Significant Erasion? YesO No(X) r.Unusual Staged,or wet Ye.O No(X) mods? g.Anll 9unWA or Xrg Yes(J No(X) Adli ,.Vegetation Al Yes O No(X) i.Am IdIMBeguinng Yes(X) No O Continue routine sproyingr igneent 7$ Tree mean 3.Dam Crest is sell Ounces,a Issues Yes(J No(xJ wit,coat rasa? L.Capita till saluemem? YesO No(X) c.Vadetanan Inn...? Yes O No(X) a.Significant Pusateri YesONo(X) VI-ADDITIONAL OBSERVATIONS AND/OR COMMENTS NONE N/A OTHER NOTES NONE APC Barry_EPA_000027 coda-4Miryaun en.Eynonecure,Re, Okon®,11,2all Page 3 of BARRY STEAM PLANT ASH & GYPSUM POND ANNUAL DAM SAFETY INSPECTION - 2017 PHOTO LOCATION PLAN-ASH POND #10 y #1 y #2 #9 /$ ti #3� �#7 #s #a ti . r Cdytil° . APC Barry_EPA_000028 mnvsa-mvriswun aory[i5noncnxpin wv.o�Fmury u.2o1, Pa 4Ms BARRY STEAM PLANT ASH & GYPSUM POND ANNUAL DAM SAFETY INSPECTION - 2017 PHOTO LOCATION PLAN-GYPSUM POND q12 - 1 y 1 ll g n12'M; r, r a �ala t APC Barry_EPA_000029 mnvsa-mvriswun aory[i5noncnxpin wv.olFmurv .rsoizt Pace 5 Ms BARRY STEAM PLANT REPORT OF ANNUAL DAM SAFETY INSPECTIONS SEPTEMBER 20-21, 2018 GENERAL The Barry Steam Plant annual dam safety inspections were conducted on September 20-21, 2018. The Gypsum Pond was inspected on the afternoon of September 20'n, while the Ash Pond inspection took place on the morning of Se Iember 21" The inspection was conducted by Mr. Jacob Jordan of SCS Fossil Dam Safety. of Plant Barry Compliance was resent for the inspections. The inspection findings and conclusions were discussed with upon the completion of each inspection. Weather conditions on the days of the inspection were clear and warm, with temperatures rising from the low 70°17's in the morning to the low 90°17's in the afternoon. Rainfall less than Ya-inch had been recorded in the week preceding the inspections. Overall, the attention to dam safety at Plant Barry is satisfactory, and the inspection team commends the plant staff for their continued commitment to dam safety. The plant staff should continue these practices in the years ahead. Based on observations in this year's inspection, the team has no specific corrective actions or recommendations forplant staff. Minor maintenance- related items were observed, and where noted these are discussed in the observations section below. These items are handled as a part of regular plant maintenance and formal recommendations specific to them were not deemed necessary in this report. The inspections included all sections of the main ash pond dam, the ash pond discharge structure, and the gypsum pond dam. Figure 1 identifies the areas referenced in the report. Pages 4 and 5 of the attached Inspecting Engineer's Checklist show the approximate photo locations noted in the findings for the ash pond and the gypsum pond dams,respectively. OBSERVATIONS AND RECOMMENDATIONS 1. Main Ash Pond Dam—West Dike The West Dike was inspected by walking from the South Evacuation Bridge toward the South Dike. The inspection alternated between the crest and toe, and also spent time walking along the downstream face of the embankment. The embankment appeared to be in good condition (see Photos 1 and 2). A few active ant mounds were observed (see Photo 3); however, we observed many more that were not active as the plant has made the eradication of the ants a priority. Construction related to the closure of the pond has resulted in a portion of the West Dike being raised by approximately 27 inches. The slope angle was maintained along the embankment to the crest, and the face was either seeded or covered with riprap. The seeded portion was observed to have a healthy turf growing during the inspection (see Photo 4). Security has also been increased, Page 1 of 12 APC Barry_EPA_000030 as new high-resolution cameras have been installed at several locations along the embankment (see Photo 5). 2. Main Ash Pond Dam—South Dike and Discharge Structure The inspection continued full length of the South Dike—the embankment structure that contains the pond area downstream of the diversion dike. Flows were clear and no problems,e.g., damage to the structures,blockage of flows,erosion at the discharge, etc., were observed in the inlet or outfall of the discharge structure (see Photos 6 and 7). Noted this year was grass growing on the inside of the walled area of the discharge structure (see Photo 6),and upon review of past reports it has been growing there for several years.Removal of this grass should be added to the normal maintenance program of the ash pond. The downstream face of the south dike appears to be in good condition, suitably vegetated, and adequately mowed(see Photo 8). No other problems or concerns relative to the embankment were observed. The downstream slopes of the embankment appear to be performing well. 3. Main Ash Pond Dam-East Dike The East Dike was walked from its junction with South Dike until its terminus at the north end of the Ash Pond. The crest and upstream face appeared to be in satisfactory condition, though the vegetation along the waterline should be cut back as much as is practicable(see Photo 9). Sighting of wild boars have increased in the past year, and evidence of their activity has been observed primarily on the East Dike as it borders the Mobile River. The plant has been repairing these areas as soon as they are observed(see Photo 10) and have received assistance to trap and/or eliminate the boars when possible. The Plant's efforts to control vegetation along the waterline appeared to be effective. The condition of the road along the crest nearer the Plant end of the East Dike has begun to deteriorate with slight rutting and potholes(see Photo 11). Continued maintenance on this portion of the road is needed to prevent progression to a more significant issue. 4. Emergency Filter Material Stockpiles The stockpiles of emergency filter material were observed (see Photo 12) and appeared to be in good condition. The materials were reconditioned shortly following the 2017 inspection. 5. Gypsum Pond Dam The Barry Steam Plant Gypsum Pond was also inspected by walking along the full length of the exterior dike(see Photos 13, 14,and 15). The team found no evidence of instability or other issues, and no evidence of animal activity affecting the structures. Similar to the Ash Pond,many dormant or inactive ant mounds were noted with very few active mounds (see Photo 16). Vegetation covered the dikes adequately and was well maintained. Page 2 of 12 APC Barry_EPA_000031 STATUS OF PREVIOUS RECOMMENDATIONS There are no open recommendations from the 2017 inspection. CONCLUSION As of October 16, 2018, the vegetation and roadway conditions along the East Dike had been addressed satisfactorily by the Plant. We appreciate the prompt attention paid to these issues, and the ongoing efforts that are required to control external factors such as wild boars. The project structures appear to be performing adequately. There were no conditions that, in the opinion of the inspection team, would immediately affect the continued safe operation of the facilities inspected. Furthermore, the inspection team would like to extend appreciation to the plant compliance staff,—in particular,for their cooperation and assistance during our visit to the site. Jac . Jordan, P.E. Page 3 of 12 APC Barry_EPA_000032 kergency Filter Stockpiles Py Main O Ash Pond i ps m Pon � i Oam Sion z� NORTH South Dike \_ Discharge Structure 1 r• M�► Photo 1: West Dike,condition of crest, typical t x kr: Photo 2: West Dike,downstream face, typical Page 5 of 12 APC Barry_EPA_OOOOM asp ij ��v� h7a'^*� ", F ,i,� l fA6 "d' N Jr1+A,+ rly I� r„ a+ � � oa _,r and rx un fir �� 1`xA1, r}t WRO • fir e� � � f Pt 6FA"MOO* Y Y�11lYA #�• AM Photo 3: West Dike, ant mound near crest, typical a Photo 4: New grass on raised embankment Page b of 12 APC Barry_EPA_000035 .. k < i Photo 5: New security camera installation Photo 6: Discharge structure with vegetation inside skimmer Page 7 of 12 APC Barry_EPA_000036 � ) ri- �� � — \ kv ± 6 ue _� _ap' � . Phome South Dike Condition «___ _, typical Photo 9: East Dike, crest and upstream embankment, typical z 4� �p')eiAy a guy 7/ ,J. Y 4i 1AFa SC :: 1'ti y` V.R� � 5 5 �5! n ' 1 W WTI' 1G ra NMI Photo 10: East Dike, damage from wild boars rake 9^^f 1, APC Barry_EPA_000038 k� z> e IV� Photo 11: East Dike, ruts / potholes in crest road r Photo 12: Emergency filter material stockpiles Page 10 of 12 APC Barry_EPA_000039 4 4 , & 3� •� a- r_-JFF� -.y . 'tw .. �.•� -�:; ,tires >.Photo 13: General Conditions, Gypsum Pond Photo 14: General Conditions, Gypsum Pond Dam Page 11 of 12 APC Barry_EPA_COOMO \ lx Photo 15: Upstream Embankment, Gypsum Pond Dam, Typical Iry��jar '.7d'.1p1�►;iFA�ii' ` . '�' '�r�lr J .NY Photo 16: Active Anthill, Gypsum Pond Dam Page 12of12 APC Barry_EPA_000M1 BARRY STEAM PLANT ASH & GYPSUM POND ANNUAL DAM SAFETY INSPECTION -2018 INSPECTING ENGINEER'S CHECKLIST Date of Inspection: September 20-21,2018 Inepeclon by- Weather/Temp: Clear,warn-low TO's to low gRs(Eeg F) Jacob Jordan,P.E. Rainfall(past 24 has): c1A inches Reservoir Elevation: EL 14 It(lower pond),Normal SUMMARY The 2018 dam safety inspection at Barry SP was Performed on September 20,2018(Gypsum Pond)and September 21,2018(Ash Pond). At the time of the inspection,both the ash pond dam and the gypsum pond dam were found to be in good wndifion and were being well-maintained. It was apparent that significant continuous effort was being applied to the embankment maintenance,and dam safety is being given a top priority. No recommendations for improvements are provided as a result of the 2018 inspection. CURRENT RECOMMENDATIONS(2018 Inspection) Description Location Photo No. NONE PREVIOUS RECOMMENDATIONS(2017 Inspection) Description Location Status OpenlCompleted NONE APC Barry_EPA_000042 ee�so-mveyyvun aorv[ra—o I.va wv Pace 1 Ms BARRY STEAM PLANT ASH & GYPSUM POND ANNUAL DAM SAFETY INSPECTION -2018 OBSERVATIONS Observations-Comments Pbobograph No. I-ASH POND DIKE 1.Upstream Face a.Slumpng or Sling? Yea() No IS,sell Cucklrp? yes() No w Simms an Depressors? Yel No e.sigmaaam Bmsion? Yel No e.Vegetation Issues? Yes(X) No O Cutback to waterline 9 G Mlmal Bon"? Yes(f No g.Am Has ropun"g Yes(1 No(c) Treatmem? 2.Dpwnaheam Fees and Tom o Slumpdga lemg? Yes O No h.Neamg? YeSO No C.sal clacking? yesO No iLSIMnor Depleaswan Yes O No e.siamaaam Bernard? Yes O No r.Unusual Sector,or wm YeSO No nines? g.Animal Burnmes or Noe Yes(X) NoOConflnuerepalroidamagedareas 10 Actiatyl n.Vessel Issues? Yes O No(X) L Am Had Residue Yes(X) No()Continue routine spreyingbeatment 3 Treatidenn 3.Dam Crest s.son Cmcpelg a lasses yes(XJ No O Maintain mad to prevent ponding/rutting 11 with chat roan? b.Dlnerarial BaWeral Yes() No c.Vag.—lessen? Yes() No a.significant Broolon? Yes(f No II-ASH POND DISCHARGE STRUCTURE 1.Unusual Cracking or YeSO No Emnan? 2.Obstructions to Flow? Yes( No(X) III-EMERGENCY FILTER STOCKPILE 1 issues wnh Stengel ? Yes O No Al Barry_EPA_00i selso-mvaress—so.",le n cnxrnn des, lFareury 11,actt Pate 2 Ms BARRY STEAM PLANT ASH $ GYPSUM POND ANNUAL DAM SAFETY INSPECTION -2018 IV-GYPSUM POND 1.Upstream Face a.slumping or Sliding? Yes O No n.sail Carl Y.. No C.skits«Deposal Yes ONo(x) a.slgn�esam Erosion? Yes O No ..inspector,Leos:? Yes() No 1.Impermeable Liner lesces Ye.O No or Dame..? ..Am Nils Efil . Yes No Tons...? 2.Dpernatreem Face and T. a.Slumping or Sliding? Yes O No D.Nnal Yes(f No c Sol Cral Yes No a.sink.er D.Pneslunn Yes O No e.Significant Emslan? YesO No r.Unusual Seepage or wet Yes No tone,? 1.Amoy Hoodoo,or Nag Yes O No Ackli n.V.g.ugen le,ue.? Yes O No(X) Tonlewls "gull Yes(X) No O Continue goddi spreyingr igneent 16 Tm.Hills 3.Dam Crest e.soll cmacn,or ls,u., Yes(J No(x) eiscleetaoaa? L.Capita ngal sememem? YesO No ..V,..n Issues? Yes O No a.Significant Erosion? Yes Nl(X) VI-ADDITIONAL OBSERVATIONS AND/OR COMMENTS NONE N/A OTHER NOTES NONE APC Barry_EPA_000044 coda-4Miryaun aoN Eynonecer's Fro, '®YII.]mI) Page 3 of �-Mlll �• � v i � e �M Sri 1111' BARRY STEAM PLANT ASH & GYPSUM POND ANNUAL DAM SAFETY INSPECTION .2018 PHOTO LOCATION PLAN-GYPSUM POND #13 r I#14, ♦11. Y; I . �Jt r . APC Barry_EPA_000046 mrysa-mvriyyvun aory[rgnoncnxpin,wv.o�Fmuy ;rzoix) Page 5 of BARRY STEAM PLANT REPORT OF ANNUAL DAM SAFETY INSPECTIONS OCTOBER 1, 2019 GENERAL The Barry Steam Plant annual dam safety inspections were conducted on October 1 2019. The inspections were conducted by Mr. Jacob Jordan of SCS Fossil Dam Safety.—and of Plant Barry Compliance were present for the inspections. The inspection findings and conclusions were discussed with the team upon the completion of each inspection. Weather conditions on the days of the inspection were mostly clear and very warm,with temperatures rising into the upper 90'17's in the afternoon.No rainfall had been recorded in the week preceding the inspections. Overall, the attention to data safety at Plant Barry is satisfactory, and the inspection team commends the plant staff for their continued commitment to dam safety. The plant staff should continue these practices in the years ahead. Based on observations in this year's inspection, the team has no specific corrective actions or recommendations for plant staff. The plant has employed an excellent maintenance program,and it is recommended that this program continue. The inspections included all sections of the main ash pond dam, the ash pond discharge structure, and the gypsum pond dam. Figure 1 identifies the areas referenced in the report. Pages 4 and 5 of the attached Inspecting Engineer's Checklist show the approximate photo locations noted in the findings for the ash pond and the gypsum pond dams,respectively. OBSERVATIONS AND RECOMMENDATIONS 1. Emergency Filter Material Stockpiles The inspection began at the emergency filter stockpiles (see Photo 1), which appeared to be in good condition.New signage was recently installed to help prevent unauthorized use of the materials. 2. Main Ash Pond Data—East Dike The East Dike was walked north to south to its junction with the South Dike. The crest and downstream embankments appeared to be in good condition,with no evidence of wild boar activity or other distress(see Photos 2 and 3). The only water received by the ash pond is rainwater that falls in its watershed. Due to this factor and the recent drought conditions, the pool elevation in the pond has dropped significantly in the past few months. Evidence of this was observed by the staff gauge and abundance of dry areas in the pond near the East Dike(see Photo 4). The waterline vegetation appeared to be under control, and we recommend the plant continue their maintenance of that area. 3. Main Ash Pond Dam— South Dike and Discharge Structure The South Dike appeared to be well maintained and in good condition.As no water is being sent to the ash pond, flows through the discharge structure(see Photo 5)are solely from the Plant's W WT system pipes (see Photo 6). The low water conditions can be observed in the spillway and the areas around the discharge structure (see Photo 7). Page 1 of 10 APC Barry_EPA_00004] 4. Main Ash Pond Dam—West Dike The inspection concluded by walking the West Dike from south to north. The crest was adequately covered with crushed stone,with larger stone at the top of the crest(see Photo 8). The vegetation on the downstream embankment was sufficient and appeared to be healthy(see Photo 9).No signs of distress, instability, or damaging animal activity were observed. 5. Gypsum Pond Dam The Barry Steam Plant Gypsum Pond was also inspected by walking along the full length of the exterior dike (see Photos 10, 11, 12 and 14). The team found no evidence of instability or other issues, and no evidence of animal activity affecting the structures. Vegetation covered the dikes adequately and was well maintained. A new road has been constructed along the toe of the west dike of the sedimentation pond(see Photo 13),which is in condition and facilitates easier inspection of the downstream embankment. STATUS OF PREVIOUS RECOMMENDATIONS There are no open recommendations from the 2018 inspection. The maintenance items mentioned in the 2018 report have been addressed or have been added to the regular maintenance program. CONCLUSION The project structures appear to be performing adequately. There were no conditions that, in the opinion of the inspection team,would immediately affect the continued safe operation of the facilities inspected. The grass on the downstream embankments were freshly mowed, which is appreciated by the inspection team. Furthermore,the inspection team would like to extend appreciation to the plant compliance staff for their cooperation and assistance during our visit to the site. Jacob A.46rdan,P.E. Page 2 of 10 APC Barry_EPA_000048 71 2 w:= ' eyn.^cy'Fl o . L^ _ f ./ ZZ- Main Ash Pond t�� um / •„fir _ � � yaoD NORTH South Dike... Discharge Structure 001,001 2.000 3.000 , III 5,000 - - 1 r II Photo 1: Emergency Filter Material Stockpiles Photo 2: East Dike,condition of crest, typical Page 4 of 10 APC Barry_EPA_000050 Photo 3: East Dike, downstream face,typical Photo 4: Interior of pond along the East Dike P',5W10 APC Barry_EPA_000051 �t gryJFt d o v � J Photo 5: Discharge structure outfall Photo 6: Pipes from W WT System Page 6 of 10 APC Barry_EPA_000052 Photo 7: Interior of pond near discharge Photo 8: Typical conditions at the south end of the West Dike Page 9 of 10 APC Barry_EPA_000053 4 � Photo 9: West Dike— Condition of downstream face, typical i• I1 Photo 10: General Conditions, Gypsum Pond Page 8 of 10 APC Barry_EPA_000054 3 Photo 11: General Conditions, Gypsum Pond Dam Photo 12: Downstream Embankment, Gypsum Pond Dam,Typical Page 9 of 10 APC Barry_EPA_000055 R r - •� r . Photo 13: New Road at the Toe of the Sedimentation Pond Y Photo 14: West Dike of the Gypsum Pond Page 10 of 10 APC Barry_EPA_000056 BARRY STEAM PLANT ASH & GYPSUM POND ANNUAL DAM SAFETY INSPECTION -2019 INSPECTING ENGINEER'S CHECKLIST Daft of Inspecflon: October 1,2019 Inspeotlen by: Weather l Temp: Clear hot had W upper 90's hie,F) Jacob Jordan,P.E. Rainfall("at 24 hre): me Reservoir Elevation: me-below spillway riser SUMMARY The 2019 dam safety inspection at Ban,SP was performed on October 1,2019. Al the time of the inspection,both the ash pond dam and the gypsum pond dam were found to be In good condition and were being well-maintained. Water is now discharged from the Plant's W Wi system Instead of the ash pond. This,combined with drought conditions,has caused a drop in the ash pond level so that there is no flow through the spillway.There are no recommendations resulting from this inspection but we recommend that the plant keep up its high level of maintenance at both the ash and gypsum facilities. CURRENT RECOMMENDATIONS(2019 Inspection) Description Location Photo No. NONE PREVIOUS RECOMMENDATIONS(2018 Inspection) Location Status OpenfCompleted NONE APC Barry_EPA_000057 ee�so.mveyyaun aory[rgnoacnxacn,aw Pace 1 of 5 BARRY STEAM PLANT ASH & GYPSUM POND ANNUAL DAM SAFETY INSPECTION -2019 OBSERVATIONS Observations-Comments Photograph No. I-ASH POND DIKE 1.Upstream Face e.Slump,or Sliding? Yes() No U.Sall Call Yes(J No w sinks or Depe.—? Yes(J No a.sigMSaaMBmaion? vesO No e.Vegenatun Issues? YesO No(X)Grand c?ndgtans during gold inspection,but ardfrequire ongoft Attention to maintain. e annual Burrows? Yes No g.AM Hus Requlnng Ye8(J No Treatnal, 2.Downso sam Face and Toe aslumgngs9lakng? Yes O No Is.Hannal ? YAsO No c sal cmckingo Y.M No a,sinks or Depresakons? Yes No e.Significant Email Yes O No f Unusual seats,or wen Yes No donna? g.Aranal Bunawa or Naa An Yes O No(X) m n.Vegallaauea? Yes O No L AM Nilka Saudi Yes ONo(X)Dormant hills were observed.Recommend ongoing maintenance. TmatuenYl 3.Dam Crest e.Sall cucprlg M Issues yes(J No wgh C.,roes? Is Dlneranual sanlemem? Yes() No a.Veg.-Indiaa? Yes() No a.BlgnmaaMEOMon? Yes(f No 11-ASH POND DISCHARGE STRUCTURE 1.Unusual Crauking or YeSO No Emam? z.ohavuouans to Flo.? Yes( Nib(X) IN-EMERGENCY FILTER STOCKPILE 1.Issues All smokpne? Z No APC Barry_EPA_000058 rules-mlwwaun aorv[rgnoacn skhas Aw.otredurvta.xotrsl Page 2 of BARRY STEAM PLANT ASH & GYPSUM POND ANNUAL DAM SAFETY INSPECTION -2019 IV-GYPSUM POND 1.Upstream Face a.smmpng or sluing? YesO No in soil crenWni Yids O NO c.sinks M Depeaslmse Yes O No a.Significant erosion? Yes O No a.VegMamn leads:? Yes O No f.Impenmeaek Liner lMuck; Yes() NO or Demean g.AM Hills Regpinng Yes Np(x) TreatmerX 2.Cpwnatream Face and T. a.Slompng or Sliding? YesO No O.Hewing? Yes(f NO s.Sol cmwmg? Yes O N,(x) a,sinks or DePmaainnn Yes O No a.Siamrpont Emaicn? Yes O No f.Unusual Seenal or AM Yes(f NO nines? g.AnlmM eanO'xs or Nog Yes(J No AMNIN? n.Vrprosion Issues? Yes O No L Am Hiva nek inns Yes O No Dormant bills were observed.Recommend ongoing maintenance. Traditional? 3.Dam Coast is soil crenlung«Issu6 Yes No(x) wlnclestroea? e.Dlflerential Saalemem? Yes O No a.Vegetation Iaeuen Yes O No(X) a.Significant Erosion? YesO No VI-ADDITIONAL OBSERVATIONS AND/OR COMMENTS NONE NIA OTHER NOTES NONE APC Barry_EPA_000059 salks-sarcepaur rory pgnorcaxasn,ass o(f tederls Iasi l Pai Mj �r M Illlrl BARRY STEAM PLANT ASH & GYPSUM POND ANNUAL DAM SAFETY INSPECTION .2019 PHOTO LOCATION PLAN-GYPSUM POND t br. - #11 —� -- e fir; u�'G #12 F x #10 r 74 1 # APC Barry_EPA_000M mnvsa-mvriswun aory[rvnoacnxacn,aw.otFeduna.xoirsl Page 5 Ms BARRY STEAM PLANT REPORT OF ANNUAL DAM SAFETY INSPECTIONS JUNE 10-11, 2020 GENERAL The Barry Steam Plant annual dam safety inspections were conducted on June 10-11,2020. The Gypsum Pond, the West Dike and Emergency Filter Stockpiles of the Ash Pond were inspected on the afternoon of June 10ih while the remainder of the Ash Pond,the East and South Dikes, were inspected on the morning of June 11°h The inspection was conducted by Mr. Jacob Jordan of SCS Fossil Dam Safety and 1jjjjjjjjjjjjLofiPIwtt Barry Compliance. The inspection findings and conclusions were discussed with upon the completion of each inspection. Weather conditions on the days of the inspection were clear and warm,with temperatures in the upper 80's on June 10°h and in the 60's early on June l la'. Over six inches of rainfall was recorded in the few days preceding the inspections. Overall,the attention to dam safety at Plant Barry is satisfactory, and the inspection team commends the plant staff for their continued commitment to dam safety. The plant staff should continue these practices in the years ahead. Based on observations in this year's inspection, the team has no specific corrective actions or recommendations for plant staff. Minor maintenance-related items were observed, and where noted these are discussed in the observations section below. These items are handled as a part of regular plant maintenance and formal recommendations specific to them were not deemed necessary in this report. The inspections included all sections of the main ash pond dam,the discharge structure, and the gypsum pond dam. Figure 1 identifies the areas referenced in the report. Pages 4 and 5 of the attached Inspecting Engineer's Checklist show the approximate photo locations noted in the findings for the ash pond and the gypsum pond dams,respectively. OBSERVATIONS AND RECOMMENDATIONS Main Ash Pond Dam—West Dike The West Dike was inspected by walking from the South Evacuation Bridge toward the South Dike. The inspection alternated between the crest and toe, and also included time walking along the downstream face of the embankment. The embankment appeared to be in good condition (see Photos 1 and 2). The water at the toe was observed to be at a high level due to recent rainfall events(see Photo 2). Ant beds were noted throughout the inspection as they tend to emerge during the spring. Dormant beds were also noted on the embankments that were treated in prior seasons. APC Barry_EPA_d]B68@ Emergency Filter Material Stockpiles The stockpiles of emergency filter material were observed(see Photo 3) and appeared to be in good condition. Main Ash Pond Dam—East Dike The East Dike was walked from its northern end to its intersection with the diversion dike. In the days preceding the inspection, the Plant observed evidence of wild hog activity on the East Dike. The original damage was repaired. Additional areas were damaged the night before the inspection(see Photo 4). The plant has been in contact with the USDA regarding removal of the hogs and have been repairing the areas within hours of their discovery. Overall,the embankments and crest of the East Dike were in good condition. Heavy rains had resulted in high water levels along the river(see Photo 5)but did not result in any damage to the downstream embankments. Pond closure efforts had resulted in lower pool elevations on both sides of the diversion dike, and water is no longer near the embankment north of the diversion dike (see Photo 6). Main Ash Pond Dam—South Dike and Discharge Structure The inspection continued full length of the South Dike—the embankment structure that contains the pond area downstream of the diversion dike. Flow through the discharge structure is primarily water that is being pumped from the ash pond through the wattreatment system located north of the ash pond and then back to the discharge (see Photo 7). Only during heavy rainfall events does the pool elevation south of the diversion dike rise enough to spill over the riser. The downstream embankment was in good condition(see Photo 8). Woody vegetation has been thriving along the waterline between the discharge structure and the southern end of the diversion dike (see Photos 9 and 10). These sbrubs should be removed from the embankment, and the grass and other vegetation kept mowed or trimmed to allow for visual inspections of the upstream embankment. Gypsum Pond Dam The Barry Steam Plant Gypsum Pond was also inspected by walking along the full length of the exterior dike(see Photos 12 through 15). The team found no evidence of instability or other issues,and no evidence of animal activity affecting the structures. Similar to the Ash Pond, many emerging ant mounds were noted. Vegetation covered the dikes adegndtelys well maintained. STATUS OF PREVIOUS RECOMMENDATIONS There are no open recommendations from the 2019 inspection. APC Barry_EPA_dbobtl CONCLUSION The Ash Pond closure project is progressing,and we appreciate being kept informed of changes to the dike and pond operation as they pertain to Dam Safety. The project structures appear to be performing adequately. There were no conditions that, in the opinion of the inspection team, would immediately affect the continued safe operation of the facilities inspected. Furthermore, the inspection team would like to extend appreciation to the plant compliance staff,—in particular, for their cooperation and assistance during our visit to the site. Jacob A. an, P.E. APC Barry_EPA_db9688 i a ~ rergencys �06, Stockpiles �Pq. r �� sr r � Main 1 rnsQ Ash Pond i fe + pe in Pond - am of e s�o^o NORTH South Dike \ Discharge ' Structure w a: Feet �. 41•I Photo 1—Ash Pond West Dike,typical conditions r Photo 2—Ash Pond West Dike toe and wetland,typical conditions APC Barry_EPA_TOOM r: Photo 3—Emergency Filter Material Stockpiles �ibh Y Yr VI h � I S � T� 9 �.,. d bAt" .I f `�• Ary Y Photo 4—Ash Pond East Dike,overnight damage from wild hogs APC Barry_EPA_dbo600 Photo 5—Ash Pond East Dike,downstream embankment and river backwater Photo 6—Ash Pond East Dike,crest and upstream embankment APC Barry_EPA_GbB680 P i e1 °rl nl.l Photo 7—Water treatment pump outfall to Discharge Structure f- ' Photo S—Downstream embankment,Ash Pond South Dike adjacent to discharge APC Barry—EPA_dbo689 Dewatering facility,Ash Pond South Dike Photo I Dike APC Barry—EPA &0113 Photo 11-Gypsum Pond South Dike,general conditions i Photo 12-Gypsum Pond, north end of divider dike,general conditions APC Barry_EPA-t1bo618 i -r Photo 13—Gypsum Pond,downstream embankment of North Dike,general conditions Photo 14—Gypsum Pond, East Dike,general conditions APC Barry—EPA—MOM BARRY STEAM PLANT ASH & GYPSUM POND ANNUAL DAM SAFETY INSPECTION -2020 INSPECTING ENGINEER'S CHECKLIST Daft of Inspection: June 10-11,2020 Inspection by: Weather l Temp: Clear,warm-1.60's to upper 80'a(deg F) Jacob Jordan,P.E. Rainfall("at 20 hi -2.3 incbes Reservoir Elevation: EL 13,07 fi(lower pond),8I11M SUMMARY The 2020 dam safety inspection at Bany SP was performed on June f 01h(Gypsum Pond and West Dike of the Ash Pond)and June 11 (East and South Dikes of the Ash Pond). At kne time of the inspection,boll me ash pond dam and the gypsum pond dam were found to be in good condition and were being well-maintained. It was apparent that significant continuous effort was being applied to the embankment maintenance,and dam safety is being given a top priority. No recommendations for improvements are provided as a result of the 20201nspeonon. CURRENT RECOMMENDATIONS(2020 Inspection) Description Location Photo No7 . ONE PREVIOUS RECOMMENDATIONS(2019 Inspection) Location Status OpeniCompleted NONE APC Barry_EPA_'IA OM 2020 Bery SP lnspanton CMvhlist BARRY STEAM PLANT ASH & GYPSUM POND ANNUAL DAM SAFETY INSPECTION -2020 OBSERVATIONS Observations-Comments Photograph No. I-ASH POND DIKE 3.Upstream Face a.Slarl or Sling? YaSO No IS,Soll cracking' Yes() No w Sims or Dews.—? yel No a.signlrpam Erosion? Yel No e.Vegemmn Issues? YasO No G selmel HNN'Ms Yes(f No g.AM Hills Regnlnng Yaw No Treatment 2.Downstsem Face and Too o SlumgngorSuemg? Yes O No h.Imandi Yale O No c Sal cral Yaw No a.Sinks or Depressions Yes No e.Senlmam Emsinm Yes O No t.Unusual Seepage or Wes YeaO No dorms? g.Animal Bumens or Hog Yes/X) No/JCongnuerepalroidamagedareas q Antsity h.Vegetation Issues? yes O No(X) i.Ant Nius Sequinng Yes(X) No Continue reudne sproongbeatment Treatment? 3.Dam Crest e.Soll CrenNng w Issues yes(f No Anhcrest goal Is Dlnerenial Sa ernem? Yes/) No o.Veg.-Issues? Yes/) No a.Slgnme In Feasn? Yes(fNo(X) II-DISCHARGE STRUCTURE 1.UnusualGracking or Yes No`X) Emsan 4.destructions to Flo,? Yes( Nub(X) III-EMERGENCY FILTER STOCKPILE t.Issues Ann Sockpnez vasO No APC Barry_EPA_1%ol 2020 Bwry SP InsaarErn Clemkist BARRY STEAM PLANT ASH & GYPSUM POND ANNUAL DAM SAFETY INSPECTION -2020 IV-GYPSUM POND 1.Upstream Face a.sumps,Or sliding? Yei No in soll creckin,? YesO NO C.Sinks«Depeaslons? Yes O No a.Significant Emsiem Yes O No a.Ve,eamn In..-? Yes O No 1.Impvmeaek Liner Issues Yes O NO or Damage? ,.AM Hills Negpn", Yes Np(xJ Treatmern 2.Doernatream Face end T. a.Slumpng orSllaing? Y.M No O.NaT'ing? Yes(f NO c.Sal concert? Yes O N,(x) a.Sinks or Depressions Yes O No a.Significant Em.inm Yes O No r.Unusual Seepage or wet Yes O NO mnea? g.Amides eunWtl or Nog Yes(J No AdNIN? n.Vegetation Issues? Yes O No i.Am cent? guiring Yes(X) No O Contlnpe roptl n,spmongrLeatneent Ton.Hill. 3.Dam Crest is soll crenitin,«Issues yes(J No(xJ wits cMst Nom? e.Dlgerengal Segiemem? YesO No ..vaginal Issue.? YesO No a.Significant Erosion Yes() AN, VI-ADDITIONAL OBSERVATIONS AND/OR COMMENTS NONE N/A OTHER NOTES NONE APC Barry_EPA_thQbI§ 2020 Ben,So In.aandon CM lint v y i i c, y tea BARRY STEAM PLANT ASH & GYPSUM POND ANNUAL DAM SAFETY INSPECTION - 2020 PHOTO LOCATION PLAN- GYPSUM POND r #13 1 ; 2 t` #f APC Barry_EPA_%000 20206arry SPInsFa -CM Iisr BARRY STEAM PLANT REPORT OF ANNUAL DAM SAFETY INSPECTIONS APRIL 28-29, 2021 GENERAL The Barry Steam Plant annual dam safety inspections were conducted on April 28-29, 2021. The Ash Pond was inspected on the afternoon of April 28",while the Gypsum Pond was inspected on the morning of April 291h. The ins ection of the Ash Pond was conducted by Mr. Jacob Jordan of SCS Fossil Dam Safety, and and—of Plant Barry Compliance. — and—also conducted the inspection of the Gypsum Pond. The inspection findings and conclusions were discussed with the Compliance personnel upon the completion of each inspection. Weather conditions on the days of the inspection were partly cloudy and warm,with temperatures in the low 80's on April 28° and in upper 60's early on April 29". Some rainfall had occurred during the previous weekend, but none in the 2-3 days leading up to the inspection. Overall,the attention to dam safety at Plant Barry is satisfactory, and the inspection team commends the plant staff for their continued commitment to dam safety. The plant staff should continue these practices in the years ahead. Based on observations in this year's inspection, the team has no specific corrective actions or recommendations for plant staff. Minor maintenance-related items were observed, and where noted they are discussed in the observations section below. These items are handled as a part of regular plant maintenance and formal recommendations specific to them were not deemed necessary in this report. The inspections included all sections of the main ash pond dam,the discharge structure, and the gypsum pond data. Figure 1 identifies the areas referenced in the report. Pages 4 and 5 of the attached Inspecting Engineer's Checklist show the approximate photo locations noted in the findings for the ash pond and the gypsum pond dams,respectively. OBSERVATIONS AND RECOMMENDATIONS Emergency Filter Material Stockpiles The stockpiles of emergency filter material were observed prior to walking the embankments (see Photo 1) and appeared to be in good condition with adequate amounts material allocated for each type. Main Ash Pond Dam—East Dike The East Dike was inspected by walking from its northern end toward the South Dike. The inspection alternated between the crest and toe, and also included time walking along the downstream face of the embankment. The embankment appeared to be in good condition(see Photos 2, 3, and 4). At locations closest to the river, water at the toe was observed to be at a high level due to recent rainfall events(see Page 1 of 10 APC Barry_EPA_000078 Photo 4). Ant beds were noted throughout the inspection as they tend to emerge during the spring. Most had already been treated; however, some active untreated mounds were also observed. Main Ash Pond Dam—South Dike and Discharge Structure The inspection continued the full length of the South Dike,which includes the discharge structure and the dewatering station. The dike appeared to be in good condition(see Photo 5). Flow through the discharge structure is primarily water that is being pumped from the ash pond through the water treatment system located north of the ash pond(see Photo 6). Only during heavy rainfall events does the pool elevation south of the diversion dike rise enough to spill over the riser and engage the discharge structure. The woody vegetation observed during the 2020 inspection has been cut back and/or treated with herbicide and is not currently an issue(see Photos 7 and 9). We recommend monitoring the waterline areas closely during the spring for any regrowth. Main Ash Pond Dam—West Dike The West Dike was walked from the South Dike northward to the South Evac Bridge. The upstream and downstream faces of the embankment appeared to be well-maintained(see Photos 8 and 9)with no visible defects or signs of instability. We recommend closely monitoring the northem end of the perimeter roads as the ash redistribution is occurring mainly in that portion of the pond. On the downstream embankment near the South Evac Bridge, several ruts were observed across the face due to mowers. The ruts were bare at the time of the inspection(see Photo 10). While not a critical issue, bare areas can lead to erosion and rainfall infiltration into the embankment. We recommend that these areas be monitored and reseeded if regrowth does not occur during the spring. Gypsum Pond Dam The Barry Steam Plant Gypsum Pond was also inspected by walking along the full length of the exterior dike(see Photos 11 through 14).Vegetation covered the dikes adequately and was well maintained. The team found no evidence of instability or erosion; however, wild hogs had been seen around the area in the days preceding the inspection and damaged two small areas below the toe near the sedimentation pond. Those areas had been repaired prior to this inspection (see Photo 12) . STATUS OF PREVIOUS RECOMMENDATIONS There are no open recommendations from the 2020 inspection. CONCLUSION The Ash Pond closure project is progressing, and we appreciate being kept informed of changes to the dike and pond operation as they pertain to Dam Safety. The project structures appear to be performing P.p2of 10 APC Barry_EPA_000079 adequately. There were no conditions that, in the opinion of the inspection team,would immediately affect the continued safe operation of the facilities inspected. Figure 1 Barry Steam Plant-Ash Pond and Gypsum Pond Dams Reference Map 14, Stockpiles > - Ash Pond m Pon G dV F; ApsM--W NORTH South Dike Discharg structu 0 5001.000 2,000 3.000 4.000 5,000 Feet Scale Page 3 of 10 APC Barry_EPA_000080 LT` t !R^ {� .. Inspection Photos Photo 1: Emergency FUter Material Stockpile y i Dike,Photo 2: East 000081 (I Photo 3: East Dike, upstream view Photo 4: East Dike,water at embankment toe Page 5 of 10 APC Barry_EPA_000082 Photo 5: South Dike, downstream embankment near discharge structure vy Photo 6: Discharge structure Page bof 10 APC Barry_EPA_000083 f e`L"= Photo 7: Dewatering equipment Photo 8: West Dike, downstream embankment Page7of 10 APC Barry_EPA_000084 y • r �a Dike,Photo 9: West Photo 10: West Dike,mower rutting on downstream embankment \ y� N 1 y 'i, •fX i, ...1 i - p tr 1 0008 Photo 11: Gypsum Pond East Dike, crest and downstream embankment Photo 12: Gypsum Pond, repaired wild hog damage near Sedimentation Pond Page 9 of 10 APC Barry_EPA_000086 r^ f 4� Photo 13: Gypsum P 1 North Dike 'b Y Photo 1 1 n dike ._ between storage and sedimentation Page 1 of 10 000087 BARRY STEAM PLANT ASH & GYPSUM POND ANNUAL DAM SAFETY INSPECTION -2021 INSPECTING ENGINEER'S CHECKLIST Dateoflnspectlon: April 28-29,2021 Inspection by: Weather f Temp: Partly cloudy,warm-mid 60's to low 80's(deg F) Jacob Jordan,P.E. Rainfall(Past M thal: none Reservoir Elayatlon: EL 10.3 fi(lower pond) SUMMARY The 2021 dam safety inspection at Barry SP was performed on April 28(Ash Pond)and April 29,2021(Gypsum Pond). At to time of the inspection,both the ash pond dam and the gypsum pond dam were found to be in good cartoon and were being wall-maintained It was apparent tat Significant ont'muous Shod was being applied to the embankment maintenance,and dam safety is being given a top priority. No recommendations for improvements are provided as a result of the 2021 Inspection.One maintenance Item Is listed below. CURRENT RECOMMENDATIONS(2021 inspection) Description Location Photo No. NONE PREVIOUS RECOMMENDATIONS(2020 Inspection) Descriptio n Location Status OpenlCompleted NONE MAINTENANCE ITEMS Description Location Status to mowers was observed on the downstream embankment of the West Dike,Ash ITRutting resulting in strips of bare soil.If grass does not spread back over these Pond Ongoing ding may be necessary.Continua to monitor. APC Barry_EPA_000088 dri-mveyyaun aory drgnoacnxaen,aw.o(redurvl3.Mal Papa 1 of 5 BARRY STEAM PLANT ASH & GYPSUM POND ANNUAL DAM SAFETY INSPECTION -2021 OBSERVATIONS Observations-Comments Photograph No. I-ASH POND DIKE 1.U,.bnU m Face a,slunplre or slil Y.. M(x) b.sal Creelcul Y. No(x) c.Sinksur Nprearel Y. No(X) e.Signicart Encel YeW No(X) ..veeeamn saner.? Y.S M(x) r Animal Bunow.? Yes O No(X) ,. aHIIIs SequlMg Y. NS ll T...el? 2.Downstream Face Sind To. ..Sul or SINK? YeW No(x) It.NeavW res() No(x) c soi necking? Y. AS,(X) a.Sinlre or Deprsevers? Yes() No(X) e.Significant Seal YeW NO(X) I.Unusual seepage or We res O No(x) mre? g�bMWleenowa wNrq YeW No(X) I.v'retamn I—.? Yes(X) W 00rwrberearsaed.Wareawermk 10 I.Aunt Hills Rura g Ye.(X) No O Condnue routine spmyingRreaiment TrenMenl? 9.Dam Crest a,sal cra.Rmg or b.uea y�O �(X) ,,,creel Foam b.Dft..,.l sem.m.nD Yes() No(X) ..vegaml:n Issues? YeW No(X) a BlgnNrant Eresl.re YesO No(X) 11-DISCHARGE STRUCTURE 1,Unusual CaoMng a ves(7 No(X7 Erosion z on.raeu.ns m Flaw? YesO No III-EMERGENCY FILTER STOCKPILE 1.Issues io 9laakpne7 Yes(7 Nu(X) APC Barry_EPA_000089 emysa-esho'en P..ersn_enxacn,asa.'F 'laxotsl Pau2Ms BARRY STEAM PLANT ASH & GYPSUM POND ANNUAL DAM SAFETY INSPECTION -2021 IV-GYPSUM POND 1.Uos4eam Face a.Slumoiog or SlidN? YesONo(x) a.Sal Croargx YesO No(x) o.Sloksor Deorewronsv Y. ft(X) a.Signifirara Erosion? Yes() No(X) e.Vegelefion laaueax Yes() No(X) f lmparmeade Llowlssuea yea() NO(X) oroemagex g.MI wnS Fequlnna Yes No(X) Toorooenlx () ( ) 2.Downstream Fad and Too a.Slumoiog or Sliain,? Yes O No(X) a.Ho.vl,? Yes O No(X) o.Sou Dreapng? Yes O No(X) a.Sinew or DeP .—? Yes() No(X) e.Sigrofirant Erosion? Yes() NO(X) fuouaualseeongocrwat YesONo(x) o x g.Mlmal fto or Ntg Yea(X) ft Conhbue immetliete mpair when EisC ve,0 12 na, n.Vegelafiao lns ? Y. No(x) i.nnl Hilt Regum, Yes(X) N. C.M.n routine sprayingRreahnent TreeMenlx 9.Dam Crest a.Sal OMEN,or tauo Y.O ft(x) wml crest Raaar c.D'merenual SememenV Yes() No(X) n.Vegelauon taumx Yes O No(X) aSlg...1 n1Eraaiom Yes N.(X) VI-ADDITIONAL OBSERVATIONS AND/OR COMMENTS NONE N/A OTHER NOTES NONE APC Barry_EPA_000090 mrrysa-Mvnyyaun aory Ergnoa Cnxacn,nw.o(reduryl3.RO1R1 Gaae3M5 BARRY STEAM PLANT ASH & GYPSUM POND ANNUAL DAM SAFETY INSPECTION -2021 PHOTO LOCATION PLAN-ASH POND i 7t6 APC Barry_EPA_000091 mnvsa-mvriswun aory[rvnoacnxacn,aw.otFeduna.xoirs� Papa MS BARRY STEAM PLANT ASH & GYPSUM POND ANNUAL DAM SAFETY INSPECTION -2021 PHOTO LOCATION PLAN-GYPSUM POND ,\ • Y 1 S- ; 't?• r t i # 1 •S APC Barry_EPA_000092 mr.ysa-mvriyyaun aorv[rgnoacnxacn,aw.o(Feduya.xotrz� Pa 5or5 BARRY STEAM PLANT ASH POND REPORT OF ANNUAL DAM SAFETY INSPECTION APRIL 28, 2022 GENERAL The Barry Steam Plant annual dam safety inspection of the Ash Pond was conducted on April 28, 2022. The inspection of the Ash Pond was conducted by Mr. Jacob Jordan and Mr. Jim Pegues of SCS Fossil Dam Safety, —of APC Environmental Affairs and — of Plant Barry Compliance. The inspection findings and conclusions were discussed with the Compliance personnel upon the completion of each inspection. Weather conditions on the day of the inspection was clear, with temperatures in the upper 60's. No rainfall had fallen in the week prior to the inspection. Overall, the attention to dam safety at Plant Barry is satisfactory, and the inspection team commends the plant staff for their continued commitment to dam safety. The plant staff should continue these practices in the years ahead. Based on observations in this year's inspection, the team has no specific corrective actions or recommendations for plant staff. The inspection included all sections of the main ash pond dam, the discharge structure, and the emergency filter material stockpiles. Figure 1 identifies the areas referenced in the report. Page 3 of the attached Inspecting Engineer's Checklist shows the approximate photo locations noted in the findings for the ash pond dam. OBSERVATIONS AND RECOMMENDATIONS Main Ash Pond Dam —West Dike The West Dike was walked from the Evacuation Bridge toward the South Dike, with the team positioned on both the crest/upstream embankment and low on the downstream embankment. The upstream and downstream faces of the embankment appeared to be well-maintained (photos 1, 2, and 3)with no visible defects or signs of instability. The ruts that were noted during the 2021 inspection were in better condition and while still visible had better vegetation cover. The inspection of the toe was somewhat limited due to high water levels in the adjacent canal (photo 3). Main Ash Pond Dam— South Dike and Discharge Structure The inspection continued the full length of the South Dike, which includes the discharge structure and the dewatering station. The dike appeared to be in good condition (photo 4). Flow through the discharge structure is primarily water that is being pumped from the ash pond through the water treatment system located north of the ash pond. Only during heavy rainfall events does the pool elevation south of the diversion dike rise enough to spill over the Pagel of8 APC Barry_EPA_000093 riser and engage the discharge structure. The photos around the dewatering area (photo 6) and discharge structure illustrate the lowered water level in the pond. Main Ash Pond Dam— East Dike The East Dike was inspected by walking its entirety from the South Dike. The embankment appeared to be in good condition (photos 7 and 8). At locations closest to the river, water at the toe was observed to be at a high level due to recent rainfall events. Emergency Filter Material Stockpiles The stockpiles of emergency filter material were observed after walking the embankments (see Photo 9) and appeared to be in good condition with adequate amounts material allocated for each type. STATUS OF PREVIOUS RECOMMENDATIONS There are no open recommendations from the 2021 inspection. CONCLUSION The Ash Pond closure project is progressing, and we appreciate being kept informed of changes to the dike and pond operation as they pertain to Dam Safety. The project structures appear to be performing adequately. There were no conditions that, in the opinion of the inspection team, would immediately affect the continued safe operation of the facilities inspected. Page 2 of 8 APC Barry_EPA_00009 �Jajffjbergency Filter 'yob J*.::-X_. • � Stockpiles r P Y \•�� Main P'"rQ Ash Pond ps m Pon pam NORTH \ t �O�thwDike__. . • Discharge Structure t Inspection Photos 1 Photo 1: West Dike, crest and downstream embankment I`y i Photo 2: West Dike, upstream embankment Page 4 of 8 APC Barry_EPA_000096 � A x L Photo 3: West Dike, toe and downstream embankment face �r s u . 'A� V Photo 4: South Dike, looking West Page 5 of 8 APC Barry_EPA_0000 7 1 y`w a Photo 5: Discharge Structure Photo 6: Dewatering equipment Page 6 of 8 APC Barry_EPA_000098 Photo !/ 2 East_e,typical ___ Photo e East Dike, upstream embankment and closure area Photo 9: Ash Pond emergency filter materials Page 8 of 8 APC Barry_EPA_000100 BARRY STEAM PLANT ASH POND ANNUAL DAM SAFETY INSPECTION -2022 INSPECTING ENGINEER'S CHECKLIST Data of Inspection: April 28,M22 Ins action by: Weather l Temp: Partly cloudy,warm-mid 80'(deg F) Jacob Jordan,P.E. Rainfall(past 21 hi none Jim Pegues,P.E. Reservoir Elewdlon: 10.5 ft-mi(soNh Pond) T.V.Davis,James Douglas SUMMARY The 2022 dam safety inspection at the Barry SP Ash Pond was conducted on April 28,2022. At the time of the inspedion,the ash Pond dam and more found to be In good condition and was being well-maintained It was apparent mat significant continuous effort was being applied to the embankment maintenance,and dam safety is being given atop priority. No recommendations for improvements ate provided as a result of the 20U inspection.The single maintenance item from M21 hes been closed. CURRENT RECOMMENDATIONS(2022 Inspection) Description PM1ato No. NONE PREVIOUS RECOMMENDATIONS(2021 Inspection) Description Location status Open)(Completed NONE MAINTENANCE ITEMS No. Description n Status RuOing from the mowers was observed on the downstream embankment of the West yyest Dlke,Ash AP-1(2021) Dike,result ng in strips of bare soil.If grass does not spread back over these areas, pond Closed reseeding may be necessary.Continue to monitor. APC Barry_EPA_000101 eery aP-era,p—emf Esg sCivor,ii .0 Peduvy t12012) Page 103 BARRY STEAM PLANT ASH POND ANNUAL DAM SAFETY INSPECTION -2022 OBSERVATIONS Observations-Comments PnotolmPIN No. -ASH POND D 1.Upstream Face a.Slumming or shags resfl NI(x) I,Sall Cndmng? Yes O No(X) u slnR w Depressions? Y.S NI(X) a.Signnmam Emsiom Yes O No(X) e.Vegearmn 1—mis? Y..O M(X) I.Animm Emro.s? YesONc(X) g.twin Rills Reemnm Y.SOM(X) Tn umon? 2.Downstream Faces and Tx a.slumping orsiiaing? Y.. M(X) b.RNeNng? res() No(x) a.awl smug? Yes() No(X) a.saw or Depreesions? Yes OW(X) a.Signiicam Erosion? Y..O M(X) I.Unnuml Seepage or wNl yeaO No(x) g.Anlmm ps.or Rog rea() No(x) Amwlryx b,Vegetation leases? Yes O W(x) i.twin Rills Rwumng Y.. M(X) Tn Omm? 3.Dam Crest a.Soil cnwng or issues Y.. M(X) wine Grit Roam? I.DuNNmmiai Sememenn Yes O W(x) a.veg novel leases? Yes() No(X) a.Slgmn.Nm Ems, Yen No(x) -DI HAR E STRUCTURE 1 Lim. mrecNng or vas O No(x) z Ooso-uosom b Ho.? yes() No(x) III-EMERGENCY FILTER STOCKPILE 1.NS—writ,soewue? Yes() ND(X) IV-ADDITIONAL OBSERVATIONS AND/OR COMMENTS NONE N/A Bury aP-aavor,peum Pmf Enplwr CMFlltt Rry 0 l mosrr 9.201n sr,203 BARRY STEAM PLANT ASH POND ANNUAL DAM SAFETY INSPECTION -2022 PHOTO LOCATION PLAN-ASH POND ri5 APC Barry_EPA_000103 Bury EP Pm E,B ,C1ef.FIBt Rry 0 P S,IS.2012) Page303 Prepared for Southern Company Services, Inc. Southern Birmingham,3535 Colonnade Parkway rmingham, Alabama 35243 Company ENGINEERING CALCULATION SUMMARY REPORT CCR ASH POND CLOSURE ALABAMA POWER COMPANY PLANT BARRY Bucks, Alabama Prepared by Geosyntec ° consultants engineers I scientists I innovators 1255 Roberts Boulevard NW; Suite 200 Kennesaw,Georgia 30144 Project Number GW6489 AUGUST 2018 APC Barry_EPA_0001N Geosynte& consultants TABLE OF CONTENTS 1. INTRODCUTION................................................................................................ 1 1.1 Terms of Reference..........................................................:.......................... 1 1.2 Background.................................................................................................. 1 1.3 Scope and Organization of the Report.............................11...........................2 2. DESCRIPTION OF CLOSURE APPROACH...........................1.......................2 3. DESIGN CRITERIA............................................................................................3 00, 4. SUMMARY OF ENGINEERING REPORT CACLUATION PACKAGES......4 4.1 Material Properties and Major Design Parameters (Data Package)............4 4.2 Settlement Calculation Packages.................................................................6 4.2.1 Final Cover Settlement..............................Y.................................6 4.2.2 Soil Containment Berm Settlement.................................................7 4.3 Stability Calculation Packages ....................................................................8 4.3.1 Closure Stability Analysis—Seismic.............................................8 4.3.2 Closure Slope Stability Analysis....................................................8 4.3.3 Veneer Stability Analysis for Final Cover Design.........................9 4.3.4 Closure Stability Analysis—Liquefaction......................................9 4.3.5 Interim Conditions Slope Stability Analysis................................ 10 4.3.6 Seepage Analyses and Mitigation Design.................................... 10 4.4 Volumetric Reduction of Coal Combustion Residuals.............................. 10 4.5 Hydrologic Evaluation of Cover Performance.......................................... 11 4.6 ClosureTurf%) Cover System Design Package .......................................... 11 5. CLOSURE.......................................................................................................... 12 REFERENCES....?!�..................................................................................................... 13 Projec lam_Barry_Report nreft_t) A T r ..dd., APC Barry_EPA_000105 Geosynte& consultants TABLE OF CONTENTS (Continued) LIST OF TABLES Table 1 Plant Barry Ash Pond Closure- Geotechnical Design Criteria LIST OF APPENDICES Appendix A Material Properties And Major Design Parameters Appendix B Settlement Calculation Packages Appendix BI Final Cover Settlement Appendix B2 Soil Containment Berm Settlement Appendix C Stability Calculation Packages Appendix C 1 Closure Stability Analysis - Seismic Appendix C2 Closure Slope Stability Analysis Appendix C3 Veneer Stability Analysis for Final Cover Design Appendix C4 Closure Stability Analysis—Liquefaction Appendix C5 Interim Conditions Slope Stability Analysis Appendix C6 Seepage Analyses and Mitigation Design Appendix D Volumetric Reduction of Coal Combustion Residuals Appendix E Hydrologic Evaluation of Cover Performance Appendix F ClosureTmlW Cover System Design Package GW6489MI.t Barry_ .,p Draft DRAFT 11 08.27.18 APC Barry_EPA_000106 Geosynte& consultants LIST OF ACRONYMS ADEM Alabama Department of Environmental Management (ADEM) APC Alabama Power Company CCR Coal Combustion Residuals CFR Code of Federal Regulations FERC Federal Energy Regulatory Commission el HDPE High-Density Polyethylene HELP Hydrologic Evaluation of Landfill Performance LLDPE Liner Low-Density Polyethylene MHSA Mine Safety and Health Administration SCS Southern Company Services USACE United States Army Corps of Engineers USEPA United States Environmental Protection Agency GW6489/Plmt_Baz _Repon_@att_DR T In 08.22I8 APC Barry_EPA_000107 Geosyntec° consultants 1. INTRODCUTION 1.1 Terms of Reference At the request of Alabama Power Company(APC)and Southern Company Services,Inc. (SCS), Geosyntec Consultants (Geosyntec)was retained for the design of the closure of the Coal Combustion Residual (CCR)impoundment(ash pond) at Plant Barry located in Bucks, Alabama. This document provides an engineering narrative that summarizes the various geotechnical engineering calculation packages prepared in support of the closure design of the ash pond. 1.2 Background Alabama Power Company's (AFC's) Plant Barry(Site) is located near the Mobile River in Bucks, Alabama. The plant began commercial operation in 1954. In 1965, the ash pond was placed into service and has been operating as a wet pond and is currently in service. Throughout its operations, the ash pond has been receiving sluiced Coal Combustion Residuals (CCR) such as fly ash, bottom ash, economizer ash, pyrites, and selective catalytic reduction (SCR) ash, as well as low-volume wastewater generated as part of the plant operations. Since 2005,the ash pond has been used for dry stacking the sluiced ash. In addition, the ash pond receives decant water from the gypsum storage area and stonnwater from various plant areas. The ash pond is the only active ash pond at the plant property and encompasses approximately 597 acres in surface area and is contained by an earthen dike providing a physical barrier between the CCR and the surrounding areas. Geosyntec understands that SCS and APC intend to close the ash pond at Plant Barry to comply with the Federal CCR Rule. In December 2016,APC and SCS on behalf of Balch and Bingham LLP retained Geosyntec to conduct a Feasibility Study for the closure alternatives for the ash pond. Following the evaluation of closure alternatives, SCS and APC retained Geosyntec to complete a detailed design for the selected closure alternative of consolidating the CCR in the central portion of the ash pond and capping this area with a final cover system. GW6489MImt Bae _Repoft Dmft DRAFT 1 08.29.18 APC Barry_EPA_000108 Geosynte& consultants 1.3 Scope and Or¢anization of the Report The purpose of this report is to provide a summary of results derived from engineering design calculations prepared in support of the detailed design of ash pond closure. The remainder of this report is organized as follows: • description of the proposed closure approach is presented in Section 2; • design criteria adopted in engineering design calculations for the ash pond closure is presented in Section 3; and • summary of design analyses results and demonstration of compliance with the design criteria are presented in Section 4. 2. DESCRIPTION OF CLOSURE APPROACH The Ash pond will be closed by a"consolidate and cap in-place"approach where the total surface area of the Ash Pond will be consolidated from 597 acres to approximately 300 acres(consolidated footprint)located in the central portion of the ash pond. Construction for this approach will include: (i) removal of CCR from areas contiguous to exiting earthen dikes and southern portions of the ash pond (Closure by Removal Area); (ii) construction of an approximately 12,000 ft soil containment berm that define the boundary of the consolidated footprint; (iii) placing the excavated CCR within the consolidated footprint; and (iv) installing a final cover system, including a ClosureTurf® cover system,over the entire consolidated footprint to prevent infiltration of precipitation. The proposed consolidated footprint includes the following features: • The consolidated footprint grades will generally be constructed at 3.5 percent to maintain geotechnical stability, and to prevent ponding of water on top of the cover system. The surface-water drainage conveyance features on the cover system (i.e., drainage benches and perimeter channels) have slopes generally ranging from 0.5 percent to 1.0 percent. • The proposed final cover system is a ClosureTurfo cover system consisting of the following components, from bottom to top: (i) a 50-mil thick textured liner low- density polyethylene(LLDPE)geomembrane(GM)with spike down and studded GW6489MImt Bae _Repoft Dmft DRAFT 2 08.29.18 APC Barry_EPA_000109 Geosynte& consultants drainage layer referred to as MicroDmin®; (ii) engineered turf, and(iii) a 0.5-in. thick sand infill which acts as a ballast. • The final closure grades incorporate drainage benches, perimeter channels, and other stormwater management features to prevent erosion and direct stormwater runoff into a stormwater management system. Additional information on the stormwater management system is presented in the Final Cover Surface Water Management System Design [Geosyntec, 2018a]. 3. DESIGN CRITERIA The closure design of the ash pond at Plant Barry was performed in accordance with United States Environmental Protection Agency's (USEPA)40 CFR§257 and §261 (the USEPA CCR Rule) [USEPA, 2015]. The USEPA CCR Rule was published on 17 April 2015 and became effective on 19 October 2015. In addition to the USEPA CCR Rule, the following references were used as guidance documents to develop the design criteria applicable to the closure of the ash pond: • Alabama Department of Environmental Management (ADEM) Land Division— Solid Waste Program,Chapter 335-13-15 titled Standards for the Disposal of Coal Combustion Residuals in Landfills and Surface Impoundments. The ADEM CCR Rule was filed on 24 April 2018 and became effective on 08 June 2018. • Alabama Department of Environmental Management (ADEM) Division 13 regulations (ADEM Solid Waste Regulations) [ADEM, 2016] • Berg R.R. and Bonaparte, R., "Long-Term Allowable Tensile Stresses for Polyethylene Geomembranes", Geotextiles and Geomembmnes (Vol. 12, 1993, pp. 287-306) [Berg and Bonaparte, 1993]; • United States Army Corps of Engineers (USACE) Slope Stability Manual (EM 1110-2-1902) [USACE,2003]; • United States Army Corps of Engineers(USACE),Hurricane and Storm Damage Risk Reduction System Design Guidelines (Interim), New Orleans District Engineering Division [USACE,20121; GW6489MImt Bae _Repoft Dmft DRAFT 3 08.29.18 APC Barry_EPA_000110 Geosyntec° consultants • United States Army Corps of Engineers (USACE); Design and Construction of Levees(EM 1110-2-1913) [USACE, 20001; • Mine Safety and Health Administration(MSHA)Engineering and Design Manual, Coal Refuse Disposal Facilities [MSHA, 20101; and • Federal Energy Regulatory Commission(FERC)"Embankment Dams" [FERC, 2006]; A summary of design criteria used in the closure design is presented in Table 1. 4. SUMMARY OF ENGINEERING REPORT CACLUATION PACKAGES The purpose of this section is to present the engineering analyses that were performed in support of the ash pond closure. The analyses are summarized herein; with specific references given to the appropriate calculation packages presented in Appendices A through F. 4.1 Material Properties and Maior Design Parameters (Data Package) This data package provides information regarding subsurface stratigraphy and the geotechnical material design parameters of the various soils encountered at the site and is included as Appendix A. This information was primarily based on results from field investigations performed by Geosyntec in 2017 and 2018 [Geosyntec 2017, 2018b], as well as historical geotechnical explorations performed by Southern Company Services (SCS) in 1991, 1997, 2013, and 2015. This Data Package includes: (i) summary of the available data from the field and laboratory investigations; (ii) description of subsurface stratigraphy; (iii) discussion of the observed trends in the material properties of the subsurface units; and (iv) selected geotechnical parameters for use with the closure detailed design. Field and laboratory data, including boring logs, tabulated laboratory testing results,CPT logs,daily field reports,laboratory testing reports,and other pertinent field information is presented separately in the Pre-Design Field Investigation Summary Report for Plant Barry [Geosyntec, 2018b]. From the data package,the subsurface stratigraphy at the Site primarily consists of, from top to bottom; • Existing CCR unit of interbedded deposits of loose fly ash and bottom ash that GW6489MImt Be _Repoft Dmft DRAFT 4 08.2218 APC Barry_EPA_000111 Geosyntec° consultants are gray to dark gray to black; fly ash is mostly silt, bottom ash is silty sand to fine gravel; fine fragments of coal and/or slag are present in the bottom ash; • Clay 1 unit of organic silt and organic clay with varying amounts of wood debris and organic material. This unit is gray to gray brown to orange, soft to stiff with low to medium plasticity, and includes trace amounts of fine sand and/or silt; • Sand 1 unit which is a mixed unit of interbedded lenses of sand, silty sand,clayey sand,and sandy clay;this unit may contain facies that are predominantly sandy in some areas and predominantly clayey in other areas; unit is not laterally continuous. • Clay 2 unit of highly plastic clay, this unit is blue-green to blue gray, soft to stiff with medium to high plasticity, includes very little to no organic matter, and this unit is not laterally continuous; and • Sand 2 unit of poorly-graded,fine-grained sand with occasional lenses of clay and silt and well-graded fine gravel interbeds at depth. Due the spatial variability in stress history and undrained shear strength parameters for subsurface units; especially for Clay 1 and Clay 2,the Site was divided into a total of 10 design reaches(Reaches 1,2A,213,2C,3A,3B,3C,4,5A and 5B)with each reach having a distinct set of undrained shear strength, stress history, and unit weight material parameters. Site-wide drained strength parameters were used for all materials.Discussion on the development of these reaches and associated design parameters are provided Appendix A. During post-closure construction, the existing CCR in the consolidated footprint will be overlain by compacted and moisture conditioned CCR that will be excavated from the other portions of the Site. Selected design geotechnical material properties for all subsurface units, CCR (existing and compacted), existing dikes and soil containment berm are summarized in Tables 8 through 10 of the data package. Design geotechnical properties include total unit weights, drained and undrained shear strengths,and compressibility parameters. It should be noted that the selected design geotechnical material parameters presented in the data package are based on available data and delineated design reaches. Conditions may vary within each design reach, and the delineation between the design reaches may also vary. Conditions will be confirmed during closure construction. These selected geotechnical GW6489IFImt Be _Repoft Dmft DRAFT 5 08.2218 APC Barry_EPA_000112 Geosyntec° consultants material properties were used in the ash pond closure design and subsequent geotechnical analyses in the individual calculation packages. 4.2 Settlement Calculation Packaees Two settlement analyses were performed as part of this detailed design as described below: • Settlement analyses to estimate the compressibility of existing CCR and subsurface soils within the consolidated footprint and to evaluate potential impacts of settlement on the final cover system grades and the integrity of the geosynthetics components. • Containment berm settlement performed to estimate post-settlement grades along the centerline alignment of new soil containment berm to evaluate final elevations of its crest and to estimate the effects of settlement on pipes that will be installed in the soil containment berm. In both analyses,settlements were calculated considering primary compression and long- term secondary compression of CCR, Clay 1 and Clay 2; and considering immediate settlement of Sand 1 and Sand 2 layers. Detailed calculations are provided in Appendices Bl and B2. Brief description of calculations and summary of results are presented in the following subsections. 4.2.1 Final Cover Settlement Three cross sections were analyzed in this package. Two cross sections were selected to represent typical cross sections of the final cover grades within the consolidated footprint and were used to evaluate the change in post-settlement final cover grades and tensile strains in the final cover geomembrane. The third cross section was selected along one of the benches on the east side of the proposed closure and is considered to evaluate the change in grades of the drainage benches. Based on the settlement calculations presented in Appendix B1,the following was concluded: • The calculated minimum post-settlement grades of the final cover system is 3.1 percent, which satisfies the design criteria(i.e., minimum of 3 percent); GW6489MImt Bae _Repoft Dmft DRAFT 6 08.29.18 APC Barry_EPA_000113 Geosyntec° consultants • The calculated minimum post-settlement grade along selected drainage bench within the CCR limits is 0.5 percent which meets the design criteria(i.e.,not less than 0.5 percent); and • The calculated maximum tensile strain within the geomembrane of the final cover system is 2.2 percent, which does not exceed the allowable tensile strain of 5 percent. It should be noted that the final cover settlement calculation was performed considering a simplified staged construction of consolidated footprint. This calculation will be updated in the upcoming submittal based on a CCR placement plan to be developed by contractor in coordination with Geosyntec. 4.2.2 Soil Containment Berm Settlement High-density polyethylene (HDPE) pipes (36-inch interior diameter) will penetrate the soil containment berm to convey storrwater from within the consolidated footprint to the stormwater ponds. In addition to the stormwater conveyance pipes, the soil containment berm will house a 4-inch forcemain pipe which will convey water collected and pumped from the internal drainage system to the on-site water treatment system. Settlement analysis of the subsurface soils due to the construction of soil containment berm was calculated and presented in Appendix B2. Post-settlement grades of the soil containment berm were evaluated to: (i) estimate the final elevations of the Containment Berm crest; (ii) provide recommendations for time of installation(toe)of the stormwater conveyance pipes and the forcemain following the construction of the soil containment berm,and(iii) evaluate the tensile strains within the forcemain. Based on the settlement calculations presented in Appendix B2, the following preliminary conclusions were obtained: • For the stormwater conveyance pipes, it is recommended that they be installed 7 years after the construction of soil containment berm. This period of time will result in an estimated pipe settlement of 0.41 It which is less than the limits specified in the design criteria(i.e., 0.5 ft); and • The maximum calculated tensile strains in the forcemain assumed that it is installed 6 years after the construction of the soil containment berm was 1.61 percent which meet the design criteria of not exceeding 3 percent. Therefore,it is recommended that the forcemain be installed 6 years or more after the completion of soil containment berm construction. GW6489MImt Ba _Repoft Dmft DRAFT 7 08.2218 APC Barry_EPA_000114 Geosyntec° consultants Further optimization and recommendations to the construction sequencing will be evaluated as the design progresses to reduce the time between completing the construction of the soil containment berm and the installation of the stormwater conveyance pipes and forcemain. 4.3 Stability Calculation Packages This section presents the results of analyses performed to assess the stability of the consolidated footprint and existing dikes under long-term and interim static, and seismic conditions. Detailed description of relevant analyses is presented in Appendices C1 through C6. Brief description of the calculation packages and analyses results are summarized below. 4.3.1 Closure Stability Analysis—Seismic This calculation package included as Appendix C1 presents the results of seismic site response analyses performed to evaluate the effects of the design earthquake (i.e., with a 2 percent probability of exceedance in 50 years)on the closure design as per requirements of USEPA CCR Rule [2015].Based on site response analyses,the horizontal pseudostatic coefficients were estimated for the consolidated footprint, existing dikes and soil containment berms. The horizontal pseudostatic coefficients were estimated to be 0.02 and 0.01 for the consolidated footprint and existing dikes/soil containment berms; respectively. These values were subsequently used in the Closure Slope Stability Analysis calculation package (in Appendix C2) to evaluate the seismic stability of under post- closure configuration. 4.3.2 Closure Slope Stability Analysis Analyses were performed to assess the long-term static and seismic stability of: (i)slopes within the consolidated footprint;(ii)existing dikes; and(iii)soil containment berm.Five critical cross sections were selected that pass through existing dikes and soil containment berm. Detailed calculations provided in Appendix C2 show that the calculated factors of safety (FS) for all cross sections exceed the minimum required FS under static and seismic conditions (i.e., 1.5 and 1.0; respectively). Summary of analyses results are provided below: GW6489MImt Bag _Repoft Dmft DRAFT 8 08.29.18 APC Barry_EPA_000115 Geosyntec° consultants Stability of Existing Dikes The minimum calculated FS under long-term,static conditions ranged between 1.52 and 2.10. Furthermore,the calculated minimum FS for seismic slope stability ranged between 1.19 and 1.91. Stability of CCR within the Consolidated Area The minimum calculated FS under long-term static conditions for potential failure surfaces that pass through CCR material were 13.93 and 14.62 for shallow(within CCR only)and deep slip surfaces(passing through the CCR and subsurface soils),respectively. In addition,the calculated minimum FS for seismic slope stability was 4.50. Stability of Soil Containment Berm The minimum calculated FS under long term static and seismic condition for slip surface passing through the south containment berm(i.e.,soil containment berm located south of the consolidated footprint)were 1.69 and 1.17,respectively. 4.3.3 Veneer Stability Analysis for Final Cover Design Analyses were performed to establish the minimum required peak and residual interface shear strength parameters for static loading; and residual interface shear strength parameters for seismic loading for the proposed ClosureTurte cover system to attain target design factors of safety. Detailed calculations are provided in Appendix C3. Based on calculation results, the minimum required peak and residual interface shear strength strengths under static conditions are 6.2 and 5.0 degrees, respectively assuming no adhesion. Furthermore, the minimum required residual shear strength under seismic conditions is 5.9 degrees, assuming no adhesion. These minimum calculated shear strength interface parameters are considered achievable with a ClosureTurf® cover system. 4.3.4 Closure Stability Analysis—Liquefaction Appendix C4 of this report provides detailed calculations performed to evaluate the potential for triggering of liquefaction of materials encountered at the Site when subjected to the design earthquake (i.e., with 2 percent probability of exceedance in 50 years). Based on calculation results, liquefaction is not expected to be triggered within the GW6489IFImt Bae _Repoft Dmft DRAFT 9 08.29.18 APC Barry_EPA_000116 Geosyntec° consultants materials encountered within the consolidated footprint and not expected to impact the stability of the CCR closure and existing dikes/containment berms. 4.3.5 Interim Conditions Slope Stability Analysis Preliminary analyses were performed to evaluate the temporary stability of different configurations of CCR cut slopes due to CCR excavation during closure construction. These analyses were performed in order to develop an optimized cut slope design; providing for both acceptable stability during construction while minimizing the amount of excavation to reduce costs and accelerate the construction schedule. Appendix C5 provide details of the analyses performed. As part of these analyses, multiple cut slope geometries(i.e,bench widths and heights)were evaluated. Based on the analyses results, it is tentatively recommended to use either 2 or 3 horizontal to I vertical slopes with benches located at heights between 5 to 10 feet and bench widths ranging between 30 and 55 feet. These analyses will continue to be refined and updated for the next design submittal to provide a comprehensive evaluation of interim closure construction stability. 4.3.6 Seepage Analyses and Mitigation Design Simplified calculations were performed to evaluate the stability of existing earthen dike in the Closure by Removal Area if a flood event on the Mobile River were to occur after CCR excavation. During a flood event,the potential exists for the emergence of seepage- related issues (i.e. piping and heave) that could lead to instability of the existing dike. These calculations are provided in Appendix C6. Results of seepage calculations indicate the need for seepage berms which are considered the preferred mitigation method based on discussions with SCS. The tentative estimates of seepage berm volume were provided and will be updated prior to the final submittal which encompass a comprehensive evaluation of seepage-related issues at the Site. 4.4 Volumetric Reduction of Coal Combustion Residuals Analysis were conducted to estimate the reduction in volume (defined by shrinkage factor)of the CCR after dredging and compaction in the consolidated footprint as part of the ash pond closure. Detailed calculations are presented in Appendix D. Based on available field investigations and laboratory testing data [Geosyntec 2017, 2018], the calculated shrinkage factor varies from 78 to 82 percent,which corresponds to an average reduction in volume of approximately 20 percent. Therefore, a 20 percent reduction in volume was used to calculate the volume of the compacted CCR for the purposes of civil GW6489MImt Bae _Repoft Dmft DRAFT 10 08.29.18 APC Barry_EPA_000117 Geosyntec° consultants design of the Site. 4.5 Hydrologic Evaluation of Cover Performance Design analyses were performed to evaluate rainfall infiltration rates through the proposed ClosureTurf' cover system and maximum hydraulic head on the cover. These analyses were performed using the United States Environmental Protection Agency (USEPA) Hydrologic Evaluation of Landfill Performance (HELP) model. Detailed calculations are provided in Appendix E. Since the ClosureTurfe is an alternative cover system to the prescriptive final cover systems described in the U.S. Environmental Protection Agency (USEPA) CCR Rule [USEPA, 2015], analyses were performed to demonstrate the equivalency of the ClosureTurf to the prescriptive final cover system. The results indicated that the ClosureTurf® final cover system reduces the total annual infiltration through the cover system by nearly 100 percent when compared to the prescriptive cover system. Therefore, the proposed ClosureTurf® final cover system is demonstrated to be equivalent to the prescriptive cover system. 4.6 ClosureTurf® Cover System Design Package This section presents the findings of an evaluation conducted to assess the suitability and performance of the ClosureTurf® cover system under final ash pond closure conditions. This evaluation was performed based on a review of WatershedGeo's (manufacturer) information,technical literature, and closure design calculations. Detailed description of ClosureTu& appended with all supporting documents and calculations are provided in Appendix F. Summary of findings from this evaluation is provided below: Erosion resistance: based on available laboratory testing data and analyses for the maximum slopes at the Site, no significant erosion of the sand infill is anticipated. If significant sand erosion is observed within the consolidated footprint, maintenance should be performed; Burrowing animals: with the lack of soil in the ClosureTurf® system,no effective habitat for a burrowing animal exists; Wind Uplift: Based on comparison between experimental wind tunnel data conducted on ClosureTurt® and maximum local historical wind speeds at the Site, there is a low potential for wind uplift of ClosureTurf cover system. However, no data was available GW6489MImt Bae _Repoft Dmft DRAFT 11 08.27.18 APC Barry_EPA_000118 Geosynte& consultants to evaluate uplift performance of the ClosureTurf' cover system for wind speeds higher than 120 mph to represent tornadoes of category F2 and higher; Resistance to UV Light: the engineered turf will have a 100+ year functional longevity. This is based on literature review, test results, and evaluations completed by Geosyntec and WatershedGeo; Thermal Effects: it is anticipated that neither the MicroDrain® geomembrane sheets nor their associated seams would be adversely affected due to the freeze-thaw cycles. The sand infrll layer may provide additional insulation for the MicroDrain®from the ambient temperature fluctuation.Additionally,calculations were performed to assess the effect of thermal contraction on the minimum length of MicroDrainorunout for different values of riprap thickness and to evaluate the factor of safety against anchor trench pull-out of MicroDraint; and Vehicle Trafficking: Even though manufacturer's design and installation manuals indicate that post-construction tire pressures as high as 120 psi are suitable to drive on the ClosureTurf® system, it is recommended that traffic be limited to roadway corridors to be installed on the ClosureTurfe system that comprise of a minimum of 1.0-ft thick base aggregate layer wrapped with a geotextile cushion layer. 5. CLOSURE A series of engineering calculations were performed in support of a detailed design to close the ash pond at APC's Plant Barry, located in Bucks, Alabama. The detail design of the ash pond closure is conducted in accordance with provisions stated in the USEPA CCR Rule and relevant documents. Based on the results of calculations summarized herein, it is demonstrated that the detailed design complies with design criteria adopted for this project. It should be noted that these calculations were performed based on the proposed site development plan and final cover grading plan of the consolidated footprint included in the engineering drawings prepared as part of this design submittal (i.e., 60 percent design). Further update/refinement of conclusions from these engineering calculations will be considered in upcoming submittal in light of additional analyses (e.g., groundwater modelling of the Site) and future information that will be provided to Geosyntec (e.g., Contractor's CCR placement plan). GW6489MImt Be _Repoft Dmft DRAFT 12 08.2218 APC Barry_EPA_000119 Geosyntec° consultants REFERENCES Alabama Department of Environmental Management (ADEM) (2016) Division 13 regulations (ADEM Solid Waste Regulations) Alabama Department of Environmental Management (ADEM) Land Division — Solid Waste Program, Chapter 335-13-15 titled Standards for the Disposal of Coal Combustion Residuals in Landfills and Surface Impoundments. The ADEM CCR Rule was filed on 24 April 2018 and became effective on 08 June 2018. Alabama Soil and Water Conservation Commission (2014) Handbook for Erosion Control, Sediment Control and Stormwater Management on Construction Sites and Urban Areas (AL Stormwater Management Handbook),Volume 1. Berg R.R. and Bonaparte, R. (1993) "Long-Term Allowable Tensile Stresses for Polyethylene Geomembranes", Geotextiles and Geomembranes (Vol. 12, 1993, pp. 287-306). Federal Energy Regulatory Commission(FERC)(2006)"Embankment Dams" Geosyntec Consultants (2017) "Ash Pond Closure Feasibility Study, Draft Phase II Summary Report, Alabama Power Company Plant Barry, Bucks, Alabama," Submitted to Alabama Power and Southern Company Services. Geosyntec Consultants(2018a) "Final Cover Surface water Management System Design and Analysis," Submitted to Alabama Power and Southern Company Services, August 2018. Geosyntec Consultants (2018b) "Draft Pre-Design Field Investigation Summary Report, Alabama Power Company, Plant Barry, Bucks, Alabama," Submitted to Alabama Power and Southern Company Services. Mine Safety and Health Administration(MSHA)(2010)Engineering and Design Manual, Coal Refuse Disposal Facilities. United States Army Corps of Engineers (USACE) (2000) "Design and Construction of Levees(EM 1110-2-1913)" GW6489MImt Bae _Repoft Dmft DRAFT 13 08.29.18 APC Barry_EPA_000120 Geosynte& consultants United States Army Corps of Engineers (USACE) (2003) Slope Stability Manual (EM 1110-2-1902). United States Army Corps of Engineers(USACE)(2012)"Hurricane and Storm Damage Risk Reduction System Design Guidelines (Interint", New Orleans District Engineering Division. United States Environmental Protection Agency (USEPA) (2015). "Code of Federal Regulations (CFR) Title 40, Parts 257 and 261, Hazards and Solid Waste Management System; Disposal of Coal Combustion Residuals from Electric Utilities; Final Rule." United States Environmental Protection Agency (USEPA) (2016). "Code of Federal Regulations (CFR) Title 40, Part 257 Hazardous and Solid Waste Management System: Disposal of Coal Combustion Residuals from Electric Utilities; Extension of Compliance Deadlines for Certain Inactive Surface Impoundments; Response to Partial Vacatm." GW6489MImt Bae _Repoft Dmft DRAFT 14 08.29.18 APC Barry_EPA_000121 TABLE APC Barry_EPA_000122 ee.rvn emalal, Darden omen. a The final Ill Ilwm tall be dawned m.11 flat MRenmbl-i—enl a fin—w,nynem w hang film,rompwineofCCRaad6:nda6wwtell,will not nine yzkrtxns l oflbvv... aety, I."ealvmvnl 6aal'I'n lat—will rot It,In,the 3III aor gmfol h'a 11'-we. FVW Cova SeXlemenl e.PI,Inielaw lo111.1i"d(I"Iem,'he vM1annvl uis)dwall oM1annvl elopaYw t.CCR hand. SWen.-he wlllnm be lem tbon Q 5 palne mr gmenlan Sl pemnt LeIndemal vharnal datme wlnd,at .IImila mal bvl In'l,.I 0.5 pen.I YI,to l opoynpbu ronAniMs. a DIRMI'al edlkal lithe filul aorc ly-nn ae Imma ofaeakmvnl olbandalim sed and CCR W WII nm uo..mneile mzm In nw final rover rynem m weead an of Iwnble wile arm,of 5 patent all'm gwmembmav lxYer, NwreTuvP final loves I,—will he Intl for alo—,watch 616 went akemmee new awnew,me IM1V EmignM1rvltl meet the,OSRPA W CFR 257,102(d)(3)(11): -An mhlnalbe later flat nM1ievee en eewdenf valaaion in infilhvfion ea le-And!ia he USRPAG0CM25L02(d)fJHO(A)led(B)NSRPAGO CFR 257,1 M(IH3J(IIJ(Aj]: Final Caver Swem P^d Coves III Dmgi An M-I layer Owl e"all 1,1weaalp inn Fam wlna ma.,IT mwioa a mated In the DSPSA 00 CFR Ill I.Idalln(Q NSBPA JOCFR Ill 1.1(d)(])IiiIB14 and Mmlmlm dwredon oflh la¢ynlY opt,fall.....'Yatem m I'—aa wing w,Indian aM whaieene J11SPPA ail CPR u]102(A)pxin(Q) a.Theminiannm an,able able fmmrs ofwiry the will be awl In,the dope NEiliry analyem'. •TM walatel an ie ant.,Offaly am&,I.--aoNdiew need,he ry,,or dewed 1,$0, The calculated wit,level of.Rly ontlenII mme emaitara(e,i ianm wratraolim and near awfmai....Mae,,)wip be anal of eevna l 30: For dike--metal of eih that lave an e"bilily m ligaefivmq the ellalma l flea,of an.,namg—,,as nwallgae(lion.,.i—will.".II o,eaeead L., Tle ulalabd what al wemat latavfeme far CCR end roan will he egal....wall f 1danew...ma tell USWa-dnlpaakeeabibynalysiv will IOU USE etlbuM on wnercedoamen6rva'M1 ve USBR(30151.F9RC RIg6).MSHA INIo).VSPAPA(1995).end -ThI emaland alum,fevtm wintery will w equal of ovntl l M b Coweratee....I uadliry thewm ofanbty Sale, Slope main, -The admitted SWk fiaorofsskly 6,law we.."ime using pdk me(shin efmate in the final men amain will he a me..nned 150, The ulalMM-1 thal Ill h1 bng-fetm voM aname wing mitlwl(e m tlkpnnagm)Imwf eaad<Menglb mthanal rove ryNemvlll he pryel.rewud I Dfall Iand.lated tweallealie RtIll af..11.15aismie heeding asing 1-11m1 lnl afale hear artmga In am f al m—mein will he w-I..nnad I do. o.flale eiawnk l..'en.1.eonn fplmn w;01rc d eewd bated o0 the?Thawtl wallwm tlweem, awarded as M¢aaed m the pm—me afUSFPA40 CFR 257 mtl m Ill with the an eve milled mmmaad gwal...givrn bale- e alone nffe.will h deel II m y me andetlnng pdk wdm,k....Infirm One n a m hl1ad%pmbahiliry et oaorzmce aft,Snannhat 10 Remelt Ill 250 years Thia b wevrn pmbabilby h .1 ben,-'e.wm 50't-,e,to an mM1nknl wahan,awn eely2,10a,ewmpvud Thit-mententcnenam,li el and smfiu water ooMMI sy9ams. alalaettknmf af9atmwefndminagvmbede eMaW nobaaM.5..v e n.t of C Menem Bemf emlemmt and wa Coda iarman Soil Coateinmam Bw Itemf b wale atram,in the HU haeaaem pipe tlo not owned J pamen That allowable waste daainia I. nlMvd hued an tmeil.maile at yield talon by anal DPP pawa andamafm(a h.,ISCD) .,In range.era B percent ntl lO pemmf and Ima itlenng a 50or ofenery of ap namely 30. aneI am,I I V`C Bafry_BPA_000123 Z )N�4s, FIGURES SK ..J APC Barry_EPA_000124 Z N& APPENDIX A MATERIAL PROPERTIES AND MAJOR DESIGN PARAMETERS APC Barry_EPA_000125 Geosyntec° Consultants CALCULATION PACKAGE COVER SHEET Client: Alabama Power Company.@ Project: Plant Barry Closure Design Project#: GW6489 Southern Company Services TITLE OF PACKAGE: DRAFT MATERIAL PROPERTIES AND MAJOR DESIGN PARAMETERS F CALCULATION PREPARED BY: Signature 27 August 2018 (Calculation Preparer,CP) Name Lucas P. Carr and Tamer Elkady Date d ASSUMPTIONS&PROCEDURES Signature 27 August 2018 CHECKED BY: (Assumptions&Procedures Checker,APC) Name Jim Hansen Date 3 COMPUTATIONS CHECKED BY: Signature 2 August 2018 (Computation Checker,CC) Name Rachael Fischer Daze x BACK-CHECKED BY: Signature 27 August 2018 (Calculation Preparer,CP) u Name Lucas P. Carr Daze APPROVED BY: Signature 27 August 2018 (Calculation Approver,CA) � Name William Tanner,P.E. Daze REVISION HISTORY: NO. DESCRIPTION DATE CP APC CC CA A Draft 50%Closure Design 8/27//2018 LPC/TE JH RAF WT APC Barry_EPA_000126 Geosyntec° consultants Pase I of 114 CP: LPC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6689 DRAFT MATERIAL PROPERTIES AND MAJOR DESIGN PARAMETERS PURPOSE AND ORGANIZATION This Draft Material Properties and Major Design Parameters calculation package(Package)was prepared in support of the design to close the existing coal combustion residuals (CCR) ash pond at Alabama Power Company's (AFC's) Plant Barry (Site), located in Bucks, Alabama. The ash pond will be closed using a "consolidate and cap-in-place" method whereby all CCR will be consolidated into an approximately 300-acre area that will be constructed in the central portion of the ash pond using soil containment berms with a final cover system. This Package establishes the selected geotechnical design parameters used to develop the closure design. Specifically, this Package presents the interpreted (i) index properties, (ii) shear strength parameters, and (iii) compressibility parameters for different subsurface units. This Package includes: (i) summary of the available data from the field and laboratory investigations; (ii) discussion of the observed trends in the material properties of the subsurface units; and(iii) selected geotechnical parameters for use with the closure design development. The organization of the Package is as follows: (i) geotechnical field and laboratory testing program; (ii) subsurface stratigraphy; (iii) engineering design parameter development for the foundation materials;(iv)design reach development; (v) selection ofundrained design parameters for the foundation materials using strength lines; (vi) selection of drained design parameters for the foundation materials; (vii) selection of compressibility parameters; (viii) selection of design parameters for existing dike fill; (ix) selection of design parameters for proposed containment dike and compacted CCR fill; and(x) a summary of selected design geotechnical material parameters for all materials. GEOTECHNICAL FIELD AND LABORATORY TESTING PROGRAM The geotechnical material properties and design parameters established in this Package were primarily based on results from field investigations performed recently by Geosyntec Consultants(Geosyntec)in 2017 and 2018([1], [2]),as well as historical geotechnical explorations performed by Southern Company Services (SCS) in 1991, 1997, 2013, and 2015 ( [3], [4], [51). The activities for each field investigation is briefly summarized below. The report titled Ash Pond Closure Feasibility Study [1] was prepared by Geosyntec. The field activities associated with this report included: • advancement of 14 soil borings using the mud-rotary drilling technique; G W W9/Barry_Material_Character mnion_Narrefive_20180827 APC Barry_EPA_000127 Geosyntec° consultants Pase 2 Of 114 CP: 6PC9E Date: 8/27/18 APC: JP1 Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6489 • collection of disturbed soil samples using the Standard Penetration Test [6] (SPT); • collection of 19 relatively undisturbed Shelby tube samples; [7]; and • installation of four sets of temporary, nested piezometers for aquifer slug and pumping testing. The report titled Draft Pre-Design Field Investigation Summary Report [2] was prepared by Geosyntec. The field activities associated with this report included: • advancement of 20 soil borings using the mud-rotary drilling technique; • collection of disturbed soils samples using the SPT [6]; • collection of 37 relatively undisturbed Shelby tube samples [7] ; • conduction of 16 vane shear tests(VSTs) [8]; • advancement of 7 soil borings using rotosonic drilling methods; • installation of 7 monitoring wells in rotosonic borings screened within the CCR or native foundation layers; • advancement of 48 Cone Penetration Tests (CPTs) [9], with one CPT adjacent to (i.e. co- located) 14 of the soil borings; • performance of 79 pore pressure dissipation tests; and • collection ofbulk samples from 10 ofthe borings. Historic investigations utilized in the development of this Package included: • thirteen(13)borings advanced in 1991 and 1997 [3]; • four(4)piezometers installed in 2013 [4]; and • ten(10)monitoring wells installed in 2015 [5] Laboratory testing was performed on soil samples collected from both the 2017 Closure Feasibility Study [1] and 2018 Pre-Design Investigation [2]. Laboratory testing was not available for the historic investigations. All available laboratory testing was performed by Excel Geotechnical Testing, located in Roswell, Georgia. The laboratory testing program included: • 228 particle-size distribution analyses in accordance with ASTM D6913 [10], including 29 hydrometer analyses in accordance with ASTM D7928 [11]; GW6489/Bany_Mat W Chareceervxtion_Nvreave_20180827 APC Barry_EPA_000128 Geosyntec° consultants Pas. s Of 114 CP: LPC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: SCS Project: Plant Barry Closure Design Project No: GW6489 214 moisture content tests in accordance with ASTM D2216 [12]; • 68 Atterberg limits tests in accordance with ASTM D4318 [13]; 46 specific gravity tests in accordance with ASTM D854 [14]; • 69 organic content tests in accordance with ASTM D2974 [15]; 15 flexible wall permeability tests in accordance with ASTM D5084 [16]; • 60 consolidated undrained(CU)triaxial tests (single specimens) in accordance with ASTM D4767 [17]; 4 unconsolidated undrained (UU)triaxial tests in accordance with ASTM D2850 [18]; • 15 one-dimensional(1-D) consolidation tests in accordance with ASTM D2435 [19]; and • 3 standard Proctor moisture-relationship tests in accordance with ASTM D698 [20]. Complete information on the subsurface data collected to date, including boring logs and field testing results, as well as laboratory testing reports, are presented in the documents referenced above. A map of the boring, sounding, and field testing locations is shown in Figure 1. GEOLOGIC SETTING AND SUBSURFACE STRATIGRAPHY The Site is located on the west bank of the Mobile River; occupying a large low-lying meander bend. Prior to the development of the Site, the area was forested wetlands [21], until the Ash Pond was constructed in the 1970s by building earthen soil dikes and enclosing an approximately 600- acre area. The wet-sluicing of coal combustion residuals (CCRs) into the Ash Pond began in the mid-1970s and is ongoing as of the date of this report, although sluicing is anticipated to cease in late 2018 or early 2019. From a geologic perspective, the Site is located on the western edge of the Mobile River delta, approximately 22 miles north of the delta front transition to Mobile Bay. The geology at the Site is largely comprised by a Holocene fluvial-deltaic transgressive sequence that is approximately 50 feet thick and uncomfortably overlies a Pleistocene erosional surface, corresponding to a lower sea level during previous ice ages. Therefore, the general geologic setting at the site is defined by an aggrading fluvial-deltaic system comprised of backwater lagoons, cutoff meanders, broad natural sand levees or splays, distributary channels,and actively meandering rivers. Given the Site's current location within the inside bend of a broad meander,the Site has likely been subjected to both fluvial erosional and depositional process associated with the Mobile River [22]. The subsurface stratigraphy at the Site was developed based on boring logs obtained from the field investigation described above. Three primary soil units were encountered at the Site: (i) CCRs; (ii) G W 6489/Barry_Material_Chareceervxtion_Nvreave_20180827 APC Barry_EPA_000129 Geosyntec° consultants Pase a Of ua CP: 6PC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6689 native soil comprising silt/clay and sand layers; and(iii)dike fill. Geosyntec [2] provides a detailed discussion of these soil units and identifies information regarding the stratigraphic interface elevations of these layers across the Site. A three-dimensional electronic stratigraphy model was developed for the Site by Geosyntec;the model contains comprehensive stratigraphy interfaces from all available explorations. A brief description of these units and some general properties/characterization of the materials follow. Coal Combustion Residuals(CCR) The CCR at the Site consists of interbedded deposits of fly ash and bottom ash. The CCR thickness is greater in the north/central section of the Ash Pond (up to 45 feet in thickness) and gradually diminishes to less than 5 feet thick near the NPDES outlet structure to the south. In general, the fly ash is a gray to dark gray silt-sized material. The bottom ash is a dark gray to black sand-to gravel- sized material; fine fragments of coal and/or slag were often present in the bottom ash. The CCR is generally saturated, loose, and contains varying amounts ofvegetation and organic materials. Native Soil For this Package, native soil underlying the CCR comprises the following four soil units, from top to bottom. Clay I (Organic Silt and Clay Unit: Clay 1 is a laterally-extensive layer of organic silt and organic clay with varying amounts of wood debris (e.g., roots, wood fragments, etc.) and other types of organic material. The thickness of Clay 1 varies across the site, with thickness ranging between approximately 3 and 25 feet. Clay 1 is generally gray, gray brown, or orange, soft to stiff, of low to medium plasticity, and can contain trace amounts of fine sand and/or silt and abundant organic matter and wood debris. The consistency of Clay 1 ranges from very soft to medium stiff, and the material is typically normally consolidated to moderately overconsolidated. Sand I ( peer Sand,10a,> Unit,!: Sand 1, where present, immediately underlies Clay 1 and consists of interbedded lenses of tan to grey loose to medium dense, sand, silty sand, and clayey sand. Some isolated zones of sandy clay were also encountered in Sand 1 This unit is not laterally continuous and, when present, is up to approximately 30 feet thick. Clay 2 (Lower Clay Unit): Clay 2 is a blue-green, soft to stiff, medium to high plasticity fat clay unit that is present in some portions of the Site. Where present, Clay 2 is typically immediately underneath Sand 1 and immediately above Sand 2. Sand 2 occasionally overlies Clay 2 but was found to always be separated from Clay 1 by either Sand 1 or Sand 2. This unit is not laterally continuous and,where present, is up to approximately 20 feet thick. The unit contains trace amounts G W W9/Barry_Material_Chmcter mnion_Narrefive_20180827 APC Barry_EPA_000130 Geosyntec° consultants Pas. s Of ua CP: LPC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6689 of organic matter. The consistency of Clay 2 ranges from soft to stiff, and the material ranges from normally consolidated to heavily overconsolidated. Sand 2(Lower Sand Unit): This unit consists of poorly graded, medium dense, alluvial fine-grained sand. Sand 2 also contains occasional thin lenses of clay and silt, and gravel. The total thickness of the Lower Sand unit at the Site is unknown,but it was present in borings advanced to 100 feet below grade. Dike Fill An existing soil dike (dike) separates the ash pond from the surrounding area. The dike has a maximum height of approximately 18 feet, crest elevation' of approximately +20 feet, and is approximately 18,000 feet long. The dike consists ofcompacted fill materials ofvariable soil types, ranging from cohesive(i.e., lean and fat clays, silts, and silty clays)to cohesionless(i.e., sandy clay, gravel, and sand)materials. The dike fill is generally well-compacted,ranging from medium stiffto very stiff or medium dense to dense. The dike fill is typically around 20 feet thick. The dike fill is underlain by Clay 1. ENGINEERING DESIGN PARAMETER DEVELOPMENT Engineering design parameters for the site were developed based on results from in situ and laboratory testing results. These design parameters were developed using an extension of the "strength line"concept used by the United States Army Corps of Engineers [231,when faced with varying data sets. Specifically, the concept suggests that values selected for design be selected such that 33 to 50 percent of the measured values from a specific test be below the selected value/line. The strength line concept was used to select "typical" or "design' values for index properties, unit weight, compressibility parameters, stress history, and undrained shear strength for Clay 1 and Clay 2. The development of drained shear strength parameters for CCR, Clay 1, and Clay 2; and drained and undrained shear strength of the Dikes did not consider strength lines. A discussion of the selection of design shear strength parameters for those soils is presented in later sections. The develop of design hydraulic conductivity properties is not included in this Package and will instead be included in a calculation package pertaining to the development of a three-dimensional groundwater model for the Site. ' All elevations in this report are in the North American Vertical Datum of 1998(NAVD88) GWM89/Barry_s1nrna1_Ch roermoion_Nvreave_20180827 APC Barry_EPA_000131 Geosyntec° consultants Pase 6 of 114 CP: 6PC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6489 Geotechnical Parameter Summary Plots Available engineering parameters are graphically presented on geotechnical parameter summary plots (GPSPs). Forty-eight GPSPs were prepared, corresponding to one unique GPSP for each of the 2018 CPTs. The GPSPs provide a graphical presentation ofpertinent geotechnical parameters versus elevation, including groundwater conditions, soil stratigraphy, and key CPT-based soil correlations, including unit weight, undrained shear strength (Clay 1 and Clay 2 only), stress history, and drained shear strength (Sand 1 and Sand 2 only). Co-located borings were available for 14 of the CPTs; GPSPs for these CPTs also include a graphical representation ofpertinent data from the co-located borings versus elevation in the form of laboratory-measured moisture content, unit weight, undrained shear strength, and stress history, as well as insitu test measurements of undrained shear strength and penetration resistance. The purpose ofthe GPSP approach was to allow for variations in key geotechnical parameters(e.g. unit weight, undrained shear strength, and stress history) to be graphically evaluated, both based on elevation and based on the spatial location of the CPT at this site. The approach allowed the site to be divided into separate design reaches (Figure 1) based on spatial variations in key engineering parameters and allowed design engineering parameters to be for each stratigraphic unit within each design reach. GPSPs for each CPT are presented in Attachment 1; the GPSPs also include selected design engineering parameters for each design reach; the selected design engineering parameters are termed "strength lines". The following sections describe the processes used to develop and process information presented on the GPSPs. Static Water Table Static water table elevations were developed for each CPT by analyzing pore pressure measurements(i.e.,u2 measurements)collected during CPT advancement versus depth.The results from pore pressure dissipation (PPD) tests conducted for a sufficient duration to allow for full dissipation ofpenetration-induced pore pressures(i.e., Goo/uloo conditions)were also analyzed. This analysis identified two distinct water tables were interpreted at the site: (i)an upper,perched, static water table within the CCR and Clay 1, typically between three feet above grade and three feet below grade; and (ii) a lower static water table within Sand 1, Clay 2, and Sand 2, approximately 20 to 25 feet below the upper water table, and generally corresponding to the pool level in the adjacent Mobile River. This indicates that Sand 1,Clay 2,and Sand 2 are hydraulically interconnected, yet hydraulically isolated from the Ash Pond by the presence of Clay 1. Tabulated upper and lower static water table elevations and depths for each CPT are presented in Table 1. It should be noted that presented static water table elevations in this table are only valid G W 6489/Barry_Material_ChareaerGxtion_Nvrefive_20180827 APC Barry_EPA_000132 Geosyntec° consultants Pase 7 of 114 CP: 6PC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6489 for the date and location of CPT advancement. Static water table elevations are expected to vary seasonally and (in the case of the lower water table) in response to the river elevation. Furthermore,the water levels may be different between exploration locations. Index Tests Index test results presented on the GPSPs includes moisture content, Atterberg limits, organic content, and unit weight. The procedures used to estimate index test parameters are discussed in the following subsections. Moisture Content Moisture content (w) testing was performed in accordance with ASTM D2216 [12]. Moisture content testing was performed for all soil units at the site, including CCR. Atterberg Limits Atterberg limit testing was performed in accordance with ASTM D4318 [13]. Atterberg limit testing was only performed for cohesive soils(i.e., Clay 1 and Clay 2). Organic Content Organic content testing was performed in accordance with ASTM D2974 [15]. Organic content testing was performed for Clay 1, Clay 2, and CCR. Organic content testing was not performed for Sand 1 and Sand 2 because significant amounts of organics were not observed. Specific Gravity Specific gravity testing was performed in accordance with ASTM D854 [14]. Specific gravity testing was performed for all soil units at the site, including CCR. Unit Weiiz The total unit weight of soil materials at the site was estimated using both laboratory data and correlations based on CPT penetration resistance. The total unit weight of CCR was estimated using laboratory data only.Laboratory unit weight testing was performed on relatively undisturbed (Shelby tube) soil samples in accordance with ASTM D7263 [24]. Unit weight testing was performed for Clay 1, Clay 2, and CCR,as Shelby tube samples ofthese soils were obtained during the field exploration. Unit weight testing was not performed on samples of Sand 1 and Sand 2 as relatively undisturbed samples of these cohesionless soils cannot be readily collected. Unit weights were also correlated using CPT penetration resistance to supplement the relatively limited laboratory unit weight data within Clay 1 and Clay 2 and to provide an estimate of the unit weights in Sand 1 and Sand 2. Unit weights were correlated using Equation 1 [25]: GW6489/Barry_Material Chareceervxtion_Nvreave_20180827 APC Barry_EPA_000133 Geosyntec° consultants Pase s of ua CP: 6PC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6689 yt = y„, [0.27(log Rf) + 0.36 log wa)) + 1.236]Gs/2 65 (1) where: yt = soil total unit weight; Rf = CPTfriction ratio= (f/qt) x 1000%; Y. = unit weight of water; qr = tip resistance; f = sleevefriction; P. = atmospheric pressure; and Gs = specific gravity. Clay 1 was found to have a variable specific gravity ranging from approximately 2.0 to 2.8. To account for this, the unit weights for Clay 1 estimated using CPT penetration resistance were adjusted based on the soil's measured specific gravity. The specific gravity of the Clay 1 at each CPT was estimated using a site-wide correlation between moisture content (as found from the closest boring to the CPT)and specific gravity(Figure 2). Compressibility Parameters A series ofone-dimensional consolidation tests were performed in accordance with ASTM D2435 [19]to estimate the compressibility parameters for CCR, Clay 1 and Clay 2.Plots ofvertical strain versus stress and time were used to estimate modified compression index (Cea), modified recompression index (Crr), modified secondary compression index (Cna), and the coefficient of consolidation(cv) from each consolidation test. For Sand 1 and Sand 2, the drained elastic modulus (E) was calculated from CPT data using the following correlation provided in Equation 2 [26]: E = as (qt —ovo) (2) where: qt = cone tip resistance; Qvo = in-situ vertical stress; and as = 0.015 [10(n.551n+1.68)] where: Ir = soil behavior type index and calculated as belowfrom Robertson GWM89/Barry_Material_ChareaerGxtion_Nv hve_20180827 APC Barry_EPA_0001 M Geosyntec° consultants Prse 9 of 114 CP: 6PC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: SCS Project: Plant Barry Closure Design Project No: GW6689 and Cabal[2015]: Ie = ((3.47 — logQt) 2 + (1ogF, + 1.22)2)0.5 where: Qr = normalized cone penetration resistance; and F, = normalized friction ratio, in %= f x 100%. (9ravo) Based on the estimated elastic modulus, the drained constrained modulus (* was calculated assuming a Poisson's ratio of 0.30 and using Equation 3 [26]: M = (1—v) E (3) where: v = Poisson's ratio Stress History Stress histories for Clay 1 and Clay 2 were estimated from laboratory consolidation data and CPT- based correlations. Stress history is presented on the GPSPs as the maximum vertical effective stress that the soil unit has experienced in the past (maximum past pressure, or P p). The procedures used to estimate maximum past pressure are discussed below. Estimated values of maximum past pressure are shown on the GPSPs for each CPT and co-located boring. Maximum past pressures were evaluated for Clay 1 and Clay 2. One-Dimensional Consolidation Testing The maximum past pressures were estimated from one-dimensional consolidation test results using the Casagrande approach [27] and assessed using the strain-energy approach [28]. Maximum past pressures are shown on the GPSPs as a single point value at the location of each one-dimensional consolidation test and are presented in Table 2. G W M89/Barry_Material_ChareaerGxtion_Nvrefive_20180827 APC Barry_EPA_000135 Geosyntec° consultants Page 10 of 114 CP: 6PC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6689 Cone Penetration Testing Maximum past pressures were correlated using CPT penetration resistance to supplement the relatively limited consolidation test data within Clay 1 and Clay 2. Maximum past pressures were correlated using two separate methods: one for inorganic clays and one for organic clays. For inorganic clays, Equation 4 [29] was utilized: aP = PP = 0.33(gt — a.) (4) where: a'', = maximum past pressure(in kPa); gr = tip resistance (in kPa); and ro = in situ total stress (in kPa). For organic clays, Equation 5 was utilized [29]: aP = PP = 0.33(gt — o.)1" (5) where: dP = maximum past pressure (in kPa); gr = tip resistance (in kPa); U = in situ total stress (in kPa), and m' = 0.9 f 0.1. For Equation 5, a m' value of 0.9 was used, based on recommendations from the author of the equation [29].. Undrained Shear Strength Undrained shear strengths for Clay 1 and Clay 2 were evaluated using laboratory tests, CPT-based correlations, vane shear strength testing, and normalization based on the soil's stress history. The procedures used to estimate undrained shear strength are discussed in the following sections. Consolidated-Undrained Triaxial Compression Consolidated-undrained triaxial compression testing with pore pressure measurements(CIU)was performed in accordance was ASTM D4767 [17]. Two to three CIU specimens were collected from each Shelby tube sample and each specimen was tested at a different consolidation stress. GWM89/Barry_Material_ChareaerGxtion_Nv hve_20180827 APC Barry_EPA_000136 Geosyntec° consultants Pase a Of ua CP: 6PC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6689 One specimen from each Shelby tube was consolidated to at or slightly above in situ vertical effective stresses, to estimate the soil's in situ undrained shear strength. The remaining specimens from the Shelby tube were consolidated well above in situ vertical effective stresses to minimize impacts of sample disturbance and allow development of normalization parameters. This approach would allow calculation of the drained shear strength parameters and the rate of increase in undrained shear strength as a function of consolidation stress. In situ undrained shear strengths were estimated using test specimens consolidated relatively close to in situ vertical effective stresses. Failure for each specimen was defined as peak obliquity, or the maximum ratio of vertical to horizontal effective stresses (di /u 3) during the test [30]. To reduce the potential for strain incompatibility between the cohesive foundation soils and CCR in future analyses, axial strains were limited to 10% at failure. For specimens where peak obliquity occurred above 10% strain, the stresses at failure were assumed to be those that occurred at 10% axial strain. Undrained shear strength from CIU specimens was defined as shear stress on the failure plane at failure(Tff) [311. This definition was used in lieu ofhalfthe compressive stress at failure(e.g. Sr= qf= 0.5(ara3)j) recommended by others [32] because: (i)rg can be significantly lower than of at low consolidation stresses due to the curvature of the Mohr-Coulomb failure envelope, (iii) Tf is similar to the shear strength measurement obtained from a consolidated-undrained direct simple shear test, where rg is directly measured by the testing apparatus, and (iv) stresses in a slope stability analysis are a combination of compressive, direct simple shear, and extensional loading, rather than purely compressional. To calculate rg; Equation 6 was derived and used: Tff = qf Cos q' (6) where: Tg = undrained shear stress on the failure plane atfailure of = one-halfcompressive stress atfailure 0' = specimen-specific effective friction angle Some of the CIU specimens intended for use in estimating insitu undrained shear strengths were consolidated to effective stresses slightly above in situ(i.e. 1.1 to 2.0 times in situ vertical effective stresses). This consolidation above insitu stresses may have lead to reductions in void ratio, and corresponding increases in undrained shear strength that are not representative of in situ conditions. To account for this, the undrained shear strength from these specimens were reduced G W 6989/Barry_Material_ChareaerGxtion_Nvrefive_20180827 APC Barry_EPA_000137 Geosyntec° consultants Page 12 of 114 CP: 6PC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6689 to represent undrained shear strengths corresponding to insitu stress conditions. This was performed by developing a plot of Tff versus consolidation stress (u 3,) for all CIU specimens in Clay 1 and Clay 2 (Figure 3). This plot indicates that a ratio of z�y'a'3e of 0.36 is an approximate best-fit for the CIU specimens consolidated to stresses of 3 ksf and less. A correction factor was derived and used for each CIU triaxial specimen(Equation 7): Tff, = Tff — (0.36[Q3c — Qvo]) (7) where: zf, = corrected undrained shear stress on thefailure plane atfailure Tff = uncorrected undrained shear strength on thefailure plane at failure o'3e = specimen effective consolidation pressure a'„a = specimen in situ vertical effective stress Corrected zf,values were used for engineering analysis and are shown on the GPSPs. CIU triaxial data, including uncorrected and corrected Tff values, is provided in Table 3. Unconsolidated-Undrained Triaxial Compression Unconsolidated-undrained triaxial compression testing (UU) was performed in accordance with ASTM D2850 [18].Each UU specimen was tested at a confining stress approximately equal to the in situ total stresse. Failure for each specimen was defined as maximum deviator stress, or the maximum difference between total axial stress and confining stress (at —a3) during the test [301. To reduce the effects of strain incompatibility and present the UU data in a similar method as CIU triaxial data, axial strains were limited to 10% for selecting failure stresses, meaning that if maximum deviator stress occurred above 10% strain, the stresses at failure were assumed to be those that occurred at 10% axial strain. Undrained shear strength from UU specimens was defined as one-half the compressive stress at failure(e.g. S.= qf= 0.5(at-a3)t),as recommended by the United States Army Corps of Engineers [301. Cone Penetration Testine CPT testing was performed in accordance with ASTM D6913 [101. The undrained shear strength Clay 1 and Clay 2 was estimated using Equation 8 [26]: GWW9M,ny_Material_Ch ctermoion_Nnnnive_20180827 APC Barry_EPA_000138 Geosyntec° consultants Psse 13 of 114 CP: 6PC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6489 Su = 9� (8) nkt where: S. = undrained shear strength; qt = CPT tip resistance during cone advancement; a, = in situ total stress; and N, = cone factor. The correlated undrained shear strength from Equation 8 is dependent on the cone factor(Nh).The cone factor typically ranges from 10 to 18, with a value of 14 recommended for an estimate of undrained shear strength midway between that measured from a CIU triaxial test and a direct simple shear strength test [261. The estimated undrained shear strength value is inversely proportional to the cone factor,meaning that undrained shear strength decreases as the cone factor increases. A cone factor of 17 was selected for the Site because it provided a reasonable agreement between undrained shear strength data estimated from CIU triaxial and stress history-based correlations. Vane Shear Testing Vane shear testing(V ST)was performed in general accordance with ASTM D2573 [8]. Undrained shear strength is calculated VST data based on the peak torque measured during testing and the dimensions of the vane using Equation 9 [8]: 12r (Su)fv — rzDzl aas(it) +bH) (9) where: ($)j,. = peak undrained shear strength from the vane; T = maximum value of measured torque or residual torque, corrected for rod apparatus and rod friction; D = vane diameter; H = height ofvane; GW6489/Barry_Material_ChareaerGxtion_Nv hve_20180827 APC Barry_EPA_000139 Geosyntec° consultants Page 14 of 114 CP: 6PC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6489 it = angle of taper at vane top; and ib = angle of taper at vane bottom. ASTM D2573 [8] recommends correcting VST data to account for the plasticity index ofthe clay and the rate of failure of during the VST test,relative to the rate of failure of actual embankments during construction. However, the application of these correction factors typically reduces the estimated undrained shear strength by 20-40%. For Clay 1, this resulted in an undrained shear strength significantly below that estimated from the CPT, CIU test data, UU test data, and stress history-based correlations. This indicates that the recommended correction factors for the VST data may not appropriate for the site, as evidenced by the wide variation in data used to develop the field vane correction factors [33] [34] and poor agreement between other methods at the Site. Therefore, uncorrected peak values ofundrained shear strength are shown on the GPSPs. Some of the VST tests conducted at the Site indicated low-quality data, manifesting in the form of (i) a poorly-defined torque curve with peak torque occurring at 15-30 degrees of vane rotation and only being slightly above the near-peak torque measured at 5 degrees; (ii) an uneven torque curve,showing increases and decreases in torque during rotation;and/or(iii)residual torque values relatively similar to peak torque values. These low-quality data tests may be due to: (i)disturbance in the soil below the base of the borehole; (ii) tightening of the vane's steel drilling rods prior to actual vane rotation;and/or(iii)measurement errors caused by the dial-gauge torque measurement system. VST tests showing the issues listed above were considered unreliable and are not shown on the GPSPs. A tabulation of each VST test and a discussion of the data quality is presented in Table 4. SHANSEP Undrained shear strength for cohesive soils (Clay 1 and Clay 2) was estimated as a function of overconsolidation ratio (stress history)using the Stress History and Normalized Soil Engineering Properties (SHANSEP) model [35] [31]. The SHANSEP model was developed for geologically- recent, lightly to moderately overconsolidated clays, such as those present at the site, and is provided in Equation 10 [31] [36]: S„ = u n X S X (OCR)rn (10) where: S. = undrained shear strength; or'„' = in situ vertical effective stress; S = normally-consolidated ratio of&to d„a; GW6489/Barry_Material_ChareaerGxtion_Nv hve_20180827 APC Barry_EPA_000140 Geosyntec° consultants Page 15 of 114 CP: 6PC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6489 OCR = overconsolidation ratio (P e/u,ro) in = empirical exponent Typical values of S range from 0.20 to 0.30 [31].A value of S was calculated to be 0.258 based on the drained friction angle of Clay 1 and Clay 2(i.e.,(p'=310 as will be presented subsequently) and using Equation 11, which was developed using critical state soil mechanics theory[361: S = sin9V (1 1) z where: S = normally-consolidated ratio of&to o',.o; and 0' = drained friction angle. Typical values of m range from 0.75 to 1.00 [31] and can be calculated based on the soil's swelling index(C,) and virgin compression index(Cr), as determined from one-dimensional consolidation test data using Equation 12 [361: m = 1 — (12) where: C, = swelling index; and Cr = virgin compression index. Data from each of the 10 one-dimensional consolidation tests performed for Clay 1 and Clay 2 indicates values of in have a relatively small variation, ranging from 0.76 to 0.90, (Table 3) therefore a mean value of 0.83 was used for the entire Site (Table 5). The SHANSEP model uses overconsolidation ratio to estimate undrained shear strength. A design profile of maximum past pressure vs. elevation was developed for Clay 1 and Clay 2 for each design reach. The maximum past pressure was then divided by the in situ vertical effective stress at each CPT to develop a function of OCR vs. elevation. This value of OCR was used to estimate undrained shear strength by the SHANSEP model. G W 6489/Barry_Material_ChareaerGxtion_Nvrefive_20180827 APC Barry_EPA_000141 Geosyntec° consultants Pase 16 of 114 CP: 6PC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6489 Sand Drained Shear Strenuth Drained shear strengths for Sand 1 and Sand 2 were estimated using CPT- and SPT-based correlations. The procedures used to develop drained shear strengths for Sand 1 and Sand 2 are discussed in the following sections. Cone Penetration Testing The drained shear strengths of Sand 1 and Sand 2 were estimated based on the normalized cone resistance (qri)using Equation 13 [37]: 17.6 + 11 log(gtr) (13) where: 0' = drained friction angle(in degrees); and qa = normalized tip resistance. The normalized cone resistance(qt1) was calculated using Equation 14 [38] qt o.s o4 qn = —) aleo (1 ) �a[m atm where: qa = normalized tip resistance; qt = corrected tip resistance; a. = atmospheric pressure; rr',a = effective vertical stress; and Correlated values of drained friction angles estimated using the preceding equations are shown in the GPSPs for each CPT and co-located boring. Standard Penetration Testing The drained shear strengths of Sand 1 and Sand 2 were estimated based on the corrected SPT(Nr)60 values(Attachment 2)using Equation 15 [39]: GW6489/Barry_Material_ChareaerGxtion_Na hve_20180827 APC Barry_EPA_000142 Geosyntec° consultants rase n Of 114 CP: LPC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6489 20 + [15.4(Nr)60)0.5 (15) where: 0' = drained friction angle(in degrees); and (Nd 6o = SPT penetration resistance, corrected for hammer efficiency and vertical effective stress, but limited to no higher than SPT penetration resistance corrected for hammer efficiency only (Nco). Correlated values of drained friction angle estimated using the preceding equation are shown on the GPSPs for each co-located boring. DESIGN REACH DEVELOPMENT The Plant Barry Ash Pond has a footprint of approximately 600 acres. An evaluation ofthe GPSPs presented previously found that key engineering parameters for Clay 1 and Clay 2(i.e., maximum past pressure, undrained shear strength, and unit weight) exhibited significant spatial variation across the site, while parameters for CCR, Sand 1, and Sand 2 exhibited only nominal spatial variation. Clay 1 and Clay 2 were found to be significantly different materials; Clay 1 typically has significantly higher moisture contents, organic contents, and plasticity indices. Sand 1 and Sand 2 are relatively similar materials, with Sand 2 exhibiting a slightly higher unit weight and fiction angle than Sand 1. To account for the spatial variations in the engineering parameters,the site was divided into a total of 10 unique design reaches (Reaches 1, 2A, 2B, 2C, 3A, 3B, 4, 5A and 5B). The spatial extent of each design reach was based on grouping similar GPSPs from individual CPTs and co-located borings and refined using historical data. The grouping of CPTs and co-located borings into design reaches was based principally on the properties of Clay 1, with the most "weight" given to maximum past pressures and unit weight. The reach delineation also considered similarities/differences in undrained shear strength.Variations the engineering parameters of Clay 1 were the primary focus in the development of design reaches; this is because Clay 1 is typically the lowest-strength soil unit present at the site, and is located immediately below CCR. Therefore, the strength of Clay 1 is a critical component for the closure of the Ash Pond, as it will directly affect the stability of the closure during and after construction. Boundaries between design reaches were initially based on the grouping of CPTs and borings. Boundaries between design reaches outside of areas of boring coverage were refined using historical pre-Ash Pond construction aerial imagery of the site from 1938, 1950, 1952, and 1974 [211.These historical aerials were electrometrically georeferenced using available site features and GW6989/13arry_Material_Chareae tion_Narrefive_20180827 APC Barry_EPA_000143 Geosyntec° consultants Page Is of 114 CP: LPC9E Date: 8/27/18 APC: JPI Date: 8/27/I8 CA: WT Date: 8/27/I8 Client: scs Project: Plant Barry Closure Design Project No: GW6489 are shown on attached Figures 4 through 7. The historical aerials showed variable ground surface elevations across the site, including high ground at the north and east sides of the site, adjacent to the Mobile River, and low ground and streams within much of the central portion of the site. Subsurface data plots located within the high ground areas indicated relatively high maximum past pressures within Clay 1 and Clay 2. This indicates that the materials are overconsolidated and that the grades in these areas were likely higher than current grades at some point in the past and subsequently lowered through fluvial erosion. GPSPs located within the historic low-ground indicate maximum past pressures equal to or slightly above current in situ vertical effective stresses. This indicates that Clay 1 in these low ground areas is normally consolidated or lightly overconsolidated, geologically recent, and of comparatively lower strength and higher compressibility than both Clay 1 and Clay 2 (if present) in the areas of higher ground. It is also possible that Clay 1 within these low-grade areas may correspond to a backwater depositional environment, rather than a dynamic depositional environment that may have been present in the higher-grade areas. A tabulated discussion of each design reach is presented in Table 6, and the spatial boundaries of each design reach are shown on the boring location plan on attached Figure 1 as well as on historical aerial photographs in Figures 4 through 7. SELECTION OF DESIGN PARAMETERS USING STRENGTH LINES Design parameters for unit weight of all soil units, maximum past pressure in Clay 1 and Clay 2, undrained shear strength in Clay 1 and Clay 2, and drained friction angle in Sand 1 and Sand 2 were developed based on the concept of strength lines. As will be shown subsequently, a unique set of design profiles were developed for each design reach at the Site. Design unit weight values were selected to correspond to a mean value of the available data within an entire reach, while design maximum past pressure and strength values were selected to correspond to a lower one- third of the available data within the entire reach. Details on the process used to select design profiles for each engineering parameter is discussed in the following subsections. Strength lines and plots that delineate the mean values for each design reach are presented in Attachment 1 and are tabulated in Table 7. Unit Weigh[ Unit weight was selected as 92 pcf for all CCR at the site and 120 pcf for all Sand 2 at the site, as the weights for these materials did not vary appreciably across the site.Reach-specific unit weights were developed for Clay 1, Sand 1, and Clay 2, as the unit weights of these materials were found to vary across the site. GW6489/Barry_Material_Ch ctermoion_Nznnaoc_20180827 APC Barry_EPA_000144 Geosyntec° consultants Pase 19 of 114 CP: 6PC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6489 Design unit weights for Clay 1 ranged from 92 pcf in Reach 2A to 110 psf in Reach 5A; design unit weights for Sand 1 ranged from 110 pcf in Reaches 1, 2A, 3B, 4, and 5A to 120 pcf in Reach 3C; and design unit weights for Clay 2 ranged from 100 pcf in Reach 2A to 110 pcf in Reach 3C. Maximum Past Pressure Reach-specific design maximum past pressures were selected for Clay 1 and Clay 2 by selecting the average (mean) of lower-third CPT-correlated values developed using Equations 4 and 5. The design values were adjusted on a reach-specific basis based on laboratory consolidation data, if present, as the laboratory consolidation data was given a higher weight than the CPT-correlated data. . Design profiles of maximum past pressure for Clay 1 were defined as a pre-overburden pressure (POP), or as a constant difference between the maximum past pressure and the in situ vertical effective stress with depth. This approach was used because the maximum past pressure was found to linearly increase with depth in Clay 1. This is indicative of unloading and suggests that additional overburden soil was present over Clay 1 before being removed by a past geologic process such as erosion. Design pre-overburden pressures ranges from 0 psf in Reach 3A (indicating normally-consolidated conditions)to 2,100 psfin Reach 4(indicating overconsolidated conditions, likely caused by erosion of overlying material). Within Reach 5A,Clay 1 was split into two separate layers (Clay IA and Clay 1B). Maximum past pressures within Clay IA, which corresponds to the top three to four feet of Clay 1, were consistent with depth (indicating a desiccated crust condition), and were assigned as a design maximum past pressure of 3,000 psf. Maximum past pressures in Clay 1 B,which underlies Clay 1 A,were found to increase with depth. Design profiles for maximum past pressure for Clay 2 were defined as a consistent value of maximum past pressure versus depth and ranged from 3,200 psf in Reach 2A to 6,000 psf in Reach 4. Clay 2 was assumed to be normally consolidated within Reaches 1, 2B, 3A, and 3B. The normally consolidated to lightly-overconsolidated nature of Clay 2 is likely due to the construction of the Ash Pond at the site and the lower static water table elevations in Clay 2 compared to Clay 1. The perched groundwater table within the CCR and Clay 1 results in the ash pond inducing a relatively low increase in effective stress in Clay 1 (only the buoyant unit weight of the CCR, approximately 30 psf, is felt by Clay 1). However, the static water table in Clay 2 is not connected to the perched water table in the CCR and Clay 1, and Clay 2 feels the total unit weight of the saturated CCR(92 pcf, more than three times that felt by Clay 1). Therefore, it is likely that the predevelopment overconsolidation ratio in Clay 2 was significantly higher than the current overconsolidation ratio, as construction of the ash pond resulted in significant increases in vertical effective stressed in Clay 2,while only causing nominal increase in vertical effective stress to Clay 1. GW6489/Barry_Material_Ch ctrrmoion_Nnnaor_20180827 APC Barry_EPA_000145 Geosyntec° consultants Page 20 of 114 CP: 6PC9E Date: 8/27/18 APC: J17 Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6489 Undrained Shear Strength Reach-specific undrained shear strengths were selected for Clay 1 and Clay 2, due to the spatially- variable nature of this engineering parameter. The design undrained shear strength profile was selected to correspond to the lower one-third of the available measurement data within the entire design reach. In cases where different types of measurement data indicated varying strengths at the same spatial location, each type of measurement data was weighted based on a hierarchy of relative data quality. The data quality hierarchy was used based on a qualitative evaluation of all available data for the site, typically with SHANSEP as the highest quality, then CIU, then CPT, then UU, and then VST. Design profiles of undrained shear strength for Clay 1 were defined as a minimum undrained shear strength(Min Sn),which was defined at an elevation generally equal to the maximum top elevation of Clay 1 within the design reach. Values of minimum undrained shear strength ranged from 200 psf in Reaches 3A, 3B, and 3C to 490 psf in Reach 4A. The undrained shear strength below this elevation was defined by a linear increase in undrained shear strength per foot of depth(dS/dz), and the rate of increase was selected as the slope of the SHANSEP-modeled undrained shear strength profile within the design reach. Rates of increase in undrained shear strength per foot ranged from 8.0 psf/ft in Reach 1 to 12.5 psf/ft in Reach 4.Within Reach 5A,Clay 1 A(a desiccated crust)was assigned a constant undrained shear strength of 550 psf. Design profiles ofundrained shear strength for Clay 2 were defined as a consistent undrained shear strength versus depth, for reaches where Clay 2 is overconsolidated. Where Clay 2 is normally consolidated,the undrained shear strength was defined using the SHANSEP model(Equation 10), but with a minimum undrained shear strength of 500 psf. It should be noted that the design undrained shear strength parameters for Clay 1 and Clay 2 are only appropriate for existing conditions.Closure construction will induce increased effective stress for both Clay 1 and Clay 2 due to the dewatering of CCR within with ash pond, the placement of CCR as compacted fill, and the construction of new soil containment berms. These increases in effective stress will induce consolidation of Clay 1 and Clay 2 and corresponding increases in undrained shear strength. To account for this, closure stability analyses for staged construction and long-tern conditions should consider consolidation-induced strength increases. This can be accomplished using the SHANSEP model developed for Clay 1 and Clay 2,based on estimates of vertical effective stresses within Clay 1 and Clay 2 under future conditions. The SHANSEP model can be utilized with a minimum undrained shear equal to current conditions at each design reach. The SHANSEP model developed for Clay 1 and Clay 2 at the site is shown in Equation 16: Su = are, x 0.258 x (OCR)083 (16) where: G W 6489/Barry_Material_ChareaerGxtion_Nvrefive_20180827 APC Barry_EPA_000146 Geosyntec° consultants Pase 21 of 114 CP: LPC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6489 S. = undrained shear strength; tz'„a = in situ vertical effective stress, and OCR = over-consolidation ratio SELECTION OF DRAINED DESIGN PARAMETERS Drained Shear Strength for CCR. Clay 1 and Clay 2 Site-wide drained shear strengths for CCR, Clay 1, and Clay 2 were developed using CIU triaxial laboratory testing data. The CIU triaxial data for all three materials utilized the same failure criteria as for the development of undrained shear strengths for Clay 1 (maximum obliquity, limited to 10% strain), and presented on p'-q plots [40]. One p'-q plot was prepared for Clay 1 and Clay 2, as both materials were found to have similar drained shear strength parameters. A second p'-q plot was prepared for CCR. Within the p-q' plots, a design failure envelope was selected to encompass results from the lower one-third of the test specimens. For CCR, a design effective friction angle of 36 degrees with no effective cohesion was selected. For Clay 1 and Clay 2, a design effective friction angle of 31 degrees with 75 psf of cohesion was selected, corresponding to effective stresses between 0 and 7 ksf. The p'-q plots are presented as Figure 8 for CCR and Figure 9 for Clay 1 and Clay 2. Drained Shear Strength of Sand 1 and Sand 2 Site-wide drained shear strengths were developed for Sand 1 and Sand 2 using the GPSPs. This is because the drained shear strengths for these materials, as estimated from the CPT-and SPT-based correlations, were relatively consistent across the entire site. The design profiles were generally selected to be encompass the lower one-third of the drained shear strength data for the entire site. Selected design effective friction angles of 35 degrees for Sand 1 and 38 degrees for Sand 2,both corresponding to in situ stress conditions. SELECTION OF COMPRESSIBILITY PARAMETERS Modified Compression index for CCR. Clay 1 and Clay 2 Based on the interpretation of laboratory consolidation data,plots of modified compression index, C.versus elevation for CCR, Clay 1 and Clay 2 are presented in Figure 10. From this figure, it is apparent that the modified recompression index for Clay 1 is variable, with most of the Clay 1 compressibility data obtained from test specimens obtained from Reach 3A. G W 6489/Barry_Material_ChareaerGxtion_Nvrefive_20180827 APC Barry_EPA_000147 Geosyntec° consultants Page 22 of 114 CP: 6PC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6489 To improve the accuracy of consolidation parameters, reach-specific Cr,, data were generated by plotting laboratory data of Caa against the initial moisture content of test specimens as shown in Figure 11. This plot indicates that there is reasonable correlation between C. and initial moisture content (i.e., R2> 0.90) which is consistent with that been reported in the technical literature [411. A site-specific equation that was used to generate C. data for each reach based on laboratory- measured initial moisture content for samples retrieved from different borings is expressed as follows: Cc, = 0.0247 x (MC)o.5195 (17) Where: Cca=calculated modified compression index; and MC = moisture content. Using Equation 17, plots for the variation of Caa with elevation for each reach are provided in Figures 12 through 13. These figures illustrate the variability in C. within each design reach; nevertheless,a representative value corresponding to the statistical mean for calculated data within each reach can be obtained. Laboratory test results for C. are also included on these plots. The modified compression index for CCR deduced from laboratory results did not vary considerably. Therefore, a mean value was assigned to this material for the entire site. Only one consolidation test was conducted on Clay 2 specimen(Figure 10) and was adopted to represent a site-wide modified compression index. Complementary Compressibility Parameters for CCR Clay 1 and Clay 2 The modified recompression index(C.) for CCR,Clay 1 and Clay 2 were derived from the results ofseries ofone-dimensional consolidation tests described earlier and results presented in Table 2. As noted earlier,the compressibility parameters interpreted from laboratory consolidation tests on CCR specimens did not vary considerably. Also, only one consolidation test was conducted for Clay 2. Therefore, for CCR and Clay 2, mean values of Cry for each distinct material are assumed to be constant for the entire site. Values of Cry for Clay 1 were assigned to each reach based on the location of borings from which test specimens were obtained. In absence of C. for Clay 1 in a reach, the C. is assumed to be one-tenth the mean modified compression index [401. Figures 14 through 17 show the plots for the modified secondary compression index (Caa) and coefficient of consolidation (C,) for CCR, Clay 1 and Clay 2. Values assigned for each layer are provided in these figures are assumed to be applied site wide. GW6489/Barry_Material_Ch ctermoion_Nznnaoc_20180827 APC Barry_EPA_000148 Geosyntec° consultants Page 23 of 114 CP: LPC9E Date: 8/27/18 APC: JP1 Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6489 Drained Constrained Modulus for Sand 1 and Sand 2 The drained constrained moduli for Sand 1 and Sand 2 were calculated from CPT data using Equations 2 and 3. Plots for drained constrained modulus versus elevation are shown in Figure 18a. Selected values are also shown in the plots which statistically represents the value of highest frequency as illustrated on Figure 18b. SELECTION OF DESIGN PARAMETERS FOR EXISTING DIKE FILL Dike fill was found to be variable at the site, consisting of both cohesive material (i.e., USCS classifications of CL, CH, MH, CL, and CL-ML) and cohesionless material (i.e., USCS classifications of SM,GW,and SP),based on historical geotechnical borings[3],historical borings to install piezometers [4], historical borings to install monitoring wells [5], and recent borings advanced by Geosyntec in 2017 [1]. The historical borings logs included field soil descriptions and SPT blowcounts; however, laboratory test data are only available for the recent borings [1]. Unit Weight of Existing Dike Fill The unit weight of dike fill was assumed to be 120 pcf, for the entire dike, based on laboratory measurements [24] collected in one Shelby tube of dike material in 2017 [1]. This value is typical for a compacted dike fill, based on Geosyntec's experience, and is consistent with relatively high SPT blowcounts within both the cohesive and cohesionless dike fill materials. Undrained and Drained Shear Strength of Existing Dike Fill The design undrained shear strength for the cohesive dike fill soils was estimated using SPT blowcounts correlations and one CIU triaxial specimen tested by Geosyntec in 2017 [1]. For soils identified as cohesive on the historical boring logs, undrained shear strengths were developed using Equation 18 [42]: Sn = 130x N,, (18) where: S. = undrained shear strength (in pounds per square foot); Nso = SPT-penetration resistance, normalized to a hammer efficiency of 60% GW6489/Barry_Material_Ch cnrGtion_Nvrefive_20180827 APC Barry_EPA_000149 Geosyntec° consultants Page 24 of 114 CP: LPC9E Date: 8/27/18 APC: JP1 Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6489 Measurements of hammer efficiency were not provided for the historical borings logs. To normalize the SPT measurements to a Nao values, typical values of automatic hammer efficiency [431 were selected,based on the type of drill rig listed on the boring log. Correlated undrained shear strengths for the dike fill, calculated using Equation 15, were plotted vs. depth below grade. The undrained shear strength from the single CIU triaxial specimen was also included on the plot, after correcting the CIU triaxial specimen to account for shear stress on the failure plane at failure (Equation 3) and in situ vertical effective stresses (Equation 4). This plot,Figure 19,was used to select a design undrained shear strength of 1,000 psf,this corresponds to a lower-bound value that is equal to or the lower one-third of the correlated data. Drained shear strength ofthe cohesionless dike fill was estimated using overburden-corrected SPT blowcounts in the same manner as Sand 1 and Sand 2 (Equation 14). The resulting correlated friction angles were plotted vs. depth below grade. This plot,Figure 20,was used to select a design effective friction angle of 32 degrees with no cohesion; this value corresponds to the lower one- third of the available data. This value may also be used for the drained shear strength of the cohesive dike materials,as it is very similar to the design drained shear strength of Clay 1 and Clay 2 and is lower than the 36-degree friction angle estimated from the CIU triaxial data on the dike soils. Furthermore, the existing dike appears to be well-compacted has performed well over the life of the ash pond; this corresponds with the selected design parameters. SELECTION OF DESIGN PARAMETERS FOR CONTAINMENT DIKE AND COMPACTED CCR FILL New containment dikes will be constructed within the footprint of the Ash Pond. These containment dikes are proposed to be constructed of compacted clay overlying a cohesionless bridging lift of sand. The selection of borrow sources for the new containment dikes is currently underway. Therefore, conservative design parameters were selected for the containment dikes, until the selection of borrow sources is complete. For the compacted clay dike containment dikes, a unit weight of 115 pcf, a drained friction angle of 27 degrees, and a drained cohesion of 50 psf should be used for design parameters, as these are typically lower-bound values for a compacted cohesive material. For undrained conditions, an undrained shear strength of 600 psf should be assumed, as this is a lower-bound value for a compacted cohesive material. The bridge lift should be assumed to have a unit weight of 105 pcf and an effective friction angle of 28 degrees with zero cohesion. These parameters will be updated as the borrow source selection process is completed. During closure construction, CCR will be excavated and compacted within the central potions of the existing Ash Pond. Compaction of the CCR will result in an increase in unit weight compared GW6489/Barry_Material Chareceervxtion_Nvreave_20180827 APC Barry_EPA_000150 Geosyntec° consultants Page 25 of 114 CP: LPC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: SCS Project: Plant Barry Closure Design Project No: GW6689 to the original ponded condition. Standard Proctor testing [20] performed in 2018 [2] indicated maximum total unit weights ranging from 101 to 105 pcf, with a mean value of 102 pcf. For engineering analysis, 97 pcf is proposed; this is 95% of the mean maximum unit weight and will be included as a minimum acceptable value within the closure construction specifications. The strength parameters for the compacted CCR should be conservatively assumed the same as the sluiced CCR(i.e., 36 degrees friction angle with zero cohesion). Design Undrained Shear Strength and Unit Weight for Soils Beneath Perimeter Dikes Undrained shear strengths for Clay 1 and Clay 2 beneath the perimeter dikes will be higher than the undrained shear strength within the Ash Pond and at the downstream toe of the dike, due to higher effective stresses induced by the compacted dike soils and the relatively low static water table within the dike. To account for this effect, the shear strength of Clay 1 and Clay 2 beneath the dike can be estimated using the SHANSEP model(Equation 15). When this approach is used, the overconsolidation ratio must be calculated by reducing the pre-overburden pressure from the adjacent design reach by the difference in situ vertical effective stress beneath the centerline of the dike and the ash pond. This will result in a lower OCR, due to stresses induced in Clay 1 and Clay 2 by construction of the existing dike. This approach should be used both beneath the centerline of the dike and at the toes of the dike, as the strength will vary between these areas. SUMMARY OF SELECTED DESIGN GEOTECHNICAL MATERIAL PARAMETERS Selected drained (i.e. effective stress) design geotechnical parameters for all soil units and CCR present at the site are presented in Table 8. Selected design maximum past pressures, total unit weights, and undrained shear strengths for all soil units and CCR present at the site are presented in Table 7. Selected design parameters for staged construction, end-of-construction, and seismic stability under consolidated conditions are presented in Table 9. Selected compressibility parameters are presented in Table 10 Field and laboratory data, including boring logs, tabulated laboratory testing results, CPT logs, daily field reports, laboratory testing reports, and other pertinent field information is presented separately in the Pre-Design Field Investigation Summary Report for Plant Barry[2]. The developed geotechnical material parameters in this Package were used for the design of the final closure design and subsequent geotechnical analyses in the individual calculation packages titled Final Cover Settlement, Interim Conditions Slope Stability, and Final Conditions Slope Stability. GWM89/Barry_Material_Ch ctermoion_Nznnaoc_20180827 APC Barry_EPA_000151 Geosyntec° consultants Pase 26 of 114 CP: LPC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6689 LIMITATIONS Design geotechnical material parameters presented in this calculation package are based on available data and delineated design reaches. Conditions may vary within each design reach, and the delineation between the design reaches may also vary. Conditions should be verified during closure construction. REFERENCES [1] Geosyntec Consultants, "Ash Pond Closure Feasibility Study, Draft Phase II Summary Report,Alabama Power Company Plant Barry, Bucks, Alabama," Kennesaw, Georgia, 2017. [2] Geosyntec Consultants, "Draft Pre-Design Field Investigation Summary Report, Alabama Power Company, Plant Barry, Bucks, Alabama," Kennesaw, Georgia, 2018. [3] Southern Company Services, Inc., Soil Boring Log Hole Nos. BA-1, BA-2, BA-3, BA-4, BA-5, BA-6, BA-7, BA-8, BA-9, BA-13, BA-14, BA-17, and BA-18, 1991 and 1997. [4] Southern Company Services, Inc., Earth Science and Environmental Engineering,Plant Barry Piezometers, Borings PZ-2, PZ-5, PZ-6, and PZ-7, 2013. [5] Southern Company Services, Inc., Earth Science and Environmental Engineering,Log of Test Boring, Borings. BY-AP-MW-01, -02, -03, -04, -10, -11, -12R, -13, -15, and-16, Bucks, Alabama, 2015. [6] ASTM International, "131586-11: Standard Test Method for Standard Penetration Test (SPT) and Split-Barrel Sampling of Soils," West Conshohocken, PA, 2011. [7] ASTM International, "ASTM D1587-15: Standard Practice for Thin-Walled Tube Sampling of Fine-Grained Soils for Geotechnical Purposes," West Conshohocken, PA, 2015. [8] ASTM International, "D2573 /D2573M-15el: Standard Test Method for Field Vane Shear Test in Saturated Fine-Grained Soils," West Conshohocken, PA, 2015. [9] ASTM International, "D5778 - 12: Standard Test Method for Electronic Friction Cone and Piezocone Penetration Testing of Soils," West Conshohocken, PA, 2012. [10] ASTM International, "D6913 /D6913M-17: Standard Test Methods for Particle-Size Distribution(Gradation) of Soils Using Sieve Analysis," West Conshohocken, PA,2017. [11] ASTM International, "D7928-17: Standard Test Method for Particle Size Distribution (Gradation) of Fine-Grained Soils Using the Sedimentation(Hydrometer) Analysis," West Conshohocken, PA, 2017. [12] ASTM International, "D2216-10: Standard Test Methods for Laboratory Determination of Water(Moisture) Content of Soil and Rock by Mass," West Conshohocken, PA, 2010. GWM89/Barry_Material_ChareaerGxtion_Na hve_20180827 APC Barry_EPA_000152 Geosyntec° consultants Pas. n Of 114 CP: 6PC9E Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6489 [13] ASTM Intemational, "D4318-17: Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils," West Conshohocken, PA, 2017. [14] ASTM Intemational, "D854-14: Standard Test Methods for Specific Gravity of Soil Solids by Water Pycnometer," West Conshohocken, PA, 2014. [15] ASTM Intemational, "D2974-14: Standard Test Methods for Moisture, Ash, and Organic Matter of Peat and Other Organic Soils," West Conshohocken, PA, 2014. [16] ASTM Intemational, "D5084-16a: Standard Test Methods for Measurement of Hydraulic Conductivity of Saturated Porous Materials Using a Flexible Wall Permeameter," West Conshohocken, PA, 2016. [17] ASTM Intemational, "ASTM D4767-11: Standard Test Method for Consolidated Undrained Triaxial Compression Test for Cohesive Soils," West Conshohocken, PA, 2011. [18] ASTM Intemational, "D2850-15: Standard Test Method for Unconsolidated-Undrained Triaxial Compression Test on Cohesive Soils," West Conshohocken, PA, 2015. [19] ASTM Intemational, "ASTM D2435/D2435M-11: Standard Test Methods for One- Dimensional Consolidation Properties of Soils Using Incremental Loading," West Conshohocken, PA, 2011. [20] ASTM Intemational, "D698-12e2: Standard Test Methods for Laboratory Determination of Compaction Characteristics of Soil Using Standard Effort," West Conshohocken, PA, 2012. [21] EDP, "The EDR Aerial Photo Decade Package, 15300 Highway 43 North, Axis, AL 3605, Inquiry Number: 4839281.L" Shelton, CT, 2017. [22] A. B. Rodriguez, D. L. J. Green, J. B. Anderson and A. R. Simms, 'Response of Mobile Bay and eastern Mississippi Sound, Alabama, to changes in sediment accommodation and accumulation," Response of Upper Gudf Coast Estuaries to Holocene Climate Change and Sea-Level Rise: Geological Society ofAmerica Special Paper 443, pp. 13-29, 2008. [23] United States Army Corps of Engineers, "Hurricane and Storm Damage Risk Reduction System Design Guidelines (Interim ," New Orleans District Engineering Division, New Orleans, Louisiana, 2012. [24] ASTM International, "D7263-09: Standard Test Methods for Laboratory Determination of Density(Unit Weight) of Soil Specimens," West Conshohocken, PA, 2009. [25] P. Robertson and K. Cabal, "Estimating soil unit weight from CPT," in 2nd International Symposium on Cone Penetration Testing, Huntington Beach, CA, USA, 2010. [26] P. K. Robertson and K. L. Cabal, "Guide to Cone Penetration Testing for Geotechnical Engineering, 6th Edition," Gregg Drilling &Testing, Inc., Signal Hill, California, 2015. [27] A. Casagrande, "Characteristics ofCohesionless Soils Affecting the Stability of Soils and Earth Fills,"Journal of the Boston Society of Civil Engineers, pp. 237-256, 1936. [28] D. Becker, L Crooks, K. Been and M. Jefferies, "Work as a criterion for determining in situ yield stresses in clays," Canadian Geotechnical Journal, vol. 24,pp. 549-564, 1987. G W 6489/Barry_Material_Chareceervxtion_Nvreave_20180827 APC Barry_EPA_000153 Geosyntec° consultants Page 28 of 114 CP: 6PC/rE Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6489 [29] P. Mayne, "Stress History of Soils from Cone Penetration Tests," in Soils and Rocks, Sao Paul, Brazil, 2017. [30] U.S. Army Corps of Engineers, EM 1110-2-1902: Engineering and Design, Slope Stability, Washington, DC: Department of the Army, 2003. [31] C. C. Ladd and D. J. DeGroot, "Recommended Practice for Soft Ground Site Characterization: Arthur Casagrande Lecture," in l2th Panamerican Conference on Soil Mechanics and Geotechnical Engineering, Cambridge, MA, 2004. [32] J. M. Duncan, S. G. Wright and T. L. Brandon, Soil Strength and Slope Stability, Second Edition, Hoboken,New Jersey: John Wiley& Sons, Inc., 2014. [33] R. J. Chandler, "The in-situ measurement ofthe undrained shear strength ofclays using the field vane: SOA paper," in Vane Shear Strength Testing in Soils Field and Laboratory Studies, Tampa, Flordia, 1988. [34] L. Bjerrum, "Embankments on soft ground: SOA Report," in Specialty Conference on Performance of Earth and Earth-Supported Structures, American Society of Civil Engineers, West Lafayette, Indiana, 1972. [35] C. C. Ladd and R. Foote, "A new design procedure for stability of soft clays,"Journal of the Geotechnical Engineering Division,American Society of Civil Engineers, vol. 100, no. GT7, pp. 763-789, 1974. [36] C. P. Wroth, "The interpretation of in-situ soil tests," Geotechnique, vol. 34, no. 4,pp. 449- 489, 1984. [37] F. H. Kulhawy and P. H. Mayne, "Manual on estimating soil properties for foundation design, Report EL-6800," Electric Power Research Institute, 1990. [38] M. Jamiolkowski, "Open Address: CPT'95," in Proceedings, International Symposium on Cone Penetration Testing, Vol. 1,Linkoping, Sweden, 1995. [39] M. Hatanaka and A. Uchida, "Empirical correlation between penetration resistance and phi of sandy soils," Soils &Foundations, vol. 36, no. 4,pp. 1-9, 1996. [40] R. D. Holtz, W. D. Kovacs and T. C. Sheahan, An Introduction to Geotechnical Engineering, 2nd Edition, Pearson, 2011. [41] A. S. Azzouz, R J. Krizek and R. B. Corotis, "Regression analysis ofsoil compressibility," Soils and Foundations, pp. 19-29, 1976. [42] K. Terzaghi, R. B. Peck and G. Mesri, Soil Mechanics in Engineering Practice, Hoboken, New Jersey: John Wiley& Sons, 1996. [43] E. Biringen and J. Davie, "Assessment of energy transfer ratio in SPT using automatic hammers," in GeoCongress 2008, New Orleans, Louisiana, 2008. GW6489/Barry_Material_Ch cnrGtion_Nvrefive_2018082/ APC Barry_EPA_00015,l Geosyntec° consultants Page 29 of 114 CP: LPCITE Date: 8/27/18 APC: 311 Date: 8/27/18 CA: WT Date: 8/27/18 Client: BCB Project Plant Barry Closure Design Project No: GW6489 TABLES Table 1 —Static Water Table(WT) Elevations Table 2—Summary of One-Dimensional Consolidation Test Interpretations Table 3 —Summary of Consolidated-Undrained Triaxial Data for Clay 1, Clay 2, and Dike Table 4—Summary of Vane Shear Testing and Data Quality Evaluation Table 5—Summary of SHANSEP Exponents Calculated from Consolidation Test Data Table 6—Summary of Design Reaches Table 7—Summary of Design Unit Weights,Undrained Shear Strengths, and Maximum Past Pressures for All Design Reaches Table 8—Summary of Design Drained Shear Strengths for CCR and All Soil Units Table 9—Summary of Design Undrained Strength Parameters for Staged,End-of- Construction, and Seismic Stability Analyses under Consolidated Conditions Table 10—Summary of Selected Compressibility Parameters GWW9/Barry_Materia1_Chaos eimtion_Na five_20180827 APC Barry_EPA_000155 Geosynte& consultants Page 30 of 114 CP: LPC/ Date: 8/27/18 APC: JD Date: 8/27/18 CA: WT Date: 8/27/18 Client: SCS Project: Plant Barry Closure Design Project No: GW6489 Table 1 -Static Water Table(WT) Elevations Ground Surface Upper WT' Lower WT Lower WT Elevation Upper WT' Depth Elevation Depth' Elevation' CPT# (ft NAVD88) (ft below grade) (ft NAVD88) (@ below grade) (ft NAVD88) PDCPT-01 24.0 2.0 22.0 23.0 0.9 PDCPT-02 21.4 0.0 21.4 20.0 1.4 PDCPT-03 21.7 0.0 21.7 21.7 0.0 PDCPT-04 20.9 0.0 20.9 17.0 3.9 PDCPT-05 20.2 0.0 20.2 20.2 0.0 PDCPT-06 19.9 -2.0 21.9 14.0 5.9 PDCPT-07 19.2 0.0 19.2 15.0 4.2 PDCPT-08 18.6 0.0 18.6 18.6 0.0 PDCPT-09 18.3 1.0 17.3 14.0 4.3 PDCPT-10 18.1 0.0 18.1 18.0 0.1 PDCPT-11 18.1 0.0 18.1 18.1 0.0 PDCPT-12 19.0 -1.8 20.7 19.0 0.0 PDCPT-13 19.0 0.0 19.0 19.0 0.0 PDCPT-14 19.2 2.0 17.2 19.2 0.0 PDCPT-15 18.9 -2.7 21.6 16.0 2.9 PDCPT-16 18.6 0.0 18.6 18.6 0.0 PDCPT-17 18.8 2.0 16.8 18.8 0.0 PDCPT-18 18.6 0.0 18.6 18.6 0.0 PDCPT-19 18.8 0.0 18.8 18.8 0.0 PDCPT-20 19.2 0.0 19.2 19.2 0.0 PDCPT-21 19.2 -1.4 20.6 15.0 4.2 PDCPT-22 19.5 0.0 19.5 19.5 0.0 PDCPT-23 19.6 0.0 19.6 19.6 0.0 PDCPT-24 19.0 -3.0 22.0 19.0 0.0 PDCPT-25 19.4 0.0 19.4 19.4 0.0 PDCPT-26 19.7 0.0 19.7 19.7 0.0 PDCPT-27 20.3 -1.0 21.3 20.3 0.0 PDCPT-28 21.3 1.0 20.3 21.3 0.0 PDCPT-29 21.6 0.0 21.6 21.6 0.0 PDCPT-30 21.4 -2.0 23.4 21.4 0.0 PDCPT-31 22.6 -2.0 24.6 20.0 2.6 PDCPT-32 22.6 0.0 22.6 20.0 2.6 PDCPT-33 22.6 -1.0 23.6 21.0 1.6 PDCPT-34 23.2 0.0 23.2 20.5 2.7 PDCPT-35 31.0 3.0 28.0 21.0 10.0 PDCPT-36 32.1 3.0 29.1 22.0 10.1 PDCPT-37 30.6 0.0 30.6 20.0 10.6 PDCPT-38 23.1 1.0 22.1 23.1 0.0 PDCPT-39 20.3 2.0 18.3 20.3 0.0 PDCPT-40 26.7 -1.5 28.2 14.0 12.7 PDCPT-41 26.3 1.0 25.3 20.0 6.3 PDCPT-42 33.9 2.0 31.9 16.0 17.9 PDCPT-43 23.2 -3.4 26.6 15.0 8.2 PDCPT-44 23.0 0.0 23.0 23.0 0.0 PDCPT-45 22.7 0.0 22.7 18.0 4.7 PDCPT-46 19.4 -2.0 21.4 14.5 4.9 PDCPT-47 19.7 -1.5 21.2 19.0 0.7 PDCPT-48 20.9 0.0 20.9 1 10.0 1 10.9 Notes: 'The upper water table is applicable to CCR and Clay 1 2The lower water table is applicable to Sand 1, Clay 2,and Sand 2 'Interpreted water table depths and elevations are only applicable for the date, time, and location of the CPT sounding. Water table depths and elevations may vary seasonally based on local precipitation,pool levels in the Mobile River, and other factors.Additionally,water table depths and elevations may vary between soundings. GW6489Mary_Mnedal_Chancten.non Namen,e_20180827 APC Barry_EPA_000156 Geosyntec° consultants Page 31 of 114 CP: EPCITE Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client sCs Project Plant Barry Closure Design Project No: GW6489 Table 2-Summary of One-Dimensional Consolidation Test Interpretations Maximum Past Pressure Compressibility Parameters P'e(psw Initial Void Modified Compression Modified Recompression Casagrande Strain-Energy Sample ID Material Ratio(ea) Index(Ca) Index (C.) [271 [28] PDS-25B(21-23) Clay 1 9.57 0.45 0.05 920 970 PDS-25B(39-41) Clay 0.86 0.11 0.03 3,200 3,100 PDS-26B(35-37) Clay 1 0.94 0.17 0.04 3,000 3,250 PDS-16(5-7) CCR 1.15 0.10 0.01 4,000 3,900 PDS-16(25-27) Clay 1 1.13 0.17 0.03 1,000 1,000 PDS-13B(6-8) CCR 0.94 0.07 0.01 6,400 6,200 PDS-13B(22-24) Clay 1 3.53 0.33 0.03 1,050 1,050 PDS-13B(25-27) Clay 1 3.22 0.31 0.04 1,100 1,030 PDS-15B(10-12) CCR 1.30 1 0.07 0.01 5,000 1 5,300 PDS-15B(26-28) Clay 1 2.94 0.33 0.06 1,000 1,150 PDS-11D(27-29) Clay 1 0.70 0.12 0.02 2,500 1,900 GSB-lD(28.5-30.5) Clay 1 1.54 0.23 .05 1,600 - GSB-3D(10-12) CCR 1.72 0.15 .01 5,000 - GSB-3D(34-36) Clay 1 1.54 0.26 .04 2,100 - GSB-7D(6-8) CCR 2.29 .09 .01 3,400 - Notes: 'The recompression index was calculated as the slope of the rebound portion of the consolidation e-log(p) curve;this is equal to the swell index. 2Maximum past pressures calculated using the Casagrande method were reported on the subsurface data plots. aW6089Ieury_Mntedal_Ch.teriut.n Nameft,_20180827 APC Barry_EPA_000157 Geosyntec° consultants Page 32 of 114 CP: EPC/rE Date: 8/27/18 AM JH Date: 8/27/18 CA: WT Date: 8/27/18 Client SC8 Project Plant Barry Closure Design Project No: GW6489 Table 3 —Summary of Consolidated-Undrained Triaxial Data for Clay 1, Clay 2, and Dike Uncorrected Shear Corrected Shear In-situ Vertical Stress on Failure Stress on Failure Triaxial Confining Effective Stress, Plane at Failure', Plane at Failure'' Sample ID Material Pressure, 0'31(psi) a'. (pst) Ta(psf) Tee(Pst) PDS-01B(26-28') Clay 1 1,008 805 484 384 PDS-02B(20-22') Clay 1 720 622 508 242 PDS-04(23-25') Clay 1 1,008 710 394 301 PDS-05 (21-23') Clay 1 864 663 522 399 PDS-05 (27-29') Clay 1 1,152 859 433 353 PDS-08(20-22') Clay 1 864 694 701 594 PDS-09D(21-23) Clay 1 864 900 984 780 PDS-10(25-27) Clay 1 1,008 1,183 869 685 PDS-26B(35-37') Clay 1 1,296 1,138 726 669 PDS-25B(21-23') Clay 1 864 864 1,547 946 PDS-25B(39-41') Clay 1,728 1,728 1,675 1,261 GSB-lOD(9-11) Dike 1 806 1 1,547 1 1,462 1 1,209 Notes: 'Failure defined as peak obliquity(6'11G'3), limited to 10% axial strain. 2Shear stresses on the failure plane at failure were corrected based on the difference between 6'3e and o'ee using a TWG'3e ratio of 0.36 (see Figure 3) aW60891nury_Matedal_Gancteriution Nameft,_20180827 APC Barry_EPA_000158 Geosynte& consultants Page 33 of 114 CP: LPC/rE Date: 8/27/18 APC: JB Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6489 Table 4—Summary of Vane Shear Testing and Data Quality Evaluation Peak Remolded Undrained Untrained Depth Shear Shear Data Boring (@) Material Strength(pst) Strength(psl) Quality Discussion PDS-0lB 24 Clay 1 238 170 Poor Test indicates disturbance. Torque-rotation curve is poorly defined,peak torque is very close to remolded torque. PDS-01B 29 Clay 1 391 119 Good Well-defined torque-rotation curve. PDS-02B 23 Clay 1 323 136 Good Well-defined torque-rotation curve. PDS-03 22 Clay 1 306 85 Poor Test indicates disturbance. Torque-rotation curve is poorly defined,remolded torque is very low. PDS-04 26 Clay 1 306 102 Poor Test indicates disturbance. Torque-rotation curve is poorly defined,remolded torque is very low. PDS-05 24 Clay 1 1122 204 Good Well-defined torque-rotation curve. Curve was corrected to account for tightening in rods before engaging vane. PDS-06 20 Clay 1 544 170 Poor Test indicates disturbance. Torque-rotation curve is poorly defined. PDS-07 25 Clay 1 255 102 Poor Test indicates disturbance. Torque-rotation curve is poorly defined,remolded torque is very low. PDS-08 18 Clay 1 374 136 Poor Test indicates disturbance. Torque-rotation curve is poorly defined,remolded torque is very low. PDS-09D 20 Clay 1 476 136 Poor Test indicates disturbance. Torque-rotation curve is poorly defined with multiple peaks,remolded torque is very low. PDS-10 18.5 Clay 1 850 Not Obtained Poor Test indicates sand. Torque is very high, and the rods jumped. PDS-10 30.5 Clay 1 816 Not Obtained Poor Test indicates sand. Torque is very high, and the rods jumped. PDS-11D 25 Clay 1 816 272 Good Well-defined torque-rotation curve. PDS-13A 25 Clay 1 425 136 Good Well-defined torque-rotation curve. PDS-15A 22 Clay 1 612 255 Good Well-defined torque-rotation curve. Curve corrected to not include initial torque peak. PDS-15B 29 Clay 1 391 68 Good Well-defined torque-rotation curve. PDS-25C 41 Clay 2 748 646 Poor Test indicates an obstruction.Torque is very high, and the remolded torque is very similar to the peak torque. PDS-25D 22 Clay 1 816 238 Poor Test indicates an obstruction. Torque is very high, and the remolded torque is very similar to the peak torque. Notes: 'Values of peak and remolded shear strength were do not include corrections for plasticity index or time to failure; these corrections were not found to be applicable for the site. GW6489IBury_Wtl l_Chancleriunon Namea,e_20180827 APC Barry_EPA_000159 Geosyntec° consultants Page 34 of 114 CP: 6 M Date: 8/27/18 AM JH Date: 8/27/18 CA: WT Date: 8/27/18 Client sCs Project: Plant Barry Closure Design Projeet No: GW6489 Table 5-Summary of SHANSEP Exponents Calculated from Consolidation Test Data Compressibility Parameters Initial Void Virgin Compression Recompression/Swell SHANSEP Exponent Sample ID Material Ratio(en) Index(C j Index(C„ C.) (m) PDS-25B (21-23) Clay 1 9.57 4.74 0.49 0.90 PDS-25B (39-41) Clay 0.86 0.26 0.06 0.78 PDS-26B (35-37) Clay 1 0.94 0.33 0.08 0.76 PDS-16(25-27) Clay 1 1.13 0.37 0.07 0.80 PDS-13B(22-24) Clay 1 3.53 1.50 0.15 0.90 PDS-13B(25-27) Clay 1 3.22 1.29 0.18 0.86 PDS-15B(26-28) Clay 1 2.94 1.32 0.23 0.83 PDS-11D(27-29) Clay 1 0.70 1 0.20 1 0.04 0.82 Minimum 0.76 Maximum 0.90 Mean 0.83 Notes: 'The recompression index was calculated as the slope of the rebound portion of the consolidation e-log(p) curve;this is equal to the swell index. 'The SHANSEP exponent was calculated as 1 -(GIQ [36] aw64891aury_Matedal_Gancteriution Na ftve_20180827 APC Barry_EPA_000160 Geosyntec° consultants Page 35 or 114 CP: LMC Date: 8/27/18 APC: Jut Date: 8/27/18 CA: WT Date: 8/27/18 Client: scs Project: Plant Barry Closure Design Project No: GW6489 Table 6—Summary of Design Reaches Reach CPT Co- Soundings Located Borings Description 1 PDCPT-02 Lightly-overconsolidated reach(POP=600 psf in Clay 1)encompassing two CPTs and one boring. PDCPT-03 PDS-01 Clay 2 is normally consolidated in this reach. Historical aerial images do not indicate significant differences in the precomtruction elevation of Reach 1 relative to adjacent Reach 3A. However,the subsurface data in Reach 1 indicates a higher Clay 1 strength than in adjacent Reach 3A. The reach boundaries were selected to encompass the three subsurface explorations within the reach. 2A PDCPT-05 Moderately-overconsolidated reach(POP= 1,100 psf in Clay 1)encompassing eight CPTs and three PDCPT-06 PDS-02D borings along the southeast portion of the existing Ash Pond dike. Clay 2 is slightly overconsolidated in PDCPT-07 this reach(P r=3,200 psf). Historical aerial images do not indicate significant differences in the PDCPT-08 preconstmction elevation of Reach 2A relative to adjacent Reaches 3A and 3B. However,the PDCPT-47 subsurface data indicates higher overconsolidation ratios and strengths in Reach 2A,relative to adjacent PDCPT-46 Reach 3A and 3B. The reach boundaries were selected to encompass the 11 subsurface explorations PDCPT-09 PDS-03 within the reach. PDCPT-12 PDS-04 2B PDCPT-14 Moderately overconsolidated reach(POP= 1,100 psf in Clay 1)encompassing one CPT, at the south side of the Ash Pond. This reach is very similar to Reach 2A. However, Clay 2 is normally- consolidated in this reach,rather than slightly overconsolidated like in Reach 2A. This reach borders Reach 3A on several sides. Historical aerial imagery indicates that this reach is higher in elevation than adjacent Reach 2A and 3B, and the imagery was used in conjunction with the location of PDCPT-14 to select the reach boundaries. 2C PDCPT-39 Moderately overconsolidated reach(POP= 1,500 psf in Clay 1)encompassing four CPTs in the PDCPT-17 southeastern region of the Ash Pond. This region is similar to Reach 2A,but Clay 1 and Clay 2 both PDCPT-19 have higher overconsolidation ratios. Historical imagery indicates that this area was higher in elevation PDCPT-20 than the surrounding reaches,particularly relative to Reach 3A, and was used in conjunction with subsurface exploration locations to select the borders of the reach based. 3A PDCPT-01 Normally-consolidated reach(POP=0 psf in Clay 1;P v=afro in Clay 2) encompassing nine CPTs PDCPT-42 and three borings the central and southern portions of the Ash Pond. Preconstruction aerial imagery PDCPT-04 indicates that this was a low-lying area traversed by several small-streams,with very limited apparent PDCPT-48 PDS-15 elevation relief. The historical imagery was used in conjunction with subsurface exploration locations PDCPT-45 to select the borders of the reach. PDCPT-15 PDS-05D PDCPT-43 PDS-16 PDCPT-40 PDCPT-37 3B PDCPT-10 Lightly-overconsolidated reach(POP=275 psf in Clay 1;P e=afro in Clay 2)encompassing five PDCPT-11 CPTs and one boring in the east-central portions of the Ash Pond. Preconstruction aerial imagery PDCPT-13 indicates that this reach is slightly higher in grade than Reach 3A and is separated from Reach 3A by PDCPT-16 several small streams. The reach partially surrounds Reach 2C; Reach 3B appears to have a higher PDCPT-18 PDS-06 preconstmction grade than Reach 3A but a lower preconstruction grade than Reach 2C. Reach 2C is significantly more overconsolidated than Reach 3B. The historical imagery was used in conjunction with subsurface exploration locations to select the borders of the reach. 3C PDCPT-21 PDS-07 Lightly-overconsolidated reach(POP=200 psf in Clay 1)encompassing one CPT along the north side of Reach 2C.This reach is similar to Reach 3B. However, Clay 2 is significantly overconsolidated in this reach(P r=6,000 psf). Preconstruction aerial imagery indicates that this reach is slightly higher in grade than Reach 3A,but lower in grade than Reach 2C.The historical imagery was used in conjunction with the location of PDCPT-21 and PDS-07 to select the borders of the reach. 4 PDCPT-22 Significantly-overconsolidated reach(POP=2,100 psf in Clay 1; P'e=4,000 psf in Clay 2) PDCPT-23 encompassing 10 CPTs and 2 borings along the northeast dike of the Ash Pond. Preconstruction aerial PDCPT-24 PDS-08 imagery indicates that this reach is higher in grade than the adjacent reaches. The historical imagery PDCPT-25 was used in conjunction with subsurface exploration locations to select the borders of the reach. PDCPT-26 PDCPT-27 PDS-09D PDCPT-28 PDCPT-29 PDCPT-38 PDCPT-44 5A PDCPT-30 PDS-10 Moderately-overconsolidated reach(POP= 1,200 psf in Clay 1)encompassing five CPTs and two PDCPT-31 borings along the northeast dike of the Ash Pond. Clay 1 also has an overconsolidated crust in this PDCPT-32 reach IF,=3,000 pst)and Clay 2 is absent. Preconstruction aerial imagery indicates that this reach is PDCPT-33 PSD-11D higher in grade than adjacent Reach 5B,but lower in grade than adjacent Reach 4. The historical PDCPT-34 imagery was used in conjunction with subsurface exploration locations to select the borders of the reach. 5B PDCPT-35 Lightly-overconsolidated reach(POP=750 psf in Clay 1)encompassing three CPTs and one boring in PDCPT-36 PDS-02 the northeast portions of the Ash Pond. This reach is similar to Reach 5A. However, Clay 1 has a lower PDCPT-41 overconsolidation ratio and strength. Preconstruction aerial imagery indicates that this reach is lower in grade than adjacent Reach 5A, but higher in grade than adjacent Reach 3A. The historical imagery was used in conjunction with subsurface exploration locations to select the borders of the reach. aW6489113ury_Mnledal_Chanclen.non Namn,e_20180827 APC Barry_EPA_000161 Geosyntec° consultants Page 36 of 114 CP: EPGrE Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client SCS Project Plant Barry Closure Design Project No: GW6489 Table 7- Summary of Design Unit Weights, Undrained Shear Strengths, and Maximum Past Pressures for All Design Reaches Clay 1 Clay 1 Sand 1 Ex.Dike Rate of Undrained Minimum Shear Shear Pre- Undrained Datum Strength Maximum Strength, Unit Overburden Shear Elevation', Increase with Unit Past S„ Weight, Pressure, Strength', zm„ Depth', Weight, Pressure', Undrained Shear Unit (psf) Design y, POP' S„ (H AS,/Az yn P'r Strength',S„ Weight,y, Reach (pct) (psf) (pat) NAVD88) (psVI0 (pef) (pat) (psQ (pef) 1 94 600 285 0 8.0 101 a'w S,Ja'w=0.258 110 Min.S.=500 psf 2A 92 1,100 320 0 8.4 100 3,200 700 110 2B 97 1,100 400 -2 9.7 105 a1- 750 115 2C 100 1,500 1 460 0 1 10.5 105 1 5,300 1 1,000 115 3A 95 0 200 0 8.4 102 a',o So/a'-=0.258 115 Min.S„=500 psf 1,000 3B 95 275 200 0 10.1 102 a'w 700 110 3C 100 200 200 0 9.5 110 6,000 1,000 120 4 105 2,100 490 4 12.5 108 4,000 800 110 5A IA: 110 IA: 3,000 IA: 550 IA:N/A IA:N/A 110 113: 105 113: 1,200 113:420 113: 0 113: 11.6 Not Present 5B 105 750 375 2 10.5 115 Notes: 'Pre-overburden pressure for Clay I (POP)refers to the difference at any elevation between the maximum past pressure(P o)and the in situ vertical effective stress(a'-). 'Undrained shear strengths for Clay I were defined as a function of elevation. The minimum undrained shear strength for Clay 1 is defined at a datum elevation. Below that elevation,the undrained shear strength increases at a set rate pef foot. 'Clay 2 is normally consolidated in some reaches. For these reaches,the maximum past pressure(P Q)is equal to the in situ vertical effective stress (a'—). Undrained shear strength in these reaches is defined as the maximum of the SHANSEP strength(S da',=0.258)and a specified minimum shear strength value. aWW9/eaz Wtedal_Chancterizrnon Namft,_20180827 APC Barry_EPA_000162 Geosyntec° consultants Page 37 of 114 CP: LPCITE Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: sCs Project: Plant Barry Closure Design Project No: GW6489 Table 8—Summary of Design Drained Shear Strengths for CCR and All Soil Units Drained Shear Strength Unit Weight,y, Friction Angle,¢' Cohesion, c' Material (pet) (deg) (Pst) Existing CCR 92 36 0 Clay 1 See Table 7' 31 75 Sand 1 See Table 7' 35 0 Clay 2 See Table 7' 31 75 Sand 120 38 0 Existing Dike Fill 120 32 0 Compacted CCR 97 36 0 New Containment Dike Fill 115 27 50 Containment Dike Bridge Lift 105 28 0 Notes: 'Design unit weights for Clay 1, Sand 1, and Clay 2 vary by design reach. The design unit weights for these materials were listed in Table 1. GWW9/Barry_Material_Chars eimtion_Na five_20180827 APC Barry_EPA_000163 Geosyntec° consultants Page 38 of 114 CP: LPC/rE Date: 8/27/18 APC: 311 Date: 8/27/18 CA: WT Date: 8/27/18 Client: SCS Project: Plant Barry Closure Design Project No: GW6489 Table 9—Summary of Design Undrained Strength Parameters for Staged, End-of- Construction, and Seismic Stability Analyses under Consolidated Conditions Material Undrained Strength Parameters Existing CCR Fully Drained' Compacted CCR Fully Drained' Clay 12 S.=a'-x 0.258 x OCRo as Sandi Fully Drained' Clay 21 Sa=a',x 0.258 x OCR°83 Sand 2 Fully Drained' Existing Dike Fill Parametric' Sa= 1,000 psf 0' =320, c' =0 psf New Containment Dike Fill S„=600 psf Notes: 'CCR, Sand 1,and Sand 2 were assumed to behave in a fully-drained manner during construction and seismic loading. 'Clay 1 and Clay 2 were assumed consolidate under added loads following the SHANSEP model. Undrained shear strength under future loading conditions can be estimated using the future vertical effective stress and the overconsolidation ratio. The overconsolidation ratio will vary between design reaches. 'The existing dike soils vary from cohesive(clayey)to cohesionless (silty). Therefore,the existing dike may behave in either a drained or undrained manner during construction and seismic loading. Slope stability analyses for the existing dike should evaluate both drained and undrained sail behavior of the dike soils;the lower factor of safety from the two soil behaviors should be reported. GWW9/Barry_Material_Chars eimtion_Na five_20180827 APC Barry_EPA_000164 Geosyntec° consultants Page 39 of 114 CP: E IrE Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client BCB Project Plant Barry Closure Design Project No: GW6489 Table 10—Summary of Selected Compressibility Parameters Compressibility parameters Modified Modified re- Modified Coefficient of Drained Material secondary consolidation, Constrained compression compression t compression Cv(cm/min) Modulus,M index,C. index,CB index,Cote 131 n1 (psf) CCR 0.10 0.01111 0.0015 0.60 - Reach 1 0.29 0.0291%1 Reach 2A/2B 0.32 0.03111 Reach 3A/3B/3C 0.26 0.041'1 0.01 0.01 - v Reach 4 0.18 0.018111 Reach 5A/5B 0.17 0.02 01 Sand 1 - - - - 2.5 x 106 Clay 2 0.14 0.014111 0.03 0.02 - Sand2 - - - - 3.0x 106 Notes: 'Modified rc-compression index is obtained from laboratory consolidation data. 'Modified re-compression index is assumed 0.1 times the modified compression index 'The modified secondary compression index and coefficient of consolidation are obtained from laboratory testing. `The drained elastic modulus for sand was obtained from correlations with CPT data conducted at the site. aW6089IBary_MWtedal_Ch.teriution Na,raft,_20180827 APC Barry_EPA_000165 Geosyntec° consultants Page 40 of 114 CP: LPC/rE Date: 8/27/18 APC: JB Date: 8/27/18 CA: WT Date: 8/27/18 Client: sCs Project Plant Barry Closure Design Project No: GW6489 FIGURES Figure 1 —Plant Barry Design Reaches with Aerial and Borings Figure 2—Correlation between Specific Gravity and Moisture Content Figure 3—Relationship of Undrained Shear Strength to Effective Consolidation Stress, Clay 1 and Clay 2 Figure 4—Plant Barry Design Reaches with Aerial Imagery from 1938 Figure 5—Plant Barry Design Reaches with Aerial Imagery from 1950 Figure 6—Plant Barry Design Reaches with Aerial Imagery from 1952 Figure 7—Plant Barry Design Reaches with Aerial Imagery from 1974 Figure 8—Drained p'-q Plot for CCR Figure 9—Drained p'-q Plot for Clay 1 and Clay 2 Figure 10—Variation of Modified Compression Index obtained from Laboratory Results with Elevation Figure 11 —Correlation between Modified Compression Index and Organic Content Figure 12—Correlation between Organic Content and Moisture Content Figure 13—Variation of Calculated Modified Compression Index with Elevation for Reaches 1,2, and 3 Figure 14—Plots of Calculated-Modified Compression Index with Elevation for Reaches 4 and 5 Figure 15—Plots of Modified Secondary Compression Index for CCR and Clay 1 from Laboratory Consolidation Test Results Figure 16—Plots of Modified Secondary Compression Index for Clay 2 from Laboratory Consolidation Test Results Figure 17—Plots of Coefficient of Consolidation of Clay 2 from Laboratory Consolidation Test Results Figure 18—Plots of Coefficient of Consolidation of Clay 2 interpreted from Laboratory Consolidation Test Results Figure 19—Plots of Calculated Constrained Modulus versus Elevation for Sand 1 and Sand 2 GW6489/Barry_Materia1_Chaosa rization_Nanative_20180827 APC Barry_EPA_000166 Geosyntec° Consultants Page 41 of 114 CP: LPCITE Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client scs Project: Plant Barry Closure Desgn Project No: GW6489 Figure 20—Undrained Shear Strength for Cohesive Dike Soils Figure 21 —Drained Shear Strength for Cohesionless Dike Soils GWW9/Barry_Material_Chama ization_Na five_20180827 APC Barry_EPA_000167 LEGEND REACH 5B - "� SCS HISTORICAL BORING REACH 5A PDCPT33XPo�P �� . (3 2013 SCS PIEZOMETER MOBILE RIVER I )Q d ° "° 2015 SCS MONITORING WELL ° 21^ ° X r. ❑ 2017 SPT BORING ❑�° 1a ID ".� Poi".Xzx * REACH 4 -17 Q 2018 SPT BORINRG we P.« Q"��„ ° °se �"° ,_, P.,- P�e10 X 2018 CPT XX ° -CPT„ aAa — — APPROXIMATE LIMITS OF CCR X ❑"°• X'-` °s° APPROXIMATE LIMITS OF DESIGN REACH P. n QT NOTES: REACH'1 A NIL P a " - 1. APPROXIMATE CCR LIMITS AS X. ° REACH 3C DEFINES IN THE SUPPLIED J m DRAWING 'VOLUME FROM El _ "°"'T` Pos,�T ❑" EXTRACTED FROM "°`PTA' P° Ta°- + P� T PERIMETER BERM THE9-09"AND „ o \ X g ,X 2. REACH BOUNDARIES WERE p REACH 2C DEVELOPED USING SUBSURFACE X 0S1 c s EXPLORATION DATA AND P g�i INTERPRETATION OF HISTORIC , � X REACH 3B AERIAL IMAGERY,AND SHOULD REACH 2A \XX T - BE CONSIDERED APPROXIMATE. X REACH BOUNDARIES LOCATED OUTSIDE THE VICINITY OF s Q �A SUBSURFACE EXCAVATIONS MAY r � a REACH 3A VARY FROM THOSE SHOWN ON h •. ; REACH 3B THIS DRAWING. 0 o ` .:... ei:a \ ` 0 700 ea; SCALE IN FEET d ❑ 13 PLANT BARRY COOLING WATER DISCHARGE CANAL 'a`i- DESIGN REACHES WITH AERIAL a t AND BORINGS 0 GeOSymecO FIGURE _ ' REACH 3A 5 PROJECTNO: GW6 89 I AUGUST2018 APC Barry_EPA_000168 Geosyntec° consultants Page 43 of lid CP: 6 M Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client BCB Project Plant Barry Closure Design Project No: GW6489 2.9 2.8 A 27 O \ \ • a 2.6 v q 25 \ Clay 1 k Selects Gs=-0.0025rw 9/6)+2.847 2.4 n \ m - d 23 N. 2 2.2 21 Clay 1 (2018) \ 2A Clay 1 (2017) s 0 50 100 150 200 250 300 350 Measured Natrual Moisture Content,w,(%) Figure 2—Correlation between Specific Gravity and Moisture Content OW6089IBury_Matedal_Ganct.r.t.n Nameft,_20180827 APC Bany_EPA_000169 Geosyntec° Consultants Page 44 of 114 CP: 6P M Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: SCS Project Plant Barry Closure Design Project No: GW6489 3 e / 2 / L / Clay 1 and Clay 2 / Selected Su a 0.36 (s,/a'x)•50 pat a /• 2 , • LL / O 1 y : 0 �/ 0 Clay 1 (2018) Clay 1 (2017) p Clay 2(2018) a p z a 6 a to Effective Consolidation Pressure,dt,(ksf) Figure 3—Relationship of Undrained Shear Strength to Effective Consolidation Stress, Clay 1 and Clay 2 eW6089IBury_Materlal_Gancterinnon Na ftve_20180827 APC Barry_EPA_000170 REACH5B `� LEGEND \ — — APPROXIMATE LIMITS OF CCR / \ -REACH SA APPROXIMATE LIMITS OF •/\/y/ DESIGN REACH \ MOBILE RIVER I �REACH 4 w NOTES: 1. APPROXIMATE CCR LIMITS AS y • 1 DEFINES IN THE SUPPLIED - DRAWING "VOLUME FROM REACH 1 \ REACH 3C 3695BAR-ASHPOND_7-29-09"AND EXTRACTED FROM THE PERIMETER BERM 2. REACH BOUNDARIES WERE \ DEVELOPED USING SUBSURFACE EXPLORATION DATA AND — �} INTERPRETATION OF HISTORIC REACH 2C AERIAL IMAGERY,AND SHOULD BE CONSIDERED APPROXIMATE. REACH 3B f REACH BOUNDARIES LOCATED ti EACH 2A OUTSIDE THE VICINITY OF SUBSURFACE EXCAVATIONS MAY _ \ VARY FROM THOSE SHOWN ON THIS DRAWING. \ ?. REACH 3A 3. HISTORICAL AERIAL IMAGERY PROVIDED BY"THE EDR AERIAL REACH 3B PHOTO DECADE PACKAGE", 2017. 0 o \ I o 700 R SCALE IN FEET � I a FUTURE LOCATION OF THE PLANT BARRY COOLING WATER DISCHARGE CANAL DESIGN REACHES WITH AERIAL IMAGERY FROM 1938 ' .. REACH 2B Geosymec° FIGURE REACH 3A 4 PROJECT NO: GM 89 AUGUST 2018 APC Barry_EPA_000171 REACH 5B �� LEGEND \ — — APPROXIMATE LIMITS OF CCR / REACH 5A APPROXIMATE LIMITS OF DESIGN REACH \ MOBILE RIVER \ \ J I \ REACH 4 1 NOTES: ,\ 1. APPROXIMATE CCR LIMITS AS 1 DEFINES IN THE SUPPLIED DRAWING "VOLUME FROM REACH 1 \ REACH 3C 3695BAR-ASHPOND_7-29-09"AND EXTRACTED FROM THE PERIMETER BERM 2. REACH BOUNDARIES WERE - \ DEVELOPED USING SUBSURFACE EXPLORATION DATA AND INTERPRETATION OF HISTORIC REACH 2C AERIAL IMAGERY,AND SHOULD BE CONSIDERED APPROXIMATE. REACH 3B REACH BOUNDARIES LOCATED \/J(. OUTSIDE THE VICINITY OF REACH 2A J SUBSURFACE EXCAVATIONS MAY _ \ VARY FROM THOSE SHOWN ON THIS DRAWING. \ REACH 3A 3. HISTORICAL AERIAL IMAGERY z PROVIDED BY"THE EDR AERIAL REACH 3B PHOTO DECADE PACKAGE", 2017. o _ o \ I o 700 SCALE - FUTURE LOCATION OF THE \ ,� PLANT BARRY a COOLING WATER DISCHARGE CANAL ai DESIGN REACHES WITH a \ AERIAL IMAGERY FROM 1950 0 GeoSj7[Itec° FIGURE REACH 3A 5 5 PROJECTNO: GW8489 AUGUST2018 APC Barry_EPA_000172 REACH 5B `� LEGEND \ — — APPROXIMATE LIMITS OF CCR / \ REACH SA APPROXIMATE LIMITS OF •/\/y/ DESIGN REACH \ MOBILE RIVER 't I REACH 4 \ r1R40 NOTES: 1. APPROXIMATE CCR LIMITS AS DEFINES IN THE SUPPLIED DRAWING "VOLUME FROM REACH 1 \ REACH 3C 3695BAR-ASHPOND 7-29-09"AND EXTRACTED FROM THE PERIMETER BERM 2. REACH BOUNDARIES WERE s \ DEVELOPED USING SUBSURFACE EXPLORATION DATA AND INTERPRETATION OF HISTORIC REACH 2C AERIAL IMAGERY,AND SHOULD BE CONSIDERED APPROXIMATE. REACH 3B REACH BOUNDARIES LOCATED REACH 2A OUTSIDE THE VICINITY OF SUBSURFACE EXCAVATIONS MAY LL \ VARY FROM THOSE SHOWN ON �- THIS DRAWING. REACH 3A 3, HISTORICAL AERIAL IMAGERY \ — PROVIDED BY"THE EDR AERIAL REACH 3B PHOTO DECADE PACKAGE", 2017. 0 °w \ 0 700 SSCALE IN FEET U \ FUTURE LOCATION OF THE PLANT BARRY COOLIN DESIGN REACHES WITH G WATER DISCHARGE CANAL AERIAL IMAGERY FROM 1962 REACH 2B \ Geosyrdec° FIGURE REACH 3A . 6 $ PROJECTNO: GW8 89 I AUGUST2018 i APC Barry_EPA_000173 REACH SB �` LEGEND — APPROXIMATE LIMITS OF CCR / \ ,=REACH 5A APPROXIMATE LIMITS OF •/\/y/ DESIGN REACH J \ r ,> . MOBILE RIVER REACH 4 y1 1 NOTES: 1. APPROXIMATE CCR LIMITS AS DEFINES IN THE SUPPLIED DRAWING "VOLUME FROM REACH 1 \ REACH 3C - 3695BAR-ASHPOND_7-29-09"AND - _ EXTRACTED FROM THE 9 PERIMETER BERM 2. REACH BOUNDARIES WERE \ DEVELOPED USING SUBSURFACE V, EXPLORATION DATA AND INTERPRETATION OF HISTORIC REACH 2C AERIAL IMAGERY,AND SHOULD BE CONSIDERED APPROXIMATE. \/J(. REACH 3B REACH BOUNDARIES LOCATED ` REACH 2A J OUTSIDE THE VICINITY OF SUBSURFACE EXCAVATIONS MAY 5 a \ VARY FROM THOSE SHOWN ON THIS DRAWING. REACH 3A k` 3. HISTORICAL AERIAL IMAGERY c \ PROVIDED BY"THE EDR AERIAL h e REACH 3B PHOTO DECADE PACKAGE", 2017. 0 a \ I o 700 5 SCALE IN FEET a FUTURE LOCATION OF THE PLANT BARRY r COOLING WATER DISCHARGE CANAL lP+ DESIGN REACHES WITH AERIAL IMAGERY FROM 1974 0 REACH 2B GeoSynkec° FIGURE REACH 3A 7 5 PROJECTNO: GW8489 I AUGUST2018 APC Barry_EPA_000174 Geosyntec° Consultants Page 49 of 114 CP: EPCrrE Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: SCS Project. Plant Barry Closure Design Projeet No: GW6489 6 C / q er / m LL CCR m O � Selected(V=SOs and 0psf a2 H O/ 41 CCR(2018) / A CCR(2017) e 0 2 q 6 8 10 Mean Effective Stress at Failure,p'f(ksq Figure 8-Drained p'-q Plot for CCR Note: Design failure envelope was converted from p'-q (V-o)space to Mohr-Coulomb (¢-c)space aW6089IBury_Materlal_Gancteriunon Na ftve_20180827 APC Barry_EPA_000175 Geosyntec° consultants Page 50 of 114 CP: EPC7fE Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: BCB Project Plant Barry Closure Design Project No: GW6489 3 / A 92 F Clay 1 ti e /d Selec and Clay Selectetll31°and c'=75 psf didil V 1 N • *A Clay 1 (2018) Clay 1 (2017) / O Clay 2(2018) 0 p 2 4 8 Mean Effective Stress at Failure,p',(ksq Figure 9-Drained p'-q Plot for Clay 1 and Clay 2 Note: Design failure envelope was converted from p'-q (V-o)space to Mohr-Coulomb (¢-c)space aW6089IBury_Materlal_Ch n teriunon Na ftve_20180827 APC Barry_EPA_000176 Geosyntec° Consultants Page 51 of 114 CP: 1,PC/rE Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client BCB Project Plant Barry Closure Design Pmjeet No: GW6489 Modified Compression Index,C.I-) 0 0.1 0.2 0.3 0.4 0.5 0.6 30 I] CCR-GSBJD:10.12(2017) Selected)CCR QD Clay 1-GSBJD:34-36(2017) _ ® CCR-GSB-7D:6-8(2017) 20 Cce — 0.11) ® Clay 1-GSB-1 D:28.5d0.5(2017) Q Clay 1-PDS-2513:21-23(2018) Clay 2-PDS-2513:39 1 (Ml8) Clay 1-PDS-2613:35 7(2018) 10 ❑ CCR-PDS-16:5-7(2018) p Clay 1-PDS-16:25-27(2018) E} Clay 1-PDS-15B:26-28(2018) Clay 1 0 CCR-PDS-13B:6-8(2018) e 0 Q CCR-PDS-15B: 10-12(2018) e Q Clay 1-PDS-11D:27-29(2018) nO AD U Clay 1-PDS-13B:22-24(2018) 0 4 d Clay 1-PDS-13B:25-27(2018) W -10 -zo elected lay 2 ce = 0.14 -30 Figure 10—Variation of Modified Compression Index obtained from Laboratory Results with Elevation GW6089IBury_Malerlal_Ch.t riu0on Namft,_20180827 APC Barry_EPA_000177 Geosyntec° consultants Page 52 of 114 CP: 6 M Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: sCs Project Plant Barry Closure Design Project No: GW6489 0.5 ..• N Ij0.4 x V=0.0247e. -' • • Rr=0.9272 —0.3 • c 0 N • p 0.2 E ♦' E • y 0.1 a 0 0 0 50 100 150 200 250 300 350 Moisture Content (%) Figure 11 —Correlation between Modified Compression Index and Moisture Content OW6089IBury_Matedal_Gancterinnon Na ftve_20180827 APC Barry_EPA_000178 Geosyntec° consultants Page 53 of 114 CP: 6 M Date: 8/27/18 APC: TH Date: 8/27/18 CA: WT Date: 8/27/18 Client: BCB Project Plant Barry Closure Design Project No: GW6489 RaacM1 1 and RnacM1 2N2B ReatM1 3AYlBI3C MOGIf.d Compression Index Meddled Compr Inon lndaa 000 Od 020 as 040 05 0,60 0.00 0.1 020 013 040 0.6 Odo 4 0 • I • w r a a Sel Cted 0.29 I Selected 0.26 1a -+2 . Readil • RaetM1� ■ ■ RnacM1 3A -14 • Reads 2B ■ ReacM1 3H13C Latwralary gala -1B Figure 12—Variation of Calculated Modified Compression Index with Elevation for Reaches 1, 2, and 3 GW6089IBury_Malerlal_Ch.tcriunon Namefi,c 20180827 APC Barry_EPA_OOOP9 Geosyntec° consultants Page 54 of 114 CP: 6 M Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: SCS Project Plant Barry Closure Design Project No: GW6489 Reach 4 Reach 5A/5B Modified Compression Wex Modified Coapeession index 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.00 0.05 0.10 0.15 0.20 0.25 4 4 • 2 2 • 0 • 0 — • • -2 -2 • 3 4 a 4 • m • a • o£ -6 c -6 © 8 -a Se cted • � -a • Selected 0.17 • -10 -10 -12 -12 • Reaeh 5A -1q • Reach4 -14 • Reaeh 5B �Serieal ■ Laboratory data • 16 -16 —Series4 _ Figure 13—Plots of Calculated-Modified Compression Index with Elevation for Reaches 4 and 5 aW6489Ma, Wtedal_Gancteriunon Na ftve_20180827 APC Bany_EPA_000180 Geosyntec° consultants Page 55 of 114 CP: 6 M Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client BCB Project: Plant Barry Closure Design Project No: GW6489 oml aw Uq V V n C C OWI C 0.08 Clay 1 c Selected 0.0015 Selected 0.01 E 6 am2 E o ON 0 R p S g amt ® w am 9 9 C y �1 O 2 p m @[ � 0.01 0.1 1 10 100 o 01 0.1 1 10 IN Stress Ratio,C,(Cp stress Ratio,cr-)a-p Figure 14—Plots of Modified Secondary Compression Index for CCR and Clay 1 from Laboratory Consolidation Test Results GW60891aury_Matedal_Ch n terinnon Na ftve_20180827 APC Barry_EPA_000181 Geosyntec° consldtants Page 56 of 114 CP: 6 = Date: 8/27/18 AM JH Date: 8/27/18 CA: WT Date: 8/27/18 Client SC8 Project Plant Barry Closure Design Project No: GW6489 W O.OnB C U f! N a c � o.00a 0 m m m $ Clay 2 E Selected 0.01 0 0.004 U A ' a c m o.ow Tff N 9 m sC 2 0 0 a at Ci 4 10 100 Stress Rail*,al)&p Figure 15— Plots of Modified Secondary Compression Index for Clay 2 from Laboratory Consolidation Test Results aW60891aury_Maledal_Chancleriunon Namative_20180827 APC Barry_EPA_000182 Geosyntec° consultants Page 57 of 114 CP: 6 M Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: BCB Project Plant Barry Closure Design Project No: GW6489 C e Ess dos u Z u - 0 0 - a v CCR v oe Clay 1 Cis Selected 0.6(cm'/min) a Selected 0.01 (cin min) U U - S `e • • 0 u° os 0 m m 0 a n o D o.ot 0.1 1 10 mo u 0.01 0.1 1 10 100 Stress Ratio,a'Jifp Stress Ratio,a'fa'p Figure 16—Plots of Coefficient of Consolidation of Clay 2 from Laboratory Consolidation Test Results aW6089I3ury_Matedal_Gancteriunon Narrative20180827 APC Barry_EPA_000183 Geosyntec° consultants Page 58 of 114 CP: 6 M Date: 8/27/18 AM JH Date: 8/27/18 CA: WT Date: 8/27/18 Client sCs Project Plant Barry Closure Design Project No: GW6489 C � O.e u U C O OA O C O V ° CCR d Selected 0.02 (cm2/min) 0.3 k m O 9 m F Y n 0 V 00' 0.' > 10 100 Stress Ratio, v')cr'P Figure 17— Plots of Coefficient of Consolidation of Clay 2 interpreted from Laboratory Consolidation Test Results aW60891aury_Matedal_Ganct.r M.n Nameft,_20180827 APC Barry_EPA_000184 Geosyntec° consultants Page 59 of 114 CP: 6 M Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client sCs Project Plant Barry Closure Design Project No: GW6489 m m 0 0 000 00o IO 0 oaf ®0`9 oro 000 0 0 �� 0 � bo 0 0 00 -z0 &n 0 � e orroo ro o a • X 0 i f•1 > 0 •• Wde 0 W 40 q•• I same 2 MSand 1= Os 1 MSand 1= 2.5 x 106 psf 2.5 x 106 psf mI I I I I 1 40 0 2XWM 40o0oo0 SMO 0 m0oo00 a0oo0o0 0=0 Calculated Constrained Modulus,M(psf) Calculated Constrained Modulus,M(psp Figure l8a—Plots of Calculated Constrained Modulus versus Elevation for Sand 1 and Sand 2 aW6089IBury_Matedal_Gancteriunon Na ftve_20180827 APC Barry_EPA_000185 Geosyntec° consultants Page 60 of 114 CP: E IrE Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: BCB Project Plant Barry Closure Design Project No: GW6489 1600 =Sand 1400 1200 T 1000 800 w 600 400 200 0 500,000 1,000,000 1,500,000 2,000,000 2,500,000 3,000,000 3,500,000 4,000,000 Drained Constrianed Modulus(pst) Figure 18b—Frequency Plots for Calculated Constrained Modulus aW6089IBury_Matedal_Gancterinnon Na ftve_20180827 APC Barry_EPA_000186 Geosyntec° consultants Page 61 of 114 CP: EPC7rE Date: 8/27/18 AM JH Date: 8/27/18 CA: WT Date: 8/27/18 Client SCS Project Plant Barry Closure Design Project No: GW6489 Estimated Undreined Shear Strength,S,(pso 0 1000 me 3010 a ■ Dike Fill Selected S,=1,000pst _ e 'c ♦ N ■ 12 ♦ ■ Dike Fill SPT(1991) ■ ■ Dike Fill SPT(2013) 16 Dike Fill SPT(2017) X Dike Fill CIU-TX(2017) AAN- Figure 19—Undrained Shear Strength for Cohesive Dike Soils GVVW9IBury_Maierlal_Ch n tcrindon Na ftve_20180827 APC Barry_EPA_000187 Geosyntec° Consultants Page 62 of 114 CP: EPGrE Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: BCB Project: Plant Barry Closure Design Project No: GW6489 Estimated Effective Friction Angle,a'(deg.) Dike Fill 29 u ae m a ae Estimated Drained Friction Angle,to'(deg.) o 25 30 35 40 45 50 0 a 5 as 32° `DI:a Fill S ecte i 0' 82° e 10 pp e s • • S d � s • • �� is Is s G a 12 e y 20 . Dike Fill SPT(1991) Dike Fill SPT(2013) 16 Dike Fill SPT(2017) 25 • SFrq'Con.(xnvuke a uvhide,1996) X Dike Fill CIU-TX(2017) ■ GsPlo (T-1F)CIUConcenedsu —Selmod is.30 zo Figure 20—Drained Shear Strength for Cohesionless Dike Soils GW6089IBury_Malenal_Chancleriu0on Narrative_20180827 APC Bany_EPA_000188 Geosyntec° CDHsultmts Page 63 of 114 CP: LPCITE Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: SCS Project Plant Barry Closure Design Project No: GW6489 ATTACHMENT 1 GEOTECHNICAL PARAMETER SUMMARY PLOTS GW6489/Barry_Material_Chama imtion_Na five_20180827 APC Barry_EPA_000189 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 1 : PDCPT-02 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (°) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 a',(Mayne, 2017) a',(Mayne, 2017-Organic Soils) duo 20 CC VT= 2P 10 Clay 1 Upper G T=21.4 ft Min S.=258 psf @ El. 0' Lower GV IT=1.4 ft ASU/A,= + 8.0 psf/it 0 CI y 1 POP=600 psf V 4P c ° -10 >y Sa d 1 W Vr- P 0 Clay 2 S nd 1 -20 Clay 2 S /o' =0.258 $' 35 d g y,= 01 p f Min S„=500 psf P.P - 7 00 Sand 2 -30 - 20 o4bf Sar d2 00 38 Ideto -40 Notes: 50 LEGEND — 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content —Design Profile 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. 0 Measured Moisture Content ♦ SPT(N,), Clay 1 3.yr-total unit weight; yd-dry unit weight. 0 Measured Total Unit Weight VrLab: V 1+MC/100 [ e'( )] • Measured a'p(1 D Consolidation) — 4. Selected yT values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. —Correlated S„of Clay 1 and Clay 2 [CPT: Nk,= 17; Su=(qt-a,)/Nk, (Robertson and Cabal,2015)] 6.o'o-preconsolidation stress;a'.-vertical effective stress. O Measured S„of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a',[Kulhawy and Mayne, 1990]. 0 Measured S„of Clay 1 and Clay 2[UU] 8.dr values were clipped to 9000 psf. ❑d Measured S.of Clay 1 and Clay 2[VST: Peak(uncorrected)] 9. SPT(N,),values were clipped to 40. eCorrelated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 1990] g pp pp y p y ------Correlated S.of Clay 1 and Clay 2 [SHANSEP S=0.258, m=0.836c Barry_EPA_000190 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 1: PDCPT-03 and co-located PDS-01 Atterberg Limits, Moisture, Preconsolidation and Effective and Organic Content (%) Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) SPT (Nj, Friction Angle (°) 0 50 100 150 200 250 300 350 70 80 90 100 110 120 130 0 500 10000 3000 6000 9000 0 5 10 15 20 25 30 35 40 25 30 35 40 45 50 30 KeyFo,(Mane, 2017) TT FF�j ne, 2017-Organic Soils) PL MC LL 20 • OC 9.0% CC yT=92P 10 Upper T=217ft Lower G T=0.6 ft Clay 1 0 • Min S 258 psf @ El. 0' ASU/A,= + 8.0 psf/ft • Clay 1 POP=600 psf V 4P OC 16.8% o -10 > • Sa d 1 W yr 10 P f Sand 1 0 0 ♦ (0'= 5 deg oho 20 Cl 2 Vr 01P P'P Clay 2 i r& Sa d 2 S ju'w=0.258 -30 - 20 f Min S. = 500 psf San 2 �'=38 deg -40 a IL 50 LEGEND EGEND CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content — Design Profile 2. ILL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content ♦ SPT(N,), Clay 1 3.yr-total unit weight; y,-dry unit weight. • Measured Total Unit Weight[Lab:yr ya*(1+MC/100)] • Measured a'p(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] — 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated S.of Clay 1 and Clay 2ICPT: N.- 17; S =Sqt-o )/N (Robertson and Cabal, 2015)] 6.a'o-preconsolidation stress;o'w-vertical effective stress.— O Measured S„of Clay 1 and Clay 2`(;U: Consolidate&to clo`1est"]n-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a'p[Kulhawy and Mayne, 1990]. 0 Measured S„of Clay 1 and Clay 2 [UU] 8.o'r values were clipped to 9000 psf. ❑o Measured S.of Clay 1 and Clay 2[VST: Peak(uncorrected)] 9. SPT(N,),values were clipped to 40. • Correlated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. -- Correlated Effective Friction Angle[CPT: SEPKulh Sy and Mayne, .83; 9 PP PP V P Y ---- Correlated S.of Clay 1 and Clay 2[SHANSEP S = 0.258, m =0.83�c Barry_EPA_000191 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 2A: PDCPT-05 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (a) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 a'p(Mayne, 2017) COP(Mayne, 2017-Organic Soils) a'w 20 C -YT=s 2 Paf 10 Clay 1 Min S. = 320pf@El. 0' AS„/A,=+8.4 1 sf/ft POP 1,100 psf 0 vx 2 an I 1 San j 1 o m-9 C r 110 PC If AL V 35d 0 9 o — -10 A 0 o g a 0 > m W Clay 2 Cial 2 S„=700 psf 20 YT=l 00 PC f P'p 3,200 psf 16 —Sat d 2 -3U '120Off San 12 Q'= 38 de -40 50 LEGEND Notes: —— 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.-50 ft. Design Profile O Measured Organic Content SPT N 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content ( �)� Clay 1 3. total unit weight; d unit weight. • Measured Total Unit Weight Lab: '(1+MC/100)] 0 Measured a'p(1 D Consolidation) Vr- 9 Ya-dry 9 9 [ Vi Va 4. Selected yT values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal,2015] 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. CorrelateA s of CIaY 1 an CIaY 2 fCPT' N ]7 S =/qt- 1/N (R be soRand Cabal, 2015)] 6.a'p-preconsolidation stress;o'w-vertical effective sVess. O Measured 5u°of aay 1 anrQclay T[cU: Co olidAtetl tb c�iS°Bst'4n-situ s�MR 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a'p[Kulhawy and Mayne, 1990]. 0 Measured S„of Clay 1 and Clay 2 [UU] 8.o'p values were clipped to 9000 psf. ❑o Measured S.of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(Nr),values were clipped to 40. 0 Correlated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 1990] ------Correlated S..of Clav 1 and Clay 2[SHANSEP S=0.258. m = 0.83]pC Barry_EPA_000192 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 2A: PDCPT-06 and co-located PDS-02 Atterberg Limits, Moisture, Preconsolidation and Effective and Organic Content (%) Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) SPT (N1)sn Friction Angle (°) 0 50 100 150 200 250 300 350 70 80 90 100 110 120 130 0 500 10000 3000 6000 9000 0 5 10 15 20 25 30 35 40 25 30 35 40 45 50 30 o'p correlat d 1 Key —a'p(correlat)d 2) PL MC LL — °w 20 CC • yr 2 pc 10 Cl a 1 Min S.=320 psf El. 0' AS Pop POP 1,100 psf 0 O Cla 1 O San 1 OC 6.4° yi 2 P �'=35 deg c • • -10 yT 10 p y o W ° C Dla 2 Clay 2 20 yr= 00 p S„=700 psf P'p 3,200 psf an 12 -30 v.=1 20 oct San J 2 • 38 de ® o -40 -50 Notes: LEGEND Desi_ _ 1. All elevations are in the NAVD88 datum.All figures were clipped to El. +30 ft and El. -50 ft. O Measured Organic Content SPT9NProfile Clay1 2. ILL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content ( +)pp 3. yr-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab: yT=yd"(1+MC/100)] • Measured a'p(1 D Consolidation) Sand 1 4. Selected yT values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] 5. S„-undrained shear strength(values were clipped to 1000 psf); OCR-overconsolidation ratio. Correlated S„of Clay 1 and Clay 2 [CPT: Nk,= 17; S,=(qt-aw)/NM (Robertson and Cabal.2015)] 6. a'p-preconsolidation stress; a',,-vertical effective stress. O Measured S„of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7. Value of k=0.33 (recommended by Robertson and Cabal,2015)was used to calculate a'p[Kulhawy and Mayne, 1990]. Measured S.of Clay 1 and Clay 2[UU] 8. a'p values were clipped to 9000 psf. ❑o Measured S.of Clay 1 and Clay 2[VST: Peak(uncorrected)] 9. SPT(N,),values were clipped to 40. t/ Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle[CPT: Kulhawy and Mayne, 1990] -----Correlated Su of Clay 1 and Clay 2 [SHANSEP S=0.258, M =0.83] APC Barry_EPA_000193 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 2A: PDCPT-07 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (°) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 'p(conelate 1) 'p(correlate J 2) w 20 C —YT=s 2 pcf 10 Clay 1 Min S.-320 p4 @El. 0' AS„/A,= +8.4 p /ft POP= 1,100 psf 0 Clay 1 Vr9 P0f San 1 �' =35 deg c C -1U San1 o0 0 .� 0Yr 70 PCf W ° -20 -Claj 2 Clay 2 r 00 p Sp=700 psf San 2 cb'= 8deg -30 -San 2 PIP=3,2 0 psf Vr= 20 P ° Bo 40 00 50 Notes: LEGEND — Design Profile — 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content N 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content SPT( ,)s° Clay 1 3. total unit weight; d unit weight.ht. • Measured Total Unit Weight Lab: (1+MC/100)] Measured a'p(1 D Consolidation) Vr- 9 Ya-dry 9 9 [ Vi Yd� 4. Selected yT values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal,2015] 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. l��rrelaterl q n�Cla 1 an CI 1�PT' N 1 S -Iqt- 1/ (R b s nand Cabal, 2015)] 6.a'p-preconsolidation stress;o'w-vertical effective stress. O 101-easured S„°oT c;la�1 an�c:l�j��`t:U: CoksohdAteCl Yo c�d3esCin-si�u�S�re?s 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a'p[Kulhawy and Mayne, 1990]. 0 Measured S„of Clay 1 and Clay 2 [UU] 8.o'p values were clipped to 9000 psf. ❑o Measured S„of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(Nr),values were clipped to 40. Correlated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. 0 Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 1990] G%Usem%ffmhehDe k %RMF edrowo°rro _ _ _ ...... Correlated Su of Clay 1 and Clay 2[SHANSEP S=0.258, m =0.8?kC earry_EPA_00m9a GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 2A: PDCPT-08 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (°) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 1 1 1 1 1 1 1 1 ',(correlat d1 'p(correlat d 2) " 20 C -YT=s 2Pelf 10 Upper GW F= 18.6ft Clay 1 Lower Gw r=0.0 ft Min S.= 320 ps @ El. 0' ASj = +8.4 pE f/ft POP= 1100 psf 0 Cla) 1 YT=s 2 Pcf c ° -10 WC w ° -20 an I 1 San 1 ,=110 Pc (p'= 5 deg 0 -30 ko °o o ° 40 San 12 Yr12 San 2 (0'=r8 deg ® o 50 LEGEND L I � I I I I I I I I i Notes:— — Design Profile 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content � SPT N 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content ( �)� Clay 1 3.yr-total unit weight; yd-dry unit weight. O Measured Total Unit Weight[Lab: yT=yd'(1+MC/100)] • Measured a'p(1 D Consolidation) 4. Selected yT values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated S„of Clay 1 and Clay 2 [CPT: N,d= 17; Su=(gtvJ/N,d (Robertson and Cabal, 2015)] — 6.o"p-preconsolidation stress;a'.-vertical effective stress. O Measured S„of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a'p[Kulhawy and Mayne, 1990]. J- Measured Su of Clay 1 and Clay 2 [UU] 8.dp values were clipped to 9000 psf. ❑o Measured S.of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(N1)pp values were clipped to 40. 9Correlated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle[CPT: Kulhawy and Mayne, 1990] cdu:emnixnenoesxwp�auF enmwocaro •..... Correlated S„of Clay 1 and Clay 2[Shansep S=0.258, m=0.83] A C Barry_EPA_000195 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 2A: PDCPT-46 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (0) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 a'p(Mayne 20 7) a'p(Mayne 2017-Ong nic its) aw 20 C Pcf 10 Upper =21.4fit Clay 1 Lower G T=4.9 ft Min S.= 320 ps @ El. 0' AS„/A= +8.4 p f/ft 0 Cla 1 _ _YT=9 2 Pcf POP= 1,100 psf c -10 0 low San 1 W �'= 5deg-20 San 1Yr=1 0 P o m -30 00 o® Sand 2 Q0 40 m'= 8 deg o yr1 0 pc o 50 LEGEND Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content � SPT(N,)80 Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; yd-dry unilweighl. • Measured Total Unit Weight[Lab:yT=yd•(1+MC/100)] • Measured o'p(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2 Id 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated S,of Clay 1 and Clay 2[CPT: Nh,= 17; S,=(qt-ow)/Nw,(Robertson and Cabal, 2015)] 6.o"o-preconsolidation stress;a'w-vertical effective stress. O Measured S„of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a',[Kulhawy and Mayne, 1990]. Measured S.of Clay 1 and Clay 2 [UU] 8.dr values were clipped to 9000 psf. ❑o Measured S.of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(N,),values were clipped to 40. 9Correlated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle[CPT: Kulhawy and Mayne, 19901 G%Users4flxheA� Uc WaA e20,7-o,aBn _ _ _ .... Correlated Su of Clay 1 and Clay 2[SHANSEP S=0.258, m=0.839 C Barry_EPA_000196 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 2A: PDCPT-47 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (°) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 a' (Mayn 2017)o a'°(Mayo , 2017- ani oils) a', 20 c -YT=s 2 Pd 10 Clay 1 Upper GW T=21.2 It Min S.= 320 ps @ El. 0' Lower GW T=0.7 ft ASj = +8.4p /ft 0 Cla 1 POP 1,100 ps Vr Pef 0 C -10 > Sand 1 0 m � W ' = 35deg o oo� San 1 0 0 >^ 10 p o 0 0 -20 0 0 0 ®8 �6b -30 CPO � ® -40 an 2 San 2 .=1 0 pc 0'= 8 deg 03 -50 LEGEND II IIII II III II Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content � SPT(Nr)dd Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab:yT=yd•(1+MC/100)] • Measured o'p(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2Id 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated Su ofClay 1 and Clay 2[CPT: Nk,= 17; Su=(qt-a„ YNk,(Robertson and Cabal, 2015)] 6.o'o-preconsolidation stress;a'.-vertical effective stress. O Measured Su of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a',[Kulhawy and Mayne, 1990]. Measured S„of Clay 1 and Clay 2 [UU] 8.dp values were clipped to 9000 psf. ❑o Measured S„of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(N,),values were clipped to 40. 9Correlated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle[CPT: Kulhawy and Mayne, 1990] 0+�.e°w:nmoesaapwamem„-aree� _ _ ---- Correlated Su of Clay 1 and Clay 2 [SHANSEP S=0.258, m=0 8*c Barry_EPA_000197 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 2A: PDCPT-09 and co-located PDS-03 Atterberg Limits, Moisture Preconsolidation and Effective and Organic Content (%) Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) SPT (N1)60 Friction Angle (0) 0 50 100 150 200 250 300 350 70 80 90 100 110 120 130 0 500 1000 0 3000 6000 9000 0 5 10 15 20 25 30 35 40 25 30 35 40 45 50 30 a'p( ayne, 01 ) Key — o'P(Mayne, 2017-Or is S 'Is) PL MC LL — °w 20 CC Yr 2 Pc 10 Upper GW F= 17.3ft Clay 1 Lower Gw r=4.3 ft Min S„=320pf@El. 0' AS,/A= + 8.4 p Wrt 410 0 Cla 1 y YT 2 psf POP= 1,100 psf � IT o -10 0 0� y Sand 1 00 da w an 1 l�'= 5 deg I -YT=l p o -20 0 0 00 0 0 0 Ct clay 2 30 V -1 0 p Clay 2 P'p 3,200 psf Sp= 700 psf -40 an 2 San 2 20 PLL C 8 deg -50 LEGEND Notes: — Design Profile C� 1.All elevations are in the NAVD88 datum.All figures were clipped to El. +30 ft and El. -50 ft. O Measured Organic Content Cla 1 2. LL-liquid limit; MC-moisture content; PL SPT N (-plastic limit; OC-or anic content. • Measured Moisture Content 1), Sand 1 3. total unit weight; y Sel 4 p g • Measured Total Unit Weight[Lab: yryd'(1+MC/100)] 0 Measured a'p(1D Consolidation) q, Sel — ected y,values were dry unit weight.e presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] 5. S„-undrained shear strength (values were clipped to 1000 psf); OCR-overconsolidation ratio. Correlated S�of Clay 1 and Clay 2 [CPT: ons lid Sri to closest i(Robertsonstyes and Cabal, 2015)] O Measured S,of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 6. a'a-Preconsolidation stress; aw-vertical effective stress. 0 Measured S„of Clay 1 and Clay 2[UU] 7.Value of k=0.33(recommended by Robertson and Cabal, 2015)was used to calculate o'P[Kulhawy and Mayne, 1990]. Measured S„of Clay 1 and Clay 2[VST: Peak(uncorrected)] 8. a'p values were clipped to 9000 psf. Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 9. SPT(N,)gp values were clipped to 40. C Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 1990] 10. GWT-groundwater table. Upper GWr is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. ....Correlated Su of Clay 1 and Clay 2 [SHANSEP S =0.258, m = 0.83] cw:ea�re:nenoees�wweme mr�-o - - - - APC Barry_EPA_090198 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 2A: PDCPT-12 and co-located PDS-04 Atterberg Limits, Moisture, Preconsolidation and Effective and Organic Content (%) Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) SPT (N1)6a Friction Angle (°) 0 50 100 150 200 250 300 350 70 80 90 100 110 120 130 0 500 10000 3000 6000 9000 0 5 10 15 20 25 30 35 40 25 30 35 40 45 50 30 Key a'p(Mayne, 2017) _ a',(Mayne, 2017-Organic Soils) PL MC LL a'�o 20 CC V 2P 10 Upper =20.7fit Lower G T=0.0 ft Clay 1 POP 1,100 psf 0 Min S =320 s El. 0' OC=13% Clay 7 c -YT=g 2 pcf G -10 .a N o0 W = t ° Sand 1 ,r110 pc ° 5de -20 _• San 2 Sad 2 yT=120 pc $' 38 de -30 o ° 0 -40 -50 LEGEND Notes: — Design Profile - 1. All elevations are in the NAVD88 datum.All figures were clipped to El. +30 ft and El. -50 ft. O Measured Organic Content 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content ♦ SPT(N,), 3. yr-total unit weight; ya-dry unit weight. • Measured Total Unit Weight[Lab: yr yd`(1+MC/100)] 0 Measured a'p(1 D Consolidation) — 4. Selected yT values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] 5. S„-undrained shear strength(values were clipped to 1000 psf); OCR-overconsolidation ratio. Correlated Sp of Clay 1 and Clay 2[CPT: Nu= 77; S,=(gt-ow)/Nk, (Robertson and Cabal.2015)] 6. a'p-preconsolidation stress; a',o-vertical effective stress. O Measured S„of Clay 1 and Clay 2[CU: Consolidated to closest in-situ stress] 7. Value of k=0.33 (recommended by Robertson and Cabal,2015)was used to calculate a'p[Kulhawy and Mayne, 1990]. 0 Measured S„of Clay 1 and Clay 2 [UU] 8. o'pvalues were clipped to 9000 psf. ❑o Measured S.of Clay 1 and Clay 2[VST: Peak(uncorrected)] 9. SPT(N,),values were clipped to 40. 0Correlated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle[CPT: Kulhawy and Mayne, 1990] ------Correlated Su of Clay 1 and Clay 2[SHANSEP S = 0.258, m =0.83] APC Barry_EPA_000199 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 2B: PDCPT-14 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (°) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 a'p(Mayn ,2017) a'p(Mayn ,2017-O ani oils) a.w 20 C -YT=s 2 Pd 10 Upper GIA T= 17.2 it Lower G =0.0 ft Clay 1 Min S. =400 psf @ El.-2' 0 OSJAZ=+9.7 psf/ft la) t Yr Pcf POP 1,100 psf ° -10 m W Sar d 1 0� San I 1 =35 de -20 YT=l 15 PC If a Cla 2 Clay 2 30 YT 05 Pc F S„=750 psf an 2 o _yr1 22 pc Sar d 2 =38 deg -40 Notes: -50 LEGEND CCR 1. All elevations are in the NAVD88 datum.All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content — Design Profile 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content ♦ SPT(N,)ap Clay 1 3. yr-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab: y,=yd'(1+MC/100)] 0 Measured a'p(1 D Consolidation) Sand 1 4. Selected yT values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. —Correlated S.of Clay 1 and Clay 2 [CPT: Nk,= 17; S,=(qt-a,)/Nk, (Robertson and Cabal,2015)] Sand E 6.a'p-preconsolidation stress;a'.-vertical effective stress. O Measured S„of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a'p[Kulhawy and Mayne, 1990]. 0 Measured S„of Clay 1 and Clay 2[UU] 8.a'p values were clipped to 9000 psf. ❑o Measured S„of Clay 1 and Clay 2[VST: Peak(uncorrected)] 9. SPT(N,)pp values were clipped to 40. 0 Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle[CPT: Kulhawy and Mayne, 1990] ------Cnrralatad S of Clav land Clav 9 LSHANSFP S=09SR. m=0 PIkPC Barry_EPA_000200 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 210: PDCPT-17 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (°) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 a'o(MByne, 2017) a'p(Mayne, 2017-Or nic oils) �w 20 C -YT=s 2 Pd 10 Upper GWI= 16.8ft Clay 1 Lower GWI=0.0 ft Min S°=460 psi @ El. 0' AS,JAz=+ 10.5 psf7ft POP= 1,300 psf 0 la) 1 c Yr1 0 P m -10 _d o® Lu an I 1 Sa d 1 0 0 -YT=l PC IF 00 -20 00 0 la 2 Clay 2 _YT= 05 pc S = 1,000psf P'p=513100 psf Sai id 2 30 0�, -30 " 2 — $=38 de d� yT=122 p -40 50 LEGEND EGEND CCR 1. All elevations are in the NAVD88 datum.All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content — Design Profile 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content ♦ SPT(NI)go Clay 1 3. total unit weight; d unit weight. • Measured Total Unit Weight Lab: '(1+MC/100)] • Measured a',(1D Consolidation) Vr' 9 Ya-dry 9 9 I Vr=Ve Sand 1 4. Selected yT values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated S°of Clay 1 and Clay 2[CPT: N,,= 17; S,=(qt-owuN,,(Robertson and Cabal, 2015)] Sand E 6.a'o-preconsolidation stress;a'w-vertical effective stress. O Measured S.of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a'p[Kulhawy and Mayne, 1990]. 0 Measured S°of Clay 1 and Clay 2 [UU] 8.&,values were clipped to 9000 psf. ❑o Measured S„of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(N,)oo values were clipped to 40. 9Correlated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle[CPT: Kulhawy and Mayne, 1990] -•-Correlated Su of Clay 1 and Clay 2[SHANSEP S=0.258, m=0.83pc Barry_EPA_000201 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 2C: PDCPT-19 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (°) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 a'p(Mayne, 2017) a'p(Mayne, 2017-O nic oils) aw 20 C —YT=s 2 PCf 10 Upper GV rT= 18.8ft— Clay 1 Lower GV fT=0.0ft Min Su =460 psi @ El. 0' AS, AZ=+ 10.5 psf/ft 0 Cie) 1 L yr1 DO PC POP= 1,300 psf m -10 m IL San I 1 San 1 LO Yr 15 P = 5 de o 0 la 2 Clay 2 —YT= 05 pc F Sp= 1,000 psf P'p=5,300 psf -30 an 2 _ yT=122 PC r Sa d 2 $= 38 de -40 1 L 50 LEGEND Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content SPT(NI)go Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab:yT=ya'(1+MC/100)] • Measured a'p(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2Id 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated Sp of Clay 1 and Clay 2[CPT: N,,= 17; S,=(qt-aw)/N,,(Robertson and Cabal, 2015)] Sand E 6.a'p-preconsolidation stress;a'w-vertical effective stress. O Measured S.of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a'p[Kulhawy and Mayne, 1990]. 0 Measured S.of Clay 1 and Clay 2 [UU] 8.&,values were clipped to 9000 psf. ❑o Measured S.of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(Nr),values were clipped to 40. 9Correlated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. 0 Correlated Effective Friction Angle[CPT: Kulhawy and Mayne, 1990] ----Correlated S.of Clay 1 and Clay 2[SHANSEP S=0.258, m=0.837.Pc Barry_EPA_000202 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 2C: PDCPT-20 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (°) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 - 7 a' (Mayne, 2017) a',(Mayne, 2017-Or nic oils) aw 20 CC yr P0f 10 Upper GWI= 19.2 ft Clay 1 Lower GkAn=0.0 ft Min S.=460 psf @ El. 0' OSJAZ=+ 10.5 Stitt 0 Cie) 1 C yr1 DO PC POP 1,300 psf - .0 -10 _m Lu an 1 ° y,=115 PC Sad 1 20 0 8 =35de r 105 pc --3 Clay 2 P'p=5,3 0 psf an 2 Su= 1,000 psf Sa d 2 r=1 2 P—YC > $=38 deg -30 -40 50 LEGEND Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content SPT(NI)„ Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; y,-dry unitweight. • Measured Total Unit Weight[Lab:y,=ya'(1+MC/100)] • Measured a',(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2Id 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated S.of Clay 1 and Clay 2[CPT: Nu= 17; S,=(qt-aw)/N,,(Robertson and Cabal, 2015)] Sand E 6.o",-preconsolidation stress;a'w-vertical effective stress. O Measured S.of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a',[Kulhawy and Mayne, 1990]. 0 Measured S.of Clay 1 and Clay 2 [UU] 8.d,values were clipped to 9000 psf. ❑o Measured S.of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(N,),values were clipped to 40. 9Correlated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. 0 Correlated Effective Friction Angle[CPT: Kulhawy and Mayne, 1990] ----•Correlated Su of Clay 1 and Clay 2 [SHANSEP S=0.258, m=0.83pc Barry_EPA_000203 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 2C: PDCPT-39 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (°) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 a',(Mayne, 2017) a'p(Mayne, 2017-Orgi nic its) aw 20 7 -YT=s 2 pd UpperGw r= 18.3ft 10 [CM,'nYS,1,,- 1 Lower G =0.0 ft 460 psf EI. 0'AS =+ 10.5 qsflft POP .m 1,300 psf 0 la 1 1 0 Said 1 -10 Vr P $= 35 de N o W San I 1 ° ° 0 0 0 0 Y? 15p o 0000 -20 0 Cla 2 Clay 2 Yr 05 p Su= 1,000 psf I -30 San 12 P'p=5,3 0 psf ° o Yr=122 p _ Sal d 2 to= 38d -40 50 LEGEND Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 fit and El.-50 ft. O Measured Organic Content SPT(NI)go Clay1 2. ILL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab:yT=ya'(1+MC/100)] • Measured a'p(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2 Id 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated Su ofClay 1 and Clay 2[CPT: Nk,= 17; Su=(qt-aw)/Nk,(Robertson and Cabal, 2015)] Sand E 6.a'o-preconsolidation stress;a'w-vertical effective stress. O Measured S„of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a',[Kulhawy and Mayne, 1990]. 0 Measured S„of Clay 1 and Clay 2 [UU] 8.a'r values were clipped to 9000 psf. ❑o Measured S„of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(N,),values were clipped to 40. 9Correlated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle[CPT: Kulhawy and Mayne, 1990] -•- Correlated Su of Clay 1 and Clay 2[SHANSEP S=0.258, m=0.83pc Barry_EPA_0002N GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 3A: PDCPT-01 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (°) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 j,'PtMayne,1220611F7)_7� a'p(Mayne, 2017-O nic its) dw 20 CC VT=92P 10 Upper GV fT=22.0 ft- Clay 1 Lower GV fT= 0.9 ft Min S.=200 ps @ El. 0' AS./Az= +8.4 1 sf/ft 0 CI y 1 POP= 0 psf Sar d i YT=95P 35 deg c 10 > Sa di ° 000 m _ d8'7 W YT 15p o 0 00 0 -20 0 000 0 0 Said 2 -30 -122 oif Sa d 2 = 38deg -40 LEGEND Notes: 50 — Design Profile CCR 1. All elevations are in the NAVD88 datum.All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content � SPT(N,)dd Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; yd-dry unilweighl. • Measured Total Unit Weight[Lab:yT=yd•(1+MC/100)] • Measured o'p(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2 Id 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated S,of Clay 1 and Clay 2[CPT: Nw,= 17; S,=(qt-ow)/Np,(Robertson and Cabal, 2015)] Sand E 6.a'p-preconsolidation stress;a'w-vertical effective stress. O Measured S.of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a'p[Kulhawy and Mayne, 1990]. Measured S.of Clay 1 and Clay 2 [UU] 8.&,values were clipped to 9000 psf. ❑o Measured S.of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(N,),values were clipped to 40. 9Correlated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle[CPT: Kulhawy and Mayne, 19901 ---- Correlated S„of Clay 1 and Clay 2[SHANSEP S=0.258, m=0.834Pc Barry_EPA_000205 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 3A: PDCPT-42 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (°) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 rtac rElev ion 33.9 ft _ a'p(Mayne, 017) —a',(Mayne, 017-Orga iicSolls) — aw 20 CC YT=92Pcf 10 UpperG =31.9ft Clay 1 Lower GW T= 17.9 ft Min Su=200 psf@ EI. 0' ASJAz=+8.4 p f/ft POP psf 0 as) 1 YT=G 5 Pcf c -10 > an 1 Sar d 1 Lu •=115p cl�=35 deg o 20 I 1 Clay 2 y� 02 p f Sula',= 0.258 Min Su=500 psi 1. P'p=a'w Sa d 2 = 38 de -30 -40 50 LEGEND Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content SPT(NI)go Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab:yT=ya'(1+MC/100)] • Measured a'p(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal,2015] Clay 2 Id 5. Su-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated S,of Clay 1 and Clay 2 [CPT: NM= 17; S,=(qt-a,o)/Na(Robertson and Cabal, 2015)] Sand E 6.o'o-preconsolidation stress;a'w-vertical effective stress. O Measured Su of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a',[Kulhawy and Mayne, 1990]. 0 Measured S„of Clay 1 and Clay 2[UU] 8.o'r values were clipped to 9000 psf. ❑o Measured S„of Clay 1 and Clay 2[VST: Peak(uncorrected)] 9. SPT(Nr),values were clipped to 40. 9Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 1990] -----Correlated Su of Clay 1 and Clay 2 [SHANSEP S = 0.258, m =0.834Pc Barry_EPA_000206 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 3A: PDCPT-04 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (0) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 0'p Mayne, 201 ) —o'p(Mayne, 2017-Or nic ils 20 CC yT= 12P 10 Upper G =20.9 ft Clay 1 Lower G =3.9 It Min S. 200 ps f @El. 0' ASjAz= + 8.4 psfht 0 C y1 Vr 95 p POP 0 psf Sad 1 t d,=35 deg -10 R Sa d1 w W YT=115 P o om o o° Cie 2 P'p=dw -20 y' 02 P -- e Clay 2 - Su/0'w=0.258 Sa d 2 ° o Min S.=500 psf = 8 deg Sai d 2 -30 x4,x 122 olf -40 50 LEGEND Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content � SPT(Nr)eo 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content Clay 1 3. total unit weight; d unit weight. • Measured Total Unit Weight Lab: *(1+MC/100)] • Measured O'p(1D Consolidation) Vr- 9 Ya-dry 9 9 [ Vr Ve Sand 1 4. Selected yT values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal,2015] Clay 2Id 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated S„of Clay 1 and Clay 2 [CPT: N.= 17; Su=(qt-ate)/N,n(Robertson and Cabal, 2015)] Sand E 6.do-preconsolidation stress;a'.-vertical effective stress. O Measured S.of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a'p[Kulhawy and Mayne, 1990]. Measured S.of Clay 1 and Clay 2[UU] 8.dp values were clipped to 9000 psf. ❑o Measured S.of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(N,),values were clipped to 40. Correlated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 1990] .... Correlated S„of Clay 1 and Clay 2 [SHANSEP S =0.258, m =0.8Ac earry_EPA_000207 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 3A: PDCPT-48 and co-located PDS-15 Atterberg Limit, Moisture, Preconsolidation and Effective and Organic Content (%) Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) SPT (Nj, Friction Angle (°) 0 50 100 150 200 250 300 350 70 80 90 100 110 120 130 0 500 10000 3000 6000 9000 0 5 10 15 20 25 30 35 40 25 30 35 40 45 50 30 a'p(Mayne, 2017) Key o'p(Mayne, 2017-Or nic Tils [TT a'w PL MC LL 20 I� • I� cc Yr 2 Pc 10 OC 6.7% Upper GA =20.9ft Clay 1 Lower G = 10.9 ft Min S, =200 psf @ El. 0' ASdAz=+8.4 psf/ft 0 la 1 O 19.0% T= Pcf. c id 1 Oc 9.7 Y. a POP= 0 psf �a 35 de 0 = -10 0 m San 1 W Yi 1 5 Pcf ° 8 0 0 0 _20 0 — Clay 2 P'p Cla 2 =0.258 Vr= 02 P Min S.= 500 psf -30 WE Sa d 2 =38 deg 40 San 2 V; 22 P -50 Notes: LEGEND — 1.All elevations are in the NAVD88 datum.All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content — Design Profile Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content ♦ SPT(N,)eo 3. total unit weight; d unit weight. • Measured Total Unit Weight Lab: '(1+MC/100)] • Measured dp(1D Consolidation) Sand 1 Yr- 9 were dry 9 i [ Yr Ye 4. Selected yr values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] — 5. S„-undrained shear strength (values were clipped to 1000 psf); OCR-overconsolidation ratio. —Correlated Su of Clay 1 and Clay 2 [CPT: Nk,= 17; S,=(qt-aw)/Nk, (Robertson and Cabal,2015)] — 6. a'p-Preconsolidation stress;dw-vertical effective stress. O Measured S.of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33(recommended by Robertson and Cabal, 2015)was used to calculate a'p[Kulhawy and Mayne, 1990]. �],Measured S.of Clay 1 and Clay 2[UU] 8. a'p values were clipped to 9000 psf. ❑i Measured S.of Clay 1 and Clay 2[VST: Peak(uncorrected)] 9. SPT(N,)sp values were clipped to 40. 9Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle[CPT: Kulhawy and Mayne, 1990] ---- Correlated Su of Clay 1 and Clay 2 [SHANSEP S=0.258, m =0.83]APc aarry_EPA_000208 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 3A: PDCPT-45 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (a) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 — a'p Mayne, 201 d,(Mayne, 2017-Or nic ils aw 20 C -YT=s 2 lad 10 Uppe Gw r=22.7ft Clay 1 Lower GW F=4.7 ft Min S.=200 psf@ El. 0' AS./Az= + 8.4 p flft 0 la) 1 c YT=9 5 pcf POP 0 psf 0 10 a� Sar d 1 Lu =35 deg San J 1 0 20 - 15 0 Cla 2 P,p —YT 02 pcf _ Clay 2 Sa d 2 -30 S,/a'_=0.258 (b= 38 deg San 2 Min S.=500 psf Yr=122 pc r -40 50 LEGEND Notes: — Design Profile CCR 1. All elevations are in the NAVD88 datum.All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content � SPT(Nr)eo 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content Clay 1 3. total unit weight; d unit weight. • Measured Total Unit Weight Lab: *(1+MC/100)] • Measured o'p(1D Consolidation) Vr- 9 Ya-dry 9 9 [ Vr Ve Sand 1 4. Selected yT values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal,2015] Clay 2 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated S.of Clay 1 and Clay 2 [CPT: N,n= 17; S,=(qt-aw)/N.(Robertson and Cabal, 2015)] Sand■ 6.do-preconsolidation stress;a'w-vertical effective stress. O Measured S„of Clay 1 and Clay 2ICU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a'p[Kulhawy and Mayne, 1990]. Measured S.of Clay 1 and Clay 2 [UU] 8.dp values were clipped to 9000 psf. ❑o Measured S„of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(Nr),values were clipped to 40. Correlated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle[CPT: Kulhawy and Mayne, 1990] ---- Correlated Su of Clay 1 and Clay 2[SHANSEP S=0.258, m =0.8?]PC Barry_EPA_000209 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 3A: PDCPT-15 and co-located PDS-05 Atterberg Limits, Moisture, Preconsolidation and Effective and Organic Content (%) Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) SPT (N1)60 Friction Angle (°) 0 50 100 150 200 250 300 350 70 80 90 100 110 120 130 0 500 10000 3000 6000 9000 0 5 10 15 20 25 30 35 40 25 30 35 40 45 50 30 — a'°(Mayne, 2017) Key a'°(Mayne, 2017-Orgi nic ils PWL MC LL — a., 20 _ CC vT 2 P 10 Upper GO =21.6ft Clay 1 Lower G =2.9 ft Min S°= 200 psf El. 0' AS./Az= + 8.4 p ti t cial 1 _ T P ak-uncorrected -C Vi Pcf == Pa O -10 OC 15.7° POP 0 psf Sa d 1 d =35de W San 1 0 0 0 0 0 Yr115 P o00 9, -20 Cla 2 lay 2 PAP aw _yT=l 02 pc f jo"=0.258 in S°=500 psf -30 San 2 Sa d 2 ° Vr 22 P =38 deg -40 -50 r ILL Notes: — Design Profile CCR 1. All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.50 ft. O Measured Organic Content SPT(N,)80 2. LL- liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content Clay 1 3.yT-total unit weight; y°-dry unit weight. • Measured Total Unit Weight[Lab:yr y°'(1+MC/100)] • Measured o'°(1 D Consolidation) Sand 1 4. Selected yT values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal,2015] Clay2n 5. S„-undrained shear strength (values were clipped to 1000 psf); OCR-overconsolidation ratio. Correlated S°of Clay 1 and Clay 2 [CPT: N,°= 17; Su=(qt-ate)/N� (Robertson and Cabal, 2015)] O Measured S°of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 6.Val a of k=solidarec stress; ed -vertical effective stress. Measured S.of Clay 1 and Clay 2 [UU] 7.Value of were lrecommended by Robertson and Cabal, 2015)was used to calculate a'°[Kulhawy and Mayne, 1990]. ❑o Measured S„of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 8.a'°values were clipped to clipped psf. Correlated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 9. SPT(N�)�values were clipped l0 40. c Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 19901 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. -.--Correlated Su of Clay 1 and Clay 2 [SHANSEP S =0.258, in = 0.831 APC Barry_EPA_000210 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 3A: PDCPT43 and co-located PDS-16 Afterberg Limit, Moisture, Preconsolidation and Effective and Organic Content (%) Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) SPT (Nt)OO Friction Angle (a) 0 50 100 150 200 250 300 350 70 80 90 100 110 120 130 0 500 1000 0 3000 6000 9000 0 5 10 15 20 25 30 35 40 25 30 35 40 45 50 30 o'°(Mayne, 20177T Key — o'°(Mayne, 2017-Org nic oils) PL MC LL — a'w 20 �l oc= .8% ICI CC Yr 2P 10 UpperG =26.6ft Clay Lower G%A =8.2ft Min S.=200 psf El. 0' AS jAz= +8.4 p f/ft 11 0 -Clay 1 POP 0 psf 2.5° put C -10 > N * Ill 0 0 Sano 11 Sad 1 20 Y.=1 5 P = 35 deg o 0 0 0 00� Cla 2 Clay 2 Pip=c`ro r 02 P S ja'_=0.258 LA ­-,k - Min Su=500 psf -30 San 12 Sad 2 -yT=l 22 P (P= 38 deg -40 -50 r CCR 1...All elevations are in the NAVD88 datum.All figures were clipped to El. +30 ft and El.-50 ft. 0 Measured Organic Content — Design Profile Clay1 2. ILL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content ♦ SPT(N,)a° 3. total unit weight; d unit weight. • Measured Total Unit Weight Lab: (1+MC/100)] 0 Measured a'°(1D Consolidation) Sand 1 Vr 9 V°-dry 9 9 I Vr V°� 4. Selected y,values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] — 5. S,-undrained shear strength (values were clipped to 1000 psf); OCR-overconsolidation ratio. —Correlated S^of Clay 1 and Clay 2 [CPT: N-= 15; S-(qt-c°)/N" (Robertson and Cabal,2015)] — 6. a',-preconsolidation stress;o'w-vertical effective stress. O Measured S�of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33(recommended by Robertson and Cabal, 2015)was used to calculate a'°[Kulhawy and Mayne, 1990]. Measured &of Clay 1 and Clay 2[UU] 8. a'°values were clipped to 9000 psf. ❑o Measured S-of Clay 1 and Clay 2[VST: Peak(uncorrected)] 9. SPT(N,)8,values were clipped to 40. Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle[CPT: Kulhawy and Mayne, 1990] .... Correlated Su of Clay 1 and Clay 2 [SHANSEP S=0.258, in =0.83]APC Barry_EPA_000211 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 3A: PDCPT-40 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (0) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 — a',(Mayne, 2017) a ayne, - nic Sis — a', 20 CC Yr= Pcf 10 CIay1 UpperG =28.2ft Lower GW F= 12.7 fit Min S.=200 psf El. 0' AS„/Az= +8.4 p f/ft 0 Cla 1 POP 0 psf YT=g 5 Pcf c ° -10 A o0 y Sar d 1 �O*o W San 1 4=35 de o YT 1 5 PC Co 20 ® e 0 Clay,2 Cie 2 SJdw=0.258 yr 02 p f Min S„=500 psf; P'P=a',- -30 an 2 Sar d 2 r=1 22 P m= 38 deg -40 50 LEGEND Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 fit and El.-50 ft. O Measured Organic Content � SPT(Nr)eo 2. ILL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content Clay 1 3. total unit weight; d unit weight. • Measured Total Unit Weight Lab: *(1+MC/100)] • Measured o'p(1D Consolidation) Vr- 9 Ya-dry 9 9 [ Vr Ve Sand 1 4. Selected yT values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2 Id 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated Su of Clay 1 and Clay 2 [CPT: Nkr= 17; Su=(qt-mo)/N", (Robertson and Cabal, 2015)] Sand E 6.do-preconsolidation stress;a'.-vertical effective stress. O Measured Su of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a',[Kulhawy and Mayne, 1990]. Measured Su of Clay 1 and Clay 2 [UU] 8.o'p values were clipped to 9000 psf. ❑o Measured Su of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(Nr),values were clipped to 40. Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 1990] .... Correlated Su of Clay 1 and Clay 2 [SHANSEP S = 0.258, in =0.84C earry_EPA_000212 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 3A: PDCPT-37 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (°) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 rtac rElev i Ad ft a'p(Mayne, 2017) a'p(Mayne, 2017-Ong, nic ils) aw 20 Cc YT=92 Pcf 10 Upper GIA =30.6ft Clay 1 Lower GkA T= 10.6 ft Min Su=200 psf @ EI. 0' ASJA2=+8.4 f/ft 0 Cla 1 x YT=G 5 pcf POP 0 psf c -10 0� y 0 Sad 1 0 W =35 deg San 1 `® 20 Yr115 pc 'e San 2 Said 2 �= 38 de -30 -40 50 LEGEND Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content � SPT(Nl)go Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab:y,=ya'(1+MC/100)] • Measured a'p(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2Id 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated Su of Clay 1 and Clay 2 [CPT: Na= 17; Su=(qt-a�)/Na (Robertson and Cabal, 2015)] Sand E 6.o'o-preconsolidation stress;a'.-vertical effective stress. O Measured Su of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a'p[Kulhawy and Mayne, 1990]. 4 Measured Su of Clay 1 and Clay 2 [UU] 8.o'p values were clipped to 9000 psf. ❑o Measured Su of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(N,),values were clipped to 40. 9Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. 0 Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 1990] ---- Correlated S.of Clay 1 and Clay 2 [SHANSEP S = 0.258, m =0.834Pc Barry_EPA_000213 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 3B: PDCPT-10 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (r) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 a'p(Mayne 2017) o'p(Mayne 2017-Org nic oils) a., 20 C pcf 10 Upper GWT= 18.1 ft Clay 1 Lower G T=0.1 ft Min S.=200 psf @ El. 0' AS,JAz= + 10.1 psf/ft POP 275 psf 0 la) 1 _YT=9 5 pcf c ° -10 m Sad 1 0 0=35 deC o o 019 111 San 1 0 0 -20 _YT=1 10 PC f o o� 0 0 0 0 8b la 2 Clay 1 P,p= oro yr Opp S„=700 psf -30 Sarr 12 Sar d 2 0 y,=120 p $=38 deg -40 50 LEGEND Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content SPT(NI)go Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab:yT=ya'(1+MC/100)] • Measured a'.(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2Id 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated Su of Clay 1 and Clay 2 [CPT: Na= 17; Su=(qt-a�)/Na (Robertson and Cabal, 2015)] Sand E 6.o'o-preconsolidation stress;a'.-vertical effective stress. O Measured Su of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a',[Kulhawy and Mayne, 1990]. 4 Measured Su of Clay 1 and Clay 2 [UU] 8.or,values were clipped to 9000 psf. ❑o Measured Su of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(N,),values were clipped to 40. 9Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. a Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 1990] ---- Correlated S.of Clay 1 and Clay 2 [SHANSEP S = 0.258, m =0.834PC Barry_EPA_000214 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 3B: PDCPT-11 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (°) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 — a'°(Mayne, 2017) —a,(Mayne, 2017-Organic Soils) or, 20 C YT=9 2 Pd 10 Upper GO T= 18.1 ft Lower GO T= 0.0 ft Clay 1 Min S.=200 psf @ El. 0' ASJAz=+ 10.1 sf/R 0 la 1 POP=2 75 psf _YT=ll5 Pcf c ° -10 Sar d 1 0 35 de W San 1 = ° _Y'=1 10 PC f 0 ° °o 0 0� -20 ° —Claj 2 gill — Clay 1 Yr 02 P S„= 700 psf P P=°- -30 San 12 ° °o Vr=1 20 PC Said 2 d'= 38 de ° -40 0 -50 LEGEND Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content SPT(N,)dd Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yr-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab:yT=yd'(1+MC/100)] • Measured a'.(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2Id 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated Su of Clay 1 and Clay 2[CPT: W= 17; Su=(qt-ow)/Nkt (Robertson and Cabal, 2015)] Sand E 6.o'o-preconsolidation stress;a'.-vertical effective stress. O Measured Sd of Clay 1 and Clay 2[CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a'.[Kulhawy and Mayne, 1990]. 0 Measured Sd of Clay 1 and Clay 2 [UU] 8.o'r values were clipped to 9000 psf. ❑o Measured S^of Clay 1 and Clay 2[VST: Peak(uncorrected)] 9. SPT(N,)dd values were clipped to 40. oCorrelated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle[CPT: Kulhawy and Mayne, 1990] -----Correlated S„of Clay 1 and Clay 2[SHANSEP S = 0.258, m =0.84pc earry_EPA_000215 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 313: PDCPT-13 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (0) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 a'p(Mayne,2017) — a'p(Mayne,2017-Organic Soils) aw 20 C -YT=s 2 Pcf 10 Upper GY 7= 19.0 ft Clay 1 Lower GY T= 0.0 ft Min S.=200 psf @ El. 0' AS„/AZ= + 10.1 psf/ft 0 la 1 POP 275 psf C r pcf ° -10 m w -20 San 1 Sar d 1 yr 1 10p $=35 de o od - o -30 an 12 Sa d 2 r1 20 PC �= 38d -40 L . . . . . . . . . . . . . . 50 LEGEND Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content � SPT(N,)so Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yr-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab: yT=yd"(1+MC/100)] 0 Measured a'p(1 D Consolidation) Sand 1 4. Selected yT values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2Id 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated Su of Clay 1 and Clay 2 [CPT: N� = 17; S,=(qt-aw)/N. (Robertson and Cabal,2015)] Sand E 6.o'p-preconsolidation stress;a'w-vertical effective stress. O Measured S„of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a'p[Kulhawy and Mayne, 1990]. 0 Measured S„of Clay 1 and Clay 2[UU] 8.a'p values were clipped to 9000 psf. ❑o Measured S.of Clay 1 and Clay 2[VST: Peak(uncorrected)] 9. SPT(N,),values were clipped to 40. 0Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. 0 Correlated Effective Friction Angle[CPT: Kulhawy and Mayne, 1990] ------Correlated S„of Clay 1 and Clay 2 rSHANSEP S=0.258, m=0.84,PC Barry_EPA_000216 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 313: PDCPT-16 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (°) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 a'o(Mayne, 2017) o"r(Mayne, 2017-Org nic oils) �w 20 C -YT=s 2 pd 10 Upper G%A = 18.6ft Clay 1 Lower G =0.0 ft Min Su= 200p @El. 0' ASu/Az= + 10.1 psf/ft 0 POP 275 psf _ la) 1 c YT=9 5 PCf ° -10 m W Yr 10p o 0 Clay 1 P,p=Q,� Sad 1 20 Cla 2 Su=700 psf �=35 deg y,=102 p Sar d 2 -30 d =38 deg -40 -50 LEGEND Notes: — Design Profile CCR 1. All elevations are in the NAVD88 datum.All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content SPT(Nr)dd Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab:yT=yd•(1+MC/100)] • Measured o'p(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2Id 5. Su-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated Su of Clay 1 and Clay 2 [CPT: NM= 17; Su=(qt-m°)/N"I (Robertson and Cabal, 2015)] Sand E 6.o'o-preconsolidation stress;a'w-vertical effective stress. O Measured Su of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a'p[Kulhawy and Mayne, 1990]. Measured Su of Clay 1 and Clay 2 [UU] 8.or,values were clipped to 9000 psf. ❑o Measured Su of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(Nr),values were clipped to 40. 9 Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 19901 ---- Correlated S.of Clay 1 and Clay 2 [SHANSEP 8 = 0.258, m =0.8?IPc Barry_EPA_000217 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH Me PDCPT-18 and co-located PDS-06 Atterberg Limits, Moisture, Preconsolidation and Effective and Organic Content (%) Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) SPT (1,11)fi0 Friction Angle (°) 0 50 100 150 200 250 300 350 70 80 90 100 110 120 130 0 500 1000 0 3000 6000 9000 0 5 10 15 20 25 30 35 40 25 30 35 40 45 50 30 I I Key o'°(Mayne, 2017) o'°(Mayne, 2017-Org nic oils PL MC LL — a�o 20 CC yT 2 Po 10 F7 UpperG = 18.6ft Clay 1 Lower G =0.0 ft Min S.= 200 ps @ El. 0' ASu/4z= + 10.1 psf/ft 0 Cla 1 POP 275 psf yT=g 5 Pd 0 10 OC15.4-4 <1 —4r d W 00 o 00 ° o 0 -20 -111 San 1 YY110 p � 0 0 Sad 1 0 0%0 �= 35d mo -30 0 an 2 85 Sad 2 Vr 20 P 0= 38 det -40 -50 Notes: LEGEND — 1. All elevations are in the NAVD88 datum.All figures were clipped to El.+30 ft and El. -50 ft. O Measured Organic Content Design Profile 2. ILL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content ♦ SPT(N,)°d jr 3. YT-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab:YT=yd'(1+MC/100)] 4/ Measured a'°(1 D Consolidation) 4. Selected yT values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] — 5. S°-undrained shear strength(values were clipped to 1000 psf); OCR-overconsolidation ratio. Correlated Su of Clay 1 and Clay 2[CPT: Nk,= 17; Su=(qt-a,A)/Nk,(Robertson and Cabal, 2015)] — 6. o'°-preconsolidation stress; a'„°-vertical effective stress. O Measured Su of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7. Value of k=0.33 (recommended by Robertson and Cabal,2015)was used to calculate a'°[Kulhawy and Mayne, 1990]. 0 Measured S°of Clay 1 and Clay 2 [UU] 8. o'°values were clipped to 9000 psf. ❑o Measured S°of Clay 1 and Clay 2[VST: Peak(uncorrected)] 9. SPT(N,)°°values were clipped to 40. eCorrelated Effective Friction Angle[SPT: Hatanaka and Uchida, 19961 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle[CPT: Kulhawy and Mayne, 1990] ....• Correlated Su of Clay 1 and Clay 2[SHANSEP S=0.258, m=0.83] A C Bary_EPA_000218 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 4: PDCPT-22 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (°) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 a'p(Mayn ,2017) a'°(Mayne,2017-Organic oils) crw 20 C pd 10 Uppe GW T= 19.5fit Clay 1 Lower G T=0.0 ft Min S°=490 ps @ El. +4' AS./Az= + 12.5 psf/ft POP 2,100 psf 0 x la 1 c yr1 5 P ° -10 > w an 11 Sa d 1 y,=110 p = 35 d o 0 -20 Y,108 Pc S =800 psf P'p=4,0 0 psf Sald 2 0 0 an 2 8 r=120 p --`) �= 38 d -30 -40 - 17 i -1111 1111 1111 111 Jill- 50 LEGEND Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 fit and El.-50 ft. O Measured Organic Content SPT(Nl)80 Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab:yT=ya'(1+MC/100)] • Measured o'°(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2Id 5. S°-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated Su of Clay 1 and Clay 2 [CPT: Na= 17; Su=(qt-m�)/Nm (Robertson and Cabal, 2015)] Sand E 6.a'°-preconsolidation stress;a'.-vertical effective stress. O Measured Su of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a'°[Kulhawy and Mayne, 1990]. 4 Measured Su of Clay 1 and Clay 2 [UU] 8.a'°values were clipped to 9000 psf. ❑o Measured Su of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(N,),values were clipped to 40. 9Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 1990] .....Correlated Su of Clay 1 and Clay 2 [SHANSEP S = 0.258, in =0.830C Barry_EPA_000219 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 4: PDCPT-23 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (°) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 a'p(Mayn jank a'p(Mayn a', 20 c r pd 10 Clay 1 Upper GW T= 19.6 ft Min S„=490 psf @ El. +4' Lower G = 0.0 ft OSjAz=+ 12.5psf/ft 0 POP=2,100 psf x la) 1 c y 1 5p ° -10 m w San I 1 Sad 1 -20 Y,==110p - pd,=35 de 74 o an2 Sa d 2 1 t= 38 de T 1 0 30 -40 50 LEGEND Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content SPT(NI)go Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab:yT=ya'(1+MC/100)] • Measured a'.(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2Id 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated Su of Clay 1 and Clay 2 [CPT: Na= 17; Su=(qt-a�)/Na (Robertson and Cabal, 2015)] Sand E 6.o'o-preconsolidation stress;a'.-vertical effective stress. O Measured Su of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a',[Kulhawy and Mayne, 1990]. 4 Measured Su of Clay 1 and Clay 2 [UU] 8.o'r values were clipped to 9000 psf. ❑o Measured Su of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(Nr),values were clipped to 40. 9 Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 1990] -•-•-Correlated S„of Clay 1 and Clay 2 [SHANSEP S = 0.258, m =0.834Pc Barry_EPA_000220 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 4: PDCPT-24 and co-located PDS-08 Atterberg Limit, Moisture, Preconsolidationand Effective and Organic Content (%) Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) SPT (N1)ao Friction Angle (°) 0 50 100 150 200 250 300 350 70 80 90 100 110 120 130 0 500 10000 3000 6000 9000 0 5 10 15 20 25 30 35 40 25 30 35 40 45 50 30 Keya'°(Mayne, 2017) —a'°(Mayne, 2017-Organic Soil) PWL MC LL a'„° 20 I _ I cc;[ Ell y,=1112 pc 10 Clay 1 Upper Gwr=22.0 ft Min Su=490 psf @ El. +4' Lower GW F= 0.0 ft AS,JAz=+ 12.5 psf/ft C .5% POP 7 2,100 psf 0 O 3.4/o Cla 1 y,1 D5 pc C -10 d W -20 San 1 Sad 1 yi 10 p P'p 4,000 psf 4) 35 de la 2 Clay 1 S =800 psf -30 -40 San 12 and 2 yi 120 p = 38 deg 50 LEGEND Notes: Design Profile 1.All elevations are in the NAVD88 datum.All figures were clipped to El. +30 ft and El. -50 ft. O Measured Organic Content 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content ♦ SPT(N,)go Clay 1 3. yT-total unit weight; ya-dry unit weight. • Measured Total Unit Weight[Lab:yr ya'(1+MC/100)] 0 Measured o'p(1 D Consolidation) Sand 1 4. Selected yT values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal,2015] — 5. S„-undrained shear strength (values were clipped to 1000 psf); OCR-overconsolidation ratio. Correlated S.of Clay 1 and Clay 2 [CPT: N„= 17; S,=(qt-a„°)/Nk, (Robertson and Cabal, 2015)] — 6. a'o-preconsolidation stress; a'„°-vertical effective stress. O Measured S„of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33(recommended by Robertson and Cabal, 2015)was used to calculate a'o[Kulhawy and Mayne, 1990]. 0 Measured Su of Clay 1 and Clay 2 [UU] 8. a'o values were clipped to 9000 psf. ❑o Measured S.of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(N,)ao values were clipped to 40. jill Correlated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 1990] ......Correlated Su of Clay 1 and Clay 2 [SHANSEP S=0.258, m =0.83] A C Barry_EPA_000221 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 4: PDCPT-25 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (a) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 — —7 ' M20177 cr'P(may O ni oils) 20 c -YT=s 2 po1 10 Clay 1 Upper GW T= 19.4 ft Min Su =490pf@ El. +4' LowerG =0.Oft OSJAz=+ 12. psf/ft PO =2,100 psf 0 Cla 1 Yr=1 5 P Sa d 2 dpo � � = 38 de ° -10 m > o N W -20 _San 2 Yr1 20 P 3 -30 — -40 50 1 1 1 LI LEGEND Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.-50 ff. O Measured Organic Content � SPT(N,)dd Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab:yT=yd•(1+MC/100)] • Measured o'p(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2 Id 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated S.of Clay 1 and Clay 2 [CPT: Nk,= 17; Su=(qt-aw)/Nk,(Robertson and Cabal, 2015)] Sand E 6.a'o-preconsolidation stress;a'.-vertical effective stress. O Measured S.of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a',[Kulhawy and Mayne, 1990]. Measured S,of Clay 1 and Clay 2[UU] 8.a'r values were clipped to 9000 psf. ❑o Measured S.of Clay 1 and Clay 2[VST: Peak(uncorrected)] 9. SPT(N,),values were clipped to 40. oCorrelated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 19901 -----Coorelated S.of Clay 1 and Clay 2 [SHANSEP S=0.258, m =0.8,*C Barry_EPA_000222 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 4: PDCPT-26 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (a) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 a'p(Mayne 2017) a',(Mayne 2017-Organic oils) Q.o 20 C -YT=s 2 pd 10 Clay 1 Upper Gw r= 19.7 ft Min S.=490 psf cCd El. +4' Lower Gw r= o.o ft ASJAz=+ 12.5 sf/ft POP 2,100 psf 0 Cla 1 yT=l 05pc � _ m 0 o ° ° -10 — o0 > Sa d 2 m u L deg -20 _San 2 Yr1 0 P 0 -30 Cd ° -40 LEGEND Notes: 50 EI — Design Profile CCR 1. All elevations are in the NAVD88 datum.All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content � SPT(Nr)dd Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab:yT=yd•(1+MC/100)] • Measured o'p(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2Id 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated Su of Clay 1 and Clay 2 [CPT: Na= 17; Su=(qt-c�)/Na (Robertson and Cabal, 2015)] Sand E 6.o"o-preconsolidation stress;a'.-vertical effective stress. O Measured Su of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a'p[Kulhawy and Mayne, 1990]. Measured S^of Clay 1 and Clay 2 [UU] 8.°'r values were clipped to 9000 psf. ❑o Measured S^of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(Nr),values were clipped to 40. 9 Correlated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle[CPT: Kulhawy and Mayne, 1990] ....Correlated S.of Clay 1 and Clay 2[SHANSEP S=0.258, m=0.84-c Barry_EPA_000223 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 4: PDCPT-27 and co-located PDS-09 Atterberg, Moisture, Preconsolidation and Effective and Organic Content (%) Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) SPT (N,),, Friction Angle (°) 0 50 100 150 200 250 300 350 70 80 90 100 110 120 130 0 500 10000 3000 6000 9000 0 5 10 15 20 25 30 35 40 25 30 35 40 45 50 30 o'p(Mayn , 2017) Key a'p(Mayn , 2017-0 an!c it ) PWL MC LL a., 20 —� CC yTa 512 pc 0410 OC= .0% Clay Upper&A T=21.3ft— Min Su=490 psf @ El. +4' Lower&A T=0.0 ft ASAz=+ 12.5psf/ft POP 2,100 psf 0 —Clay 1 C=1.9% _Y'=1 05 PC f -10 �11 > N _ W -20 Sa d 2 y, 20 p f Sa d 2 (1,= 38 deg jo -30 J � -40 -50 Notes: LEGEND CCR _ 1. All elevations are in the NAVD88 datum.All figures were clipped to El.+30 ft and El.-50 ft. O Measured Organic Content Design Profile 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content ♦ SPT(N,)°p Clay 1 q p g • Measured Total Unit Weight Lab: ' 1+MC/100 0 Measured a',(1 D Consolidation) Sand 1 ' 3. y,-total unit weight; y,-dry unit weight. 9 I Vi Va ( )1 4. Selected y,values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal,2015] — 5. S„-undrained shear strength(values were clipped to 1000 psf); OCR-overconsolidation ratio. Correlated Su of Clay 1 and Clay 2 [CPT: Nm= 17; Su=(qt-m°)/Ne (Robertson and Cabal, 2015)] — 6. o'p-preconsolidation stress; a'„,-vertical effective stress. O Measured Su of Clay 1 and Clay 2[CU: Consolidated to closest in-situ stress] 7. Value of k=0.33 (recommended by Robertson and Cabal,2015)was used to calculate a',[Kulhawy and Mayne, 1990]. 0 Measured Su of Clay 1 and Clay 2 [UU] 8. o'pvalues were clipped to 9000 psf. ❑o Measured Su of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(N,)pp values were clipped to 40. 9Correlated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 19901 Correlated Sp of Clay 1 and Clay 2 [SHANSEP, S =0.258, m = 0.83]APC Barry_EPA_000224 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 4: PDCPT-28 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (a) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 1 ,,,I ayn ,2017) a'p(Mayne,2017-OF@ anicoils) aw 20 C r Pcf 10 Upper GWI=20.3ft Clay 1 Lower GWI=0.0 It Min S. =490 psf @ El. +4' AS,JAz=+ 12.5psf/ft POP 2,100psf 0 Cla 1 _ YT1SPC ° -10 d Sar d 2 W ¢= 38 deg Q81 -20 _San 2 Yr1 20 P -30 -40 50 Ell I I I I I I I I I I I I I LEGEND Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content � SPT(Nr)80 Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab:yT=yd*(1+MC/100)] • Measured o'p(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2Id 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated Su of Clay 1 and Clay 2 [CPT: NM= 17; Su=(qt-c�)/NM (Robertson and Cabal, 2015)] Sand E 6.a'o-preconsolidation stress;a'w-vertical effective stress. O Measured Su of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a',[Kulhawy and Mayne, 1990]. Measured S^of Clay 1 and Clay 2 [UU] 8.a'r values were clipped to 9000 psf. ❑o Measured S^of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(Nr),values were clipped to 40. 9Correlated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle[CPT: Kulhawy and Mayne, 1990] ----•Correlated S.of Clay 1 and Clay 2[SHANSEP S=0.258, m =0.83APC Barry_EPA_000225 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 4: PDCPT-29 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (°) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 a'°(Mayo , 2017) o'°(Mayo , 2017-Organic oils) crw 20 _91M IF CC —yT=l 2Pcf 10 Upper GW = 21.6ft Clay 1 Lower G = 0.0 ft Min S°=490 psi@ El. +4' As jAz= + 12.5 psf/ft POP 2,100 psf 0 Cla 1 yT 1 5 P 0 C o 00 > } Sal d 2 m _ d'= 38 de W -20 _San 2 1 ) Yr 0 P -30 -40 -50 LEGEND Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 fit and El.-50 ft. O Measured Organic Content SPT(Nr)go Clay1 2. ILL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; yd-dry unitweight. • Measured Total Unit Weight[Lab:yT=yd•(1+MC/100)] • Measured o'°(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2Id 5. S°-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated Su of Clay 1 and Clay 2 [CPT: Na= 17; Su=(qt-c�)/Na (Robertson and Cabal, 2015)] Sand E 6.o'°-preconsolidation stress;a'.-vertical effective stress. O Measured Su of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a'°[Kulhawy and Mayne, 1990]. Measured Su of Clay 1 and Clay 2 [UU] 8.o'°values were clipped to 9000 psf. ❑o Measured Su of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(Nr),values were clipped to 40. 9Correlated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle[CPT: Kulhawy and Mayne, 1990] ---- Correlated S.of Clay 1 and Clay 2[SHANSEP S=0.258, in =0.831Pc Barry_EPA_000226 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 4: PDCPT-38 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (°) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 a'p(Mayn ,2017) a'p(Mayn ,2017- ani oils) a' 20 Cc -YT=9 2PCf 10 Clay 1 Upper GW F= 22.1 ft Min S.=490 psf @ El. +4' Lower G = 0.0 ft ASJAz=+ 12.5 psf/ft POP 2,100 psf 0 Cal 1 YT=1 05 PC x ° Z -10 0� I c`� �� o W Sai id 2 (i,= 38d -20 Sam 1 2 Y 0 PC -30 -40 50 LEGEND Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 fit and El.-50 ft. O Measured Organic Content SPT(Nr)80 Clay1 2. ILL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab:yT=ya'(1+MC/100)] • Measured a'.It D Consolidation) Sand 1 4. Selected yT values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2Id 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated Su of Clay 1 and Clay 2 [CPT: Na= 17; Su=(gI (Robertson and Cabal, 2015)] Sand E 6.o'o-preconsolidation stress;a'.-vertical effective stress. O Measured Su of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a',[Kulhawy and Mayne, 1990]. 4 Measured Su of Clay 1 and Clay 2 [UU] 8.o'r values were clipped to 9000 psf. ❑o Measured Su of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(N,)00 values were clipped to 40. 9Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. a Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 1990] .... Correlated S.of Clay 1 and Clay 2 [SHANSEP S = 0.258, m =0.834Pc Barry_EPA_000227 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 4: PDCPT-44 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (°) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 a°(Mayo , 2 17) ep(Mayni i, 2017-OrIani oil) a' 20 cc Yr= 2 Pcf 10 Upper Gw r=23.0 ft Clay 1 Lower GW F=0.0 ft Min S, =490p f@ El. +4' ASJAz=+ 12.1 i psf/ft POP= ,100 psf 0 Cla 1 c° Yi 1 -10 5 P m lu -20 Sad 1 San 1 m= 35 de -30 yT 1 0 P ° 0,50 0 00* moo -40 50 LEGEND Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content SPT(NI)go Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab:yT=ya'(1+MC/100)] • Measured a'.(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2Id 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated Su of Clay 1 and Clay 2 [CPT: Na= 17; Su=(qt-a�)/Na (Robertson and Cabal, 2015)] Sand E 6.o'o-preconsolidation stress;a'.-vertical effective stress. O Measured Su of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a',[Kulhawy and Mayne, 1990]. 4 Measured Su of Clay 1 and Clay 2 [UU] 8.o'r values were clipped to 9000 psf. ❑o Measured Su of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(Nr),values were clipped to 40. 9 Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 1990] ""Correlated S.of Clay 1 and Clay 2 [SHANSEP S = 0.258, m =0.834Pc Barry_EPA_000228 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH M PDCPT-30 and co-located PDS-10 Atterber Limit, Moisture, Preconsolidation and Effective and Organic Content (%) Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical effective Stress (psf) SPT (Nje, Friction Angle (°) 0 50 100 150 200 250 300 350 70 80 90 100 110 120 130 0 500 10000 3000 6000 9000 0 5 10 15 20 25 30 35 40 25 30 35 40 45 50 TT 30 o'p(Mayne 20 7) — I F Key o'p(Mayne 2017-0 nic its PL MC ILL a., 11 20 CC V 2j 10 OC= .4% Clay 1A Upper GIA =23.4ft Sp=550 psf Lower GIA T=0.0 ft t C=: .5% CI to P' =3,000 psf 0 y 10p Cl 1 B y, OS OC=1.8% c -10 0 Clay I POP 1,200 psf o y _ Min S.=420 psf El. 0' W _ �S /4= + 11.6 Wit Sar d 2 _ San 2 =38 deg 20 V 1 0 pc -30 -40 -50 Notes: LEGEND cCR ' 1.All elevations are in the NAVD88 datum.All figures were clipped to El. +30 ft and El. -50 ft. O Measured Organic Content SPT9NProfile Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content ( '), 3.yr-total unit weight;y°-dry unit weight. 41 Measured Total Unit Weight[Lab: yry,*(1+MC/100)] • Measured a'p(1 D Consolidation) Sand 1 4, Selected y,values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] — 5. S„-undrained shear strength (values were clipped to 1000 psf); OCR-overconsolidation ratio. Correlated &of Clay 1 and Clay 2[CPT: Na= 17; Su=(qt-aw)/Na (Robertson and Cabal,2015)] — 6. a',-preconsolidation stress; a'„°-vertical effective stress. O Measured S-of Clay 1 and Clay 2[CU: Consolidated to closest in-situ stress] 7.Value of k=0.33(recommended by Robertson and Cabal, 2015)was used to calculate o'p[Kulhawy and Mayne, 1990]. 0 Measured Su of Clay 1 and Clay 2 [UU] 8. a',values were clipped to 9000 psf. ❑o Measured Su of Clay 1 and Clay 2[VST: Peak(uncorrected)] 9. SPT(N,),,values were clipped to 40. Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWi is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. 0 Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 1990] --- Correlated S.of Clay 1 and Clay 2 [SHANSEP S = 0.258, m = 0.83] APC B,rry_EPA_000229 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 5A: PDCPT-31 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (a) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 o'P(Mayne, 2017) a',(Mayo , 2017-O ani oils) aw 20 CC YT=92 Pcf 10 Clay 1A Upper Gw r=24.6 ft S„= 550 psf Lower Gw r=2.6 ft P'p 3,000 PSL- Clav 1A YT=1 0 P la) 113 r1 15 PC r c 0 m -10 POP 1,200 psf ° Clay 1 B Sa d 2 y an 2 Min S„ =420 psf @ El.0' W Vi+ 0 P osJ4=+ ++.s sf/ft $= 38 deg -20 -30 -40 50 LEGEND Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content SPT(NI)go Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab:yT=ya'(1+MC/100)] • Measured a'.(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2Id 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated Su of Clay 1 and Clay 2 [CPT: Na= 17; Su=(qt-a�)/Na (Robertson and Cabal, 2015)] Sand E 6.o'o-preconsolidation stress;a'.-vertical effective stress. O Measured Su of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a',[Kulhawy and Mayne, 1990]. 4 Measured Su of Clay 1 and Clay 2 [UU] 8.o'r values were clipped to 9000 psf. ❑o Measured Su of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(Nr),values were clipped to 40. 9Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 1990] ---. Correlated S.of Clay 1 and Clay 2 [SHANSEP S = 0.258, m =0.834Pc Barry_EPA_000230 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 5A: PDCPT-32 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (°) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 a'p(Me yne 2017) a'p(Mayne 2017-0 nic oils -FT a' 20 cc —YT=9 2 pcf Upper Gw r=22.6ft 10 Lower GWIF=2.6 ft Clay 1A S„=550 psf P'p=3,00 psf 0 C 1 y 110 cf "T1 y 105 cf c ° -10 Y ° i lay 1B POP= 1,2 Opsf o' m an 2 - Min Su=420 psf @ El. 0' o W YT=1 0 PC ASJA.= + 11.6 psf/ft Sar d 2 = 38 deg -20 -30 -40 -50 LEGEND Notes: — Design Profile CCR 1. All elevations are in the NAVD88 datum.All figures were clipped to El. +30 fit and El.-50 ft. O Measured Organic Content SPT(Nr)dd Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab:yT=yd•(1+MC/100)] • Measured o'p(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2 Id 5. Su-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated Su of Clay 1 and Clay 2 [CPT: NM= 17; Su=(qt-m°)/NM (Robertson and Cabal, 2015)] Sand E 6.o"o-preconsolidation stress;a'.-vertical effective stress. O Measured Su of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a'p[Kulhawy and Mayne, 1990]. Measured Su of Clay 1 and Clay 2 [UU] 8.o'r values were clipped to 9000 psf. ❑o Measured Su of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(Nr),values were clipped to 40. 9Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 19901 ----•Correlated S.of Clay 1 and Clay 2 [SHANSEP S = 0.258, m =0.83APc Barry_EPA_000231 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 5A: PDCPT-33 and co-located PDS-11 Atterberg Limits, Moisture, Preconsolidation and Effective and Organic Content (%) Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) SPT (Nt)o Friction Angle (°) 0 50 100 150 200 250 300 350 70 80 90 100 110 120 130 0 500 1000 0 3000 6000 9000 0 5 10 15 20 25 30 35 40 25 30 35 40 45 50 30 Key a',(Mayne, 2017) o'r(Mayne, 2017-Orgi inic oils PWL MC LL _ a 20 I _ CC Vr 92 p Upper GV rr=23.6 Lower GV rr= 1.6 ft 10 Clay 1A S„=550 psf P'p=3,0011 psf 0 0 = . % Y•=110 PC f ❑OC= .7% Cla I O = .5% PC f C -10 San 1 Clay1B pO Sa d 1 .M T==1 0 pCi Min S.=420 psf @ El. 0' POP= 1,2110 psf (l,= 35 de AS = + 11.6 sf/0 °o° o W San 2 20 Vr120 PC f Sad 2 • ¢ 38 deE -30 -40 -50 Notes: LEGEND CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content — Design Profile Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content ♦ SPT(N,)go • Measured Total Unit Weight Lab: '(1+MC/100)] • Measured a',(1D Consolidation) Sand 1 3.yT-total unit weight; yd-dry unit weight. 9 I Vr Va 4. Selected yT values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated Su of Clay 1 and Clay 2 [CPT: Na= 17; Su=(qt-c�)/Na (Robertson and Cabal, 2015)] O Measured Su of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 6. Val a of k=0.33 (recommended stress; ed -vertical effective stress. 0 Measured Su of Clay 1 and Clay 2 [UU] 7.Value of were lrecommended by Robertson and Cabal, 2015)was used to calculate a',[Kulhawy and Mayne, 1990]. 0 Measured Su of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 8. SPTcrp (ues were clipped clipped pped psf. �Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 9. SPT T-groundwater were clipped to 40. u Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 1990] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. ----.Correlated S.of Clay 1 and Clay 2 [SHANSEP S = 0.258, m =0.83] APC Barry_EPA_000232 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 5A: PDCPT-34 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (0) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 a'p(Mayne 2017) a',(Mayn ,2017- ani oils) w 20 CC -YT=9 2 pcf Upper GV 7=23.2 ft Lower G =2.7 ft 10 Clay 1A S„=550 psi P'p=3,00 psf Cla 1A 0 Cla 1B yr 105 p Sad 1 d'= 35 deg ° -10 m 1 1 1 0 pc -- _ POP= 1,200 psf o`8 d W Clay 1 B Min Su=420 ps @ El. 0' Sat d 2 San 2 ASJA,= + 11.6 sf/ft 4)=38 de -20 yT=l 20 P -30 -40 50 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 LEGEND Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum. All figures were clipped to El. +30 fit and El.-50 ff. O Measured Organic Content � SPT(Nr)dd Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab:yT=yd•(1+MC/100)] • Measured o'p(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2 Id 5. Su-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated Su of Clay 1 and Clay 2 [CPT: NM= 17; Su=(qt-ow)/NM (Robertson and Cabal, 2015)] Sand E 6.o'o-preconsolidation stress;a'w-vertical effective stress. O Measured Su of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a',[Kulhawy and Mayne, 1990]. Measured Su of Clay 1 and Clay 2 [UU] 8.o'p values were clipped to 9000 psf. ❑o Measured Su of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(Nr),values were clipped to 40. 9Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 19901 -•-•-Correlated S.of Clay 1 and Clay 2 [SHANSEP S = 0.258, m =0.8?IPc Barry_EPA_000233 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 51B: PDCPT-35 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (°) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 -Surl 3ce E vati n=31.04 ft MSL — o'°(Mayne, 2017) ono(Mayne, 2017-Orgc nic oils) 20 CC -YT=s 2 Pcf 10 Clay Upper GVY =28.Oft Min Su=375 psf @ El. +2' Lower GW T= 10.Oft ASA= + 10.5 psf/ft 0 Cla 1 Yr1 5 P POP 750 psf x c -10 R v San 1 w W yr 1 5 pc Sar d 1 0 0 0 C�=35 deg o -20 an 2 Sad 2 Yr1 20 Pc ¢= 8 deg -30 -40 50 1 1 1 1 1 1 1 1 LEGEND Notes: — Design Profile CCR 1.All elevations are in the NAVD88 datum.All figures were clipped to El. +30 ft and El. -50 ft. O Measured Organic Content � SPT(N,)80 Clay1 2. LL- liquid limit; MC- moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3.yT-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab:yr yd'(1+MC/100)] • Measured o'°(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. —Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2 , 5. S°-undrained shear strength (values were clipped to 1000 psf); OCR-overconsolidation ratio. —Correlated S„of Clay 1 and Clay 2 [CPT: N,d= 17; Su=(qt-aa)/N,d (Robertson and Cabal, 2015)] Sand E 6.d°-preconsolidation stress; a'.-vertical effective stress. C Measured S.of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33(recommended by Robertson and Cabal, 2015)was used to calculate o'°[Kulhawy and Mayne, 1990]. Measured S.of Clay 1 and Clay 2 [UU] 8.d°values were clipped to 9000 psf. ❑o Measured S°of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(Nj,values were clipped to 40. Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. o Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 1990] •---Correlated S.of Clay 1 and Clay 2[SHANSEP S = 0.258, m = 0.831PC aarry_EPA_0002M GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 513: PDCPT-36 and co-located PDS-12 Atterberg Limit, Moisture, Preconsolidation and Effective and Organic Content (%) Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) SPT (N,)ao Friction Angle (°) 0 50 100 150 200 250 300 350 70 80 90 100 110 120 130 0 500 10000 3000 6000 9000 0 5 10 15 20 25 30 35 40 25 30 35 40 45 50 30 Sul face Eleva on=3 .13 -MS o'p(Ma ne 20 7) o'p(Mayne 2017-Or nic ils Key aw PL MC LL 20 OC= .0% 1 0 Cc Y. 2 Pc 10 Upper G =29.1 ft 41 Clay 1 Lower G = 10.1 ft OC 7.2% Min S„= 375ps @El. +2' AS,JA=+ 10.5 psf/ft 0 C- .2 a la 1 POP 750 psf C= .5% ri Sp C -10 d W -20 Ban 2 � YT= 20 p ♦ Sa 2 ° �= 8 deg o -30 -40 -50 Notes: 1.All elevations are in the NAVD88 datum.All figures were clipped to El. +30 ft and El.-50 ft. I.E�EdQ — Design Profile 2. ILL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. O Measured Organic Content SPT(N ) • Measured Moisture Content fi0 3.yT-Selected total unit weight; y,-dry unit weight. • Measured a'p(1 D Consolidation) ,y,*(1+MC/100)] 4. Selected yr values were presented on the figure. • Measured Total Unit Weight[Lab:yCorrelated Total Unit Weight[CPT: Robertson and Cabal. 2015] 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. —Correlated Su of Clay 1 and Clay 2 [CPT: N-= 17: S (qt-c°)/N- (Robertson and Cabal, 2015)] 6.a'p-preconsolidation stress;a'„p-vertical effective stress. O Measured Su of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal,2015)was used to calculate a'p[Kulhawy and Mayne, 1990]. 0 Measured Su of Clay 1 and Clay 2 [UU] 8.a'p values were clipped to 9000 psf. Measured Sp of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(N,),values were clipped to 40. ♦Correlated Effective Friction Angle [SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. 0 Correlated Effective Friction Angle [CPT: Kulhawy and Mayne, 19901 .... Correlated Su of Clay 1 and Clay 2 [SHANSEP S = 0.258, m =0.83]' C earry_EPA_000235 GEOTECHNICAL PARAMETER SUMMARY PLOT REACH 5B: PDCPT-41 Preconsolidation and Effective Total Unit Weight (pcf) Undrained Shear Strength (psf) Vertical Effective Stress (psf) Friction Angle (a) 70 80 90 100 110 120 130 0 500 10000 3000 6000 900025 30 35 40 45 50 30 a',(Mayne, 2017) ap ayne, - rq, me ois aw 20 CC Yr= Pcf 10 Upper GV 7=25.3ft- Clay 1 Lower GV T=6.3 ft Min S� =375 psf El. +2' POP 750 psf 0 Clal 1 yi 1 D5 p c ° -10 m m W IMF Said 2 �= 38 de -20 San 2 1 20 pc 00 -30 e� -40 -50 LEGEND Notes: — Design Profile CCR 1. All elevations are in the NAVD88 datum.All figures were clipped to El. +30 ft and El.-50 ft. O Measured Organic Content SPT(Nr)go Clay1 2. LL-liquid limit; MC-moisture content; PL-plastic limit; OC-organic content. • Measured Moisture Content 3. yT-total unit weight; yd-dry unit weight. • Measured Total Unit Weight[Lab:yT=yd•(1+MC/100)] • Measured o'p(1D Consolidation) Sand 1 4. Selected yT values were presented on the figure. Correlated Total Unit Weight[CPT: Robertson and Cabal, 2015] Clay 2 ld 5. S„-undrained shear strength (values were clipped to 1000 psf);OCR-overconsolidation ratio. Correlated Su of Clay 1 and Clay 2 [CPT: NM= 17; Su=(qt-ow)/NM (Robertson and Cabal, 2015)] Sand E 6.o'o-preconsolidation stress;a'w-vertical effective stress. O Measured Su of Clay 1 and Clay 2 [CU: Consolidated to closest in-situ stress] 7.Value of k=0.33 (recommended by Robertson and Cabal, 2015)was used to calculate a'p[Kulhawy and Mayne, 1990]. Measured S^of Clay 1 and Clay 2 [UU] 8.o'p values were clipped to 9000 psf. ❑o Measured S^of Clay 1 and Clay 2 [VST: Peak(uncorrected)] 9. SPT(Nr),values were clipped to 40. 9Correlated Effective Friction Angle[SPT: Hatanaka and Uchida, 1996] 10. GWT-groundwater table. Upper GWT is applicable to CCR and Clay 1, Lower GWT is applicable to Sand 1, Clay 2 and Sand 2. 0 Correlated Effective Friction Angle[CPT: Kulhawy and Mayne, 1990] ....Correlated S.of Clay 1 and Clay 2[SHANSEP S=0.258, m =0.831Pc Barry_EPA_000236 Geosyntec° CDD3liltmts Page 112 of 114 CP: LPCITE Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: SCS Project Plant Barry Closure Design Project No: GW6489 ATTACHMENT 2 CALCUATION OF SPT(Nl)6o VALUES GW6489/Barry_Material_Chama imtion_Na five_20180827 APC Barry_EPA_000237 Geosyntec° consultants Page 113 of 114 CP: LPC/rE Date: 8/27/18 APC: JH Date: 8/27/18 CA: WT Date: 8/27/18 Client: SCS Project: Plant Barry Closure Design Project No: GW6489 In Situ Testing-Standard Penetrometer Tests(SPT) The SPT N-value was measured as the number of"blows"needed to advance the split spoon sampler six inches which was recorded over 4 intervals for a total of 24 inches. The middle two 6-inch intervals were summed and reported as a "SPT N-value". The standard SPT N- value measured in the field corresponds to a 140-pound(lb) hammer falling 30 inches with a 60 percent efficient hammer system;therefore,the field measured SPT N-value was corrected for variations in drill rigs, hammer efficiency, and sampling methods. The corrected SPT N- value is then used in engineering correlations and computations. The corrected N-value(NO) is computed as follows: N60 = Nmeas CECBCSCR (i) where: N60 = SPT N-value corrected to 60 percent efficiency(blows/ft); Nmeas = SPT N-value measured in the field (blows/ft); Cg = correction factor for the applied energy of the hammer; CB = correction factor for the borehole diameter; CS = correction factor for the sampling method; and CR = correction factor for the rod length. Correction factors for the borehole diameter, sampling method, and rod length were provided in Table A. The correction factor for the applied energy is computed as follows: Cg = ER 60 (11) where: ER = Energy Ratio of the hammer on the drilling rig used during the field investigation. ER is 85 for the drill rig used during the site investigation. In many correlations, corrected SPT N-values were normalized to account for the in-situ effective vertical stress at the sampling depth. The normalized, corrected blow count [(N1)60) is computed as follows: (NS)60 = CNN60 (iii) where: CN = correction factor for overburden stress. GW6489/Barry_Material_Chars eimtion_Na five_20180827 APC Barry_EPA_000238 Geosyntec° consultants Page 114 of 114 CP: LPCITE Date: 8/27/18 APC: JB Date: 8/27/18 CA: WT Date: 8/27/18 Client: SCR Project: Plant Barry Closure Design Project No: GW6489 The correction for overburden stress is computed as follows: CN = (Wuvo)n (1P) where: Ps = atmospheric pressure(pst); UVO = effective vertical stress (pst); and n = exponent based on soil type. The exponent, n, is typically 1 for clays and ranges from 0.5 to 0.6 for sands. Soil specific correlations for the exponent have been developed for various geomaterials, but were not locally available. For this Package, the value of n was conservatively assumed to be 0.5. SPT N-values were measured at approximately 5-11 intervals within the CCR and at intervals ranging from continuous (2-ft intervals) to approximately 5-ft intervals in the native soil within the borings, except at depths where Shelby tube samples were collected. The measured SPT N-values were corrected(N61) and normalized for overburden stress ((Nl)60)- Table A. Borehole Diameter, Sampling Method, and Rod Length Correction Factors (adapted from Skempton [19861) Correction Factor Variable Value 2.5—4.5 inches 1.00 Borehole diameter factor, CB 6.0 inches 1.05 8.0 inches 1.15 Standard sampler 1.00 Sampling method factor, Cs Sampler without liner 1.20 not recommended 10-13feet 0.75 13 —20 feet 0.85 Rod length factor, CR 20—30 feet 0.95 > 30 feet 1.00 GW6489/Barry_Material_Chars eimtion_Na five_20180827 APC Barry_EPA_000239 APPENDIX B 1 FINAL COVER SETTLEMENT APC Barry_EPA_000240 Geosyntecc' Consultants CALCULATION PACKAGE COVER SHEET Client: Alabama Power Company & Project: Plant Barry Ash Pond Closure Project#: GW6489 Southern Company Services Project TITLE OF PACKAGE: DRAFT-FINAL COVER SETTLEMENT F CALCULATION PREPARED BY: Signatuue 27 August 2018 (Calculation Preparer,CP) Name Gabriel J.Colorado Urrea Date ASSUMPTIONS&PROCEDURES Signaure 27 August 2018 CHECKED BY: (Assumptions&Procedures Checker,APC) Name Tamer Elkady/William Tanner Date 3 S Signature 27August 2018 COMPUTATIONS CHECKED BY: (Computation Checker,CC) Maria Limas Name Date BACK-CHECKED BY: Signature 27 August 2018 y (Calculation Preparer,CP) Name Gabriel J.Colorado Urrea Dare a m APPROVED BY: Signatu, 27 August 2018 m (Calculation Approver,CA) Name William Tanner Date REVISION HISTORY: NO. DESCRIPTION DATE CP APC CC CA A Draft Closure Design Calculation Package 08/27/18 GJC TYE/WT NIL WT APC Barry_EPA_000241 Geosynte& consultants Page 1 of 45 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6499 DRAFT-FINAL COVER SETTLEMENT PURPOSE This Draft Final Cover Settlement calculation package(Package)was prepared in support of the design to close the existing coal combustion residuals (CCR)ash pond at Alabama Power Company's(APC's)Plant Barry(Site), located in Bucks,Alabama. The ash pond will be closed using a "consolidate and cap-in-place" method whereby all CCR will be consolidated into an approximately 300-acre area (consolidated footprint) that will be constructed in the central portion of the ash pond using soil containment berms and with a final cover system. The purpose of this Package is to present engineering calculations to estimate the settlement of the existing CCR, and subsurface sand and clay soils as a result of the placement of dredged CCR and construction of a final cover system in the consolidated footprint as part of the proposed closure. Specifically, this Package presents settlement calculations of the final cover system along sections typical for the side slopes and drainage channels and compares the calculated settlements to design criteria. The remainder of this Package is organized to present: (i) design criteria; (ii) analysis methodology; (iii)design parameters; (iv)results; and(v) conclusions. All elevations presented in this package are based on North American Vertical Datum of 1988 (NAVD 88). DESIGN CRITERIA The design of the proposed consolidated footprint will be performed in accordance with the provisions of the United States Environmental Protection Agency's (USEPA's) federal CCR Rule contained in 40 CFR §257 (and 40 CFR §261 by reference), as amended [USEPA, 2015; USEPA, 20161. The following design criteria were selected from the regulations above, recommendations in technical literature, and appropriate engineering practice, and are considered for the settlement calculations presented in this Package: • the post-settlement grades of the final cover system side slopes may not be less than 3 percent nor greater than 25 percent; GW6489Ma 50%Desip Cover Senlement Draft APC Barry_EPA_000242 GeosyntecO consultants Page 2 of 45 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6499 • the post-settlement grades along drainage channels within the CCR limits may not be less than 0.5 percent nor greater than 33 percent; • differential settlements of the final cover system may not cause a grade reversal; and • differential settlements of the final cover system may not cause tensile strains that exceed an allowable tensile strain of 5 percent for the geosynthetic components of the final cover system [Berg and Bonaparte, 1993]. ANALYSIS METHODOLOGY As discussed below under the section titled Subsurface Stratigraphy and Design Parameters,the subsurface materials at the Site consist, from top to bottom, of existing CCR, Clay 1, Sand 1, Clay 2 and Sand 2. Settlements of these materials were calculated using equations for elasticity theory and one-dimensional (1-D) consolidation theory [Holtz and Kovacs, 1981]. Settlements of the subsurface materials are caused by the following mechanisms: • Immediate settlement that occurs during construction; • Primary consolidation of the due to the loads imposed by the additional CCR that will be placed in the consolidated footprint and the fmal cover system; and • Secondary compression (long term, after primary consolidation is complete) resulting from the plastic realignment of the material structure (i.e., creep)under sustained loading. Immediate settlement occurs during construction and is relatively small compared to consolidation settlement for fine-grained soils, and thus was not calculated for the existing CCR, Clay 1 and Clay 2 layers. However, settlement of the Sand 1 and Sand 2 layers was calculated considering immediate settlement only since settlement occurs only as the load is applied and primarily due to immediate distortion and compression of the material. The general description for elastic settlement, primary consolidation, and secondary compression settlements and the forms of the corresponding equations are provided in the following sections. GW64891Ba 50%Desip Cover Senlement Draft APC Barry_EPA_000243 Geosyntec° consultants Page 3 of 45 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6499 Staves of Construction The duration considered in settlement analysis in this Package is 45 years (analysis period),which includes 8 to 10 years for closure construction and 35 to 37 years of post- closure care. The settlement of the final cover system was calculated in two stages to better estimate the settlements expected to occur during the closure construction and post- closure care. Staging of construction was evaluated for two distinct areas at the Site: (i) Zone 1 represents the perimeter area of the CCR consolidation that encompasses zones of excavation of the existing CCR and placement of the new CCR to obtained bottom of final cover design elevations; (ii) Zone 2 represents the central area of the CCR consolidated footprint. Figure 1 shows a plan view of the Site and the approximate footprints of the different zones considered in the staged construction approach for calculating settlements. Figure 2 shows conceptual sketches of the expected loadings and settlements that will occur during and after construction for the modeled stages of construction within Zones 1 and 2. Details for the stages of construction (i.e., loadings and expected settlements) are provided below. It should be noted that the staged construction presented herein is considered a simplified staged construction and may be updated in the upcoming submittal based on a CCR placement plan to be developed by the contractor in coordination with Geosyntec. Stage 1 Construction Stage 1 construction models the settlements at 2 years after the initial CCR placement. For the settlement analysis of Stage 1 construction, the new CCR was conservatively modeled to be placed instantaneously to the design elevations of bottom of final cover system within Zone 1 and to an elevation 5 feet (ft) below the design elevation of the bottom of final cover system within Zone 2. No final cover system will be placed during Stage 1 Construction.The settlements calculated during the Stage 1 construction are used to estimate the additional CCR that will need to be placed during Stage 2 construction to achieve the proposed bottom of final cover grades, after a portion of Stage 1 settlements have occurred. Also, the long-term settlements due to Stage 1 construction that occur beyond 2 years due to the remainder of primary consolidation settlement and secondary compression settlement (i.e., during Stage 2 construction) are also calculated for the analysis period of 45 years. The settlements calculated within the consolidated footprint for 45 years are used to estimate the final elevations and grades of the final cover system GW64891Ba 50%Desip Cover Senlement Draft APC Barry_EPA_000244 Geosyntec° consultants Page 4 of 45 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6499 and strains in the geomembrane component of the final cover system for the consolidated footprint. Stage 2 Construction Stage 2 construction modeled the time from the end of Stage 1 construction(i.e., 2 years) to the end of analysis period(i.e.,45 years).During Stage 2 construction,additional CCR and the final cover system were conservatively modeled to be placed instantaneously within Zones 1 and 2.A portion of the additional CCR placed during Stage 2 construction will replace the thickness of CCR that consolidated during Stage 1 construction. The settlements caused by the placement of CCR and final cover system during Stage 2 construction were calculated as the sum of the following: • Settlements within Zones 1 and 2 due to the placement of additional CCR to reach bottom of final cover design elevations during Stage 2 construction were calculated for a period of 43 years (i.e., the remaining analysis period for the proposed closure after 2 years of construction); • Total settlements within Zones 1 and 2 were calculated as the settlements due to the placement of the additional CCR and the final cover system during Stage 2 construction, plus the settlements that occur as a result of Stage 1 construction from the end of Stage 1 construction to the end of analysis period (i.e., a period of43 years). Under the post-closure conditions, the water table within the consolidated footprint is expected to drop due to the encapsulation of the consolidated footprint with final cover system and soil containment dikes and the effects of operating an internal drainage system to lower water table in the Consolidation Area. This water table lowering will induce an additional increase in vertical effective stresses within the subsurface soils,which results in additional settlements. For the purpose of evaluating water drawdown settlements,the water table within the consolidated footprint was modeled to be lowered from the top of the existing CCR to a long-term elevation of 3 ft. This water table lowering was conservatively modeled to take place instantaneously at the beginning of Stage 2 construction together with the placement of CCR and final cover system (i.e., initial conditions of the drawdown are final conditions of Stage 1). GW6489/13 y 50%Desip Cover Senlement Draft APC Barry_EPA_000245 Geosyntec° consultants Page 5 of 45 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6499 Effective Vertical Stress Settlements of the subsurface materials were calculated for the increase in vertical effective stress caused by two factors: (i)the placement of additional CCR and final cover system(Ao',e), and(ii)the water table drawdown (Ad,w). The increase in vertical effective stress due to the placement of additional CCR and final cover system(Aa',-,e)was calculated using Equation 1 below: Aav,e = Hey, + HCCR YCCR (1) where: Ao'v, = increase in vertical effective stress due to placement of additional CCR and final cover system(pounds per square foot[psf]); H = thickness of the final cover system(ft); ye = unit weight of the final cover system(pounds per cubic foot[pcf]); HccR = thickness of the additional CCR(ft); and yccR = unit weight of the additional CCR(pcf). For each stage of construction, the additional CCR and final cover placed during that stage were used to calculate the corresponding increase in vertical effective stress. The increase in vertical effective stress was used to calculate immediate settlement of Sand 1 and Sand 2, and primary consolidation settlements of the existing CCR and Clay 1 and Clay 2 soils. The increase in vertical effective stress due to the water table dmwdown (AG',) was calculated using Equation 2 below: Aav,w = AH.y. (2) where: Ad", = increase in vertical effective stress due to the water table GW6489Ma 50%Desip Cover Senlement Draft APC Barry_EPA_000246 Geosyntec° consultants Page 6 of 45 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6499 drawdown(psf); 4Hw = drop in water table elevation (ft); and Yw = unit weight of water(i.e., 62.4 pcf). The increase in vertical effective stress due to the water table drawdown(oa',w)was used to calculate primary consolidation settlements of the existing CCR and Clay 1 during Stage 2 of construction. Immediate Settlement Immediate settlement,Si, occurs as the load is applied and is primarily due to distortion and compression within the material. The immediate settlements for Sand 1 and Sand 2 were calculated using Equation 3 obtained from linear elastic theory [Qian et al., 2002]: Si = ms H (3) where: Si = immediate settlement(ft); Da'� = increase in vertical effective stress(psf); H = initial thickness of compressible layer(ft); and M, = constrained modulus of material (psf). Primary Consolidation Settlement The primary consolidation settlement, Sp,is related to the increase in the effective vertical stress in the subsurface materials due to the loads imposed by the additional CCR and final cover system. The primary consolidation settlement was calculated using the equation below: Sp = CrcH log(o,vo+no,ul for or',, + Sda < a'p (4a) o J GW6489Ma 50%Desip Cover Settlement Draft APC Barry_EPA_000247 Geosyntec° consultants Page 7 of 45 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6499 Sp = C,eH logO+CrEH log(6�vu <Acly) for u'„n < u'pa'„o +da'„ (4b) P Sp = C,,H log/a,oe+na,p) for a'vo = a'p (4c) where: Sp = primary consolidation settlement(ft); Cra = modified recompression index; Cxe = modified compression index; H = initial thickness of compressible layer(ft); 6� = initial effective vertical stress at the mid-point of each soil layers (psf); and �p = preconsolidation pressure (psf). The existing CCR was considered to be in a normally-consolidated state (i.e., the initial vertical effective stress is approximately equal to the pre-consolidation pressure), and thus Equation 4c was used to calculate the primary consolidation settlement of this material. For Clay 1 and Clay 2, Equations 4a, 4b, and 4c need to be considered to calculate the primary consolidation of these materials depending on the state of consolidation of the native clays (i.e., normal consolidated or overconsolidated) and the magnitude of increase in effective vertical stress. The time required to reach the end of primary consolidation (tr) was calculated using Equation 5: To tHdrl q = (5) ra where: it = time required to reach the end of primary consolidation settlement (years); GW64891[ntrty 50%Uesiill Cover Statement [haft APC Barry_EPA_000248 Geosyntec° consultants Page 8 of 45 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6499 T = dimensionless time factor (1.129 for 95 percent consolidation, which represents the end of primary consolidation in this Package Cv = coefficient of consolidation (square feet per day [ft2/day]); and Ha, = longest drainage path of the consolidating layer(ft). In this Package, the existing CCR was modeled to be single-drained (i.e., drains at top only so the longest drainage path equals thickness of the CCR). The Clay 1 and Clay 2 were modeled to be double-drained(i.e.,drains at top and bottom so the longest drainage path equals the half of the thickness of the native soils)because the clay layers are located between two free draining materials. To calculate settlements occurring during Stage 1 construction, it was necessary to evaluate if primary consolidation ends within each of the subsurface materials before or after the end of Stage 1 construction (i.e., 2 years) at each calculation point. For calculation points and subsurface materials where the calculated time to reach end of primary consolidation(tt)was greater than 2 years,only part of the primary consolidation settlement calculated in Equation 4a, 4b, or 4c would be expected to occur during Stage 1 construction. The percent of consolidation (0 occurring at the end of Stage 1 construction was calculated using Equations 6 and 7 below [Sivaram& Swamee, 1977]: TO __ r c,. (6) r (Hd,)2 U% e 4 o r1 + `,To 2.8]-0.179 (7)100 n LI \ rz1 where: t = duration of Stage 1 construction(years) (i.e.,2 years); T = dimensionless time factor; C' = coefficient of consolidation(ft2/day); and GW6489Ma 50%Desip Cover Sentement (haft APC Barry_EPA_000249 Geosyntec° consultants Page 9 of 45 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6499 Ha. = longest drainage path of the consolidating layer(ft). For calculation points and subsurface materials where the calculated time to reach end of primary consolidation(h)was greater than 2 years, the primary consolidation settlement (Sp), calculated using Equation 4a,4b, or 4c,was multiplied by the percent consolidation (0 to calculate the settlement at the end of Stage 1 construction. Secondary Compression Settlement The secondary compression settlement (S) is related to the plastic realignment of the material structure (i.e., skeleton) and is the result of sustained loading (i.e., time- dependent creep). The secondary compression settlement, Ss, was calculated using Equation 8 below: Ss = C.H log where: S, = secondary compression settlement(ft); Cyr = modified secondary compression index(dimensionless); tl = time required to reach the end of primary consolidation settlement (years); and t2 = time at which settlement due to secondary compression is computed(years). The time required to reach the end of primary consolidation (it) was calculated using Equation 5. For calculation points within Zones 1 and 2 where the end of primary consolidation was calculated to occur before the end of Stage 1 construction (i.e., it< 2 years), secondary compression settlement was computed at 2 years (i.e., t2 = 2 years) to estimate the secondary compression settlement occurring at the end of Stage 1 construction. Secondary compression settlements within Zones 1 and 2 that result from the new CCR placement during Stage 1 but occur after 2 years were then calculated at the analysis GW6489/13 y 50%Desip Cover Senlement Draft APC Barry_EPA_000250 Geosyntec° consultants Page 10 of 45 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6499 period(i.e, t2=45 years). Secondary compression settlements that result from the CCR and final cover system within Zones 1 and 2 during Stage 2 construction were calculated for the remaining analysis period(i.e, t2=43 years) at all calculation points. Total Settlement The total settlement(S) for each stage of construction was calculated using Equation 9: S = S; +SP +S, (9) Total settlements of the final cover system at the end of the analysis period (S45yr), considering the two stages of construction modeled in the analyses presented in this Package,were calculated using Equations 10 below. For the final cover system within Zones 1 and 2: S45yr — (Sstagel,45yr —Sstagel,2yr) +Sstage2,43yr +Swt,43yr (10) where: S45yr = total estimated settlement of final cover system at the end of the analysis period of the proposed closure (i.e, 45 yew) (ft); Ssmgel,45yr = total estimated settlement after 45 years due to placement of CCR during Stage 1 (ft); Ssrage1,2rr = total estimated settlement after 2 years due to placement of CCR during Stage 1 (ft); Ssca,2,43yr = total estimated settlement after 43 years due to placement of CCR and final cover system during Stage 2 (ft) ; and Sw1p3yr = total estimated settlement after 43 yews due to lowering the water table at the start of Stage 2 (ft). Total settlements calculated for the end of the analysis period(S45y.)were used to estimate the final elevations and grades for the top of the final cover system and the strains in the GW6489Ma 50%Desip Cover Senlement Draft APC Barry_EPA_000251 Geosyntec° consultants Page 11 of 45 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6499 geomembrane component of the final cover system. Strain Calculations The length between adjacent calculation points was calculated using Equation 11 below: L = (El,,, — Elx)2 + (STAx+r —STAx)2 (11) where: L = length between adjacent calculation points; E1 = elevation at calculation points x and x+1 (ft); and STA = stations of calculation points x and x+l (ft). The change in length relative to the initial length between calculation points was used to calculate strain in the geomembrane component of the final cover system using Equation 12 below: e = L�Lo (12) 0 where: e = strain in the geomembrane component (+ indicates tension; - indicates compression); Lf = final length between adjacent calculation points based on post- settlement elevations; and Le = initial length between adjacent calculation points based on pre- settlement elevations. SUBSURFACE STRATIGRAPHY AND DESIGN PARAMETERS The subsurface stratigraphy, geotechnical parameters, and water table elevations are required for the settlement calculations. GW6489ma 50%Design Lever settlement Draft APC Barry_EPA_000252 Geosyntec° consultants Page 12 of 45 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6499 Subsurface Strati¢raphy and Geotechnical Parameters The data used to develop the subsurface stratigmphy and the geotechnical parameters for the analyses presented in this Package were obtained from field and laboratory investigations performed at the Site. This data is presented in the Draft Material Properties and Major Design Parameters package (Data Package) submitted as part of this detailed design [Geosyntec, 2018]. Based on the Data Package, the subsurface stratigraphy at the Site primarily consists, from top to bottom; of existing CCR, Clay 1, Sand 1, Clay 2 and Sand 2. Due the spatial variability in stress history and undrained shear strength parameters for subsurface units; especially for Clay 1 and Clay 2, the Site was divided into a total of 10 design reaches (Reaches 1,2A, 2B,2C, 3A, 3B, 3C, 4, 5A and 5B) with each reach having a distinct set of material parameters. Discussion on the development of these reaches and associated design parameters are provided in Data Package. Under post-closure configuration, the existing CCR in the consolidated footprint will be overlain by compacted CCR that will be excavated from the southern portion of the Site (Closure by Removal Area) placed on top of the existing CCR. A summary of the geotechnical design parameter values used to model the subsurface materials at the Site in this Package is presented in Table 1. The final cover system proposed for the closure of the Site is a ClosureTurfo cover system. The final cover system detail consists of, from bottom to top: (i) a geocomposite drainage layer, (ii) a 0.5-ft prepared subgrade soil; (iii) a structured geomemImme (50- mil); and(iv) 0.5-in thick sand fill and engineered turf. For the purpose of this analysis, the final cover system modeled to be 0.5-ft thick with a total unit weight of 120 pcf. Water Level Elevations Based on information provided in the Data Package [Geosyntec, 2018], there are two distinct water levels at the Site: (i)an upper,perched water level within the existing CCR and Clay 1 (referred to as Upper WL); and(ii) a potentiometric water level for the Sand 1, Clay 2, and Sand 2 layers generally corresponding to the pool level in the adjacent Mobile River (referred to as Lower WL). These water levels are considered in the analysis presented herein as follows: GW6489Ma 50%Desip Cover Settlement Draft APC Barry_EPA_000253 Geosynte& consultants Page 13 of 45 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6499 • the Upper WL was assumed to be at the top of the existing CCR at all calculation points analyzed and was used in the computation of pore pressure and effective stress for the existing CCR and Clay 1 (i.e.the uppermost clay layer in the deposit) • the Lower WL was assumed to be at elevation 3 ft which represents the average pool elevation in the Mobile River. This water level is applied for the computation of the pore water pressure and effective stress of the sublayers Sand 1,Clay 2(i.e. deepest native clay) and Sand 2. As described earlier in Stages of Construction section,the Upper WL(water table in the consolidated footprint) is expected to lower to the steady-state post-closure elevation of 3 ft under post closure conditions. Consideration of the effect of water table lowering was discussed in the Analysis Methodology section. It is conservatively modeled to be instantaneously lower to the steady-state post-closure elevation to 3 ft prior to the beginning of Stage 2 construction (i.e., initial conditions are the end of Stage 1 construction). The increase in vertical effective stresses caused by the drawdown of the water table are used in the settlement calculations presented in this Package as previously described. CROSS SECTIONS ANALYZED The locations of the three critical cross sections selected for analysis in this Package are shown on Figure 1. Cross section A-A'runs approximately from West to East along the passing through the peak of the proposed consolidated footprint limited by the containment berms at both ends.Cross section C-C'runs from North to South with similar characteristics as mentioned for section A-A'. These cross sections are considered to represent a typical cross section of the side slopes grades of the consolidated footprint and are used to evaluate the change in side slope grades of the final cover system after settlement. Cross section B-B' runs along one of the benches on the east side of the proposed closure and is considered to evaluate the change in grades of the drainage benches. The subsurface profiles and construction stages for cross sections A-A', B-B' and C-C'are shown in Figures 3, 4 and 5, respectively. The elevations and grade changes in the final cover system and tensile strains in the geosynthetic components of the final cover system were evaluated at the calculation points shown on Figures 3,4 and 5. GW6489Ma 50%Desip Cover settlement Draft APC Barry_EPA_000254 Geosynte& consultants Page 14 of 45 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6499 COMPUTATIONS The settlement calculations were performed by coding equations 1 through 12 into a Microsoft Excel® spreadsheet. The following steps were used to perform the settlement calculations presented earlier: 1. Three critical cross sections were selected for the settlement analyses of the proposed closure (i.e., Section A-A',13-13'and C-C'). 2. Calculation points were selected at key points along the cross sections (e.g., changes in the slopes of the proposed final cover and significant changes in elevation of the native soils and existing CCR) or approximately every 100 ft. 3. For each calculation point, the existing subsurface was discretized into sublayers with thicknesses of 5 ft. 4. To account for the phasing of proposed closure construction (i.e., placement of dredged CCR into the consolidated footprint prior to placement of the final cover system), a staged construction approach (i.e., Stage 1 and Stage 2) was used to calculate the settlement of the three cross sections. 5. For each stage of construction, the increase in vertical effective stress due to the placement of additional CCR and,if placed for that stage of construction,the final cover system (oa',.,,) was calculated at each calculation point by assuming 1-1) loading and no stress attenuation with depth(Equation 1). 6. The increase in vertical effective stress due to the water table drawdown was calculated at each calculation point using Equation 2. 7. For each stage of construction, immediate settlement (Si), primary consolidation settlement (S), and secondary compression settlement (S) of each sublayer was calculated using Equations 3 through 8. 8. Total settlements at each calculation point were calculated by summing the settlements (i.e., Sy Sp, and S for all sublayers (Equation 9). Total settlements were calculated for: Stage 1 loading after 2 years(S,,,i,2yr), Stage 1 loading after 45 years (S o-getp5y,), Stage 2 loading after 43 years (S enge2,4sy,)., and water table drawdown after 43 years(St,43y,) 9. The total settlement of the final cover system at the end of the analysis period GW6489,13 y 50%Desip Cover Senlement Drd t APC Barry_EPA_000255 Geosyntec° consultants Page 15 of 45 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6499 (S45,)was calculated using Equation 10. 10. Post-settlement grades were calculated using the post-settlement elevations and the horizontal distance between adjacent calculation points. 11. Pre-and post-settlement elevations between adjacent calculation points were used in Equations 11 and 12 to calculate elongation and strain of the geomembrane component of the final cover system. 12. The calculated post-settlement grades of the final cover system and tensile strains of the geomembmne component of the final cover system were compared to the design criteria. RESULTS Settlements were calculated using the methodology presented in this Package, as coded in Microsoft Excel® spreadsheets. The pre-settlement and post-settlement calculated elevations of the surface after Stage 1 construction (i.e., 2 years) and of the final cover system at the end of analysis period (i.e., 45 years) at the calculation points along cross section A-A' are presented in Figure 6 and 7, respectively. Figures 8 and 9 respectively present the pre- and post-settlement calculated elevations of the surface after Stage 1 construction and of the final cover system at the end of analysis period at the calculation points along cross section B-B'. Figures 10 and 11 respectively show the pre- and post- settlement calculated elevations of the surface after Stage 1 construction and of the final cover system at the end of analysis period at the calculation points along cross section C- C. Example calculations for cross section GC at station 1669 (Point 317) are provided in Attachment 1. Total Settlement The calculated total settlements for calculation points along cross sections A-A',B-B'and C-C after Stage 1 construction (i.e., 2 years) and at the end of analysis period (i.e., 45 years) are presented in Tables 2 through 4; respectively. After Stage 1 construction, the calculated settlements range from 0 ft (between stations 784 and 878 and 4243 and 4428)to 4.27 ft (at stations 2577 and 2606) for cross section A-A',and from 0.05 ft(at station 0)to 2.01 ft(at station 2354)for cross section B-B',and from 0 ft(between stations 584 and 783 and stations 4086 and 4186)to 4.27 ft(at station GW64891Ba 50%Desip Cover Senlement Draft APC Barry_EPA_000256 Geosynte& consultants Page 16 of 45 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6499 2384 and 2385) for cross section C-C'. The larger settlements generally occurred at calculation points with larger additional CCR thicknesses and thicker subsurface layers (i.e.,existing CCR and native soils). Smaller settlements generally occurred at calculation points where the final elevation of the CCR was lower than the existing condition. For Stage 2 construction(i.e.,the placement of additional CCR and the final cover system at the end of analysis period and drawdown of perched water table), additional CCR and the final cover system were placed to achieve the final design elevations.The CCR placed during Stage 2 construction consists of a thickness equal to the calculated settlements after Stage 1, plus the remaining CCR thickness required to achieve the design elevation for the CCR (i.e., 0.5 ft below the top of final cover system design elevation). The calculated maximum total settlements of the final cover system at the end of analysis period for selected sections we 2.29 ft at station 1470, 2.95 ft at station 0, and 3.42 ft at station 1203 of cross sections A-A', B-B'and C-C'. Grade Change The calculated grades for cross sections A-A',B-B'and C-C'of the final cover at the end of analysis period are presented in Tables 2 through 4, respectively. The calculated minimum post-settlement grade of the final cover system along the side slopes is 3.1 percent (station 1914 of cross section C-C'), which satisfies the design criteria of minimum of 3.0 percent post-settlement grades. In addition, the calculated minimum post-settlement grade of along the drainage channel is 0.5 percent at station 500 of cross section B-B'. Geomembrane Tensile Strain The maximum post-settlement tensile strain within the geomembrane of the final cover system is calculated to be 2.21 percent for cross section A-A' (at station 1467), 0.82 percent for cross section B-B' (at station 6), and 0.79 percent for cross section C-C' (at station 1182). These calculated maximum tensile strains are below the allowable tensile strain of 5 percent. CONCLUSIONS Settlement of existing CCR and native soils due to the placement of additional CCR and a final cover system were calculated. The post-settlement elevations of the final cover GW6489Ma 50%Desip Cover Senlement Draft APC Barry_EPA_000257 Geosyntec° consultants Page 17 of 45 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6499 system were evaluated to verify the final grades met the design criteria. Settlement- induced tensile strains in the geosynthetic components of the final cover system were also evaluated and compared to the design criteria. Based on the settlement calculations presented in this Package the following observations are made: • the calculated minimum post-settlement grade of the final cover system on the side slopes is 3.1 percent, which satisfies the design criteria(i.e., minimum of 3 percent); • the calculated minimum post-settlement grade along selected drainage bench within the CCR limit is 0.5 percent which meets the design criteria(i.e.,not less than 0.5 percent); and • the calculated maximum tensile strain within the geomembrane of the final cover system is 2.21 percent, which does not exceed the allowable tensile strain of 5 percent. GW6489Ma 50%Desip Cover Senlement Draft APC Barry_EPA_000258 Geosyntec° consultants Page 1a of 45 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6499 REFERENCES Berg, R.R., and Bonaparte, R. (1993). "Long-Tenn Allowable Tensile Stresses for Polyethylene Geomembranes." Geotextilea and Geomembranes, Vol. 12, pp. 287- 306. Geosyntec.(2018)."Draft Material Properties and Major Design Parameters,"calculation package submitted to Alabama Power Company and Southern Company Services, August 2018. Holtz, R.D.,Kovacs, W.D., and Sheahan, T.C. (2011). "An Introduction to Geotechnical Engineering, 2n6 Edition."Pearson, Upper Saddle River,N.J. Qian, X., Koerner, R.M., and Gray, D.H. (2002). "Geotechnical Aspects of Landfill Design and Construction'. Prentice-Hall Inc.,Upper Saddle River,N.J. Sivaram, B., and P. Swamee. (1977) "A Computational Method for Consolidation Coefficient."Soils and Foundations Journal,Vol. 17,No. 2,pp.48-52. United States Environmental Protection Agency (USEPA) (2015). "Code of Federal Regulations (CFR) Title 40, Pans 257 and 261, Hazards and Solid Waste Management System; Disposal of Coal Combustion Residuals from Electric Utilities; Final Rule." United States Environmental Protection Agency (USEPA) (2016). "Code of Federal Regulations (CFR) Title 40, Part 257 Hazardous and Solid Waste Management System: Disposal of Coal Combustion Residuals from Electric Utilities; Extension of Compliance Deadlines for Certain Inactive Surface Impoundments; Response to Partial Vacatur." GW6489Ma 50%Desip Cover settlement Draft APC Barry_EPA_000259 Geosyntec° consultants Page 19 of 45 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6499 TABLES GW6489Ma 56%Desip Cover Senlement Draft APC Barry_EPA_000260 Geosynte& consultants Page 20 of 45 CP: GIC Date: O8R7/18 APC: TYE Data: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Table 1. Geotechnical Design Parameters for Subsurface Materials Compressibility Parameters mW Pre Over Constrained Total Unit Max Past Modulus Material Weight Burden Pressure Modified Coefficient of (s) Pressure POP Modified Modified (part (Per) re O) (Pap Compression Recompression Secondary Conaolidatioq Index,Ca Index,Ca Compression a Index,C..0) (cmr/min))a) New Coal Combustion Residual(CCR)(e) 97 - - - -Existing Coal Combustion Residual(CCR) 92 - - 0.10 0.01(l) 0.0015 0.6 - Reach 1 94 600 - 0.029 0.0290) - Reech2A 92 1,100 - 0.32 0.03a) - Reach2B 97 1,100 - 0.32 0.03a) - Reach3A/3B 95 0 0.26 0.04(2) Clay 1 0.002 0.01 Reach 3C I00 200 - 0.26 0.04(a - Roach 105 2,100 - 0.18 0.0180) - Reach 5A 1,200 - Reach 5B 105 750 - 0.17 0.02a) - Sand 1 120 - _ _ _ 2,500,000 GW6489Barty 50°/e Desip Cover Settlement Draft APC Barry_EPA_000261 Geosynte& consultants Page 21 of 45 CP: GIC Date: OU7/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project project No: GW6489 Table 1. continued Compressibility Parameters Iran Constrained Total Unit Pre-Over Burden Max Past Modulus Material Weight Pressure POP Pressure Modified Modified Modified Coefficient of tPsOm (pcq (psQ of (Pat) Secondary Consolidation, Recompression Compression a Index,Ca Index,C.. Index,C..W bmI/mim(o Reach 1 125 - Reach2A too - 3,200 - Reach 2B 105 a'- 0.14 0.0140) 0.003 0.02 Clay 2 Reach 3A/3B 102 - aSo - Reach3C 110 - 6,000 - Reach 4 108 - 4,000 - Reach 5A/5B Not Present - Sand 2 - 3,000,000 Notes: 1. Pre-overburden pressures refers to the difference between the max past pressure(P'e)and in sim vertical effective stress 2. Modified re-compression index is obtained from laboratory consolidation data. 3. Modified re-compression index is assumed 0.1 times the modified compression index. 4. The modified secondary compression index and coefficient of consolidation are obtained from laboratory testing. 5. The drained elastic modulus for sand was obtained from correlations with CPT data conducted at the site. 6. The new CCR will be compacted in the consolidated footprint and,therefore was considered incompressible GW648943arty 50°/e Desip Cover Senlement Draft APC Barry_EPA_000262 Geosynte& consultants Page 22 of 45 CP: GJC Date: (HIM/la APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Table 2. Calculated Total Settlements and Grades of the Surface for Cross Section A-A' Total Total Settlement at Design Cover Calculation Settlement Due End of Cover Grades at Cover Point ID Station([[) Zone to Stage 1 Analysis Grades year 45 Strain Construction Period [at 45 (%) (%) (%) [at 2 years](it) can ft 1011'1 781 1 0.18 1.70 30.43 32.95 0.729 10201 784 1 0.00 1.63 4.93 4.90 0.003 10301 828 1 0.00 1.67 0.00 -0.07 0.000 104 838 1 0.00 1.67 4.43 4.34 -0.004 105 1 878 1 1 0.00 1 1.71 3.50 3.46 1 -0.001 106 949 1 0.12 1.90 3.50 4.04 0.020 107 1100 1 1.77 1.16 3.50 3.42 -0.003 108 1200 1 1.93 1.28 3.50 3.45 -0.002 109 1300 1 1.84 1.33 3.50 3.20 -0.010 110 1400 1 1.63 1.68 3.50 3.62 0.004 11101 1446 1 1.99 1.78 9.46 10.05 0.057 11201 1467 1 1.71 1.85 0.00 -21.13 2.207 113 1470 1 0.70 2.29 3.50 3.92 0.016 114 1500 1 0.92 2.20 3.50 3.75 0.009 115 1 1600 2 1 1.43 1 2.08 3.50 3.54 1 0.002 116 1700 2 1.67 2.15 3.50 3.60 0.003 117 1800 2 1.93 2.17 3.50 3.83 0.012 118 1909 2 2.62 1.89 3.50 3.60 0.004 119 2000 2 2.88 1.87 3.50 3.86 0.013 12001 2099 2 3.53 1.42 9.58 9.73 0.014 12101 2119 2 3.41 1.43 0.75 0.75 0.000 122 2123 2 3.41 1.42 3.50 3.63 0.005 123 2200 2 3.60 1.35 3.50 3.55 0.002 124 2300 2 3.80 1.33 3.50 3.54 0.001 125 1 2400 1 2 1 3.97 1 1.33 1 3.50 1 3.53 1 0.001 12601 2577 2 4.27 1.35 0.49 0.50 0.000 12701 2606 2 4.27 1.36 1.81 1.82 0.000 128 2661 2 4.23 1.37 3.50 3.53 0.001 129 2749 2 4.10 1.39 3.50 3.52 0.001 Notes: 1.This calculation point is located within drainage benches or interior perimeter channel and does not represent the design grade final cover side-slope.Drainage at these location is promoted by longitudinal(out- of-the-page)slopes. GW6489Ma 50%Desip Cover Settlement Draft APC Barry_EPA_000263 Geosynte& consultants Page 23 of 45 CP: GJC Date: WIM/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pend Closure Project Project No: GW6489 Table 2. (Continued) Total Settlement Total Design Cover Settlement at Cover Calculation Station Due to Stage 1 Cover Grades at Point ID (it) 7O°e Analysis Construction[at 2 End Grades year 45 Strain years] (it) Period d lot 45 (�) (�) (%) 130 2840 2 3.99 1.39 3.50 4.10 0.023 131 2874 2 3.70 1.72 3.50 4.31 0.032 132 2918 2 3.18 2.23 3.50 3.54 0.001 133 3000 2 3.06 2.19 3.50 3.53 0.001 134 3100 2 2.92 2.12 3.50 3.43 -0.031 1350) 3110 2 2.99 2.00 0.13 6.31 0.199 1360) 3113 2 3.32 1.73 9.70 10.30 0.059 137 3134 2 3.50 1.62 3.50 3.57 0.002 138 3200 2 3.40 1.63 3.50 3.52 0.001 139 3300 2 3.20 1.61 3.50 3.56 0.002 140 3400 2 2.96 1.61 3.50 3.59 0.003 141 3500 2 2.67 1.63 3.50 3.58 0.003 142 3600 2 2.41 1.63 3.50 3.66 0.006 143 3700 2 2.00 1.69 3.50 3.64 0.005 1440) 3762 2 1.76 1.72 0.77 0.73 0.000 1450) 3765 2 1.76 1.72 9.33 11.19 0.189 146 3786 2 2.61 1.48 3.50 3.42 -0.003 147 3900 2 1.78 1.10 3.50 3.45 -0.002 148 4000 1 1.65 0.99 3.50 3.71 0.007 149 4100 1 1.10 1.18 3.50 3.72 0.008 150 4200 1 0.49 1.35 3.50 4.06 0.021 151 4243 1 0.00 1.42 3.50 3.41 -0.003 1520) 4328 1 0.00 1.34 5.46 5.35 -0.006 1530) 4369 1 0.00 1.29 0.40 0.54 0.001 1540) 4380 1 0.00 1.27 5.63 5.78 0.009 1550) 4417 1 0.00 1.22 6.96 7.05 0.006 1560) 4425 1 0.00 1.21 33.33 33.42 0.027 1570) 4428 1 0.00 1.21 0.49 0.46 0.000 Notes: 1.This calculation point is located within drainage benches or interior perimeter channel and does not represent the design grade final cover side-slope.Drainage at these location is promoted by longitudinal(out- of-the-page)slopes. GW"Man, 50%Desip Cover Settlement Draft APC Barry_EPA_00026 Geosyntec° consultants Page 24 of 45 CP: GJC Date: (HIM/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Table 3. Calculated Total Settlements and Grades of the Surface for Cross Section B-B' Total Total Settlement Cover Design Calculation Settlement Due at End of Cover Grades Cover Point 1D Station(it) Zone to Stage 1 Analysis Grades at year Strain Construction Period[at (�) 45 (a/o) [at 2 yearsl(it) 45 years] (°/.) n 2010) 0 2 0.05 2.94 0.51 0.6 0.00 20201 6 2 0.06 2.94 22.39 26.0 0.82 20301 17 2 0.90 2.54 2.67 2.9 0.01 204 127 2 1.56 2.27 1.01 1.0 0.00 205 200 2 1.44 2.27 1.01 1.1 0.00 206 300 2 1.17 2.34 1.01 1.2 0.00 207 400 2 0.78 2.48 1.01 0.7 0.00 208 500 2 1.13 2.16 1.01 0.5 0.00 20901 547 2 1.42 1.92 24.10 25.5 0.32 21001 554 2 1.12 2.01 0.00 -0.1 0.00 21101 565 2 1.13 2.00 24.11 26.3 0.53 212 571 2 1.47 1.85 1.00 1.1 0.00 213 600 2 1.55 1.81 1.00 1.1 0.00 214 700 2 1.67 1.75 1.00 1.1 0.00 215 800 2 1.83 1.70 1.00 1.0 0.00 216 873 2 1.94 1.68 1.00 1.0 0.00 217 1000 2 1.76 1.73 1.00 1.0 0.00 218 1100 2 1.66 1.75 1.00 1.1 0.00 21901 1175 2 1.54 1.79 24.08 25.6 0.35 22001 1181 2 1.24 1.89 0.00 0.0 0.00 22101 1192 2 1.24 1.89 24.10 25.5 0.33 Notes: 1.This calculation point is located within stormwater downcutes and does not represent the design grade along the drainage bench. GW6489Ma 50%Desip Cover Settlement Draft APC Barry_EPA_000265 Geosynte& consultants Page 25 of 45 CP: GJC Date: 08M/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pend Closure Project Project No: GW6489 Table 3. (Continued) Total Total Settlement Design Cover Calculation Settlement Due at End of Cover Grades Cover Point 1D Station(it) Zone to Stage 1 Analysis Grades at year Strain Construction Period[at (�) 45(�) (a/o) [at 2 yearsl(it) 45 years] n 222 1199 2 1.54 1.79 1.01 1.0 0.00 223 1300 2 1.71 1.83 1.01 0.9 0.00 224 1416 2 1.87 1.93 1.16 1.3 0.00 225 1500 2 1.73 2.06 1.16 1.3 0.00 2260) 1603 2 1.53 2.21 24.01 25.6 037 2270) 1610 2 1.22 2.32 0.05 0.2 0.00 220)8 1620 2 1.23 2.33 24.25 25.1 0.21 229 1627 2 1.53 2.27 1.02 0.9 0.00 230 1700 2 1.64 2.38 1.02 0.9 0.00 231 1800 2 1.85 2.53 0.97 0.9 0.00 232 1914 2 1.97 2.61 1.00 0.9 0.00 233 2000 2 1.91 2.55 1.00 0.8 0.00 234 2100 2 1.83 2.40 1.00 0.9 0.00 2350) 2199 2 1.76 2.31 24.24 24.6 0.08 2360) 2208 2 1.43 2.34 0.03 0.1 0.00 2370) 2218 2 1.44 2.33 24.05 24.6 0.12 238 2227 2 1.78 2.28 1.13 1.2 0.00 239 2254 2 1.83 2.26 L13 1.2 0.00 240 2354 2 2.01 2.20 1.03 1.0 0.00 241 2454 2 1.91 2.17 1.03 1.0 0.00 2420) 2495 2 1.86 2.17 24.23 24.6 0.08 Notes: 1.This calculation point is located within stormwater downchute and does not represent the design grade along the drainage bench. GW6489Ma 50%Desip Cover settlement Draft APC Barry_EPA_000266 Geosyntec° consultants Page 26 of 45 CP: GIC Date: 01IM/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Table 4. Calculated Total Settlements and Grades of the Surface for Cross Section C-C' Total Total C Settlement at Design Cover Cover n End of Cover Grades Poi Station(ft) Zone to Stage 1 Strain Pointt ID D Settlement Due Analysis Grades at year Construction[at 2 years] (ft) (a Period[at 45 (n/o) 45 /o) (�) years](ft) 30101 584 1 0.00 2.63 25.23 25.3 0.02 30201 602 1 0.00 2.65 0.14 -0.3 0.00 30301 644 1 0.00 2.83 7.36 7.1 -0.02 304 1 684 1 1 0.00 1 2.93 3.50 1 3.4 0.00 305 783 1 0.00 3.02 3.50 3.7 0.01 306 966 1 0.56 2.95 3.50 4.1 0.02 307 1008 1 0.97 2.81 3.50 3.9 0.02 308 1083 1 1.50 2.63 3.50 3.8 0.01 309 1133 1 1.78 2.53 3.48 3.8 0.01 31001 1182 1 2.02 2.45 9.55 15.8 0.78 31101 1203 1 2 0.73 3.42 0.01 0.1 0.00 312 1207 1 2 0.73 3.41 3.50 4.1 0.02 313 1286 1 2 1.37 3.05 3.50 3.6 0.00 314 1369 1 2 1.55 3.06 3.50 3.7 0.01 315 1444 1 2 1.79 3.00 3.50 3.9 0.02 316 1519 1 2 2.24 2.76 3.50 3.4 0.00 317 1669 1 2 2.22 3.03 3.50 3.7 0.01 318 1752 1 2 2.46 2.94 3.50 3.8 0.01 31901 1835 2 2.76 2.77 9.56 10.0 0.05 3200/ 1856 2 2.58 2.81 0.01 0.0 0.00 321 1859 2 2.58 2.81 3.50 4.3 0.03 322 1914 2 312 2.34 3.50 3.1 401 323 1970 2 2.89 2.72 3.50 4.1 0.02 324 2048 2 3.52 2.17 3.50 3.9 0.01 325 2120 2 3.85 1.84 3.50 3.5 0.00 Notes: 1.This calculation point is located within drainage benches or interior perimeter channel and does not represent the design grade final cover side-slope.Drainage at these location is promoted by longitudinal(out- of-the-page)slopes. GWW9,1i y 56%Desip Cover Settlement Draft APC Barry_EPA_000267 Geosynte& consultants Page 27 of 45 CP: GIC Date: WIM/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pend Closure Project Project No: GW6489 Table 4. (Continued) Total Total Design Cover Calculation Settlement Due Settlement at Cover Grades Cover Point ID Station(ft) Zone to Stage 1 Final Analysis Grades at year Strain Construction period]at 45 Grades 45 (%) ]at 2 years] (D) years](it) (%) 326 2270 2 4.09 1.82 3.50 3.5 0.00 3270) 2384 2 4.27 1.78 0.00 0.0 0.00 328 2385 2 4.27 1.78 3.50 3.5 0.00 329 2466 2 4.16 1.80 3.50 3.6 0.00 330 1 2616 1 2 3.92 1 1.84 3.50 1 3.6 0.00 331 2766 1 2 3.64 1.89 3.50 3.6 0.00 3320) 2847 1 2 3.50 1.90 8.22 8.4 0.02 333 2871 1 2 3.62 1.86 3.50 4.1 0.02 334 2925 1 2 3.22 2.25 3.50 5.7 0.10 335 2951 1 2 2.44 2.94 3.50 3.5 0.00 336 3040 1 2 2.20 2.69 3.50 3.5 0.00 337 3190 1 2 2.20 2.69 3.50 3.7 0.01 338 3340 1 2 1.72 2.83 3.50 3.4 0.00 3390) 3506 1 2 1.75 2.65 8.22 8.8 0.05 340 3530 1 2 2.03 2.58 3.50 3.2 -0.01 341 3678 1 2 2.15 2.31 3.50 3.7 0.01 342 3751 1 1 1.87 2.44 3.50 3.8 0.01 343 3828 1 1 1.50 2.57 3.50 3.9 0.01 344 3900 1 1.08 2.70 3.50 4.0 0.02 345 3978 1 0.43 2.91 3.50 3.4 0.00 3460) 4086 1 0.00 2.59 5.18 5.2 0.00 3470) 4126 1 0.00 2.58 0.58 0.6 0.00 3480) 4139 1 0.00 2.58 5.69 5.7 0.00 3490) 4183 I 0.00 2.55 33.32 32.2 -0.32 3500) 4186 1 0.00 2.58 0.51 0.5 0.00 Notes: 1.This calculation point is located within drainage benches or interior perimeter channel and does not represent the design grade final cover side-slope.Drainage at these location is promoted by longitudinal(out- of-the-page)slopes. GW6489Ma 56%Design Cover settlement Draft APC Barry_EPA_000268 Geosynte& consultants Page 28 of 45 CP: GJC Date: 08M/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client. ASCS Project: Plant Barry Ash Pend Closure Project Project No: GW6489 FIGURES GW6489Ma 50%Desip Cover Settlement Draft APC Barry_EPA_000269 Geosynte& consultants Page 29 of 45 CP: GJC Date: 08/27/18 APC: TVE Date: 08127/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Burry Ash Pond Closure Project Project No: GW6489 C B, Zone 2 -r B Zone 1 I\ a A -ry FSgure 1. Plan View of Selected Cross Sections and Zones of Proposed Closure GW6489Barry 5WIo Desip Cover settlement Draft APC Barry_EPA_000270 Geosyntec° consultants Page 30 of 45 CP: GJC Date: OSR7/la APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pend Closure Project Project No: GW6489 rose,t 2years 4syears ce:gemen:aft 3 galad1,e,s loads(.¢.,WPI _ pla[t ]w i-Syee- c AcIcti I at grnnipg c`Stsg -t0epas this_etemens. 4 N -------------- — Serleme ddue rolans placed dunn,Stage l 1 3ea,w Uet oorurdunng Stage 215a...+w-Sa.nssr4 Senlement due to water table drew doxn at Ims sing of Slag¢21Sua.1. Sawn Setdementdue to loos lies,adddium al mt and anal onrc Aend placed dunngstage2canrournon Is.w.w.l Stagel Stage De",Dte Fral Deli Eleratinn final Oseilan Elevation Final Dean eevatinn _Tinal mesi Ele_va_bun 5 1 St v,2a a�wmtl —�SaN. — S.iaY 7 Stage l Lend �® r F2Lead w 5[y^ellmtl Stage lld . a Stage 11nad ulsrng Elvhng -. Fsutmg Ez saw 1=0 t=zrears- t=zy rsi t=0.5years Figure 2.Conceptual Sketch of Staged Construction for Area 1 and Area 2 Gsk'"Man, 5W/e Deaip Cover Settlement DmO APC Barry_EPA_000271 Geosynte& consultants Page 31 of 45 CP: GJC Date: OJIM/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCH Project: Plant Barry Ash Pend Closure Project Project No: GW6489 'a 888 "d8 ^o "d 8 0«vs v m m m R&£ 44 n YJ Rrn 8 A;,8 `d 7. Ad ;A g Bze a :4%P: e B a Sh 'al"�!.$MM CalWation Point(Typical) 100 90 80 70 Go Stage 1 Coratrusuon Elevalirrs 50 Final ElevationnStage 2 � Top of Existing CCR C40 Con,fitction Elevations Ln 30 z020 — 10 w 0 Topd Clayl -- ,Top of Sandl C 1 10 .Top of Clap 7 . 20 /® Sand 1 -Top of Sand 213 30 Sand 2B FO -t00 2+00 4 M 6+00 a+u0 lawn 12+oo 141Co 16+00 WM 20,00 22AO 24+00 26+00 28wo 30wG 32+Oo 34+00 36+no 38+W 4owo 42+00 44+00 4e+00 48+00 50+0o DISTANCE(FEET) Figure 3. Subsurface Stratigraphy, Staged Construction,and Calculation Points for Cross Section A-A' GW"Man, 5W/e Desip Cover Settlement Dadl APC Barry_EPA_000272 Geosynte& consultants Page 32 of 45 CP: GJC Date: 011M/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pend Closure Proleet Project No: GW6489 .Calculation Point(Typical) NNN N N N NNNN C1NN N N N N NNN NNNN N N N NNNNN N N N NNNNN N N N N NN NNN N NNN 100 90 80 70 60 50 r,40 F ial I leval ons- tage2 U! New nsti uc0o i Elevations LL30 - - - - Stage 1 Construction Elevations Top of Existing CCR Z 020 QExisting 10 CCR Top of Clay 1 w 0 — -10 Top of Sand 1 Clay 1 Sand1 Top of Clay ... - lay 2' -20 -30 Top of Sand 2B Sand 2B -40 -50 -60 0+00 2+00 4-00 6-00 8+00 10-00 12.00 14-00 16+00 18-00 20+00 22-00 24+00 DISTANCE(FEET) Figure 4. Subsurface Stratigraphy, Staged Construction,and Calculation Points for Cross Section B-B' GW"Man, 50°/e Desip Cover settlement Draft APC Bary_EPA_000273 Geosynte& consultants Page 33 of 45 CP: GJC Date: (HIM/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pend Closure Project Project No: GW6489 AU R Calculation Point(Typical) 100 90 80 70 Fi t iV Elwas to se 2 60 C A sl L clior Elevati ins Stage 1 Construction Elevations 50 _40 CCR 1- m Top of Existing CCR na 30 - - - 4 20 --_ EExisting 10— CCR _ Top of Clay I m 0 Top of Sand 1 Clay 1 -30 Sand 1 Tap of Ct3y 2 -20 --- ... . _________--__ Sand2A Top of Sand 2A rby 2 -30 — -40 Surd 20 Top of Sand 2B b0 -U+DO 2+00 4+00 6+80 8+00 10+00 12+OD 14+00 15+00 18+00 20+00 22+C0 24+00 26+00 28+00 30+00 32+00 34+00 36+00 38+00 40+00 42+00 44+80 46+00 48+00 DISTANCE(FEET] Figure 5. Subsurface Stratigraphy,Staged Construction,and Calculation Points for Cross Section C-C' GW"Man, 5W/e Desip Cover Settlement Draft APC Barry_EPA_000274 Geosyntec° consultants Page 34 of 45 CP: GJC Date: OSR7/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pend Closure Project Project No: GW6489 80 +Top of cover Pre-Settlement(Stage 1) t Top of Cover Post-Settlement(Satage 1( 70 —Final Top of Cover Pre-Settlement 60 50 0 a 40 w 30 20 10 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500 2700 2900 3100 3300 3500 3700 3900 4100 4300 4500 4700 Distance(ft) Figure 6. Calculated Pre-and Post-Settlement Elevations of the Surface after Stage 1 Construction(2 Years)for Cross Section A'-A' GW6489Bmry 5W/e Desip Cover Settlement Draft APC Barry_EPA_000275 Geosyntec° consultants Page 35 of 45 CP: GJC Date: (HIM/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pend Closure Project Project No: GW6489 80 +Top of cover Pre-Settlement 70 +Top of Cover Post-settlement 60 50 c 0 w 40 ru 30 20 10 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500 2700 2900 3100 3300 3500 3700 3900 4100 4300 4500 4700 Distance(ft) Figure 7. Calculated Pre-and Post-Settlement Elevations of the Final Cover System for Cross Section A'-A'at End of Analysis Period (45 Years) GW64891san, 5W/e Desip Cover Settlement Draft APC Barry_EPA_000276 Geosyntec° consultants Page 36 of 45 CP: GJC Date: (HIM/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pend Closure Project Project No: GW6489 44 +Top of Cover Pre-Settlement Stage 1 42 t Top of Cover Post-Settlement Stage 1 40 —Final Top of Cover Pre-Settlement 38 36 x c 2 34 a w 32 30 28 26 24 0 200 400 600 800 2000 1200 1400 1600 1800 2000 2200 2400 2600 Distance(ft) Figure 8. Calculated Pre-and Post-Settlement Elevations of the Surface after Stage I Construction(2 Years)for Cross Section B-B' GW6489Bmry 5W/e Design_Cover Settlement Draft APC Barry_EPA_000277 Geosyntec° consultants Page 37 of 45 CP: GJC Date: (HIM/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pend Closure Project Project No: GW6489 44 +Top of Cover Pre-Settlement 42 40 +Top of Cover Post-Settlement 38 36 c 0 44 m u+ 32 — 30 28 26 24 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 Distance(ft) Figure 9. Calculated Pre-and Post-Settlement Elevations of the Final Cover System for Cross Section B'-B'at End of Analysis Period(45 Years) GW"Man, 5W/e Desip Cover Settlement Draft APC Barry_EPA_000278 Geosyntec° consultants Page 38 of 45 CP: GJC Date: 08M/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pend Closure Project Project No: GW6489 80 t Top of Cover Pre-Settlement(Stage 1) 70 �Top of cover Post-Settlement(Stage 1) —Final Top of Cover Pre-Settlement 60 50 0 a w 40 30 20 10 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500 2700 2900 3100 3300 3500 3700 3900 4100 4300 Distance (ft) Figure 10. Calculated Pre-and Post-Settlement Elevations of the Surface after Stage l Construction(2 Years) for Cross Section C'-C' GW6489Bmry 5W/e Design_Cover Settlement Draft APC Barry_EPA_000279 Geosyntec° consultants Page 39 of 45 CP: GJC Date: (HIM/la APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pend Closure Project Project No: GW6489 80 +Top of cover Pre-Settlement 70 +Top of Cover Post-settlement 60 x 50 c 0 q 40 w 30 20 10 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500 2700 2900 3100 3300 3500 3700 3900 4100 4300 Distance(ft) Figure 11. Calculated Pre-and Post-Settlement Elevations of the Final Cover System for Cross Section C'-C'at End of Analysis Period (45 Years) GW6489Barty 5W/e Desip Cover Settlement Draft APC Barry_EPA_000280 Geosynte& consultants Page 40 of 45 CP: GJC Date: 08M/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client. ASCS Project: Plant Barry Ash Pend Closure Project Project No: GW6489 ATTACEEVIENT 1 EXAMPLE SETTLEMENT CALCULATION CROSS SECTION C-C'STATION 1669(POINT 317) GW6489Ma 50%Desip Cover Settlement Draft APC Barry_EPA_000281 Geosynte& consultants Page 41 of 45 CP: GJC Date: OJIM/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ARCH Project: Plant Barry Ash Pend Closure Project Project No: GW6489 C.I.Ram Point 317 m ut ammeter Horizontal imatien 16027 Results Notes 1 NewaR(streamed as a load,it does notmnsoliXMe. Unitwei MMwil flnit Weigbtof Exom CCR,ysm(pd) 92 flnit Weigbtof Dike,y`.Ipcfl lb Dnit WeigM1tof Clayl ...Dart) 95 Dnit WeigM1tof Clayi ...Dart) 102 mit Weigbtof SanE 1,ynMdaxn 1. mit Weigbtof Sandi,Yovon fl ]LI Existing Conditions Final Conditions Thickness.!Exbtin CCR(in 34.618E Thickness of New CCR 16. 5omma .f Unlements Elevation of Existing CCR lhf 30. doatbodomof New CtR 1 1579.55 mgel Stage b2 nickners of Clay l(it) 1L1989 Searle ant Settlementaker45 ma.mng a omen a ems min ins from lnitlal C[R CCRPla4amantand Thicknesml5antllk 135 Stae tM1izknesml new CCR years an initial years from initial Plxemenat m2W45 Lower Waternadeafter TadlSNtlennM Elevaion To of Sand 1ft -10.9 1 11.2W CCR%acement CCR Placement Thickness of Clay2Ik ]3ID 22ID 3.040 O..0 2, D 3.029 Elevation Ta of City2 -205633 Thickness of Sand iA 1t 0.20 Elevation To of Sand Mnt -20.3 Elevation PemM1etl W..,Table ft 348484 Elevation Vh ernble Sand 1,Cl ;Sand 2 It 3 Thicknen of Sand 2e k LS Elevation T. of Sand 2Rn -2¢5633 Exlstl CCR ProartarrinCiarrandinflonSefflementSI Sewntla Emotional-Seelemen Ss Water]ede n t2 SeMement We MidMssor cePfafwm Top Niger o Tv for Har IEMol Icesign Total Six rolnitial Loss Tbidrcsim COE Cawlation layers Y® MUR ea: cc. C. H. PaM Sp Total Sp G 91 (maidid PXmnY) Cifel Cv. T.1 Ss t Tv U (Stage 11 (Stage l) Dal Inl non On Imo Inl Iftl IaaFl 1 ifl gain 1 dl (pa" Iftl On In`/vaar Inl hot IYrsI In) Year Iftl On 306E 5 92 0 lON.55 0.1 0.01 5 15 155 230 74 JO ]169 0.593E 3.00 339<51 1.119 U62 3.93 2 Owns O.tlp] 2 D566 OeIU 1.60 1.663 3295 5 93 0 Jfi0.i9 5 ]5 aiR 690 w .2 1317 03%5 339.451 1. 32.95 3.61 0.5 nD]]5 Doi 45 127afi 093] 1. 2.127 5 1 5 Jag 1150 370 370 1M`5 ni 5 175 1092 1610 518 518 1613 02466 5 2E5 1404 20M YE HS 1761 02111 5 2].5 1716 B30 814 814 1909 0.18M 4.6182 32.3091 2016.M XJR.I3] 956 556 2051 0.1530 GVit"Mimry 5M Deeip Cover Settlement Draft APC Barry_EPA_000282 Geosynte& consultants Page 42 of 45 CP: GJC Date: O8/27/18 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ARCH Project: Plant Barry Ash Pend Closure Project Project No: GW6489 Cl,I Ptlma consollaxmn seRlemem,sP Semnaa Com ression SeNemen Ss WxerTable n 12 Senlementoue Thidnessol OeptM1lrom Top Dep[M1to To for Htlr (FntlW (OesIP Toal Sp to Initial Loatl ThiaFnessaf ClaYl Ulmlaliantayen y i W&iating CCR Aa.' 4. G. H. Point as Sp Total Sp G 95% (double) Primary) ISre) (m Tetalss t Ty II ISGge 1) (Stage 1) Ifll Ift) IPon Ifll (PA (h) Pat Ipnl WO half) (Pull hall) Ihl (h) vehewl Pnl (y.) Iyn) Pat year Ifll nn 11.20 5 95 0 10]0.55 0.26 O.Oa 5 2.5 2311176 3422.374 11W 11W 2201 03884 0.819 SM751 1.129 5.60 6.26 2 0.01 aC011 2 0.361 0665 C545 C545 10.65 5 95 0 ]W.29 5 7.5 2SM176 3897.374 1269 120 2361 0.3511 5.65751 1.U9 133 iW a5 0.01 e.pb9 45 8.120 0.997 0.816 0.912 1.1989 1n 593A5 2B21.SR1 a191022 13N 1370 2afi5 OOAS 19[Y55 Cl.,2 Pa aryConsofidlationSenlennera,$ 5" nary Compression Settlement Ss Penh boom fl.3 It 12 Senlement... Th16nessol Prot.,of Clay Dour to Nbr Par PEntlof IOeslgn iobl5p to Pit wad ThiMess of Clay2 Glmlalion tayen y a 2 �111 4. Cr. H. Point sy Sp Total Sp C. 95% double) Primary) rile( G. Total Ss [ Tv 11 ISGge n (Stage 11 Ifll Ifll Ip81 Ifll (ft) Oft) (Pul) WO (alf) Ial0 hall) Inl (ft) Rehear On Iya) Nm) rn year Ifll in) 0.W 5 102 27IB 0.1a o0K 0 0 1719.888 SSM226 4116 5141 5211 oW]J 0.0.tl 11315 1.129 0.W 0.W 2 0.W3 a00.0 2 o.WJ OOW O.aW obm 0.In 5 1oz z7.s623 -2.5 11.315 2.129 0.0] Ion as 1. r0000 45 o.W o.WJ 0.W0 o.aW GW"Man, 5W/e Desip Cover Settlement Draft APC Barry_EPA_000283 Geosynte& consultants Page 43 of 45 CP: GJC Date: OSM/15 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pend Closure Project Project No: GW6489 Prim Consolidation Settlement,See secon arvCompressionsettlementss Louvred WaterTable:Prima Consolidation Settlements U. t2 Final Water Table After Total Sp Total mph. Nfor Hdr (Fndoi (Opi Nestl e from Top Prlor,.LowM eg for Lowered de-f.. awering Duets Settlemen Point ew so Total so 4 M (Singlel Prim ary) Life) Cs, of Total Ss CCR Water Table Water Table dawdown Water Table Sp Lowering WT t5 e2 h h sf two oP i h h Ih'/yearl h h f i i f ft (h) (h) 0.1 0.01 5 IS 0.0 025 1325 D25 2M nM5 OAS 339L 5 7 1.129 3295 3.61 43 Long 0.0532 31.85 110 0.0 156 136 00272 0.7022 1.158 5 7.5 0.0 17M D85 1785 250.5 0.0771 1317 0.0 Nd 1785 n0Y/0 5 12.5 0.0 2245 2245 n45 3005 0.0633 1445 0.0 7W n2 0.0927 5 17.5 0.0 27M 2m 2W6 3465 0AV8 162 0.0 3092 2705 01M 5 22.5 0.0 3165 3165 310 39B (I0468 1761 0.0 1404 310 0.1273 5 27.5 0.0 W25 3625 M25 43E5 0.01,114 2M) 0 1716 3625 Ores 195488 31.47744 0.0 Lo67 406/ Q67 4827 0.0220 2051 0 2016.W784 406/ 0.1373 -L02256 PrimaryconsolidationSettlernmeni Se nalarrComposelonSanderreentSs Lowered Watertable:Prima Consolidation Settlemem,5 ti t2 Final WaterTable d.. Ur After Total Sp JIM neptHm Who Hdr hadof (Design Depth from Top Prlorm lowedng foe arrested aeowfrom mwering Ouem H. Point ew, Sp Total so C, M (douhle) Primary) Life) C. Total Sr of CCR Water Table Water Table drewdown Water Table Sp Lowering WT h h sf P5 oPi h h (h`tyearl h rs h f i i i ft (h) 0.2fi 0.04 5 IS 328.8 4516.9n 41M 41M 4948 0.0942 0.197 1..1511 1.129 5.33 5.66 43 0.01 nosh 31.85 2201 328a 1987.3 4188 03633 n7M 5 7.5 6418 4931.922 4351 4351 5111 0.P]03 2YM Farts 1967.3 4351 0.3445 0.654348 10.32717 817.3 5286.37 40(1 4469 52N 0.0116 24fi5 817.3 2004.3 4459 0.0606 -2.1728 GW64891pany 5W/o Deaip Cover Senlement Draft APC Barry_EPA_0002M Geosynte& consultants Page 44 of 45 CP: GJC Date: OSM/15 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pend Closure Proje Project No: GW6489 Prima Consolidation Senlement,5 Seaonda Comm on Senlement Ss tl t2 Depth to Nfar Hdr (End of (oeslgn Total Settlement C.. Cn Ile ppd yp ow a-. a, pi Sp Total Sp C. 9s% (doublel Primary) tile) C. Total Ss 5 e 2 k k 1 f s ft ft (ft'/year) It rt rt ft ft a 0.014 0 0 1719.888 6931 5211 5211 5971 0.0000 0.000 11.31502 1.129 OAO 0.00 43 O.W3 0.0000 0.000 GW"Man, 5MI)esip Cover Sedlement Draft APC Barry_EPA_000285 Geosynte& consultants Page 45 of 45 CP: GJC Date: OSM/15 APC: TYE Date: 08/27/18 CA: WT Date: 08/27/18 Client: ASCS Project: Plant Barry Ash Pend Closure Proje Project No: GW6489 Wd1 FWvvl,sealemen Se Thldnessof a msnetl ThisNnessal5artll elahtlan layeR y . .. Aa: Motlulus Sheln(.) Total Se X X X 13.59 13.59 115 3J34.63 3034.5 EFNN 0.00N0 am 13.59 1359 111 3J34.63 JGO.E EaOSN 00.UID am S od}A flatie SeXlement�5e Thidneuor Caamineel Thidnea of5ntl}R Calmlation layen ys..oa Ae: Metlulus B m l-) Todl Se h fl h 0.J0 0. ]J0 41I6 EJ I .55 WOOO 00]136 am 0.A OJ(I ]J(I 411fi$ ]6:1.39 3WCOJi1 OW12s A. I LE SaW 3B Elatie RXlemen45e Thidnaz er CaaRinM laldnen ofSwtl]B Cwlltllon 4ayen yame Ao: Motlulua Sbeln l-) iWel Se X % h ss.44 ss.a4 ]3U s042.W ]PN 31%CQU 0.0003H849 a. ss.40 vs.a4 ]M I SOU.E0 1760 4M 31p[IXtl o.000zs313v am GW"Man, 5W/e Uesip Cover Settlement I ft APC Barry_EPA_000286 z . APPENDIX B2 SOIL CONTAINMENT BERM SETTLEMENT APC Barry_EPA_000287 Geosyntecc' Consultants CALCULATION PACKAGE COVER SHEET Client: Alabama Power Company & Project: Plant Barry Ash Pond Closure Project#: GW6489 Southern Company Services Project TITLE OF PACKAGE: DRAFT—SOIL CONTAINMENT BERM SETTLEMENT F CALCULATION PREPARED BY: Signal 27 August 2018 (Calculation Preparer,CP) Name Gabriel J.Colorado Uuea Date ASSUMPTIONS&PROCEDURES Signature 27 August 2018 CHECKED BY: (Assumptions&Procedures Checker,APC) Name Tamer Elkady/William Tanner Date 3 m S COMPUTATIONS CHECKED BY: Signature 27 August 2018 (Computation Checker,CC) Name Maria Limas Dare BACK-CHECKED BY: Signature 27 August 2018 (Calculation Preparer,CP) Name Gabriel Colorado Urrea Date a w APPROVED BY: Signature 27 August 2018 (Calculation Approver,CA) Name William Tanner Dace a REVISION HISTORY: NO. DESCRIPTION DATE CP APC CC CA A Draft Closure Design Calculation Package 08/27/18 GCU TE ML WMT APC Barry_EPA_000288 Geosynte& consultants Peg. 1 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client APC/8C8 Project: Plant Barry Ash Pond Closure Project Project No: GW6489 DRAFT—SOIL CONTAINMENT BERM SETTLEMENT PURPOSE This Drat Soil Containment Berm Settlement calculation package (Package) was prepared in support of the design to close the existing coal combustion residuals (CCR) ash pond at Alabama Power Company's (APC's) Plant Barry (Site), located in Bucks, Alabama. The ash pond will be closed using a "consolidate and cap-in-place" method whereby all CCR will be consolidated into an approximately 300-acre area(Consolidated Footprint) that will be constructed in the central portion of the ash pond using soil containment berms and with a final cover system. The purpose of this Package is to present engineering calculations to estimate the settlement of the subsurface soils as a result of the construction of the new soil containment berm (Containment Berm) along the perimeter of the Consolidated Footprint Specifically,this Package presents settlement calculations for points along the centerline alignment of Containment Berm to evaluate final elevations of its crest and to estimate the effects of settlement on pipes that will be installed in the Containment Berm for post-closure operations. The remainder of this Package is organized to present: (i) construction sequence and analysis scenario; (ii) design criteria; (iii) analysis methodology; (iv) subsurface stratigraphy design parameters; (v)results; and(vi) conclusions. All elevations presented in this package are based on North American Vertical Datum of 1988 (NAVD 88). CONSTRUCTION SEQUENCE AND ANALYSIS SCENARIO Constmction activities for the closure of the Plant Barry site involves the construction of a Containment Berm to define the boundary of the Consolidated footprint. The general construction sequence for the construction of the Containment Berm is summarized below: (i) excavation of existing CCR to the top of the uppermost native soils layer(i.e., Clay 1 as defined in the section titled Subsurface Stratigraphy and Design GW6392IWarieley_50Io Desip Containment Berm settlement Dmft.docx APC Barry_EPA_000289 Geosyntec° consultants Page 2 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Parameters section), starting from the existing perimeter dike and extending beyond the footprint of the proposed Containment Berm; (ii) construction of the Containment Berm in lifts up to crest elevation of approximately 21.5 ft; and (iii) backfilling of CCR cut slopes on the interior of the Containment Berm using excavated CCR from the Closure by Removal Area. The duration considered for settlement analysis is 45 years (analysis period), which includes 8 to 10 years for closure construction and 35 to 37 years of post-closure care. For the settlement computations, the entire Containment Berm is modeled as an instantaneously applied load on top of uppermost native soil layer. In addition to total settlement, time rate of settlement is considered to estimate the effects on pipe infrastructure placed along the Containment Berm. DESIGN CRITERIA The Containment Berm will consist of a network of pipes that are required during the post-closure period (Post Closure Pipes). These Post Closure pipe include a series of storm water culverts that will be installed perpendicular to the Containment Berm alignment.These stormwater culverts will be used to convey storm water from the interior final cover drainage channel to the storm water ponds located outside of the Consolidated Footprint. In addition,the Containment Berm will house a 4-in high-density polyethylene (HDPE)forcemain pipe of the internal drainage system which will convey water pumped from within the Consolidated footprint to the on-site water treatment system.As such,the design criteria adopted is intended to establish maximum settlements and tensile strains to ensure adequate performance of the Post Closure Pipes. The selected criteria are: maximum total settlement of storm water drainage culverts should not exceed 0.5- ft as a result of Containment Berm settlement; and tensile strains in the HDPE forcemain pipe do not exceed 3 percent. This allowable tensile strain is selected based on tensile strains at yield reported by several HDPE pipe manufacturers (e.g., ISCO) which range between 8 percent and 10 percent and considering a factor of safety of approximately 3.0. GW6392IWareley_50Io Desip Containment Berm settlement Dmft.docx APC Barry_EPA_000290 GeosyntecO consultants Page 3 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client APC/8C8 Project: Plant Barry Ash Pond Closure Project Project No: GW6489 ANALYSIS METHODOLOGY As discussed later under the section titled Subsurface Stratigraphy and Design Parameters, the foundation soils beneath the Containment Berm consist, from top to bottom, of: Clay 1, Sand 1, Clay 2 and Sand 2. Settlement of these soils were calculated using equations for elasticity theory and one-dimensional (1-D) consolidation theory [Holtz and Kovacs, 1981]. Settlements of the Containment Berm foundation soils are caused by the following mechanisms: • immediate settlement that occurs during construction; • primary consolidation due to the loads imposed by the new dike; and • secondary compression (long term, after primary consolidation is complete) resulting from the plastic realignment of the material structure (i.e., creep)under sustained loading. Immediate settlement occurs during construction and is relatively small compared to consolidation settlement for fine-grained soils,and thus was not calculated for the Clay l and Clay 2. However, settlement of the Sand 1 and Sand 2 layers was calculated considering immediate settlement only since settlement occurs only as the load is applied and primarily due to immediate distortion and compression of the material. The general description for elastic settlement, primary consolidation, and secondary compression settlements and the forms of the corresponding equations are provided in the following sections. Effective Vertical Stress Settlements of the subsurface materials were calculated for the increase in vertical effective stress caused by the construction of the Containment Berm(An',,).This increase in vertical effective stress is used to calculate the compressibility of the Containment Berm foundation soils. The increase in vertical effective stress due to the placement of Containment Berm(Ad,-,,)was calculated using Equation 1 below: Aac,d = HDike YWke (1) GW6392IWaris1ey_50°PoDesi,Containment Been Settlement Drnft.docx APC Barry_EPA_000291 Geosyntec° consultants Peg. d of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client APC/8C8 Project: Plant Barry Ash Pond Closure Project Project No: GW6489 where: Au"', = increase in vertical effective stress due to construction of Containment Berm(pounds per square foot[psf]); HDlke = design height of the Containment Berm (ft); and y1a, = unit weight of the Containment Berm (pcf). Immediate Settlement Immediate settlement,Si, occurs as the load is applied and is primarily due to distortion and compression within the material. The immediate settlement for the Sand 1 and Sand 2 layers was calculated using Equation 2 obtained from linear elastic theory [Qian et al., 2002]: Si = M°H (2) where: Si = immediate settlement(ft); Acl" = increase in vertical effective stress(psf); H = initial thickness of compressible layer(ft); and M = constrained modulus of material (psf). Primary Consolidation Settlement The primary consolidation settlement, Sp,is related to the increase in the effective vertical stress in the subsurface materials due to the loads imposed by the Containment Berm.The primary consolidation settlement was calculated using the equations below: Sp r= CreH log(M9Oa/yo°r9) for a'vo + Au', < a'p (3a) Sp = CrcH log\o,o)+CeEH log l ar�o pparal for or'vo :5Qp :5avo +4av (3b) GW6372 ansley_50°/e Desip Containment Berm Settlement Draft.doca APC Barry_EPA_000292 Geosynte& consultants Page 5 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client APC/8C8 Project: Plant Barry Ash Pond Closure Project Project No: GW6489 SP = Cc,H log(ar°a V°ar°) for c'„o = u'P (3c) where: Sp = primary consolidation settlement(ft); C" = modified recompression index; C., = modified compression index; H = initial thickness of compressible layer(ft); 6,,, = initial effective vertical stress at the mid-point of each soil layers (psf); and �P = preconsolidation pressure (pst). For Clayl and Clay 2 ,Equations 3a, 3b, and 3c depend on the state of consolidation(i.e., normal consolidated or overconsolidated) and the magnitude of increase in effective vertical stress. The excavation of the existing CCR during the construction of the Containment Berne will produce an overconsolidation effect in Clay 1 and Clay 2 layers due to the reduction in the effective vertical stress. Therefore, the preconsolidation pressure(a',)was calculated at each calculation point based on the initial effective stress and pre-overburden pressure (POP)provided for each native clay soil. These parameters are further discussed in the Data Package. The time required to reach the end of primary consolidation (df) was calculated using Equation 4: o lHdrl t1 = (4) e° where: it = time required to reach the end of primary consolidation settlement (years); Tr = dimensionless time factor (1.129 for 95 percent consolidation, GW6392IWareley_50Io Desip Containment Berm Settlement Dmft.docx APC Barry_EPA_000293 Geosyntec° consultants Page 6 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client APC/8C8 Project: Plant Barry Ash Pond Closure Project Project No: GW6489 which represents the end of primary consolidation in this Package); C = coefficient of consolidation (square feet per day [ft2/day]); and Ha, = longest drainage path of the consolidating layer(ft). In this Package, the Clay 1 and Clay 2 were modeled with double drainage (i.e., drains form the top and bottom, so the longest drainage path equals the half of the thickness of the native soils). The percent of consolidation(0 occurring at different times after the construction of the Containment Berm was calculated using Equations 5 and 6 below [Sivaram& Swamee, 1977]: T = tcy (5) urf (H/dr)2 U% _ 4 o L1 + /4T`2.8]-0.179 6 100 n ` `A n //1 ( ) where: t = time after the construction of the Containment Berm(years); T = dimensionless time factor; C„ = coefficient of consolidation(ft2/day); and Ha. = longest drainage path of the consolidating layer(ft). Secondary Compression Settlement The secondary compression settlement (S) is related to the plastic realignment of the material structure (i.e., skeleton) and is the result of sustained loading (i.e., time- dependent creep). The secondary compression settlement, Ss, was calculated using Equation 7 below: GW6372 ansley_50°/e Desip Containment Berm Settlement Dmft.docx APC Barry_EPA_00029t Geosyntec° consultants Page 7 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client APC/8C8 Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Ss = CacH log lt2) (7) where: S, = secondary compression settlement(ft); Co = modified secondary compression index (dimensionless); it = time required to reach the end of primary consolidation settlement (years); and t2 = time at which settlement due to secondary compression is computed(years). The time required to reach the end of primary consolidation (it) was calculated using Equation 4. t2 was established for the Containment Berm as 45 years as explained in section titled Construction Sequence and Analysis Scenario. Total Settlement The total settlement(S) for the Containment Berm was calculated using Equation 8: S = Si +SP +S, (8) Total settlements calculated for the end of the duration considered (S4syr) were used to estimate the final elevations and tensile strains in the Post Closure Pipes installed in the Containment Berm. The settlement of the Post Closure Pipes at each calculation point were computed using the equation below: Spipe= S45yrs-So. (9) Where: Spipe = total estimated settlement of the pipe after installation S45yr = total settlement of Containment Berm at the end of the analysis period of the proposed closure(i.e.,45 years); and GW6392IWareley_5M Desip Containment Berm settlement Dma.docx APC Barry_EPA_000295 Geosyntec° consultants Page 8 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Sew = total estimated settlement of Containment Berm at the time of installation of pipe (i.e., t.) To estimate the settlement at the time of pipe installation(tm),the primary consolidation settlement (Sp), calculated using Equation 3a, 3b, or 3c, was multiplied by the percent consolidation(0 computed using Equation 6. Tensile Strain in Forcemain Pipe As indicated in the Design Criteria section, the tensile strains in the forcemain pipe should not exceed a limiting value of 3.0 percent to ensure its proper functioning. The tensile strain in the HDPE forcemain pipe was calculated based on the calculated pipe settlement using Equation 10: Lf_L siv�tau tZ� FV/%) L L XLUO Where: e = tensile strain (%); Lt = length after settlement(ft); A = differential settlement between two calculation points calculated from the SPIPe in Equation 8 (ft); and L = Initial length of the pipe calculated as the distance between two calculation point stations. SUBSURFACE STRATIGRAPHY AND DESIGN PARAMETERS The subsurface stratigmphy, geotechnical parameters, and water table elevations are required for the settlement calculations. Subsurface Stratieraphy and Geotechnical Parameters The data used to develop the subsurface stratigmphy and the geotechnical parameters for the analyses presented in this Package were obtained from field and laboratory investigations performed at the Site. This data is presented in the Draft Material GW6372 ansley_50°/e Desip Containment Berm Settlement Dmft.docx APC Barry_EPA_000296 Geosynte& consultants Page 9 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Properties and Major Design Parameters package (Data Package) submitted as part of this detailed design [Geosyntec, 2018]. Based on the Data Package, the subsurface stratigraphy at the Site primarily consists, from top to bottom; of existing CCR, Clay 1, Sand 1, Clay 2 and Sand 2. Due the spatial variability in stress history and undrained shear strength parameters for subsurface units; especially for Clay 1 and Clay 2, the Site was divided into a total of 10 design reaches (Reaches 1,2A, 2B,2C, 3A, 3B, 3C, 4, 5A and 5B) with each reach having a unique set of material parameters. Discussion on the development of these reaches and associated design parameters are provided in Data Package. Under closure configuration construction, the existing CCR within the Consolidated Footprint will be excavated to construct the Containment Berm.A summary of the geotechnical design parameter values used to model the subsurface materials at the Site in this Package is presented in Table 1. Water Level Elevations Based on information provided in the Data Package [Geosyntec, 2018], there are two distinct water levels at the Site: (i)an upper,perched water level within the CCR and Clay 1 (referred to as Upper WL); and(ii) a potentiometric water level for the Sand 1, Clay 2, and Sand 2 layers generally corresponding to the pool level in the adjacent Mobile River (referred to as Lower WL). These water levels are considered in the analysis presented herein as follows: • the Upper WL was assumed to be at the top of the Clay 1 layer after excavating to the elevations of Containment Berm base and was used in the computation of pore pressure and effective stress for the and Clay 1 (i.e., the uppermost native soil in the subsurface stratigraphy). • the Lower WL was modeled to be at elevation 3 fit which represents the average pool elevation in the Mobile River. This water level is applied for the computation of the pore water pressure and effective stress of the sublayers Sand 1,Clay 2,and Sand 2. CROSS SECTION ANALYZED The location of cross section D-D'selected for analysis in this Package is shown on Figure 1. Cross section D-D'runs along the centerline of the Containment Berm at the perimeter of the Consolidated Footprint. The subsurface profiles and calculation points for cross GW6392IWareley_50Io Desip Containment Berm settlement Dmft.docx APC Barry_EPA_000297 Geosynte& consultants Peg. 18 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client APC/8C8 Project: Plant Barry Ash Pond Closure Project Project No: GW6489 section D-D'are shown in Figure 2. COMPUTATIONS The settlement calculations were performed by coding equations 1 through 8 into a Microsoft Excel® spreadsheet. The following steps were used to perform the settlement calculations presented earlier: 1. One cross section was selected for the settlement analyses of the Containment Berm(i.e., Section D-D�. 2. Calculation points were selected at key points along the cross section (e.g., significant changes in elevation of the Clay 1 surface,excavation grades or design reaches) or otherwise,approximately every 200 ft. 3. For each calculation point, the existing subsurface was discretized into sublayers with thicknesses of 5 ft. 4. The increase in vertical effective stress due to the placement of Containment Berm (Ao',-,d) was calculated at each calculation point by assuming 1-D loading and no stress attenuation with depth(Equation 1). 5. Immediate settlement (Sr), primary consolidation settlement (Sp), and secondary compression settlement (S,) of each sublayer was calculated using Equations 2 through 7. 6. Total settlements at each calculation point were calculated by summing the settlements (i.e., Si, SP, and S) for all sublayers (Equation 8). Calculations of settlement were computed for the total at 45 years. 7. The settlement of the Post Closure Pipes (SPiPe)was calculated by subtracting the total settlement at the end of analysis period(S45,,)minus the estimated settlement at the time of pipe installation(Srw).Figure 3 provides a sketch that illustrates the approach for calculating SPiPe. SPiPe was calculated assuming tins times of 2, 6 and 10 years(representing the end of closure construction period). Sd.was calculated based on the percentage of consolidation obtained using Equation 6 and the total settlement at the end of analysis period(S45,). 8. The calculated differential settlement and tensile strain between two calculation GW6392IWarieley_50Io Desip Containment Berm settlement Draft.docx APC Barry_EPA_000298 Geosyntec° consultants Peg. 11 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 points along the SPip.profiles were calculated and compared to the design criteria for the HDPE forcemain pipe. RESULTS Settlements were calculated using the methodology presented in this Package, as coded in Microsoft Excel® spreadsheets. The pre-settlement and post-settlement calculated elevations of the Containment Berm at the end of analysis period (i.e., 45 years) for calculation points along cross section D-D' are presented in Figure 4. Example calculations for cross section D-D'at station 1731 (Point 414)me provided in Attachment 1. Total Settlement The calculated total settlements for the surface cross section D-D' after 45 years are presented in Table 2. The calculated settlements of the surface range from 0.29 It (at station 8100) to 3.14 ft (at station 4784.13). The larger settlements generally occurred at calculation points with thicker native Clay 1 at reach 3A. Smaller settlements generally occurred at calculation points where Clay 1 and 2 are within reaches 4, 5A, and 5B. For the Post Closure Pipes installed in the Containment Berm, total settlement of pipe (SP,,e) was calculated assuming it. to be 2, 6, and 10 years are presented in Table 2. As shown in Table 2,the Spipe was estimated to be 1.21 ft, 0.52 and 0.22 ft for tins of 2, 6, 10 years,respectively. Tensile Strains in Forcemain Table 2 presents the computed tensile strains in the forcemain pipe based on post- settlement grades along cross section D-D'and assuming ti.at 2, 6, and 10 years. From Table 2, the tensile strain ranged from 0 to 4.36 percent for tine at 2 year; and from 0 to 1.67 percent for tme at 6 years; and from 0 to 0.41 percent for a.at 10 years. It should be noted that tensile strains computed at station 6935 were not considered in the previously stated ranges because it represents a virtual boundary of sudden transition between Clay 1 design reaches with significantly different compressibility parameters. In the field, it is anticipated that there will be a gradual transition in clay characteristics that will limit the development of excessive tensile strain in the forcemain pipe. GW6392IWarieley_5WIo Desip Containment Berm settlement Dmft.docx APC Barry_EPA_000299 Geosynte& consultants Peg. 12 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 SUMMARY AND CONCLUSIONS Settlement of the native soils due to the placement of the Containment Berm was calculated in this Package. Post-settlement grades of the Containment Berm were evaluated to estimate the final elevations of the post-closure pipes and the tensile strains within the forcemain to be installed along the alignment of the Containment Berm. Based on the settlement calculations presented in this Package the following conclusions are arrived: • For the storm water drainage culverts, it is recommended that they be installed 7 years after the construction of Containment Berm. This will result in an estimated Spoe of 0.41 ft(at station 6925)which is less than the limits specified in the design criteria(i.e., 0.5 ft); • the calculated tensile strains in the forcemain assuming line at or beyond 6 years meet the design criteria of 3 percent; therefore, it is recommended that the forcemain to be installed 6 years after the completion of Containment Berm construction. GW6392IWarieley_50Io Desip Containment Berm settlement Draft.doca APC Barry_EPA_000300 Geosyntec° consultants Page 13 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 REFERENCES Geosyntec. (2018). "Draft Material Properties and Major Design Parameters," Calculation package submitted to Southern Company and Alabama Power Company, Plant Barry Ash Pond Closure Project,August 2018. Holtz, R.D.,Kovacs, W.D., and Sheahan, T.C. (2011). "An Introduction to Geotechnical Engineering, 2nd Edition."Pearson, Upper Saddle River,N.J. ISCO Industries. High density plyethylene pipe typical physical properties. Relieved from: http://www.isco-pipe.com/workspace/uploads/typical-properties.pdf Qian, X., Koerner, R.M., and Gray, D.H. (2002). "Gemechnical Aspects of Landfill Design and Construction". Prentice-Hall Inc.,Upper Saddle River,N.J. Sivaram, B., and P. Swamee. (1977) "A Computational Method for Consolidation Coefficient"Soils and Foundations Journal, Vol. 17,No. 2,pp.48-52. GW6392IW Iey_50Io Desip Containment Berm settlement Draft.doca APC Barry_EPA_000301 Geosyntec° consultants Peg. 14 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 TABLES GW6392IWarieley_5WIo Uesip Containment Beem settlement Dmft.doca APC Barry_EPA_000302 Geosyntec° consultants Page 15 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client APC/SCS Project. Plant Barry Ash Pond Closure Project Project No: GW6489 Table 1. Geotechnical Design Parameters for Subsurface Materials Compressibility Parameters tt 4 Total Unit Pre Max Past Constrained OverBurden Modified Coefficient of Modulus Material Weight Pressure Modified Modified Isl (Pet) PUp sI (Psf) Compression Recompression Pressure s r 4 Secondary Consolidation, (Pat) Index,C. Index,C..tt> Compression c9 Index,C,.ft (cm'/min)ft Containment Berunt`t 115 - - - - - - - CoalCombustionResidual 92 - - CCR 0.10 O.Olpl 0.0015 Q6 - Reach 1 94 600 - 0.029 0.02901 Reach2A 92 1,100 - 0.32 0.03C> - Reach2B 97 1,100 - 032 203t3I Reach 3A/3B 95 0 - 0.26 0.0412t Clay 1 0.002 0.01 Reach 3C 100 200 - 0.26 0.040t - Reaoh4 105 2,100 - 0.18 0.01801 Reach 5A 105 1,200 - Reach 513 105 750 - 0.17 0.02G1 Sand l 120 - - - GW6372 ansley_5WIo Desip Containment Benn settlement D,nft.doc APC Bany_EPA_000303 Geosynte& consultants Page 16 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Table 1, continued Compressibility Parameters(1)(r) Total Unit Pre Max Past Constrained Material Weight Overburden Pressure,dP Modified Modified Modified Coefficient of Modulus, e Pressure, Secondary Consolidation M(psn (P f) POp(Psf)m (Psi) Compression Recompression Compression ,c. (cm'/min) Index,C„ Index,Ca Index,Cml'I (•) Reach 1 125 - Reach 2A 100 - 3,200 - Reach 2B 105 - d,.a - 0.14 0.014t3> 0.003 0.02 Clay 2 Reach 3A/3B 102 - a'w - Reach 3C 110 - 6,000 - Reach 4 108 - 4,000 - Reach 5A/5B Not Present Sand 2 - - - - _ _ 3,000,000 Notes: 1. pre-overburden pressure refers to the difference between the max past pressure(P'P)and in sim vertical effective stress(a',o)at pre-excavation conditions 2. modified re-compression index is obtained from laboratory consolidation data. 3. modified re-compression index is assumed 0.1 times the modified compression index. 4. the modified secondary compression index and coefficient of consolidation are obtained from laboratory testing. 5. the drained elastic modulus for sand was obtained from correlations with CPT data conducted at the site. 6. the Containment Berm is assumed in this analysis to be incompressible and is treated as a load on top of foundation soils GW6392IWansley_50Io Design Containment Benn settlement Dmft.docx APC Barry_EPA_000304 Geosynte& consultants Page 17 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Table 2. Calculated Total Settlements and Tensile Strain of the Surface for Cross Section D-D' Total Settlement Srm•forye.=2 `5rh.br q.,=6 Sro,6rta,=ID Temae Strainln Tensile Strainin Tensile Stralnin Stadon(R) after45years Ye. years Yeyrt Forcemm br G„ Forcemtln br 4.�= Fortemvo far q„= (ft) (e) (ft) (R) -2Yem 6yem 10yean 0 1.97 0.42 0.05 0.02 300 1.97 0.43 0.05 0.02 0.00 0.0000 0.0000 544 1.49 0.25 0.03 0.01 0.00 0.0000 0.0000 735 1.69 0.47 0.09 0.03 0.00 0.0000 0.0000 745 1.44 0.19 0.02 0.01 3.56 0.2606 0.0220 1035 1.85 0.26 a02 0.01 0.00 0.0000 0.0000 1046 2.03 1 0.45 0.06 0.02 1.48 0.0515 0.0035 1196 1.78 0.23 0.02 0.01 0.00 0.0000 0.0000 1206 1.87 0.31 0.03 0.01 0.36 0.0071 0.0004 1456 1.80 0.20 0.02 0.01 0.00 0.0000 0.0000 1469 1.90 0.30 0.03 0.01 0.21 0.0035 0.0002 1635 0.67 0.01 0.00 0.00 0.W 0.a" 0.0000 1645 0.69 0.01 0.00 0.00 0.00 0.0000 a0000 1731 0.65 0.01 0.00 0.00 0.00 0.0000 0.0000 1746 0.70 0.02 0.00 0.00 0.00 0.0000 0.0000 1940 0.77 0.04 0.00 0.00 0.00 0.0000 0.0000 1950 0.79 0.06 0.00 0.00 0.02 0.0001 0.0000 1992 0.93 0.16 0.02 0.01 0.00 0.0000 0.0000 2004 0.91 0.09 0.01 0.00 0.12 0.0023 0.0001 2200 0.97 0.11 0.01 0.00 0.00 0.0000 0.0000 2400 0.90 0.06 0.01 0.00 0.00 0.0000 0.0000 2544 0.94 0.12 0.01 0.00 0.00 0.0000 0.0000 2700 1.09 0.17 0.02 0.01 0,M 0.0000 0.0000 2836 1.17 0.25 0.04 0.01 0.00 0.0000 0.0000 2845 1.07 0.17 0.03 0.01 0.37 0.0052 0.0003 3000 0.98 0.10 0.01 0.00 0.00 0.a" 0.0000 3154 1.35 0." 0.01 0.00 0.00 0.0000 0.0000 3195 1.32 0.08 0.01 0.00 0.00 0.0000 0.0000 3225 1.34 a 08 0.01 0.00 OAO 0.0000 0.0000 GW6372/Wansley 50°/e I)esip Containment Berm settlement Dmft.docx APC Barry_EPA_000305 Geosynte& consultants Page 18 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Table 2. (Continued) Tota[Senlement Spipefor Bn,2 SPipefortin,6 Splpefordns=lo Tensae S6vaia Tamils Stminm Te.N&Stmiaia Stadon(ft) after45years Years years yearn Forcemainfortim ForcemvW 6rtwa ForcemaW br daa (ft) (a) (8) (a) =2 Years =6,. -10 yearn M) (%) (°G) 3246 1.20 0.03 0.00 0.00 0.01 0.0000 0.0000 3457 1.24 0.04 0.00 0.00 0.00 0.00o0 0.0000 3700 1.12 0.02 0.00 0.00 0.00 0.0000 0.0000 3974 1.37 0.15 0.01 0.00 0.00 0.moo 0.0000 38M 1.70 0.44 0.07 0.02 4.36 0.1690 0.0123 4200 1.87 0.61 0.14 0.04 0.00 0.0000 0.0000 4400 2.46 0.74 0.17 0.05 0.00 0.0000 0.0000 4774 IN 1.08 0.39 0.15 OAO 0.0000 0.moo 47M 3.14 1.19 0.48 0.19 0.62 0.4206 0.12M 5000 2.25 1.01 0.41 0.17 0.00 0.0000 0.0000 5300 0.97 0.39 0.16 0.07 0.00 0.0000 0.0000 5600 0.91 0.34 0.12 0.05 0.00 0.moo 0.0000 5974 0.86 0.31 0.10 0.03 OAO 0.0000 0.Woo 5984 0.87 0.30 0.09 0.03 0.00 0.0037 0.0008 6200 0.90 0.35 0.12 0.05 0.00 0.0000 0.0000 M13 2.34 1.04 0.36 0.13 0.00 0.moo 0.0000 6424 2.48 1.21 0.50 0.21 0.91 0.6220 0.1865 6600 2.48 1.18 0.48 0.20 0.00 0.0000 0.0000 6775 2.46 1.21 0.50 0.21 0.00 0.0000 0.0000 6785 2.44 1.20 0.50 0.21 0.00 0.Not 0.M02 6925 2.42 1.21 0.52 0.22 0.00 0.0000 0.Woo 6935 0.45 0.18 0.08 0.04 43.84 8.8637 1.6129 7200 0.45 0.19 0.10 0.05 0.00 0.0000 0.0000 7500 0.45 0.19 0.10 0.05 0.00 0.0000 0.0000 7600 0.48 0.22 0.13 0.08 0.00 0.0000 0.Woo 7800 0.37 0.08 0.01 0.00 0.00 0.0000 0.0000 7900 0.31 0.02 0.00 0.00 0.00 0.0000 0.0000 8100 0.29 0.01 0.00 0.00 0.00 0.0000 0.0000 8193 0.29 0.01 1 0.00 0.00 0.00 0.0000 0.Woo 8193 1 0.34 1 0.04 1 0.00 1 0.00 0.04 0.0005 0.0000 8400 0.36 0.06 0.01 0.00 0.00 OA000 0.0000 GW6372/Wamley 50°/e I)esip Containment Berm Settlement Dmft.docx APC Barry_EPA_000306 Geosyntec° consultants PaBc 19 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client. APC/SCS Project Plant Barry Ash Pond Closure Project Project No: GW6489 Table 2. (Continued) TOW Setnemen[ br Wr�3 lortim�6 S ' brlina Flo Temile Sn In Temae Shalnin Temik$M1alo io SPiPe SPiP PW Forcemaln krtlm Fomemlobr0m PortemYo brtlm Stolonoo aaer O5 m Vem Yeah Vean M (2) (b) lm -2 Years =6,m In years M (x) (%) 8602 0.35 0.05 0.01 0.00 0.00 0.0000 0.0000 8922 0.36 0O6 0.01 0.00 0.000 onom 0.0000 $932 0.34 0.04 0.00 0.00 0.008 0.0004 0.0000 9121 0.38 0.03 0.00 0.00 0.000 0.0000 0.0000 9131 0.38 0.04 0.00 0.00 0.01 0.0000 0.0001 9259 0.41 0.07 0.01 0.W 0.000 onom 0.0000 9600 0A1 0.07 0.01 0.00 0.000 0.0000 0.0000 9843 0.43 0.10 0.02 0.01 0.000 0.0000 0.0000 10016 0.44 0.10 0.02 0.01 0.00 0.0000 0.0000 10026 0.43 0.11 0.02 0 01 0.003 0.0013 0.0002 10200 0.41 0.09 0.02 0.01 0.000 0.0000 0.0000 10339 0.64 0.09 0.02 0.01 0.000 0.0000 0.0000 10349 0.61 0.09 0.02 0.01 0.02 0.0000 0.0000 10400 0.57 0.07 0.01 0.00 0.000 onow 0.0000 10617 0.38 0.06 0.01 0.W 0.000 0.0000 0.00W 10627 0.40 0.05 0.01 0.00 0.005 0.0003 0.0000 10719 0.45 0.09 0.02 0.00 0.00 0.0000 0.0000 10884 0.73 0.14 0.02 0.01 0.000 0.0000 0.0000 10894 0.75 0.15 0.03 0.01 0.014 0.0013 0.0001 lim 0.79 0.21 0.05 0.02 0000 0.0000 0.0000 11058 0.79 0.21 0.05 0.01 0.004 0.0018 0.0003 11165 1 0.85 1 0.29 0.10 1 0.04 0.000 0.0000 0.0000 11400 0.82 0.29 0.10 0.03 0.000 0.0000 0.0000 11485 2.25 109 0.43 0.17 0006 0.0010 0.0002 11495 2.03 0.84 0.25 0.08 3.013 1.6739 0.4124 11648 1.96 0.75 0.20 0.06 0.000 0.0000 0.0000 11658 1.89 0.66 0.15 0.05 0.388 0.1151 0.0158 11911 1.87 0.64 0.13 0.04 0000 0.0000 0.0000 11821 1.82 0.57 0.11 0.03 0.185 0.0347 0.0038 11900 1.89 0." 0.13 0.04 0.000 0.0000 0.0000 12000 2.17 0.76 0.17 0.05 0.000 0.0000 0.0000 GW6372AVa Iey_50°Po Desip Containment Beem Settlement Dmft.doc2 APC Barry_EPA_000307 Geosyntec° consultants Page 20 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client APC/SCS Project Plant Barry Ash Pond Closure Project Project No: GW6489 FIGURES GW6392INanaley_50°Po Desip Containment Berm Settlement Dmft.doc APC Barry_EPA_000308 Geosyntec° consultants Page 21 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client APC/SCS Project Plant Barry Ash Pond Closure Project Project No: GW6489 D' Figure 1. Plan View of Selected Cross Section D-D'Along the Soil Containment Berm GW6392AVan Il 50°/e Desip Containment Berm Senlemert Dmft.doc APC Barry_EPA_000309 Geosynte& consultants Page 22 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client. APC/SCS Project Plant Harry Ash Pond Closure Project Project No: GW6489 D Calullalipn PoM{TyPlral) 401 462 403 d d 1 b 4 3 4M 431 432 435 46 4A44d 441 ]0 60 50 40 m -- ---- - — - -- Fscavalion Grade -- --SOLI ntarr `Top of Existing CCR Tap p(Soll rnntainmenl Berm Bear O 0 Top ofCIWI .Top of Sano 1 _ Top Msore 2B EB - -'... sana2D �B -100 0 0.00 2b0 4.00 6.00 8 00 10-M 12.00 14�0 16.00 18w0 M-00 24.00 26w0 28-M M-00 32�0 34.00 3F 0 38.00 40 0 42-M 44.00 46M0 48-M M-00 52�0 54.00 56.00 58�M 60.00 DISTANCE(MET) Figure 2. Subsurface Stratigraphy and Calculation Points for Cross Section D'-D' GW6392/W=Is 50°/e Desip Containment Berm Settlement Dmft.docx AEC Barry_EPA_000310 Geosynte& consultants Page 23 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client. APC/SCS Project Plant Harry Ash Pond Chance Project Project No: GW6489 ly Calcalatnr Pard CTyni h mm a ] 52 4M 4A 45546 97vv 4fi0 41 46 4 ] 4 41 v4]4 Tl �v 2 4 a4 91 80 m 60 50 40 30 GR w10 .Excavation Gratle of mn lumen Top of Eaaln9 CTop MClay1 Top of Sol mantalnment Berm 2 F .. - --_ ------ CIaY1 Topof Send 10 m-20 _ Sand 2B - Tap of Santl 213 - Santl 1 IaV 2 Top of Clay 2 d0 50 EO _R� p8+Of3 6N00 &t+00 66-M 68+00 70+00 T-M 74+00 T6+00 76+00 W+00 82+00 04+00 85+00 80b 9000 92+00 94+00 96+00 98+00 10[+00 102+00 1M+M 106+00 108+00 110+00 112+09 114+00 116+f111 118+0 129+00 DISTANCE(FEET) Figure 2. (Continued) GW6392/Wana1ey 50°/e Desip Containment seem Settlement Dmft.docx APC Barry_EPA_000311 Geosyntec° consultants Page 24 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client. APC/SCS Projet: Plaut Barry Ash Pond Closure Project Project No: GW6489 Time 2 years 6years 10 years 45 years S,=2years S,,,,,,-6years %,,10 years e ........... ......_-------------------------------_-------------------------------- Sax_ } _ ._____..____.. S0. E _______ ________________________________ _________________________;____.S ________________________________.____...F___._____._ _ .___ _ _____________ after6years a ker2 ye ars akerl0Ya ._ ----------------------------------------{------------.---------. .{ ..................... Settlement due to the j construction of Containment Berm Figure 3. Conceptual Sketch of Settlement After Construction of the Soil Containment Berm GW6392/Wansley 50°/e Desip Containment Beem Senlement Dmft.doc APC Barry_EPA_000312 Geosyntec° consultants Page 25 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client. APC/SCS Projet: Plant Barry Ash Pond Closure Project Project No: GW6489 30 25 — 20 x 15 o tTop of Dike Pre-Settlement > 10 tTop of Dike Post-Settlement w Excavation Grade 5 0 -5 0 2000 4000 6000 8000 10000 12000 14000 Distance(ft) Figure 4. Calculated Pre-and Post-Settlement Elevations of the Containment Berm at the end of analysis period for Cross Section D-D' GW6392/W=Ia 50°/e Desip Containment Berm Senlement Dmft.doc APC Barry_EPA_000313 Geosyntec° consultants Page 26 of 28 CP: GJC Date: 0&77/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client APC/SCS Project Plant Barry Ash Pond Closure Project Project No: GW6489 ATTACHMENT EXAMPLE SETTLEMENT CALCULATION CROSS SECTION D-D'STATION 1731 (POINT 414) GW6392INanaley_50Io Desip Containment Berm Settlement Dmft.doc APC Barry_EPA_000314 Geosynte& consultants Page 27 of 28 CP: GJC Date: 08/27/18 APC: TYE Date: 08/27/18 CA: WMT Date: 08/27/18 Client. APC/SCS Project Plant Harry Ash Pond Chance Project Project No: GW6489 Cildlatlon POIM In u drdme[er HnMeMalbroHen 1I30.0.56 Result, Notts 1 Structural dike is treated as a load,it does not consolidate. Unitevei htm,61 Unit Weight of CCR,Ym(pd) 92 Unit Weight of Dike,Yei.(pd) 115 Unit Weight of Clay 1,Ye.a.(ped) 92 Unit Weight of Clay 2,Ye 2(lad) ISO Unit Weight of Sand 1,Yon.(Pd) 115 Unit Weight of Sand 2,YonO(Pd) 122 ExiWn Conditions FIMIConditions Summary of Settlements Thickness of Exirtin CCR X 213037 Thickness of the Dike(fit) 20.623 Total Prima Consolidation ft 0.4n o at bottom of CCR(Psf) 1950.55 da at bottom Of Dike(plf) I B71.65 Total Sewndary Compression(ft) 0,1122 Thickness of Clay I(ft) 4.6141 Total Elastic Settlement(ft) DOSS Thickness of Sand ft 100066 Elevation Top of Sand l(ft) 3.6II1 Thickness of Clay 2 ft 9.515 Elevation Top of Clay 2 -13,6192 Thickness of Sand ft 369663 Elevation Top of Sand 2(X) -23.1337 Elevation Perched WaterTable X 22.2032 Elevation WaterTable Sandl,Clay 2,Sand 2(X) 3 Clay I Prideary0ensolidation SeNement 5 SevendarwConnorassimiSettlerodntS, Rate of Consolidaion Wrtertabld t1 t2 Total omaininb Thi kado;0 Depthfcan Top pa:l4om Depth" Who Halt (Endof (Design SeMementof t N U Sp SeXlemeM ThiMesz MClayl CalrulMion layers Yang M Clay 1 Dike) C- Cm He paint F0.393 M (double) Primary) Ufe) Cm .1 Se clay1 X X d X (psf) k k k ITq (X) year (In on 4,61 5 92 0 232165 DR 0.0 4.6141 2?0205 143.959) 21L2485 68 1A6 2440 1.129 2.31 LOS 45 DOI DUST 0.461, Lm L13 0.99 039 Dm -0.19295 4.m 4.25 TOO 039 Dm - - - - - - 6.W &M TOO 0.39 O.w am am TOO 0.39 O.w 1010 U163 TOO 0.39 O.w 1200 1L76 TOO 0.39 O.w 14110 14.E TOO 0.39 O.w GW6372/Warish, 50a/e Deai:gn_Co minment Berm Settlement Dmft.docx APC Barry_EPA_000315 Geosynte& consultants Page 28 of 28 CP: GJC Date: 08/27/18 APC: TYE Daft: 08/27/18 CA: WMT Date: 08/27/18 Client. APC/SCS Project Plant Harry Ash Pond Chance Project Project No: GW6489 Sand 1 Elutie SeNamen%Se Thickness of Colsnralnad Thickness of Sandi Cal=:1nnlayen y Aw Modulus SXYn I-) Total Se Ihl (a) gall n f 1001 1 10.01 1 lls I 2MC8 1 237165 25CCCKO 1 0JUDO w a0W Clayz Poma Consolidation Settlement So Secondam Con nnakin Settlement Ss race of Consolidation wawrrable ceprh from El. tl aTobl Remaining Thlckneuof "no of Clay Aa,'arom Monte Wfor Xdr (Endof (Canlgn Settlenentof t N X SF Settlement ThlMess of Clay2 Calculation layers yens 2 blMe) Q. C. H. Point h ew a® of Sp Total Sp 4 M (amble) Mowry) hfe) Cm Total Ss Cl.r IN IXI (pa) (a) Ipol (ft) Oft) (pd) (pall (pal) (pall (pall (a) IXI (W/year (a) (M) (M) IXI (ft) year IXI IXI 9.52 5 100 16.618) 23ri.65 0.14 0.014 5 2.5 1193.007 M25.2% 02 3200 3004 0.0474 Calls 11.315 LU9 4.76 2.26 45 O.M 0.0371 0.1E 200 1.00 0.93 Ow 001 4.515 ).25)5 1489.075 2331.006 811 3200 3M 0.0375 4M 2.00 0.99 Om CA -0.205 600 3.00 0.99 One CA - - - - - - - 8.00 4.00 LOO One am 12.03 6110 LIIO am am 14.p2 ).W LW am am Sand2 antic Utaenem,Se o"n"Table aepfbfrom El. Thioknessof fttotop or Conabained Thlcknonsci S.W2 Caeulationlayen ys..p Sand e.e' Aar Modulus Sbein(d TM.15e fl X k d f fl 3697 36.81 0 1 26133) 1 31"86 2371. .3rKKKC0 OOOM05 am GW6372/Wansley 5o°/e Ueaip Containment Berm Seftlement Draft.do� APC Barry_EPA_000316 Z%L APPENDIX C I CLOSURE STABILITY ANALYSIS - SEISMIC APC Barry_EPA_000317 Geosyntec° Consultants CALCULATION PACKAGE COVER SHEET Client: Alabama Power Company& Project: Plant Barry Ash Pond Closure Project#: GW6489 Southem Company Services Project TITLE OF PACKAGE: DRAFT CLOSURE STABILITY ANALYSIS—SEISMIC t- CALCULATION PREPARED BY: Signature 27 August 2018 (Calculation Preparey CP) a. Name Clinton P.Carlson Date �a 6 ASSUMPTIONS&PROCEDURES Signaunc 27 August 2018 CHECKED BY: (Assumptions&Procedures Checker,APC) Name Sid Nadukura Date 3 Glenn J.Rix COMPUTATIONS CHECKED BY: Signanuc 27 August 2018 (Computation Checker,CC) Name M.Gizem Bozkurt Date BACK-CHECKED BY: Signature 27 August 2018 (Calculation Preparer,CP) U Name Clinton P.Carlson Date a m APPROVED BY: Signature 27 August 2018 a (Calculation Approver,CA) Name William Tanner Date REVISION HISTORY: NO. DESCRIPTION DATE CP APC CC CA A Draft Closure Design Calculation Package 08/27/2018 CPC SN/GJR NIGH WMT APC Barry_EPA_000318 Geosynte& consultants Page 1 of 37 CP: CPC Date: 08/27/18 APC: SN/GdR Date: 08/27/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 CLOSURE STABILITY ANALYSIS—SEISMIC PURPOSE This Draft Closure Stability Analysis — Seismic calculation package (Package) was prepared in support of the design to close the existing coal combustion residuals (CCR) ash pond at Alabama Power Company's (APC's) Plant Barry (Site), located in Bucks, Alabama. The ash pond will be closed using a"consolidate and cap-in-place" method whereby all CCR will be consolidated into an approximately 300-acre area (i.e., consolidated area) that will be constructed in the central portion of the ash pond using soil containment berms and a final cover system. The purpose of this Package is to present the earthquake hazard for the Site and engineering calculations to evaluate the effect of local Site conditions on expected earthquake shaking at the Site. Specifically, this Package presents: (i) the earthquake hazard for the Site; (ii) the dynamic properties (i.e., shear wave velocity profile and shear modulus reduction and damping curves) of the materials encountered at the Site;(iii)results of equivalent-linear seismic site response analyses for the proposed consolidated area (both existing and post-closure elevations) and the existing dikes and containment benns constructed during closure at the Site; and (iv) the estimated pseudostatic coefficients required for the seismic slope stability analysis of the consolidated area and dikes/containment berms and the seismic veneer stability analysis of the final cover system. The remainder of this Package is organized to present: (i) design criteria; (ii) analysis methodology; (iii)subsurface stmtigraphy and design parameters; (iv)computations; (v)results of analysis and calculations; and(vi) a summary. DESIGN CRITERIA The U.S. Environmental Protection Agency(USEPA) CCR Rule [2015] defines a seismic impact zone as "an area having a 2 percent or greater probability that the maximum expected horizontal acceleration, expressed as a percentage of the earth's gravitational pull (g), will exceed 0.IOg in 50 years." The USEPA CCR Rule at 40 CFR §257.63 requires that existing CCR surface impoundments located in seismic impact zones be designed such that all "structural components including liners, leachate collection and removal systems, and surface water control systems, are designed to resist the maximum horizontal acceleration in lithified earth material for the site." Based on the 2014 U.S. Geological Survey (USGS) seismic hazard maps [Petersen et al., 2014], the Site has a 2 percent probability of exceeding a maximum horizontal acceleration of 0.05g in 50 years and, for the purposes of this Package, is considered to be in a seismic impact zone. As a result, a site response analysis was performed to evaluate the seismic stability of the CCR impoundment based on ground motions from a seismic event with a 2 percent probability of GW"89MB _100%Desi,_Sriemic_DRAFT2 APC Barry_EPA_000319 Geosynte& consultants Page 2 of 37 CP: CPC Date: 08/27/18 APC: SN/GdR Date: 08/27/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 exceedance (PE) in 50 years (i.e., "probable earthquake within approximately 2,500 years") in accordance with the USEPA CCR Rule (Federal Register,Vol. 80,No. 74,p. 21316) [20151. The preamble to the CCR Rule [2015] states that the seismic design of existing CCR impoundments should be based on a"withstand without discharge" standard which they describe as requiring(Federal Register,Vol. 80,No. 74,p. 21366)"any new CCR unit located in a seismic impact zone to be designed to withstand seismic motion from a credible earthquake without damage to the foundation or to the structures that control leachate, surface drainage, or erosion." In other words, "the CCR unit must be able to withstand an expected earthquake without discharging waste or contaminants." The calculations presented in this Package address the "withstand without discharge" criterion by limiting displacements of the project structures to the tolerable displacements for municipal solid waste (MSR) landfills (Table 1) discussed in Kavazanjian [1999] and referenced in the preamble of the CCR Rule [2015]. A displacement of 0.5 feet(ft), or 15 centimeters (cm),was considered tolerable for the calculations presented in this Package. The selected tolerable displacement corresponds to typical allowable displacements for liner systems and is less than typical allowable displacements for cover systems as shown in Table 1. ANALYSIS METHODOLOGY Site Resoonse Analysis For the seismic site response analysis presented in this Package,the earthquake hazard for the Site was first evaluated and then ground motions representative of this hazard were propagated through site-specific profiles for the consolidated area and dikes/containment berms to obtain response spectra at the ground surface. The computer program Strata [Kottke and Rathje, 20081 was used to perform the site response analysis. Strata computes the dynamic site response of a one-dimensional soil column using linear wave propagation with strain-dependent dynamic soil properties. This is commonly referred to as the equivalent-linear analysis (EQL) method, which was first used in the computer program SHAKE [Schnabel et al., 1972; Idriss and Sun, 1992]. Strata computes the response for vertically propagating and horizontally polarized shear waves propagated through a site with horizontal layers. Strata performs EQL site response analysis in the frequency domain using time domain input motions or random vibration theory (RVT) methods and allows for randomization of the site properties. Randomization allows the user to perform Monte Carlo simulations to account for random variability in soil properties. Monte Carlo simulations estimate the response of the system GW"89MB _100%Desi,_Sriemic_DRAFT2 APC Barry_EPA_000320 Geosynte& consultants Page 3 of 37 CP: CPC Date: 08/27/18 APC: SN/GdR Date: 08/27/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 based on defined statistical distributions and computing the response for each set of input parameters. The response is computed for many realizations and is then used to estimate statistical properties of the system's response. For the analyses presented in this Package, the statistical properties were obtained from 150 realizations. Site response analysis is typically performed using a suite of firm rock acceleration time histories prescribed at the base of a soil column and propagated to the ground surface. However, a large number of input motions must be used to develop statistically stable estimates of the site response. An alternative is the RVT approach. In this approach,time domain input motions are not required; rather, a single input motion is specified as a Fourier amplitude spectrum (FAS), the FAS is propagated through the soil column using the equivalent-linear approach, and RVT is used to predict peak time domain estimates of motion (i.e., peak ground acceleration and spectral acceleration)at the ground surface. The FAS can be determined from the bedrock uniform hazard spectrum(UHS) [Kottke and Rathje, 2008; Rathje and Kottke, 2008]. Due to its stochastic nature, RVT analysis can provide median estimates of the site response with a single analysis and no time domain input motions. Therefore, RVT is a powerful tool for site response analyses to estimate the surface ground motion or amplification factors at a site [Kottke and Rathje, 2013]. For the seismic site response analyses presented in this Package, the RVT approach was used in lieu of selecting a suite of acceleration time histories. Pseudostatic Coefficient Calculations The approach suggested by Bray and Travasarou [2009] was used to estimate the pseudostatic coefficients(kn)for a tolerable displacement of 0.5 ft(i.e., 15 cm)through the following equations: a+f7l kh _— CXp a = 2.83 — 0.5661n So (2) 6 = a2 - 1.33fln(Da) + 1.10 - 3.041n So + 0.244[ln Sa]2 - 1.STs - 0.278(Mn, - 7) — E} for T,>0.05 sec (3) b = a2 — 1.33{ln(Da) + 0.22 — 3.04lnSa + 0.244[In Sa]2 — 1.5Ts — 0.278(MB, — 7) — e} for T<0.05 sec (4) where: T, = initial fundamental period of the sliding mass (seconds [sec]); GW"89/3emy_100%Desi,n_Sriemic_DR 172 APC Barry_EPA_000321 Geosynte& consultants Page 4 of 37 CP: CPC Date: 08/27/18 APC: SN/G4R Date: 08/27/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 S. = median surface spectral acceleration for 5 percent damping, at a period of 1.577,(units of gravitational acceleration constant[g]); Do = tolerable displacement= 15 cm; M. = moment magnitude of design earthquake; and 9 = normally distributed random variable with a mean of zero and standard deviation of 0.66. The design surface spectral accelerations calculated in this Package for profiles representative of the consolidated area and dikes/containment berms were used as input into Equations 1 through 4. For the calculations presented in this Package, a value of zero was used for the random variable (E) in order to calculate median values for the pseudostatic coefficients. The initial fundamental period was calculated using the following equation: Ta = C s (5) where: C = coefficient depending on the type of critical slip surface (i.e.,block-type or circular-type); H = height of sliding mass for observed critical slip surface (ft); and V = average shear wave velocity for the height of the sliding mass (feet per second [ft/sec]). Depending on the type of critical slip surfaces observed in the Draft Closure Slope Stability Analysis calculation package [Geosyntec,201 Sal the coefficient in Equation 5 was either set equal to 2.6 (for block-type slip surfaces) or 4.0 (for circular-type slip surfaces). For the seismic slope stability and seismic veneer stability of the consolidated area,the coefficient was set equal to 2.6. For the seismic slope stability of the dikes/containment berms,the coefficient was set equal to 2.6 for critical slip surfaces extending below the dikes/containment berms but was set equal to 4.0 for critical slip surfaces within the dikes/containment berms. SUBSURFACE STRATIGRAPHY AND DESIGN PARAMETERS Information required for the seismic site response analyses and pseudostatic coefficient calculations includes: a Earthquake hazard(i.e., input UHS and design earthquake); GW"89MB _100%Desi,_Sriemie_DR T2 APC Barry_EPA_000322 Geosynte& consultants Page 5 of 37 CP: CPC Date: 08/27/18 APC: SN/GdR Date: 08/27/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 • Representative subsurface stratigraphy of the consolidated area (both existing and post- closure elevations)and existing dikes and constructed containment berms; • Water table elevations for the representative profiles; • Unit weights of the different materials encountered at the Site; • Shear wave velocity profiles for the different representative profiles; and • Nonlinear properties (i.e., shear modulus reduction and damping curves) of the different materials encountered at the Site. Earthquake Hazard The earthquake hazard at the Site, defined by ground motions with 2 percent PE in 50 years (i.e., return period of approximately 2,500 years),was represented by a UHS.The approximate location of the Site is 33.0000 N and 81.0000 W. These coordinates were used to obtain the input UHS for the BC boundary (i.e., boundary between National Earthquake Hazard Reduction Program (NEHRP) site classes B and C with a mean shear wave velocity of 2,500 ft/sec) from the USGS hazard toot [2014]. Figure 1 shows the UHS obtained for the Site, which was used as input to the Strata models. The design earthquake moment magnitude (M)and source-to-site distance (R)were also selected from the USGS hazard tool [2014]. A design earthquake with a moment magnitude of 5.9 and source-to-site distance of 151 kilometers, which was obtained from the USGS deaggregation of the PGA with a 2 percent PE in 50 years (shown in Figure 2),was considered in this Package. The design earthquake corresponds to the mean earthquake event estimated by the deaggregation. The design earthquake moment magnitude was also used in the Draft Closure Stability Analysis — Liquefaction calculation package [Geosymec, 2018b]. Subsurface Stratieraohv The data used to develop the subsurface stratgmphy for the models were obtained from field and laboratory investigations performed at the Site. These data are presented in the Draft Material Properties and Major Design Parameters calculation package(Data Package) [Geosyntec,2018c]. Based on the data sources presented in the Data Package, the subsurface stratigraphy at the Site primarily consists of(from top to bottom) existing CCR, Clay 1, Sand 1, Clay 2, and Sand 2. For the "consolidate and cap-in-place" method, CCR will be dredged and placed on top of existing CCR to consolidate into an approximately 300-acre area within the central portion of the Site(i.e., consolidated area). Dikes currently exist at the Site, but containment berms will be constructed around the consolidated area during closure. Materials below the Sand 2 layer were not G W"89/Bamy_100%Desi,_Sriemic_DRAFT2 APC Barry_EPA_000323 Geosynte& consultants Page 6 of 37 CP: CPC Date: 08/27/18 APC: SN/G4R Date: 08/27/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 characterized during the field and laboratory investigations, so they were tensed "firm ground' and considered to extend to firm rock. Firm rock,which is generally used to represent the NEI-IRP BC boundary (i.e., material with a shear wave velocity greater than 2,500 ft/sec) for site response analyses, was not encountered during the field investigations performed at the Site. Therefore, a soil profile representative of expected conditions for the Gulf Coast was used to identify the depth to the top of finn rock and the thickness of the firm rock. Based on the profile from the Electrical Power Research Institute (EPRI) for the Waterford project [20141, the top of firm rock (i.e., BC boundary) was modeled at an elevation of-1,420 If mean sea level (ft-msl) and modeled to be approximately 2,560-ftthick. Cone penetration tests performed during the pre-design field investigation (PDCPT) [Geosyntec, 2018d] were used to develop the subsurface stratigraphy for the representative profiles. The locations of these tests are shown in Figure 3. In this Package, four PDCPT (i.e., PDCPT-09, -19, -33, and 43) were selected from across the Site and used to develop the subsurface stratigraphy for the representative profiles of the consolidated area and dikes/containment berms. Figure 4 shows the interpreted subsurface stratigraphy at these four PDCPT. The subsurface profiles were modeled as one-dimensional (1-D) columns in the analysis. Consolidated Area Two representative profiles were modeled for the consolidated area: (i)a profile representative of the existing elevations (which is also expected to represent the post-closure elevations around the perimeter of the consolidated area); and(ii) a profile representative of the post-closure elevations with additional CCR placed on top of the existing CCR. Figure 5 shows the profiles used to represent the existing and post-closure consolidated area. The existing profile for the consolidated area was modeled to have a surface elevation of 20 ft-msl with the existing CCR having a thickness of 20 ft. The thickness of the additional CCR placed on top of the existing CCR within the consolidated area will vary from 0 ft to approximately 50 ft Therefore, the additional CCR in the post-closure profile for the consolidated area was modeled using the average thickness of approximately 30 ft,resulting in a surface elevation of 50 ft-msl for the profile. In the post-closure consolidated area profile, the existing CCR was also modeled to have a thickness of 20 ft. The Clay 1, Sand 1, Clay 2, and Sand 2 layers in both profiles for the consolidated area were modeled with thicknesses of 10 ft, 10 ft, 10 ft, and 20 ft,respectively. Finn ground was modeled below the Sand 2 layer and extended to the top of the ft= rock (i.e., thickness of approximately 1,370 ft). The final cover system was not modeled because it is very thin (i.e., approximately 0.5 ft for the combined cover system of ClosureTurt®,prepared subgrade, and a geocomposite drainage layer). GW"89MB _100%Desi,_Sriemic_DR T2 APC Barry_EPA_000324 Geosynte& consultants Page 7 of 37 CP: CPC Date: 08/27/18 APC: SN/GdR Date: 08/27/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Dikes/Containment Berms Figure 6 shows the profile used to represent both the existing dikes and the containment berms that will be constructed around the consolidated area during closure. The heights of the existing dikes and containment berms that will be constructed vary across the Site. Therefore, the dikes/containment berms were modeled using the approximate average surface elevation of 20 ft- msl and average thickness of 20 ft. The Clay 1, Sand 1, Clay 2, and Sand 2 layers were modeled with thicknesses of 10 ft, 10 ft, 10 ft,and 20 ft,respectively. Firm ground was modeled below the Sand 2 layer and extended to the top of the firm rock(i.e.,thickness of approximately 1,370 ft). Water Table Elevations The water table within the existing CCR is approximately at or above the existing ground surface and must be lowered to provide a more stable working platform prior to construction of the CCR closure. During and immediately after construction of the CCR closure (i.e., post-closure), the water table within the existing CCR was considered to be 2 ft below the top of the existing CCR. For long-term conditions (i.e., many years after closure), the water table elevation within the existing CCR is expected to approach an elevation of approximately 3 ft-msl. The representative profiles for the consolidated area were conservatively modeled with the water table elevation for post-closure conditions in this Package. Prior to construction of the containment berms for the closure, the water table elevation will be drawn down to an elevation of approximately 0 ft-msl around the perimeter of the consolidated area. The water table elevation within the existing dikes is also considered to be at 0 ft-msl for the purposes of this Package. Therefore, the representative profile for the dikes/containment berms was modeled with a water table elevation of 0 ft-msl. Unit Weiahts As presented in the Data Package, the unit weights of the materials encountered across the Site vary [Geosyntec, 2018c]. To simplify the site response analyses, average total unit weights of 92, 100, 115, 105, and 120 pounds per cubic foot (pcf) were modeled for the existing CCR, Clay 1, Sand 1, Clay 2, and Sand 2, respectively. The dredged CCR will be compacted as it is placed on top of the existing CCR; thus, the compacted CCR was modeled with a total unit weight of 110 pcf. The dike/containment berm materials were modeled with a total unit weight of 120 pcf based on typical values observed in similar projects. The firm ground was considered to have a total unit weight of 130 pcf because it is encountered below the Sand 2 layer and expected to be denser. The total unit weight of the firm rock was modeled to be 161 pcf based on Frankel et at. [1996]. GW"89MB _100%Desi,_Sei nie_DRAFT2 APC Barry_EPA_000325 Geosynte& consultants Page 8 of 37 CP: CPC Date: 08/27/18 APC: SN/GdR Date: 08/27/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Shear Wave Velocity Profiles Shear wave velocities of the existing CCR and subsurface materials at the Site were estimated using cone tip resistances measured during the PDCPT and correlations presented in Robertson and Cabal [2015]. PDCPT-09, -19, -33, and -43 shown in Figure 3 were used to develop an idealized shear wave velocity profile for the existing CCR and subsurface materials encountered at the Site. Figure 7 shows the shear wave velocities for the existing CCR,Clay 1, Sand 1,Clay 2, and Sand 2 estimated from the four PDCPT considered. The shear wave velocity modeled for the existing CCR varies from 150 ft/sec at the surface to 250 ft/sec at the bottom. Clay 1,Sand 1,Clay 2, and Sand 2 were modeled to have shear wave velocities of 300 ft/sec, 600 ft/sec, 350 ft/sec,and 800 ft/sec, respectively. The shear wave velocities of the additional CCR placed on top of the existing CCR and the dike/containment benn materials were both modeled to be 1,000 ft/sec based on observed values for similar materials in similar projects. The shear wave velocity profile developed by EPRI for the Waterford project [EPRI, 20141 was used to represent the shear wave velocities expected for the firm ground and firm rock. The shear wave velocities for the finn ground and firm rock varied from 1,000 ft/sec to approximately 3,050 ft/sec and extended from the bottom of the Sand 2 layer to the elastic half-space.The elastic half-space was modeled to have a shear wave velocity of 9,200 ft/sec as recommended by Hashash et al. [2014]. Figures 8 and 9 show the shear wave velocity profiles modeled for the consolidated area(both existing and post- closure elevations) and the dikes/containment berms,respectively. Both the near-surface and deep shear wave velocity profiles are shown in Figures 8 and 9. During the construction of the CCR closure, the placement of additional CCR within the consolidated area will result in an increase in the vertical effective stresses. Therefore, the shear wave velocity profile modeled for the post-closure consolidated area shown in Figure 8 has been adjusted based on the equation below [Idriss and Boulanger, 20081: nw —�Vs-ald (6) av-am where: I'I_ = shear wave velocity adjusted for increase in vertical effective stress(ft/sec); Yaa = initial shear wave velocity(ft/sec); a',. = vertical effective stress after placement of additional CCR (pounds per square foot [psf]); and a', Wd = initial vertical effective stress (psf). G W"89/Beny_100%Desi,_Sriemie_DRAFT2 APC Barry_EPA_000326 Geosynte& consultants Page 9 of 37 CP: CPC Date: 08/27/18 APC: SN/GdR Date: 08/27/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 As noted previously, the shear wave velocity profile may be randomized in the site response analyses to account for random variability.The shear wave velocities are varied using a lognormal distribution. The lognormal standard deviation of the shear wave velocity for the materials was selected to be 0.35 for the analysis presented in this Package based on the recommendations documented on the ASCE 4-98 [ASCE,20001. Nonlinear Properties Nonlinear properties of subsurface materials are key inputs to the EQL site response analysis. The nonlinear material properties used for input are the shear modulus reduction (GIG„.) and hysteretic damping (D) curves, which are both a function of cyclic shear strain. Laboratory tests on soils encountered at the Site indicated that the Sand 1 and Sand 2 are generally non-plastic; thus, Sand 1 and Sand 2 were modeled using the shear modulus reduction and damping curves corresponding to a plasticity index of zero based on Vucefic and Dobry [1991]. The average plasticity indices for the Clay 1 and Clay 2 encountered at the Site are approximately 50 and 30 based on results from laboratory tests. Therefore, the Vucetic and Dobry [1991] models for plasticity indices of 50 and 30 were used to model the nonlinear properties for Clay 1 and Clay 2, respectively. The dike/containment berm materials are expected to have a slightly lower plasticity index than the Clay 2 material, so the Vucetic and Dobry[1991] curves for a plasticity index of 15 were used to model the nonlinear properties for the containment berm materials. In the absence of site-specific resonant column or cyclic triaxial test data, the existing and compacted CCR were modeled using the Vucetic and Dobry [1991] shear modulus reduction and damping curves corresponding to a plasticity index of zero (i.e., CCR is likely non-plastic). The firm ground and firm rock were modeled as linear materials to avoid over-damping [Silva et al., 19971. Implicit in the linear material is a purely elastic response(GIG, = 1)accompanied by hysteretic damping that remains constant with cyclic shear strain. For soil sites in the Central and Eastern United States with depths greater than 3,000 ft to encounter material with a shear wave velocity greater than 9,200 $/sec, the expected kappa value (K) of the site is approximately 0.04 seconds[EPRI,20131.The damping ratio(N)for the firm ground was estimated using the equations below [Liu et al., 19941: Q = ,'—r fo a dz (7) d = 21Q (8) where: K = kappa value=0.04 sec; GW"89MB _100%Desi,_Sriemie_DR T2 APC Barry_EPA_000327 Geosynte& consultants Page 10 of 37 CP: CPC Date: 08/27/18 APC: SN/GdR Date: 08/27/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Q = quality factor; H = thickness of each subsurface layer(ft); Ps = shear wave velocity of each subsurface layer(ft/sec); and T = damping ratio. Based on the expected kappa value and the idealized shear wave velocity profile for the firm ground, a damping ratio of 1.2 percent was used for the finn ground. A damping of 0.5 percent was used for the firm rock. Figures 10 through 13 respectively present the shear modulus reduction and damping curves used for: (i) the CCR(existing and compacted), Sand 1, and Sand 2; (ii) Clay 1; (iii) Clay 2; and (iv) the material for the existing containment berms and berms that will be constructed during closure. Given that site-specific resonant column or cyclic triaxial test results were not available to develop the shear modulus reduction and damping curves for the materials encountered at the Site, the nonlinear properties were stochastically randomized during the Monte Carlo simulations. A correlation coefficient of-0.5 was used in the randomization of the shear modulus reduction and damping curves. Figures 10 through 13 present the input shear modulus reduction and damping curves (i.e., the curves based on Vucetic and Dobry [1991]) and the median and plus and minus one standard deviation shear modulus reduction and damping curves resulting from the randomization process. COMPUTATIONS The representative seismic site response analysis models were excited by inputting the UHS (i.e., RVT method) at the top of firm rock (i.e., BC boundary). Stochastic variation of the shear wave velocity profiles and nonlinear properties was performed for 150 realizations. The results of the model excitation were monitored in the spectral domain(i.e., spectral accelerations at the surface of the models). For each representative profile (i.e., existing and post-closure consolidated area and dikes/containment berms), the median surface acceleration response spectra were computed. The surface acceleration response spectra were used with Equations 1 through 4 to estimate the horizontal pseudostatic coefficients for use in the seismic analyses. The surface acceleration response spectra were also used to calculate cyclic stress ratio profiles in the Draft Closure Stability Analysis—Liquefaction calculation package [Geosyntec, 2018b] to evaluate the potential for triggering of liquefaction within the subsurface materials for the design earthquake. Because randomization of the shear wave velocity profiles and nonlinear properties was considered for a large number of realizations(i.e., 150)in Monte Carlo simulations,the median surface acceleration response spectra were considered. GW"89MB _100%Desi,_Sriemic_DR T2 APC Barry_EPA_000328 Geosynte& consultants Page 11 of 37 CP: CPC Date: 08/27/18 APC: SN/GdR Date: 08/27/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 RESULTS OF ANALYSIS AND CALCULATIONS Site Response Analysis The calculated median surface acceleration response spectra for the profiles representative of the consolidated area (existing and post-closure elevations) are shown in Figure 14. Figure 15 shows the calculated median surface acceleration response spectrum for the dike/containment berm representative profile. The input UHS is shown in Figures 14 and 15 for comparison with the calculated surface acceleration response spectra. Figure 16 shows a comparison of the surface acceleration response spectra calculated for the representative profiles modeled in this Package (i.e.,existing and post-closure consolidated area and the dikes/containment berms). Consolidated Area The surface spectral accelerations calculated for the existing consolidated area are approximately 0.08g and 0.20g at spectral periods of 0.01 and 1 second, respectively. For the post-closure conditions of the consolidated area,the calculated surface spectral accelerations are approximately 0.04g and 0.1 Og at spectral periods of 0.01 and 1 second,respectively. Dikes/Containment Berms The surface spectral accelerations calculated for the existing dikes and the containment berms that will be constructed around the consolidated area are approximately 0.06g and 0.14g at spectral periods of 0.01 and 1 second, respectively. Pseudostatic Coefficients The surface acceleration response spectra computed for the profiles representative of the existing and post-closure consolidated area and dikes/containment berms were used as inputs in Equations 1 through 4 to calculate the pseudostatic coefficients. Figures 17 and 18 present the calculated pseudostatic coefficients for the consolidated area, existing and post-closure elevations, respectively, and Figure 19 presents the calculated pseudostatic coefficients for the dikes/containment berms as a function of the fundamental period of the sliding mass for a tolerable displacement of 0.5 ft. Consolidated Area Static slope stability analyses indicated that critical slip surfaces within the consolidated area were block-type and estimated to extend to the bottom of the Clay 1 layer,which corresponds to depths of approximately 30 ft below ground surface (bgs) for existing conditions and 80 ft bgs for post- closure conditions(see the Draft Closure Slope Stability Analysis calculation package [Geosyntec, 2018a]). The calculated average shear wave velocities for sliding masses within the consolidated GW"89MB _100%Desi,_Sriemie_DR T2 APC Barry_EPA_000329 Geosynte& consultants Page 12 of 37 CP: CPC Date: 08/27/18 APC: SN/G4R Date: 08/27/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 area with these depths are approximately 220 ft/sec for existing conditions and 430 ft/sec for post- closure conditions, which equate to fundamental periods of approximately 0.36 and 0.49 seconds, respectively. For a tolerable displacement of 0.5 ft, the pseudostatic coefficients estimated for the consolidated area for existing and post-closure conditions are approximately 0.02 and 0.01 as indicated on Figures 17 and 18,respectively. Therefore,the seismic slope stability analyses of the consolidated area conservatively consider a pseudostatic coefficient of 0.02. For seismic veneer stability of the final cover system,the sliding mass depth is very shallow; thus, the fundamental period is approximately zero seconds (approximated as 0.01 seconds). For a tolerable displacement of 0.5 ft and a block-type slip surface within the cover system, the pseudostatic coefficient estimated for the post-closure consolidated area(i.e.,with the final cover system in place)for a fundamental period of 0.01 seconds is less than 0.01, as shown in Figure 18. To be conservative, a pseudostatic coefficient of 0.01 is used in the seismic veneer stability analyses for the final cover system of the CCR closure. Dikes/Containment Berms Static slope stability analyses indicated that critical slip surfaces were estimated to have depths of approximately 30 ft for block-type slip surfaces extending below the dikes/benns and depths of approximately 20 ft for circular-type slip surfaces within the dikes/benns (see the Draft Closure Slope Stability Analysis calculation package [Geosyntec, 2018a]). The calculated average shear wave velocities for sliding masses extending below the dikes/berms and sliding masses within the dikes/herms are approximately 560 ft/sec and 1,000 ft/sec, respectively. The calculated fundamental periods for the sliding masses extending below the dikes/berms and sliding masses within the dikes/berms are approximately 0.14 to 0.08 seconds, respectively. For a tolerable displacement of 0.5 ft,the pseudostatic coefficient estimated for the containment berms for periods between 0.08 and 0.14 seconds is less than 0.01, as indicated by the shaded region in Figure 19. However, a pseudostatic coefficient of 0.01 is conservatively used in the seismic slope stability analyses for the dikes/containment berms. SUMMARY Seismic site response analyses were performed based on the USEPA CCR Rule [2015] seismic requirement for sites in seismic impact zones, which the Site is considered to be for the purposes of this Package,to evaluate the effects of earthquake ground motions with a 2 percent probability of exceedance in 50 years for the design of CCR surface impoundments and associated structural components. The UHS and the corresponding seismic event magnitude for firm rock (i.e., BC boundary) at the Site were calculated using the USGS hazard tool [USGS, 2014]. Soil profiles were developed using available site-specific data from in-situ testing to represent the existing and GW"89MB _100%Desi,_Sriemic_DRAFT2 APC Barry_EPA_000330 Geosynte& consultants Page 13 of 37 CP: CPC Date: 08/27/18 APC: SN/GdR Date: 08/27/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 post-closure consolidated area elevations and the dikes/containment berms. The shear wave velocities were modeled using estimated values from four in-situ PDCPT (i.e., PDCPT-09, -19, - 33, and-43)performed by Geosyntec at the Site [Geosyntec,2018d]. The nonlinear properties for the existing and compacted CCR,Clay 1, Sand 1,Clay 2,and Sand 2 and native soil were modeled based on site-specific test results for plasticity index. Soil profiles representative of expected conditions for the Gulf Coast and Central and Eastern United States [Frankel et al., 1996; EPRI, 2013;EPRI,2014; Hashash et al.,2014] were used to develop the stratigraphy,unit weights, shear wave velocity profiles, and damping ratios for the firm ground and firm rock. A one-dimensional EQL site response analysis in the frequency domain was performed using RVT for 150 Monte Carlo simulations as implemented in the computer program Strata. Pseudostatic coefficients were estimated for the consolidated area and the existing dikes and containment benns that will be constructed around the consolidated area as part of the closure, using the Bray and Travasarou [2009] method and the results from the site response analysis. Results from the seismic site response analyses are shown in Figures 14 through 16. Pseudostatic coefficients were estimated for the consolidated area and dikes/containment berms using results of the site response analyses and the Bray and Travasarou [2009] method presented in this Package. For the seismic slope stability analyses of the consolidated area (existing and post-closure elevations), considering a tolerable displacement of 0.5 ft, the estimated pseudostatic coefficient is 0.02.A pseudostatic coefficient of 0.01 is conservatively considered for use in the seismic slope stability analyses of the dikes/containment berms and the seismic veneer stability of the final cover system. The seismic stability analyses are presented in the Draft Closure Slope Stability Analysis calculation package [Geosyntec, 2018a]. The median surface acceleration response spectra computed for the representative profiles ofthe consolidated area and dikes/containment berms(see Figure 16) we also used in the calculations presented in the Draft Closure Stability Analysis — Liquefaction calculation packages [Geosyntec, 2018b]. REFERENCES ASCE. (2000)."Seismic Analysis of Safety-Related Nuclear Structures(4-98),"American Society of Civil Engineers, Reston, VA, 132 p. Bray,J. and Travasarou, T. (2009). "Pseudostatic Coefficient for Use in Simplified Seismic Slope Stability Evaluation," Journal of Geotechnical and Geoenvironmental Engineering, Vol. 135,No. 9,pp. 1336-1340. EPRI. (2013). "Seismic Evaluation Guidance: Screening, Prioritization and Implementation Details (SPID) for the Resolution of Fukushima Near-Tern Task Force Recommendation 2.1: Seismic,"Electric Power Research Institute,Palo Alto,CA,February. GW"89MB _100%Desi,_Sriemic_DR T2 APC Barry_EPA_000331 Geosynte& consultants Page 14 of 37 CP: CPC Date: 08/27/18 APC: SN/GdR Date: 08/27/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 EPRI. (2014). "Waterford Seismic Hazard and Screening Report," Electric Power Research Institute,Palo Alto, CA,February. Geosyntec. (2018a). "Draft Closure Slope Stability Analysis," calculation package submitted to Alabama Power Company and Southern Company Services,August 2018. Geosyntec. (2018b). "Draft Closure Stability Analysis — Liquefaction," calculation package submitted to Alabama Power Company and Southern Company Services, August 2018. Geosyntec. (2018c). "Draft Material Properties and Major Design Parameters," calculation package submitted to Alabama Power Company and Southern Company Services,August 2018. Geosymec. (2018d). "Draft Pre-Design Field Investigation Summary Report," submitted to Alabama Power Company, June 2018. Hashash, Y.M., Kottke, A.R., Stewart, J.P., Campbell, K.W., Kim, B., Moss, C., Nikolaou, S., Rathje, E.M., and Silva, W.J. (2014). "Reference Rock Site Condition for Central and Eastern North America," Bulletin of the Seismological Society of America,Vol. 104,No. 2, pp. 684-701. Idriss, I.M. and Sun, J.I. (1992). "SHAKE91: A Computer Program for Conducting Equivalent Linear Seismic Response Analyses of Horizontally Layered Soil Deposits," Center for Geotechnical Modelling, Department of Civil and Environmental Engineering, University of California, Davis, CA. Idriss, I.M. and Boulanger, R.W. (2008). "Soil Liquefaction During Earthquakes," Monograph MNO-12, Earthquake Engineering Research Institute, Oakland, CA. Kavazanjian,E. (1999). "Seismic Design of Solid Waste Containment Facilities,"Proceedings of the 8th Canadian Conference on Earthquake Engineering, Vancouver, BC, June, pp. 51- 89. Konke, A.R. and Rathje, E.M. (2008). "Technical Manual for Strata. PEER Report 2008/10," University of California, Berkeley,CA. Kottke,A.R.and Rathje,E.M. (2013)."Comparison of Time Series and Random-Vibration Theory Site-Response Methods,"Bulletin of the Seismological Society of America,Vol. 103,No. 3,pp. 2111-2127. GW"89MB _100%Desi,_Sei nie_DRAFT2 APC Barry_EPA_000332 Geosynte& consultants Page 15 of 37 CP: CPC Date: 08/27/18 APC: SN/GdR Date: 08/27/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Liu,Z.,Wuenscher,M.E.,and Herrmann,R.B.(1994)."Attenuation of Body Waves in the Central new Madrid Seismic Zone," Bulletin of the Seismological Society of America, Vol. 84, No. 4, pp. 1112-1122. Petersen, M.D., Moschetti,M.P.,Powers,P.M.,Mueller,C.S.,Haller,K.M.,Frankel,A.D.,Zeng, Y., Rezaeian, S., Hamisen, S.C., Boyd, O.S., Field, N., Chen, R., Rukstales, K.S., Luca, N., Wheeler, R.L.,Williams,R.A., and Olsen, A.H. (2014). "Documentation for the 2014 Update of the United States National Seismic Hazard Maps," U.S. Geological Survey Open-File Report 2014-1091, Reston,VA,243 p. Rathje, E.M. and Kottke, A.R. (2008). "Procedure for Random Vibration Theory Based Seismic Site Response Analyses," Geotechnical Engineering Report GR08-09, The University of Texas,Austin, TX. Robertson, P.K. and Cabal, K.L. (2015). "Guide to Cone Penetration Testing for Geotechnical Engineering," 6' ed., Gregg Drilling& Testing, Inc. Signal Hill, CA. Schnabel,P.B.,Lysmer,J. and Seed,H.B. (1972). "SHAKE:A Computer Program for Earthquake Response Analysis of Horizontally-Layered Sites,"Report No.EERC 72-12,University of California, Berkeley,CA. Silva,W.,Abrahamson,N.A.,Toro,G.R.,and Costamiino,C. (1997). "Description and Validation of the Stochastic Ground Motion Model," report submitted to the Engineering Research and Applications Division Department of Nuclear Energy, Pacific Engineering and Analysis, El Cerrito, CA. United States Environmental Protection Agency (USEPA). (2015). "40 CFR Parts 257 and 261: Hazardous and Solid Waste Management System; Disposal of Coal Combustion Residuals from Electric Utilities,"Federal Register,Vol. 80,No. 74. United States Geological Survey (USGS). (2014). "Dynamic: Conterminous U.S. 2014 (v4.1.1) Interactive Deaggregations,"<httns://earthuuake.usgs.goy/hazards/interactive/> Vucetic, M. and Dobry, R. (1991). "Effect of Soil Plasticity on Cyclic Response," Journal of Geotechnical Engineering,Vol. 117,No. 1,pp. 89-107. GW"89/Bamy_100%Desi,_Sriemic_DR T2 APC Barry_EPA_000333 Geosyntec° COBSUItantS Page 16 of 37 CP: CPC Date: 08/27/18 APQ SN/GJR Date: 08MAS CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 TABLES GW6389/Bevy 100%Design Seismic DR U APC Barry_EPA_0003M Geosyntec° consSultant8 Page 17 of 37 CP: CPC Date: 08/27/18 APQ SN/GJR Date: ORM/I8 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Proje Project No: GW6489 Table 1. Typical Tolerable Seismic Displacements for Municipal Solid Waste(MSW) Landfills [Kavazanjian, 1999] Allowable Calculated Component Displacement Comment Liner System ISO to 300 mm Actual expected deformation is very small. Cover System 300 nun to 1 an Damage is repaimblc Waste Mass Im For displacement not impacting cover or liner. Roadways,Embankments 1 m Conventional geotechnical criteria. Surface Water Controls 1 an Conventional geomchnical criteria. Gas Collection System No Limit Breakage common under normal operating conditions. GWW9nme, 100%Design Seismic_DRAFT2 APC Barry_EPA_000335 Geosyntec° conI ultBRts Page 18 of 37 CP: CPC Date: 08/27/18 APQ SN/GJR Date: 08MAS CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 FIGURES GW6489/Bevy 100%Design Seismic DR T2 APC Barry_EPA_000336 Geosyntec° Con3ultant3 Page 19 of 37 CP: CPC Date: 08/27/18 APQ SN/GJR Date: 0827/I8 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 0.12 0.10 g 0.08 m 0.06 U Q t� b 0.04 N C4 0.02 0.00 0.01 0.1 1 10 Period (see) Figure 1. Uniform Hazard Spectrum for a BC Boundary at the Site with a 2 Percent Probability of Exceedance in 50 Years (Obtained from USGS Hazard Tool [2014]) GW6389nx, 100%Design Seismic_DRAFT2 APC Barry_EPA_000337 Geosyntec° con3ultant3 Page 20 of 37 CP: CPC Date: 08/27/18 AFC: SN/GJR Date: 08MAS CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 ■6=(—..-2.5) e=62.5..-2) ■e=62..-1.5) '5S 1.5..a) e ❑6=61..-0.5) ❑e-60s..0) p �lJ b5 O o ee /SP ❑E=I0-0.5) ., � OeeO^�O 3Z'r 'fiOs� L]E=I05. 1) a0 yam• 9�.Ore �e=I1..1.5) • RPO/� ■e=I1.5..2) ..(2.5�e= 5) S . . ■e=[2.5 �1 l6 - sss rl%3zS � 65 PSt0 qe 1ci st a S ore ky b .tpa a/4�� aos b5ttaQc pS 94s n summary statisties for,Deaggregadon:Total Deaggregationtargein Rttovered taWe Totals M.(farallsourree) kNumrei.d:IM,S Retum Betled: 2R05678M Binned: 100% n151E6km .edenwnte: 0.OW4.4.1' Bueedenu Me:0A00396)3602 yr' Reswutl: O% m:593 R6Ggroundmotlon: 0.04B883212g rearn 2.M% me..O.11o Figure 2. Deaggregation of 2 Percent Probability of Exceedance in 50 Years Earthquake Event for Peak Ground Acceleration at a BC Boundary at the Site(Obtained from USGS Hazard Tool [20141) GW6389unrry 100%Design Seismic_DRAFT2 APC Barry_EPA_000338 Geosyntec° coreSultants Page 21 of 37 CP: CPC Date: 08/27/18 APQ SN/GJR Date: 08MAS CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure ProjeM Project No: GW6489 r-----------------------------T-----------------------------1 I 1 I I I I 1 I 1 / lI 77> 1 I I I n. p I ' rcm ea I — I { I 1 1 I I R 1 I I I I Y• I I I I I I I I I 1 I I I "^• I Figure 3. Locations of Cone Penetration Tests (CPT)Performed during the Pre-Design Field Investigation [Geosyntec, 2018d] Note: 'The circled PDCPT were used to develop the subsurface stratigraphy and idealized shear wave velocity profiles for the representative profiles presented in this Package. GW6489/Bevy 100%Design Seismic_DRAFT2 APC Barry_EPA_000339 Geosyntec° consultants Page 22 of 37 CP: CPC Date: 08/27/18 APQ SN/GJR Date: 0827/I8 CA: WMT Date: 0827/18 Client. APC/SCS Project: Plant Barry Ash Pond Closure Projett Project No: GW6489 PDCPT-09 PDCPT- 19 PDCPT-33 PDCPT-43 30 30 30 30 CCR Clay 1 Swd 1 20 20 20 20 10 10 10 10 0 0 0 0 -10 -10 -10 -10 > v w -20 -20 1 -20 -20 -30 -30 -30 -30 -40 -40 -40 40 -50 -50 -50 -50 Figure 4. Interpreted Subsurface Stratigraphy at PDCPT-09, -19, -33, and-43. GW6489/nan, 100%Design Seisn ic_DR U APC Barry_EPA_000340 Geosyntec° consultants Page 23 of 37 CP: CPC Date: 08/27/18 APQ SN/GJR Date: 08n7/I8 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Projett Project No: GW6489 100 100 50 50 Compacted CCR ;S.Il'Id g CCR Existing CCR 0 — 0 y 1 Clay 1 I Sand 1 ay 2 Sand 2 Sand 2 -50 -50 Firm Ground Firm Ground Firm Rock at Finn Rock at elevation -1,420f elevation -I,420ft -100 1 -100 Figure 5.Representative Profiles of the Consolidated Area for Existing(left) and Post- Closure(right) Elevations in the 1-D Equivalent-Linear Site Response Analysis Notes: 'The water table was modeled at the expected post-closure elevation of 18 ft-msl (indicated by the blue line). 'The firm ground was modeled with a thickness of approximately 1,370 ft and extended down to the firm rock. 'The firm rock was modeled with a thickness of approximately 2,560 ft. GWW9um, 100%Design Seismic_DRAFT2 APC Barry_EPA_ODOM1 Geosyntec° consultants Page 24 of 37 CP: CPC Date: 08/27/18 APQ SN/GJR Date: 08MAS CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 100 50 Containment a Berms a° O Clay 1 W Sand MIIIMMr- Clay 2 Sand 2 -50 Firm Ground Firm Rock a el evation-1, -100 Figure 6.Representative Profile for Dikes/Containment Berms in the 1-D Equivalent-Linear Site Response Analysis Notes: 'The water table was modeled at an elevation of 0 ft-msl (indicated by the blue line). 'The firm ground was modeled with a thickness of approximately 1,370 ft and extended down to the firm rock. 'The firm rock was modeled with a thickness of approximately 2,560 ft. GW6389/Bevy 100%Design S6,.ic_DRAFT2 APC Barry_EPA_000342 Geosyntec° Consultants Page 25 of 37 CP: CPC Date: 08/27/18 APQ SN/GJR Date: 0827/I8 CA: WMT Date: 0827/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 CCR Clay L Sand 1 Clay 2 Sand 2 30 30 30 30 30 .PDCPT-09 •PDCPP-09 .PDCPT-09 •Pf=P •PDCPr-09 a PDCPP-L9 •PDCPP-19 •PDCPT-19 •PDCPT-19 20 ♦PDCPP-33 20 .PDCPP-33 20 .PDCPT-33 20 aPDCPT 19 20 •PDCPT-33 •PDCPP-03 •PDCPPA3 •PDCPT-43 •PDCPT43 •PDCPT43 10 10 10 10 10 0 1� 0 0 0 0 n -10 -10 • -10 waft -10 -10 • S••.Pi•• •T� •M � i• . . -20 -zo -zo • e'�j -20 -zo 40 •• . •• .. - no 0 4 30 -30 -30 -30 -30 a� -00 -00 -40 -00 • • •8� 40 -50 -50 -50 -50 -50 0 200 400 600 800 1000 0 200 400 600 900 1000 0 200 400 600 800 1000 0 200 400 600 900 1000 0 200 400 600 800 1000 Shear Wave Velocity (B/sec) Shear Wa Velocity *sec) Shear Wave Velocity (#/see) Shear Warr Velocity tw/ ) Shear Wave Velocity (It/sec) Figure 7. Shear Wave Velocities Estimated for Materials Encountered at the Site based on Measurements at PDCPT-09, -19, -33, and-43 Notes: 'The locations of the PDCPT are shown in Figure 3. 'The interpreted subsurface stratigraphy for the PDCPT are shown in Figure 4. GW6489/nany 100%Deign Seisnuc_DRAFT2 APC Barry_EPA_000343 Geosyntec° consultants Page 26 of 37 CP: CPC Date: 08/27/18 APQ SN/GJR Date: 08MAS CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 500 100 —Existing ExisBng —Post-Closure —Post-Closure 0 -500 50 -1000 -1500 19 G .19 -2000 0 W 6� -2500 -3000 -50 -3500 -4000 -4500 -too 0 1000 2000 3000 4000 0 5D0 1000 1500 2D00 Shear Wave Velocity (ft/sec) Shear Wave Velocity (ft sec) Figure 8. Shear Wave Velocity Profiles Modeled for the Existing and Post-Closure Elevations of the Consolidated Area Notes: 'Figure 5 shows the corresponding models for these profiles. 'The figure on the right is zoomed in to show the shear wave velocities near the surface from the left figure. 'The shear wave velocity profile for post-closure has been corrected to account for the increase in overburden stress induced by the placement of additional CCR on top of the existing CCR. GWW9/11evy 100%Design Seismic DR U APC Barry_EPA_000344 Geosyntec° consultants Page 27 of 37 CP: CPC Date: 08/27/18 APQ SN/GJR Date: 08MAS CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 500 100 0 -500 50 -1000 1500 ba m G G b? -200D 0 B N -250D -3000 50 3500 ,000 -4500 -100 0 1000 2000 3000 4000 0 500 ID00 1500 20D0 Shear Wave Velocity ($lsec) Shear Wave Velocity (ftisec) Figure 9. Shear Wave Velocity Profile Modeled for the Dikes/Containment Berms Notes: 'Figure 6 shows the corresponding model for this profile. 'The figure on the right is zoomed in to show the shear wave velocities near the surface from the left figure. GW6389/13evy 100%Design S6smic_DRAFT2 APC Barry_EPA_000345 Geosyntec° consultants Page 28 of 37 CP: CPC Date: 08/27/18 APQ SN/GJR Date: 08MAS CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 e1.0 ........... —Input 7 —Median -0.8 +/- Standard Deviation a 0.6 d cC 0.4 0.2 `d y 0.0 0.0001 0.001 0.01 0.1 1 10 Shear Strain (0/o) 30 —input 25 —Median ----- +!- Standard Deviation 0 20 ------------- �" LS LO Ca 5 00001 0001 001 0.1 1 10 Shear Strain (c/a) Figure 10. Shear Modulus Reduction and Damping Curves for the Existing and Compacted CCR, Sand 1, and Sand Note: 'The input curves represent the shear modulus reduction and damping curves of Vucetic and Dobry [1991] corresponding to a plasticity index of zero, which were used to model the nonlinear properties of the existing and compacted CCR, Sand 1, and Sand 2. GW6389/Bevy 100%Design S6,.ic_DRAFT2 APC Barry_EPA_000346 Geosyntec° consultants Page 29 of 37 CP: CPC Date: 08/27/18 APQ SN/GJR Date: 08MAS CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 1.0 -------------��\ 0.8 a 0.6 d cC .gY 0.4 o —Input 0.2 —Median +/- Standard Deviation y 0.0 0.0001 0.001 0.01 0.1 1 10 Shear Strain (0/o) 30 —Input 25 —Median e +/- Standard Deviation 20 15 6 10 _ m Ca 5 ----------------- 0.0001 0.001 0.01 0.1 1 10 Shear Strain (%) Figure 11. Shear Modulus Reduction and Damping Curves for Clay 1 Note: 'The input curves represent the shear modulus reduction and damping curves of Vucetic and Dobry [1991] corresponding to a plasticity index of 50, which were used to model the nonlinear properties of Clay 1. GW6389/Eeny 100%Design Seismic_DRAFT2 APC Barry_EPA_000347 Geosyntec° consultants Page 30 of 37 CP: CPC Date: 08/27/18 APQ SN/GJR Date: ORM/I8 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 10 c7 CT 0 a c 0 a 0.6 v 04 a v —Input 42 —Median i7 ---- +.�- Standard Deviation 00 0.0001 0.001 0.01 0.1 1 10 Shear Strain (n/u) 34 —Input 25 —Median ----- +!- Standard Deviation 0 24 A �" LS 10 Ca _ 5 ---' ------------ 00001 0001 001 0.1 1 10 Shear Strain (c/a) Figure 12. Shear Modulus Reduction and Damping Curves for Clay 2 Note: 'The input curves represent the shear modulus reduction and damping curves of Vucetic and Dobry [1991] corresponding to a plasticity index of 30, which were used to model the nonlinear properties of Clay 2. GW6389um, 100%Design Seismic_DRAFT2 APC Barry_EPA_000348 Geosyntec° consultants Page 31 of 37 CP: CPC Date: 08/27/18 APQ SN/GJR Date: 08MAS CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 ^� 1.0 —Input E 90 —Median 0.8 —+/- Standard Deviation 0.6 d 0.4 0.2 `d y 0.0 0.0001 0.001 0.01 0.1 1 10 Shear Strain (0/o) 30 —Input 25 —Median e +/- Standard Deviation 20 15 6 10 Q 0 0.0001 0.001 O.OI 0.1 1 10 Shear Strain (%) Figure 13. Shear Modulus Reduction and Damping Curves for Dike/Containment Berm Materials Note: 'The input curves represent the shear modulus reduction and damping curves of Vucetic and Dobry [19911 corresponding to a plasticity index of 15, which were used to model the nonlinear properties of the existing dike and constructed containment berm materials. GW6389ue 100%Design S6,.ic_DRAFT2 APC Barry_EPA_000349 Geosyntec° Con3ultants Page 32 of 37 CP: CPC Date: 08/27/18 APQ SN/GJR Date: 08MAS CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 0.25 —Existing —Post-Closure 02 —Input UHS C 0.15 v U U 6 Q.1 U N h 0.05 0 0.01 0.1 1 10 Period (sec) Figure 14.Median Surface Acceleration Response Spectra Calculated for the Existing and Post-Closure Consolidated Area Representative Profiles Note: 'The input UHS represents the uniform hazard spectrum calculated for a seismic event with a 2 percent probability of exceedance in 50 years using the USGS hazard tool [USGS, 2014]. The UHS is used as input in the 1-D equivalent linear site response analyses. GW6389/Bart, 100%Design Seismic DR U APC Barry_EPA_000350 Geosyntec° Consultants Page 33 of 37 CP: CPC Date: 08/27/18 APQ SN/GJR Date: 08MAS CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 0.25 —Median 0.2 —Input UHS C 0.15 — U U 6 0.1 U N h 0.05 0 0.01 0.1 1 10 Period (sec) Figure 15. Median Surface Acceleration Response Spectrum Calculated for the Dikes/Containment Berms Representative Profile Note: 'The input UHS represents the uniform hazard spectrum calculated for a seismic event with a 2 percent probability of exceedance in 50 years using the USGS hazard tool [USGS, 2014]. The UHS is used as input in the 1-D equivalent linear site response analyses. GW6389nx, 100%Design Seismic DR U APC Barry_EPA_000351 Geosyntec° Consultants Page 34 of 37 CP: CPC Date: 08/27/18 APQ SN/GJR Date: 08MAS CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 0.25 —Existing Consolidated Area —Post-Closure Consolidated Area 0.2 — —Dikes/Containment Bemis —Input UHS 0.15 v U U Q 0.1 b N 0. 0.05 - 0 0.01 0.1 1 Period (sec) Figure 16. Design Surface Acceleration Response Spectra Calculated for the Consolidated Area(Existing and Post-Closure) and Dikes/Containment Berms Representative Profiles Notes: 'The input UHS represents the uniform hazard spectrum calculated for a seismic event with a 2 percent probability of exceedance in 50 years using the USGS hazard tool [USGS, 2014]. The UHS is used as input in the 1-D equivalent linear site response analyses. 'The calculated surface acceleration response spectra are used in this Package to calculate the pseudostatic coefficients and in the Draft Closure Stability Analysis-Liquefaction calculation package [Geosyntec,2018b]. GW6389ue 100%Design S6,.ic_DRAFT2 APC Barry_EPA_000352 Geosyntec° consultants Page 35 of 37 CP: CPC Date: 08/27/18 APQ SN/GJR Date: 0827/I8 CA: WAIT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Projett Project No: GW6489 Calculated Pseudostatic Seismic Coefficient 0.09 007 t x o ob d 005 0 u 0.04 e 003 0 9 002 a 0.01 0 001 01 1 Fundamental Period,T.=2.6EVV,(see) Figure 17. Estimated Pseudostatic Coefficients for the Existing Consolidated Area as a Function of the Fundamental Period of the Sliding Mass Notes: 'The pseudostatic coefficient is calculated using the median surface acceleration response spectrum for the existing consolidated area shown in Figure 16 and the Bray and Travasarou [2009] method. 'The fundamental periods for the critical slip surfaces are calculated using the height of the sliding mass for the predicted slip surface (F) from the static slope stability analyses and the equivalent shear wave velocity(V) corresponding to that height. 'For a fundamental period of approximately 0.36 seconds and a tolerable displacement of 0.5 ft,the estimated pseudostatic coefficient is approximately 0.02. GW6389ue 100%Design S6,.ic_DRAFT2 APC Barry_EPA_000353 Geosyntec° ConSldtants Page 36 of 37 CP: CPC Date: 08/27/18 APQ SN/GJR Date: 08MAS CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Calculated Pseudostatic Seismic Coefficient 0.08 0.07 Y e 0.06 m 0.05 d 0 U 0.04 u t a h 0.03 e 9 ao 0.02 m W 0.01 0 0.01 0.1 l Fundamental Period,T, =2.6H/V,(sec) Figure 18. Estimated Pseudostatic Coefficients for the Post-Closure Consolidated Area as a Function of the Fundamental Period of the Sliding Mass Notes: 'The pseudostatic coefficient is calculated using the median surface acceleration response spectrum for the post-closure consolidated area shown in Figure 16 and the Bray and Travasarou [2009] method. 'The fundamental periods for the critical slip surfaces are calculated using the height of the sliding mass for the predicted slip surface (H) from the static slope stability analyses and the equivalent shear wave velocity(V) corresponding to that height. 'For fundamental periods between 0.01 and 0.49 seconds and a tolerable displacement of 0.5 ft,the estimated pseudostatic coefficient is less than 0.01. GW6389/Bevy 100%Design S6,.ic_DR U APC Barry_EPA_000354 Geosyntec° consultants Page 37 of 37 CP: CPC Date: 08/27/18 APQ SN/GJR Date: 0827/I8 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Calculated Pseudostafic Seismic Coefficient 0.08 0.07 Y G 0.06 v 0.05 v 0 U 0.04 u L A y 0.03 e 9 v 0.02 m P. 0.01 0 0.01 0.1 1 Fundamental Period,T.=C*H/V,(see) Figure 19. Estimated Pseudostafic Coefficients for the Dikes/Containment Berms as a Function of the Fundamental Period of the Sliding Mass Notes: 'The pseudostatic coefficient is calculated using the median surface acceleration response spectrum for the dikes/ontainment berms shown in Figure 16 and the Bray and Travasarou [20091 method. 'The fundamental periods for the critical slip surfaces are calculated using the height of the sliding mass for the predicted slip surface (H) from the static slope stability analyses and the equivalent shear wave velocity(V) corresponding to that height. 'For fundamental periods between 0.08 and 0.14 seconds and a tolerable displacement of 0.5 fit, the estimated pseudostatic coefficient is less than 0.01. GW6489/Bevy 100%Design S6,.ic_DR U APC Barry_EPA_000355 Z%L APPENDIX C2 CLOSURE SLOPE STABILITY APC Barry_EPA_000356 Geosyntec° consultants CALCULATION PACKAGE COVER SHEET Client: Alabama Power Company & Project: Plant Barry Ash Pond Closure Project#: GW6489 Southern Company Services Project TITLE OF PACKAGE: DRAFT CLOSURE SLOPE STABILITY ANALYSIS CALCULATION PREPARED BY: Signature 27 August 2018 (Calculation Preparer,CP) Name Tamer Y.Elkady Date d ASSUMPTIONS&PROCEDURES Signature 27 August 2018 CHECKED BY: (Assumptions&Procedures Checker,APC) Name Lucas Cart Date 3 m S COMPUTATIONS CHECKED BY: Signatme 27 August 2018 (Computation Checker,CC) Name Daniel Woeste Date Y� BACK-CHECKED BY: Signamre 27 August 2018' 4 (Calculation Preparey CP) Name Tamer Y. Elkady Date APPROVED BY: Signature 27 August 2018 m (Calculation Approver,CA) Name Glenn J Rix Date REVISION HISTORY: NO. DESCRIPTION DATE CP APC CC CA A Draft Closure Design Calculation Package 8/27/2018 TYE LPC DW GJR APC Barry_EPA_000357 Geosyntec° consultants Page 1 of 30 CP: TYE Date: 08/27/18 APQ LPC Date: 8/27/2018 CA: GAR Date: 08/27/2018 Client: APC/SCS Project. Plant Barry Ash Pond Closure Project Project No: GW6489 DRAFT CLOSURE SLOPE STABILITY ANALYSIS PURPOSE This Draft Closure Slope Stability Analysis calculation package (Package) was prepared in support of the design to close the existing coal combustion residuals (CCR) ash pond at Alabama Power Company's (APC's) Plant Barry (Site), located in Bucks, Alabama. The ash pond will be closed using a"consolidate and cap-in-place"method whereby all CCR will be consolidated into an approximately 300-acre area (Consolidated Footprint) that will be constructed in the central portion of the ash pond using soil containment berms and with a final cover system. This Package presents engineering calculations to evaluate the long-term static and seismic slope stability of the existing perimeter dikes (existing dikes), south pond containment berm (South Containment Berm) and CCR stack under post-closure conditions. The slope stability under short-term (end-of-construction) static loading conditions will be addressed in the next design submittal of the Draft Interim Closure Slope Stability calculation package. The stability analyses of the final cover system are presented in the Draft Veneer Stability Analysis for Final Cover Design calculation package submitted as part of this detailed design [Geosyntec, 2018a]. The remainder of this Package is organized to present: (i) design criteria; (ii) analysis methodology; (iii) subsurface stratigrapby and design parameters; (iv)cross sections and cases analyzed; (v) analysis results; and(vi) conclusions. All elevations presented in this Package are based on North American Vertical Datum of 1988 (NAVD 88). DESIGN CRITERIA The closure design at Plant Barry will be performed in accordance with the provisions of the United States Environmental Protection Agency's (USEPA's) federal CCR Rule contained in 40 CFR§257 (and 40 CFR§261 by reference),as amended [USEPA, 2015; USEPA,2016]. The USEPA federal CCR Rule states that the CCR surface impoundment must meet the structural integrity criteria in 40 CFR 257.73(e)(i)-(iv),which are: GR6601MH DRAff Clos Slope Stability APC Barry_EPA_000358 Geosyntec° consultants Page 2 of 30 CP: TYE Date: 08/27/18 APQ LPC Date: 8/27/2018 CA: GAR Date: 08/27/2018 Client: APC/SCS Project. Plant Barry Ash Pond Closure Project Project No: GW6489 • The calculated static factor of safety (FS) under the long-term condition must equal or exceed 1.50; • The calculated static factor of safety under the maximum surcharge pool loading condition must equal or exceed 1.40; • The calculated seismic FS must equal or exceed 1.00; and • For dikes constructed of soils that may experience strength loss due to liquefaction, the calculated liquefaction (i.e., post-eartbquake) FS most equal or exceed 1.20. After closure,the Consolidated footprint will no longer retain a free water pool;therefore, analysis of the maximum surcharge pool loading condition is not required. From the calculation package titled Draft Closure Stability Analysis - Liquefaction submitted as part of this detailed design [Geosyntec 2018b], it was concluded that the materials in the CCR consolidated Footprint and dikes would not experience triggering of liquefaction under the design 2,500-year seismic event; therefore, the liquefaction (i.e., post- earthquake)FS was not evaluated. ANALYSIS METHODOLOGY Slope stability analyses were performed using Spencer's method of analysis [Spencer, 1973], as implemented in the computer program SLIDE, version 8.016 [Rocscience, 2018]. The SLIDE program generates potential slip surfaces, calculates the FS for each of these surfaces, and identifies the slip surface with the lowest FS (i.e., the critical slip surface). Non-circular, and block-type slip surfaces were analyzed in SLIDE. Searches for the critical slip surface in SLIDE were performed with the optimization feature enabled. SUBSURFACE STRATIGRAPHY AND DESIGN PARAMETERS Information required for the slope stability analyses includes: • slope geometry; • representative subsurface stmtigraphy of beneath the Site; GR6601MH DRAff Clos Slope Stability APC Barry_EPA_000359 Geosyntec° consultants Page 3 of 30 CP: TYE Date: 08/27/18 APQ LPC Date: 8/27/2018 CA: GAR Date: 08/27/2018 Client: APC/SCS Project. Plant Barry Ash Pond Closure Project Project No: GW6489 • unit weights and shear strengths of different subsurface units and different materials encountered at the Site; • water level elevations; and • the horizontal pseudostatic coefficient(for seismic slope stability only). Subsurface Stratieraohv and Geotechnical Parameters The data used to develop the subsurface stratigraphy and derive the geotechnical parameters were obtained from field and laboratory investigations at the Site. These data are presented in the Draft Material Properties and Major Design Parameters package (Data Package) submitted with this detailed design [Geosyntec, 2018c]. Based on the Data Package, the subsurface stratigraphy at the Site primarily consists of five units; existing CCR, Clay 1, Sand 1, Clay 2, and Sand 2. Due the spatial variability in stress history and undrained shear strength parameters for subsurface units; especially for Clay 1 and Clay 2, the Site was divided into 10 design reaches (Reaches 1, 2A, 2B, 2C, 3A, 3B, 3C, 4, 5A and 5B) with each reach having a distinct set of material parameters. Discussion on the development of these reaches and associated design parameters are provided in Data Package. Tables 1 through 3 provide a summary of design reach parameters considered for long- term static and seismic slope stability analyses. Drained shear strength parameters were used for all materials in the long-term, static slope stability analyses (Table 1). The analyses under seismic conditions were conducted assuming Clay 1 and Clay 2 exhibit undrained shear strengths (Sa) expected under the consolidated post-closure configuration due to the construction of the Consolidated Footprint and CCR removal from the southern portion of the site(Closure by Removal Area). As such,the undrained shear strengths under post-closure conditions were estimated using the SHANSEP model in which the anticipated future vertical effective stress and overconsolidation ratio(OCR) me considered. For the purpose of modelling the undrained shear strength in SLIDE, discretized profiles for the variation of So of Clay 1 versus elevation were computed for different locations along the analysis cross sections and input into SLIDE utilizing the discrete function strength type. Values of S. between profiles were interpolated. CCR (existing and placed)were considered drained because the majority of the CCR material will be above the elevation of steady-state water level in the Consolidated Footprint under post closure conditions (i.e., El. 3 ft). For Sand 1 and Sand 2, the computed factor of GR6601iHany_DRAff Clos Slope Stability APC Barry_EPA_000360 Geosyntec"' consultants Page 4 U 30 CP: TYE Date: 08/27/18 APQ LPC Date: 8/27/2018 CA: GAR Date: 08/27/2018 Client: APC/SCS Project. Plant Barry Ash Pond Closure Project Project No: GW6489 safety against liquefaction exceeds 1.10 (as presented in the Draft Closure Stability Analysis — Liquefaction; [Geosyntec, 2018b]); therefore, drained shear strengths were assigned to these materials. The existing dike soils vary from cohesive(clayey and silt) to cohesionless (sand). Therefore, the existing dike may behave in either a drained or undrained manner during seismic loading.Seismic slope stability analyses for the existing dike were evaluated considering both drained and undrained soil behavior of the dike soils; and the lower factor of safety from the two soil behaviors was reported. In addition to the soil units discussed in the Data Package,the final cover system materials are also considered in the analyses. The final cover detail comprises of a ClosureTurlg cover system underlain by a 0.5-ft thick layer of compacted subgmde soil. Therefore,the final cover system was modeled to be 0.5-ft thick with weight of 120 pef and an internal friction angle of 30 degrees with no cohesion. Water Level Elevations The existing water level elevations at the Site is provided in the Data Package submitted as part of this detailed design [Geosyntec, 2018c]. The Data package identifies two distinct water levels at the Site: (i)an upper,perched water level within the CCR and Clay 1 (referred to as Upper WL)located at a depth between 3 feet above and 3 feet below top of existing CCR; and(ii) a potentiometric water level for the Sand 1, Clay 2, and Sand 2 layers generally corresponding to the pool level in the adjacent Mobile River(referred to as Lower WL). During post-closure, it is expected that the Upper WL elevations will be altered while the Lower WL will remain unaltered. Under post-closure conditions, the Upper WL in the Consolidated Footprint is anticipated to drop to a steady-state elevation of 3 ft because of the encapsulation of the CCR material and operation of the internal drainage system. Furthermore, the water level in the Closure by Removal Area is expected to be at elevation 6 ft MSL which corresponds to the invert elevation of the outfall structure located at the south end of the Site. In summary, the water levels considered in the stability analyses under long-term static and seismic conditions are as follows: • The water level for CCR and Clay 1 within the Consolidated Footprint is modeled at elevation 3 ft. • Water level for Clay 1 in the Closure by Removal Area is modeled at elevation 6 ft GR6601MH DRAff Closure Slope Stability APC Barry_EPA_000361 Geosyntec° consultants Page 5 of 30 CP: TYE Date: 08/27/18 APQ LPC Date: 8/27/2018 CA: GAR Date: 08/27/2018 Client: APC/SCS Project. Plant Barry Ash Pond Closure Project Project No: GW6489 • For the stability of the existing dikes, water elevations in Mobile River and the discharge canal (located along the western boundary of the Site) are modeled at the normal pool elevation of 3 ft. • The Lower WL for Sand 1, Clay 2 and Sand 2 layers is modeled at elevation 3 ft corresponding to the normal pool elevation in Mobile River to which these layers are assumed to be hydraulically connected. Horizontal Pseudostatic Coefficients The estimation of horizontal pseudostatic coefficients for the seismic slope stability analyses is presented in the Draft Closure Stability Analysis — Seismic calculation package submitted as part of this detailed design [Geosyntec, 2018d]. A horizontal pseudostatic coefficient of 0.01 was used for local slip surfaces passing through the existing dikes and soil containment berms and 0.02 for global slip surfaces passing through the CCR and underlying foundations soil. CROSS SECTIONS AND CASES ANALYZED Five cross sections(A-A',B-B',C-C',D-D',and E-E')were selected for performing long- term static and seismic slope stability analyses. The locations of the selected cross sections superimposed on the proposed grading plan of the Consolidated Footprint and design reaches are shown on Figure 1. Figure 2 also shows the location of the selected cross sections on isopachs for Clay 1 thickness. The modeled geometries of the selected cross sections, including water level conditions are presented on Figures 3 through 7. Cross sections A-A', D-D', and E-E' were used to evaluate the stability of the existing dikes under post-closure configuration. Cross sections A-A' (Figure 3) represents the configuration of the existing dike along the western boundary of the Consolidated Footprint. Cross section D-IY (Figure 6)represents the configuration of the existing dike in the Closure by Removal Area. Cross section E-E' (Figure 7) represents the configuration of existing dike in the laydown area located in the northwest corner of the Site. Cross section B-B' (Figure 4) trends in an approximate north-south direction passing through the peak elevation of the Consolidated Footprint and through the South Berm. This section is considered critical because it one of the longest slopes of the final cover GR6601iHany_DRAff Clos Slope Stability APC Barry_EPA_000362 Geosyntec° consultants Page 6 of 30 CP: TYE Date: 08/27/18 APQ LPC Date: 8/27/2018 CA: GAR Date: 08/27/2018 Client: APC/SCS Project. Plant Barry Ash Pond Closure Project Project No: GW6489 system and cuts through Reach 3A,which has the lowest design undrained shear strength (Table 3). The section was used to assess the stability of the South Berm and the CCR Stack in the Consolidated Footprint. Cross section C-C' (Figure 5) is a section that passes through the existing dike and Soil Containment Berm on the eastern boundary of the Consolidated Footprint. This cross section was selected to evaluate the stability of the existing dike and the Soil Containment Berm because it represents a section where Clay I has the greatest thickness in the Consolidated Footprint and has the lowest design shear strength along the eastern boundary of the Consolidated Footprint(Reach 4). Additional rationale for the selection of the five cross sections is provided in Table 4 together with information on main characteristics of each cross section. For each cross section,the following potential slip surfaces were considered for the long- term static and seismic slope stability analyses performed: • local slip surfaces passing only through the existing dike/South Berm materials; • local slip surfaces passing through the existing dike/South Berm and underlying foundation soils; • shallow slip surfaces passing through the CCR(placed and existing CCR); and • global Slip surfaces passing through the existing CCR and underlying foundation soils(placed and existing CCR). ANALYSIS RESULTS A summary of calculated FS for critical slip surfaces evaluated for long-term static and seismic slope stability analyses is presented in Table 5. Slope stability results are provided in accompanying figures Cross Sections A-A'C-C D-D', and E-E' (existing dikes) The calculated critical slip surfaces for the long-term, static and seismic slope stability analyses for sections A-A', C-C,D-IY, and E-E' are shown in Figures 8 and 12 through 17, respectively. For the potential slip surfaces considered in this analysis, the minimum calculated FS under long-term,static conditions ranges between 1.52(Section A-A')and 2.10 GR6601MH DRArr Clos Slope Stability APC Barry_EPA_000363 Geosyntec° consultants Page 7 U 30 CP: TYE Date: 08/27/18 APQ LPC Date: 8/27/2018 CA: GAR Date: 08/27/2018 Client: APC/SCS Project. Plant Barry Ash Pond Closure Project Project No: GW6489 (Section D-D').The critical slip surface with the lowest calculated FS(i.e., 1.52)is observed to pass through the existing dike only.For seismic stability analyses,the minimum FS values computed assuming the existing dike behaves as drained material were lower than those assuming the existing dike to behave as undrained material. The calculated minimum FS (assuming drained conditions for existing dike material)ranged between 1.19(Section E-E') and 1.91 (Section C-C) for a slip surface passing through the existing dike and underlying soils Cross Section C-C' (Soil Containment Berm) Section C-C' was also used to evaluate the long-term and seismic stability of the Soil Containment Berm. The calculated slip surfaces and minimum FS conditions are presented in Figure 12 and 13. The calculated minimum FS values were 2.14 and 2.49 under long-term static and seismic conditions,respectively. Cross Section B-B' (South Berm and CCR Stack) For the South Berm,the minimum calculated FS under long-term static conditions is 1.69 for a critical sip surface that passes through the South Berm only as shown in Figure 10. Figure 10 also presents the potential slip surfaces through the CCR with calculated FS values of 13.93 and 14.62 for shallow and deep slip surfaces,respectively. The calculated critical slip surfaces for seismic slope stability analyses are shown in Figure 11. The minimum calculated FS ranged between 1.17 (for critical slip surface passing through South Berm and underlying foundation soil) and 4.50 (for critical slip surface passing through the CCR and underlying foundation soil). CONCLUSIONS Long-term static and seismic slope stability analyses were performed on five critical cross sections located at existing dikes and the South Berm. Each cross section was analyzed for long-term static conditions using drained shear strength properties and seismic (pseudostatic) conditions using undrained shear strength properties for native clay soils and drained shear strengths for CCR(placed and existing)and native sand soils. The FS for each condition analyzed was calculated using the computer program SLIDE. Based on the analysis results, the calculated FS values for all cross sections meet or exceed the minimum required FS under both static and seismic conditions. GR6601IBury_DRAff Ctos Slope Stability APC Barry_EPA_0003&t Geosyntec° consultants Page 8 of 30 CP: TYE Date: 08/27/18 APQ LPC Date: 8/27/2018 CA: GAR Date: 08/27/2018 Client: APC/SCS Project. Plant Barry Ash Pond Closure Project Project No: GW6489 REFERENCES Geosyntec (2018a). "Draft Veneer Stability Analysis for Final Cover Design." Prepared for Southern Company. August 2018. Geosyntee (2018b). "Draft Closure Stability Analysis - Liquefaction." Prepared for Southern Company. August 2018. Geosyntec(2018c)."Draft Material Properties and Major Design Parameters."Prepared for Southern Company. August 2018. Geosyntec (2018d). "Draft Closure Stability Analysis—Seismic."Prepared for Southern Company. July 2018. Rocscience. (2018). "SLIDE v8,"Rocscience, Inc. Toronto,Ontario, July. Spencer, E. (1973). "Thrust Line Criterion in Embankment Stability Analysis," Gdotechnique,Vol. 23(l),pp. 85-100. United States Environmental Protection Agency (USEPA) (2015). Code of Federal Regulations (CFR) Title 40, Parts 257 and 261, Hazards and Solid Waste Management System; Disposal of Coal Combustion Residuals from Electric Utilities; Final Rule. United States Environmental Protection Agency (USEPA) (2016). Code of Federal Regulations (CFR) Title 40, Part 257 Hazardous and Solid Waste Management System:Disposal of Coal Combustion Residuals from Electric Utilities;Extension of Compliance Deadlines for Certain Inactive Surface Impoundments; Response to Partial Vacatur. GR6601MH DRAff Ctos Slope Stability APC Barry_EPA_000365 Geosyntec° consultants Page 9 of 30 CP: TYE Date: 08/27/18 APQ LPC Date: 8/27/2018 CA: GAR Date: 08/27/2018 Client: APC/SCS Project. Plant Barry Ash Pond Closure Project Project No: GW6489 TABLES GM60IMH DRAff Clos Slope Stability APC Barry_EPA_000366 Geosyntec° consultants Page la of 30 CP: TYE Date: 08/27/18 APC: LPC Date: 8/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Table 1. Summary of Material Properties Used in Slope Stability Analyses for Long-term (Drained)Analysis Drained Shear Strength Unit Weight,yt Friction Angle, Cohesion,c' Material (pcQ (deg) (psf) Existing CCR 92 36 0 Compacted CCR 97 36 0 Clay 1 See Table 3' 31 75 Sand 1 See Table 3' 35 0 Clay 2 See Table 3' 31 75 Sand 120 38 0 Existing Dike 120 32 0 Soil Containment Berm 115 27 50 Notes: 'Design unit weights for Clay 1,Said 1,and Clay 2 vary by design reach.The design unit weights for these materials me listed in Table 3. GR6601/13 ry DRAPf Closure Slope Stability APC Barry_EPA_000367 Geosyntec° consultants Page 11 of 30 CP: TYE Date: 08/27/18 APC: LPC Date: 8/27/2018 CA: Gin Date: 08/27/2018 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Table 2 Summary of Shear Strength Parameters Used in Slope Stability Analyses Under Seismic Condition Material Undrained Strength Parameters Existing CCR Fully Drained' Compacted CCR Fully Drained' Clay 12 Varies by Reach- See Table 3 Sand 1 Fully Drained' Clay 22 Varies by Reach- See Table 3 Sand 2 Fully Drained' Existing Dike' So— 1,000 psf 0'—32o,c' —0 psf Soil Containment Berm So=600 psf Notes: t CCR,Sand 1,and Sand 2 were assumed to behave in a fully-drained manner seismic loading.These parameters are listed in Table 1. 2 Clay 1 and Clay 2 were assumed to consolidate under added loads following the SHANSEP model.Undmined shear strength under future loading conditions can be estimated using the future vertical effective stress and the overconsolidation ratio.Overconsolidation mhos vary between design reaches and are listed in Table 3. 'The existing dike soils vary from cohesive(clayey and silt)to cohesionless(sand).Therefore,the existing dike may behave in either a drained or uncharted manner during seismic loading.Seismic slope stability analyses for the existing dike were evaluated considering both drained and undrained soil behavior of the dike soils;and the lower factor of safety from the two soil behaviors was reported. GR6601/13or, DRAff Clos Slope Stability APC Barry_EPA_000368 Geosyntec° consultants Page 12 of 30 CP: TYE Date: 08/27/18 APC: LPC Date: 8/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Table 3. Summary of Design Unit Weights,Undrained Shear Strengths and Maximum Past Pressures for Design Reaches Clay 1 Clay 2 Sand 1 Pre- Overburden Minimum Undrained Unit Pressure, Undrained Shear Undrained Unit Maximum Past Shear Design Weight,It POP' Strength', S. Strength Weight,yt Pressure',P'p Strength', S. Unit Weight,It Reach (pcf) (Psf) (psf) Parameters (pcf) (psf) (pat) (PC) 1 94 600 285 101 a1,o 110 2A 92 1,100 320 100 3,200 110 2B 97 1,100 400 105 a,_ 115 2C 100 1,500 460 105 5,300 S„=0'_ x 115 3A 1 95 1 0 200 102 a'„a 0.258 x OCRa" 115 S.—a',. x 0.258 x 110 3B 95 275 200 OCRa.s' 102 a',.o 3C 100 200 200 110 6,000 120 4 105 2,100 490 108 4,0)0 110 5A IA: 110 1A:3,000 1A: 550 110 1B: 105 111: 1,200 111: 420 Not Present 511 105 750 375 115 Notes: 'Pre-overburden pressure(POP)for Clay 1 refers to the difference at any elevation between the maximum past pressure(P'p)and the in situ vertical effective stress(a'.). 2Theundrained shear strengths for Clay l and Clay 2 used in seismic slope stability conditions is defined as the maximum of the SHANSEP strength (S„/a'„o=0.258)and a specified minimum shear strength value. GR6601i13u,y_DRAff Closure Slope Stability APC Barry_EPA_000359 Geosyntec consultants Page 13 of 30 CP: TYE Date: 08/27/18 APC: LPC Date: 8/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Table 4.Purpose, Selection Criteria and Characteristics of Analyses Cross Sections Section Description Purpose of this Cross Rationale for Cross Section Selection Water levels/Buttress 1 Clay 1 Section Thickness Design (ft) Reach Representative section of existing (i). Passes through Reach 3A where Clay 1 has the lowest design - WL=El. 3 ft within the Consolidated Footprint A-A' dike on along the western Evaluate the stability undrained shear strength for the entire Site(see Table 3). - WL=El. 3 ft in the discharge canal 8_I0 ft 3A boundary of the Consolidated of existing dike Footprint Evaluate the stability (ii). Represents one of the longest and steepest slopes of the final - WL—El. 3 ft within the Consolidated Footprint Representative section of the of CCR Stack and cover system. - WL—El. 6ft in the Closure by Removal Area B-B I5-16 ft 3A South Containment Berm South Containment (iii).Passes through Reach 3A where Clay 1 has the lowest design Berm undrained shear strength for the entire Site(see Table 3). (i). Thickness of Clay 1 layer beneath the existing dike and - WL=El. 3 ft within the Consolidated Footprint containment berm is considered the largest in the Consolidated - WL=El. 3 ft in the discharge canal. Footprint. Representative along tee section of existing Evaluate the stability (ii). Passes through Reaches 4 and 3A where Clay 1 has the lowest C-C' dike along the eastern boundary of so existing dike and design undrained shear strength along the eastern boundary of 22 ft 3A and 4 Consolidated Footprint soil containment berth. Consolidated Footprint(see Table 3). (iii). Represents a cross section with the smallest buttress for the soil containment bean. (i). Thickness of Clay 1 layer beneath the existing dike is - WL for Mobile River at normal pool elevation Representative section of existing considered the largest in the Closure by Removal Area. of 3 ft MSL D-D' dike in the Closure b Removal Evaluate the stability WL=El. 6ft in the Closure b Removal Area. 25 ft 3A Y (ii). Passes through Reaches 3A where Clay 1 has the lowest design Y Area. of existing dike Ri ra Buttress/seepage berm laced on the undrained shear strength for the entire Site. (see Table 3). P PP downstream of the existing dike. Representative section of existing Evaluate the stability (i). Represents the steepest slope of the laydown area. - WL=El. 3 ft within the Consolidated Footprint E-E' dike in the laydown area of existing dike (ii). Passes through Reaches 3A where Clay 1 has the lowest design - WL=El. 3 ft in the discharge canal loft 3A undrained shear strength for the entire Site(see Table 3). Notes 1 The dimensions of the rip rap buttress/seepage berm shown on analysis cross section D-D' and located on the downstream side of the existing dikes in the Closure by Removal Area were based on preliminary analysis. these dimensions will be updated in the next design submittal. GR6601/13nr, DRAff Clos Slope Stability APC Barry_EPA_000370 Geosyntec consultants Page 14 of 30 CP: WE Date: 08/27/18 APC: LPC Date: 8/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Table 5. Calculated Critical FS for Long-Term Static and Seismic Slope Stability Analyses Calculated Minimum Cross Section Stability considered Condition FS Design Design Criteria Met? Figure Criteria FS A-A' Existing Dike' Long-term static 1.86 1.50 Yes 8 (local) Seismic(existing dike assumed drained) 1.36 1.00 Yes 9 Long-term static-Shallow slip surface 13.93 1.50 Yes Consolidated Footprint 10 (Global and Shallow) Long-term static-Deep Slip Surface 14.62 1.50 Yes B-B' Seismic 4.50 1.00 Yes 11 South Containment Berm Long-term static 1.69 1.50 Yes 10 (local) Seismic 1.17 1.00 Yes 11 Existing Dike' Long-term static 1.75 1.50 Yes 12 C-C' (local) Seismic(existing dike assumed drained) 1.91 1.00 Yes 13 Soil Contaimnen[Berm Long-term static 2.14 1.50 Yes 12 (local) Seismic 2.49 1.00 Yes 13 Long-term static-Inboard Stability 1.56 1.50 Yes 4 D Existing Dike' Long-term static-Outboard StabiliStability2.10 1.50 Yes (local)) Seismic-Inboard Stability(existing dike assumed drained) 1.24 1.00 Yes 15 Seismic-Outboard Stability(existing dike assumed drained) 1.30 1.00 Yes Existing Dike' Long-term static 1.52 1.50 Yes 16 E-E' (local)) Seismic(existing dike assumed drained) 1.19 1.00 Yee 17 Note: 1.For seismic conditions,analyses were conducted assuming existing dike material to behave either as an undrained or drained material.All shear strength parameters for other soil units and berm remain the same for both analyses as per Table 2. Calculated FS evaluated assuming existing dike to behave as undrained material was not presented as it consistently had FS greater than those computed assuming dike material to behave as drained material. GR6601r13ury_DRAff Cloaare Slope Stability APC Barry_EPA_000371 Geosynte& consultants Page 15 of 30 CP: TYE Date: 08/27/18 APC: LPC Date: 8/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 FIGURES 6106601MH DRAff Clos Slope Stability APC Barry_EPA_000372 Geosyntec° consultants Page 16 of 30 CP: TYE Date: 08/27/18 APC: LPC Date: 8/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 V E _ C �\\\ B D D a Figure 1.Selected Cross Section Locations over Consolidated Footprint Grading Plan for Slope Stability Analysis 6126601MH DRAff Clos Slope Stability APC Barry_EPA_000373 Geosynte& consultants Page 17 of 30 CP: TYE Date: 08/27/18 APC: LPC Date: 8/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 i E aacx i+ rarsaocxwarr aax � � `. � " 4 Figure 2.Selected Cross Section Locations over Clay Thickness Isopach for Slope Stability Analysis 6106601MH DRAff Clos Slope Stability APC Barry_EPA_000374 consultants .. Date: Client APCISCS Project: Plant Barry Ash Pond Closare Protect project No: GW6489 Discharge Canal Existing Dike Existing prior to Closure Soil ............................................................:::::::::::::......... Figure 3 Geometry of Selected Cross Section A-A! Now: 1. The cross section in this figure shows the water table elevation within the Consolidated Footprint modeled at 3 ft MSL under long-term,steady-state post-closure conditions.Water level in the discharge canal is modeled at 3 ft MSL. Existing CCR Existing Ground prior to Closure South Containment Berm Closure-by-rernoval Arc� New CCR Clay I Sand I Figure 4. Geometry of Selected Cross Section 11-11' Note: 1. The cross section in this filume shows the water table elevation within the Consolidated Footprint modeled for long-term,steady-state post-closure conditions.In the Closime-by Removal area,the water table elevation is assumed to be at 6 ft MSL. ............................................................................... ............................................................................ ......................................................................... ----- i � Geosyntec consultants Page 19 of 30 CP: TYE Date: 08/27/18 APC: LPC Date: 8/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 - Reach 3A Reach 4 Soil Containment Berm Mobile River Existing Dike Existing Ground prior to Closure Figure 5 Geometry of Selected Cross Section C-C' Note: 1.The cross section in this figure shows the water table elevation within the Consolidated Footprint modeled at 3 It MSL under long-term,steady-state post-closure conditions.Water level in Mobile River is modeled at 3 ft MSL. Riprap buttress/Seepage berm - Existing Dike Mobile River Figure 6 Geometry of Selected Cross Section D-U Note: 1. The cross section in this figure shows the water table elevation within the Closure-by-Removal Area modeled at 6 ft MSL under long-term,steady-state post-closure conditions.Water level in Mobile River is modeled at 3 ft MSL. 1. The dimensions of rip rap buttress/seepage berm(140 It long and 5 ft thick)are based on preliminary slope stability analyses conducted as part of this detailed design.These dimensions will be optimized in next design submittal. GR6601/Bany_DRAff Closure Slope Stability APC Barry_EPA_000376 Geosyntec consultants Page 20 of 30 CP: TYE Date: 08/27/18 APC: LPC Date: 8/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project: Plant Harry Ash Pond Closure Projeot Project No: GW6489 Existing Dike New CCR x Discharge Canal % % Existing CC Clay 1 Sand 1 Sand 2 8- Figure 7 Geometry of Selected Cross Section E-V Noted. The cross section in this figure shows the water table elevation within the Consolidated Footprint and water level in discharge canal modeled at 3 ft MSL under long-term,steady-state post-closure conditions. GR6601/Barry_DRAPf Closare Slope Stability APC Barry_EPA_000377 Geosyntec consultants Page 21 of 30 CP: TYE Date: 08/27/18 APC: LPC Date: 8/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project: Plant Harry Ash Pond Closure Project Project No: GW6489 llli[Npi�t cohesion PH Malarial mare n1a own) 64 Q _ fEwWl ❑ 97 AMr{alarb 0 36 om 92 I T-Coularb 0 36 Oay1(R3AD) ❑ 95 Ww-Coularta 75 31 nay2(R3AD) ❑ 102 MAr{bularh 75 31 _ Sand 1(R3AD) ❑ no mdrSnularb o 35 1 .86 Sand2(RMD) ❑ 12o WT-Coulon) 0 38 WwDikep) ❑ 115 Wr-Gnularb SO 27 Edsnrsoikep) El Ivbfr{oulnrrb o 32 'v . . . . . . .2A0 . . . . . . .2✓10 . . . . . . . .366 . . . . . . . .3�0 . . . . . .340 . . . . . . .A0 • . . . . .3A0 . . . . . . .4U0 • . . . . .C10 . . . . . . . .446 . . . . . . . .a40 . . . .e86 . . . .566 . . . . . . .520 . . . . . . .S46 . . . . . . .560 . .SiO .600 . . Figure 8. Slope Stability Analysis Results for Cross Section A-A! —Long-Term Static Condition GR6601/13arry_DRAff Closare Slope Stability APC Barry_EPA_000378 Geosyntec consultants Page 22 of 30 CP: TYE Date: 08/27/18 AM LPC Date: 8/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project: Plant Harry Ash Pond Closure Project Project No: GW6489 Uitmaht ftictlm lFi rtivm WsdcJ Mrmamc aa 6R[erhl Wre ma PW631 M Ids TIPe ma@6Usd1 _ f (XR ❑ 47 Nthr comb o 35 Cat 0 92 MhrG mb 0 36 SaMI(MAD) ■ ns 6Mvtalmb 0 3S 1.36 _ Sard2FGAD) 0 M Nthrialmb 0 38 Kwglu(lD) fis MbrSalmb 600 0 Eassmale((D) ❑ M Mhrcalmb 0 32 aW2"AtD) M Wn.1R.R4a 0.258 500 Oayl(R39Yfb&gsrrete) ❑ 95 gsnetefunilm T rte . . . . .Asi . . . . Z i .A6 . . . . . . .3}0 . . . . . . .350 . . . . . . ]90 . . .AI . . . . . . .466 . .. .. . .416 . . . . . . .446. . .. i .. . .466 . . . i . . � 1116 � � . � � � . .s66 . . . i . . . a!(. . . . i .. . .146 . . . i . . . .Aa. . Figure 9. Slope Stability Analysis Result for Cross Section A-A' —Seismic Condition Notes: 1. The failure surface passing through the existing dike assuming its material in be undrained was not presented as it has a FS greater than shown on this Figure(FS=1.67). 2. A horizontal pseudostatic coefficient of 0.01 was used for potential slip surfaces passing through the existing dikes Undrained shear strengths parameters ofmaterials are defined as shown in Table 3. GR6601/Barry_DRAff Closure Slope Stability APC Barry_EPA_000379 Geosyntec consultants Page 23 of 30 CP: TYE Date: 08/27/18 APC: LPC Date: 8/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 14.62 Mteilal&re W. Well aradltT� hM (w ftwmi ❑ 97 Mtr{ donb 0 36 Cot 092 htl Ionb 0 36 awl( AD) ❑ % hthr{ to f, 75 31 CIW2(&V ❑ 102 h?drCb larb 75 31 %odIWAQi 116 mt,{ Ienb o 36 SaN2lR34D) ❑ 121 h 4dulonb 0 M h ute(n) ❑ lz hbFrtalonb M 27 13.93 1.69 w Slow- 1300 1W0 loot T%00 1800 1800 2000 21.. 2zoo 2300 2Go0 260 Figure 10. Slope Stability Analysis Results for Cross Section B-W —Long-Term Static Condition GR6601/13arry_DRAff Cloacae Slope Stability APC Barry_EPA_000380 Geosyntec consultants Page 24 of 30 CP: TYE Date: 08/27/18 APC: LPC Date: 8/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project: Plant Harry Ash Pond Closure Project Project No: GW6489 4.50 ftiv Uitwso �laie ml®m Ri g Mnmm 9inaePA s�5 its") lodl ft pyu 'Arerehan,I tedl 7.U.M. ❑ 9] hHrtnularrb 0 36 M Wt-Godonta 0 36 is 6kFr{ndart 0 % M WrGa1mA 0 38 115 hHrlalm6 E00 0 DaYlI834lA5HMbEPd501k1q ❑ % ascmufvxtim 0 02 Oay1(Rl4lASW," ❑ % 51WSB 0 Q258 0.83 Oar2 fGAW) 1(a tErOYolstressastio am 500 1.17 � ► 0.01 W IYI�rLI,WN o- 1400 1.�00 400o '1 6 +900 '+aoo 2000 'zioo 2100 296 2400 Figure 11. Slope Stability Analysis Result for Cross Section B-9 —Seismic Conditions Notes: 1. A horizontal pseudostatic coefficient of 0.01 was used for potential slip surfaces passing through the soil containment berm and 0.02 for potential slip surfaces passing through the CCR and underlying foundations soil 2. Undrained shear strengths parameters of materials are defined as shown in Table 3. GR6601/Baery_DRAff Closure Slope Stability APC Barry_EPA_000381 Geosyntec consultants Page 25 of 30 CP: TYE Date: 08/27/18 APC: LPC Date: 8/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project: Plant Harry Ash Pond Closure Projecl Project No: GW6489 h0kalsINM War bM 9h'eplrTlpe Wiesen It MWOM ❑ 97 W r{oularb 0 36 OCR 92 WY-Onjarb 0 36 tlayl(Ri4D) ❑ 95 hMr{ajarb 75 31 _ a yl(R4D) ❑ 105 KOw-Gajmb 75 31 _ a y2(R4D) ❑ 108 KUT-GnJarb 75 31 _ S3rdl(MAD) 115 Wr{nJarb 0 35 Sardl(PAD) 110 Nhhr{ndont 0 35 Sard2 120 KUY-GnJarb 0 38 WwDikep) ❑ 115 MirLod.1b 50 27 Bjstirgnke(D) ❑ 120 NtMlnjmh 0 32 2.14 0 W tioo . " 't iso . . . . . . . i�ou . . . . " "tz'so . . . 1300 . . . . " "tiso . . . . . . , idoo . " 'tdso . . . . " "thou . . . . . . . i950 . . . "tsao . . . . " "tusu . . . . " "t)ao . . . . . 456 . . . . " "teou . . . . " "te'so Figure 12. Slope Stability Analysis Result for Cross Section C-C —Long-Term Static Condition GR6601/13arry_DRAff Closare Slope Stability APC Barry_EPA_000382 Geosyntec consultants Page 16 of 30 CP: TYE Date: 08/27/18 AM LPC Date: 8/27/2018 CA: CM Date: 08/27/2018 Client: APC/SCS Project: Plant Barry Ash Pond Choate Project Project No: GW6489 llitVtEo Calledon Phi Wedw Kift6al Nare cola PbM) 9 w6hTwe 60 (ded 70e o- NeWCM ❑ 97 Nlir{aulorrb 0 36 OCR 92 Nbir{nularb 0 36 Sarall(R3AD) ❑ 115 Wir{nultrrb 0 35 Sarldl(M) 110 Ww-Coulonb 0 35 Sard2 ❑ 120 Ww-Coulont 0 38 NewOkeW 115 Ww-Coulonb 600 0 o- o— �- FaasbrgDke(D) ❑ 120 Wr-Coulomb 0 32 Oayl(MSONSEPDm) ❑ 105 Disaetefunction tlayl(R3A5fIMSFPwoke) ❑ 95 Disaetefurlctim Clay2(R4UD) 108 Wdrained 800 Carstant 2.49 1.91 - 001 001 in o- �" 1150. . . . . . . i200. . . . . . . 1z'so. . . . . . . 130o. . . . " ' 13s0. . . . . . . idoo. . . . . . . 1460. . . . . . . id00" " ' . . isso. . . . . . . 1d0o. . . . . . . ids0. . . . . . . 1 lto. . . . . . ' qso. . . . . . . 1d00. . . . . . ' 1eso' Figure 13. Slope Stability Analysis Result for Cross Section C-C' —Seismic Condition Notes: 1. The failure surface passing through the existing dike assuming its material to be undmined was not presented as it has a FS greater than shown on this Figure(i.e.,FS—2.22) 2. A horizontal pseudostatic coefficient of 0.01 was used for potential slip surfaces passing through the existing dikes and soil containment berms 3. Undrained shear strengths parameters of materials are defined as shown in Table 3. GR6601/13arry_DRAPf Gosare Slope Stability APC Barry_EPA_000383 Geosyntec consultants Page 27 of 30 CP: TYE Date: 08/27/18 APC: LPC Date: 8/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project: Plant Barry Ash Pond Closure Projech Project No: GW6489 Ber i} Material Nam Color Uritmg1 t Strc�llType Cohesion Phi PbM) (Psi) (deg) - Oayl(R3AD) ❑ 95 MhhrLoulon'b 75 31 aay2(3AD) ❑ 102 M1hr{oulonb 75 31 ^= Sardl(R4AD) 115 iWMCoulorrb 0 35 - Sard2(R9AD) 120 MirCoulonb 0 38 o= 1.56 210 UstirgDilie(D) ❑ 120 Mlhr-Goulonib 0 32 �- RockRittress ❑ 120 MhhrCnulonb 0 35 YZ AL (V - 1 o- in— II I II II II II II II II II II . 375 . . . . . 4b0 . . . . . 425 . . . 46 . . . . . 475 . . . . . 5b0 . . . . . 525 . . 56 . . . . . 575 . . . . . 600 . . . . . 625 . . . . . �66 . . . . . 675 . . . . . 700 . . . . . 725 . . . . . 76 Figure 14. Slope Stability Analysis Result for Cross Section D-d —Long Term Static Condition GR6601/13arry_DRAff Closare Slope Stability APC Barry_EPA_000384 Geosyntec consultants Page 28 of 30 CP: WE Date: 08/27/18 AM LPC Date: 8/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 - WtvMft Rrergiesim PH Veracal Mrimm9tew ISsnete nfBterial nt re Caltx per) +Twe W Wed W Puxtion - tlay2(R3ALA) 102 Vertical Stress Patio 0.259 SOD Clay2(3AD) ❑ 102 Nbhr{nulonb 75 31 - Sardl(MAD) ❑ 11s Nbhr{oulcrrb 0 35 - Sard2(BAD) ❑ 120 Nbhr-C=Iorrb 0 38 bdstirgOike(D) ❑ 120 Nbhr{oulorrb 0 32 F1.301 aay1(R3ASWtWDISGTM ❑ 95 Discretefurrtoll 9 o- Im kMless ❑ 120 NbhrCoularb 0 35 1.24 001 — � 601 'AO'" , , 'Bbo" , , 'AO, , ,abo, , ,abo' , "sbo' , "AO" , ,sbo, , ,sbo'" , ,7bo" , ,AO Figure 15. Slope Stability Analysis Result for Cross Section D-Dr —Seismic Condition Notes: 1. The failure surface passing through the existing dike assuming its material in be undmined was not presented as it has a FS greater than shown on this Figure(FS=1.36 inboard stability/1.47 outboard stability). 2. A horizontal pseudostatic coefficient of 0.01 was used for potential slip surfaces passing through the existing dikes. 3. Undrained shear strengths parameters of materials are defined as shown in Table I. GR6601/Barry_DRAff Closare Slope Stability APC Barry_EPA_000385 Geosyntec consultants Page 29 of 30 CP: TYE Date: 08/27/18 APC: LPC Date: 8/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project: Plant Harry Ash Pond Closure Project Project No: GW6489 o- Miterial Plane Odor lhit Nkij ItRmn TYPe Caltesan Phi Qom) OA (deg) PIewOCR ❑ 97 M1hrCoulorrb 0 36 OCR 92 M1hrCoulonb 0 36 �- Qayl(BAD) ❑ 95 M1hr-Gmlonb 75 31 aay2(3AD) ❑ 102 M1hr-Cmlonb 75 31 = Sandl(BAD) ❑ 115 M1hr-Cmlonb 0 35 1.52 o- �= Sand2(R3AD) ❑ 120 M1hr-Cmlorrb 0 38 BdstirgDike(D) 120 M2hr-Cmlorrb 0 32 N N N- O 250 . . . i . . .275 . . . i . . 3b0 . . i . . . .3115 . . i . . . 350375 4b0 4j25 . . . i 450 . . . i . . 475 . . . i . . . .51�0 . . . i . . . .5115 i . . . 550575 6b0 . .6j25 Figure 16. Slope Stability Analysis Result for Cross Section E-V —Long Term Static Condition GR6601/13arry_DRAff Closare Slope Stability APC Barry_EPA_000386 Geosyntec consultants Page 30 of 30 CP: TYE Date: 08/27/18 AM LPC Date: 8/27/2018 CA: CJR Date: 08/27/2018 Client: APC/SCS Project: Plant Harry Ash Pond Closure Project Project No: GW6489 lkitv"O Callesion PN Cohesion Strength MrimintShear Mteial fVarre Cda Pam) StrergthType (A (deg) Type Moh Strergth(psf) %WCCP ❑ 97 MthfLoulorcb 0 36 OCR 92 Whr-Coulorrb 0 36 o- aay2(MAtA) 102 Vertical Stress Patio 0.259 500 Sandl(iw) ❑ 115 WY-Coularb 0 35 1.19 Sard2(R3AD) ❑ 120 Miri'nuloni) 0 38 5dstlrgDike(D) ❑ 12o Mtr-Coulorrb 0 32 Oayl(RiAMti) ❑ 95 ftrained 200 CbrIstant tlayl(RiA9iM EPDiscrete) ❑ 95 Discretefunction 00 - 1 = I � „'zbo . . . . . . . s4es . . . . . . . ,zbo . . . . . . . .2,9 . . . . . . . .366 . . . . . . . .31; . . . . . . . abo . . . . . . . .3'9 . . . . . . . 4bo . . . . . . . .44s . . . . . . . .4bo . . . . . . . 414 . . . . . . . .sbo . . . . . . . .519 . . . . . . . .sba Figure 17. Slope Stability Analysis Result for Cross Section E-E' —Seismic Condition Notes: 1. The failare surface passing through the existing dike assuming its material to be undrained was not presented as it has a FS greater than shown on this Figure(i.e.,FS=1.21). 2. A horizontal pseudostatic coefficient of 0.01 was used for potential slip surfaces passing through the existing dikes. 3. Undmined shear strengths parameters of materials are defined as shown in Table 3. GR6601/san, DRAPE Closure Slope Stability APC Barry_EPA_000387 Geosynte& consultants Page 31 of 30 CP: TYE Date: 08/27/18 APC: LPC Date: 8/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 6106601MH DRAff Clos Slope Stability APC Barry_EPA_000388 APPENDIX C3 VENEER STABILITY ANALYSIS FOR FINAL COVER DESIGN APC Barry_EPA_000389 Geosyntec° consultants CALCULATION PACKAGE COVER SHEET Client: Alabama Power Company and Project: Plant Barry Ash Pond Closure Project#: GW6489 Southern Company Services Project TITLE OF PACKAGE: DRAFT VENEER STABILITY ANALYSIS FOR FINAL COVER DESIGN o f CALCULATION PREPARED BY: Signatue 27 August 2018 i (Calculation Preparer,CP) Name Tamer Y.Elkady Date 6 ASSUMPTIONS&PROCEDURES Signature 27 August 2018 CHECKED BY: (Assumptions&Procedures Checker,APC) Nsure Glenn J.Rix,Ph.D.,P.E. Date 3 gnature 27 Au COMPUTATIONS CHECKED BY: Si gust 2018 (Computation Checker,CC) Name M.Gizem Bozkurt Date v BACK-CHECKED BY: Sipanue 27 August 2018 ry x 4 (Calculation Preparer,CP) aName Tamer Y.Elkady Date m a APPROVED BY: Signature 27 August 2018 °a (Calculation Approver,CA) Name Glenn J.Rix,Ph.D.,P.E. Date REVISION HISTORY: NO. DESCRIPTION DATE CP APC CC CA A Draft Closure Design Calculation Package 08/27/2018 TYE GIR MGB GJR APC Barry_EPA_000390 Geosyntec consultants Page 1 of 19 CP: TYE Date: 08/27/18 APC: GJR Date: 08/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project. Plant Bury Ash Pond Closure Project Project No: GW6089 DRAFT VENEER STABILITY ANALYSIS FOR FINAL COVER DESIGN PURPOSE This Draft Veneer Stability Analysis for Final Cover Design calculation package (Package) was prepared in support of the design to close the existing coal combustion residuals (CCR) ash pond at Alabama Power Company's (APC's) Plant Barry (Site), located in Bucks, Alabama. The ash pond will be closed using a "consolidate and cap-in-place" method whereby all CCR will be consolidated into an approximately 300-acre area that will be constructed in the central portion of the ash pond using soil containment berms and with a final cover system. The purpose of this Package is to evaluate the static and seismic veneer stability of the final cover system proposed for the closure of the Site. Specifically, this Package presents calculations to estimate the minimum required interface shear strengths for the cover system design to attain target design factors of safety. The remainder of this Package is organized to present: (i) design criteria; (ii) analysis methodology; (iii) design parameters; (iv) analysis results; and(v) summary and conclusions. DESIGN CRITERIA The final cover veneer stability is typically analyzed along planar slip surfaces of soil-geosynthetic interfaces where small overburden stresses are applied. The minimum required factor of safety (FS) depends on the analysis condition(i.e., short term vs long term and static vs seismic) and the interface shear strength considered (i.e., peak versus residual) [Bonaparte and Othman, 1995; Bonaparte et al., 1996; Gilbert and Byrne, 1996]. The design criteria considered in this Package me consistent with the provisions of USEPA CCR rule(USEPA,2015)stated in the Draft Closure Slope Stability Analysis calculation package submitted as part of this permit application [Geosyntec, 2018a] as well as recommendations in technical literature that represent the state of practice for the geotechnical design of landfills [Bonaparte et al., 1996;Bonaparte et al.,2004]. The design criteria used in evaluating the stability of final cover system can be summarized as follows: e The calculated FS for long-term conditions using residual (large-displacement) interface shear strength in the final cover system must equal or exceed 1.20; e The calculated FS for long-term conditions using peak interface shear strength in the final cover system must equal or exceed 1.50; and GW689Ma -DRAFT Venm SB bihty APC Barry_EPA_000391 Geosyntec consultants Page 2 of 19 CP: TYE Date: 08/27/18 APC: GJR Date: 08/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project. Plant Bury Ash Pond Closure Project Project No: GW6089 • The calculated pseudo-static factor of safety for seismic loading using residual interface shear strength in the final cover system must equal or exceed 1.00. ANALYSIS METHODOLOGY Minimum required values for interface shear strength parameters(i.e., friction angle and interface adhesion) were back-calculated for the proposed final cover system by setting the FS in the equations below to the minimum required FS presented in the design criteria. Static Veneer Stabiliri Slope stability of a final cover system can be analyzed based on infinite- or finite-slope methods. The infBlite-slope method considers an infinite slope length whereby driving and resisting forces only occur parallel to an interface (i.e., slip plane). The finite-slope method considers a slope of finite length and accounts for the effect of buttress at the toe of the slope.The static veneer stability analyses in this Package were performed using the finite-slope method(Equation 1)developed by Giroud et al. [1995]. The slope geometry used to derive the equation is shown in Figure 1. FS = yt(t—tW)+Ybtn I tan d + a/sin P )+Yt(t—twYsattu, tang Yt(t—tw)+Ysattw + Ir Yt(t—t)+Ybt` I Irtanrb/(zsm j;cos2j6) t LYt(t—tw)+YsattwJ L 1—tan)3tano h f 1 1I Ir1/(2 sin Q cos2(i)1I ct + LYt(t—tw)+YsattwJL 1—[an/i tangy J h (1) where: FS = calculated factor of safety; S = interface friction angle(degrees); a = interface adhesion intercept(pounds per square foot [psf]); = soil internal friction angle (degrees); c = soil cohesion intercept(psf); 71 = total soil unit weight(pounds per cubic foot [pcf]); 7sat = saturated soil unit weight(pcf); yb = buoyant soil unit weight(pcf)=ysar—yw; GW689Ma -DRAFT Venm SB bihty APC Barry_EPA_000392 Geosyntec° consultants Page 3 of 19 CP: TYE Date: 08/27/18 APC: GJR Date: 08/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project. Plant Bury Ash Pond Closure Project Project No: GW6489 yw = unit weight of water=62.4 pcf; t = thickness of cover soil above critical interface(feet [ft]); N = water flow thickness above critical interface (ft); t* = water flow thickness at the toe of slope(ft); (i = slope inclination (degrees); and h = vertical height of slope(ft). While the above equation is specifically for an interface above a geomembrane or similar layers, it can also be applied to interfaces below the geomembrane by changing the coefficient of the first term (i.e., the coefficient of tan 6 / tan [t) to 1. It is noted that tension in the geosynthetic has conservatively not been included in the above equation, and that the equation is only applicable for seepage parallel to the slope,which is expected for the analyses presented in this Package. Seismic Veneer Stability Pesudostatic slope stability analysis of the final cover system in this Package was performed using the equation developed by Matasovic [1991] for infinite-slope stability conditions: n Yw(z-dw) FS = Ysat�+tanS�l- Ysata -kstan(itanS ks+tan/d (2) where: FS = calculated factor of safety; S = interface friction angle(degrees); a = interface adhesion intercept(psf); P = slope inclination (degrees); y,nt = saturated soil unit weight(pef); Y. = unit weight of water=62.4 pcf, k, = pseudostatic coefficient; z = depth of the estimated slip surface (ft); and dw = depth to water surface(ft). The slope geometry used to derive the above equation is shown in Figure 2. This equation is only applicable if the steady-state seepage is parallel to the ground surface, which is expected for the analyses presented in this Package. Based on the Draft Closure Stability Analysis — Seismic GW6489/13 y-DRAFT Von=SB bitity APC Barry_EPA_000393 Geosyntec° consultants Page 4 of 19 CP: TYE Date: 08/27/18 APC: GJR Date: 08/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project. Plant Bury Ash Pond Closure Project Project No: GW6489 calculation package[Geosyntec,2018 b],the pseudostatic coefficient was estimated for a tolerable displacement of 0.5 inches (in.). Therefore, the required interface shear strengths calculated from the seismic veneer stability analysis are considered to be residual (i.e.,large-displacement)values. DESIGN PARAMETERS Information required for the veneer stability analyses presented in this Package includes: • slope geometry; • final cover system design details; and • pseudostatic coefficient(for seismic veneer stability analysis only). Slope Geometry Veneer stability analyses were performed for the longest and steepest slope of the proposed final cover system. The location of the selected slope is shown in Figure 3. Based on the design grades of the final cover system, the maximum side slope angle is approximately 2.0 degrees (i.e., 3.5 percent pre-settlement slope) and the maximum slope height is approximately 22 ft. Cover Svstem The proposed final cover system is a ClosureTurf® cover system (Figure 4) consisting of the following components, from bottom to top: • A 50-mil thick textured geomembrane (GM) with spike down that is part of a liner low- density polyethylene(LLDPE)MicroDrain®; • 130-mil thick studded drainage layer that is part of the LLDPE MicroDraino; and • 0.5-in. thick sand infill and engineered turf. Critical interface for the ClosureTurf® cover system is the interface between the engineered turf and the geomembrane. In the Draft Hydraulic Evaluation of Cover Performance calculation package submitted as part of this detailed design [Geosyntec, 2018c], the average calculated hydraulic head over the geomembrane was 0.522-in thick. Therefore, the 0.5-in. thick sand infill was modeled to be fully saturated (i.e., water depth of 0.5 in.) for the veneer stability analyses presented in this Package. In addition, the sand infill is modeled to have a total unit weight of 120 pcf,an internal friction angle of 30 degrees, and no cohesion. These parameters are representative of typical values used for similar soils in general engineering practice. GW6489Ma -DRAFT Venm SB bihty APC Barry_EPA_000304 Geosyntec consultants Page 5 of 19 CP: TYE Date: 08/27/18 APC: GJR Date: 08/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project. Plant Bury Ash Pond Closure Project Project No: GW6489 The detail shown in Figure 4 indicates that the ClosureTurf® cover system will be placed on top of 0.5-ft thick subgrade soil layer which is underlain by a geocomposite gas relief layer(GGRL). The interface between the GGRL and subgrade soil layer provides another potential slip surface for veneer failure. Therefore, veneer stability was also evaluated along the interface between the GGRL and the subgrade soil layer assuming depth of the water flowing above the interface (i.e., tw)equal to zero. The subgrade soil was modeled to have a total unit weight of 120 pcf,an internal friction angle of 30 degrees, and no cohesion. Pseudostatic Coefficient The pseudostatic coefficient at the surface of the final cover system for the CCR consolidation area was estimated to be 0.01 as detailed in the Draft Closure Stability Analysis — Seismic calculation package submitted as part of this detailed design [Geosymcc, 2018b]. ANALYSIS RESULTS The minimum interface shear strength parameters required for the ClosureTurf®cover system and GGRL-subgrade soil interface to meet the target FS values were evaluated using the methodologies presented in this Package. Calculations for the peak and residual interface shear strength parameters required for the ClosureTurf®cover system to satisfy the design criteria under static conditions are shown in Tables 1 and 2,respectively. The calculations show that the minimum required peak and residual interface friction angle if the interface adhesion is set to 0 psf are 6.2 and 5.0 degrees, respectively. If the interface friction angle is set to zero degrees,the interface adhesion required to meet the target FS under static conditions for peak and residual interface shear strengths for the ClosureTurf® cover system is calculated to be negligible(e.g., approximately 0.3 psf for peak interface shear strength) as a result of the small thickness of the cover system. Table 3 shows the back-calculation for the residual interface friction angle of the ClosureTurf® cover system required to meet the target FS for seismic veneer stability. The computed minimum required residual interface friction angle is 5.4 degrees For the potential slip surface along the GGRL-subgrade soil interface, calculations revealed that minimum required peak and residual interface friction angles required to satisfy the target FS for static veneer stability are 2.6 and 2.0 degrees,respectively. Tables 4 and 5 show back-calculations performed to evaluate the minimum required peak and residual interface shear strength parameters. Similar to the ClosureTurf®,if the interface friction angle is set to 0 degrees,the interface adhesion required to satisfy the target FS for peak and residual interface shear strengths along the GGRL- subgrade soil interface was computed to be very small (e.g., 2.9 psf for peak interface shear GW689Ma -DRAFT Venm SB bihty APC Barry_EPA_000395 Geosyntec consultants Page 6 of 19 CP: TYE Date: 08/27/18 APC: GJR Date: 08/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project. Plant Barry Ash Pond Closure Project Project No: GW6089 strength). For seismic veneer stability, the residual interface friction angle of the ClosureTurf® cover system required to meet the target FS for seismic veneer stability was calculated to be 2.6 degrees as presented in Table 6. SUMMARY AND CONCLUSIONS The analyses presented in this Package were used to establish acceptable combinations of peak and residual interface shear strength parameters for static loading; and residual interface shear strength parameters for seismic loading for ClosureTurf cover system and along the GGRL- subgmde soil interface that satisfy the design criteria. These analyses revealed that the minimum interface adhesion required to satisfy the target FS for peak and residual interface shear strengths (assuming interface friction angle to be zero)were very small. Therefore, it is recommended that the final cover system be evaluated based only on interface friction angles from laboratory test results and have minimum peak and residual(for both static and seismic loading)interface friction angles of 6.2 and 5.4 degrees,respectively.Typical interface shear strength values for the interface between the 50-mil LLDPE GM and engineered turf for normal stresses between 10 and 50 psf were reported in the manufacturer's Design Guidelines Manual as 33 degrees for residual (i.e., large-displacement) strength and 39 degrees for peak strength with an adhesion intercept of 1 psf and 3 psf, respectively [WatersbedGeo, 2017]. Therefore, the required minimum interface shear strengths are achievable with the ClosureTu&cover system. Furthermore, the required minimum interface shear strength values are considered achievable with commercially-available products used in final cover detail (i.e., geocomposite layer) [Koerner and Narejo, 2005]. All calculated minimum interface shear strengths presented in this package will be incorporated into the construction quality assurance (CQA) plan as specifications that must be verified by project-specific testing prior to construction. GW6489Ma -DRAFT Veneer Stability APC Barry_EPA_000396 Geosyntec consultants Page 7 of 19 CP: TYE Date: 08/27/18 APC: GJR Date: 08/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project. Plant Bury Ash Pond Closure Project Project No: GW6489 REFERENCES Bonaparte, R. and Othman, M.A., "Characteristics of Modern MSW Landfill Performance," Geotechnical News,Vol. 13,No. 1, 1995,pp. 25-30. Bonaparte, R., Gross, B.A., Daniel, D.E., Koerner, R.M., and Dwyer, S. "(Draft) Technical Guidance for RCRA/CERCLA Final Covers," EPA 540-R-04-007 OSWER 9283.1-26, USEPA Office of Solid Waste and Emergency Response,Washington, DC, 2004. Bonaparte, R., Othman, M.A., Rad, N.S., Swan, R.H., and Vander Linde, D.L. "Evaluation of Various Aspects of GCL Performance," Appendix F in Report of 1995 Workshop on Geosynthetic Clay Liners, D. E. Daniel and H. B. Scranton, authors, EPA/600/R-96/149, USEPA National Risk Management Research Laboratory,Cincinnati,OH, 1996,pp.F 1-1734. Geosyntec. (2018a). "Draft Slope Stability Analysis," calculation package submitted to Alabama power Company and Southern Company Services,August 2018. Geosyntec. (2018b). "Draft Closure Stability Analysis—Seismic," calculation package submitted to Alabama power Company and Southern Company Services, August 2018. Geosyntea (2018c). "Draft Hydraulic Evaluation of Cover Performance," calculation package submitted to Alabama power Company and Southern Company Services, August 2018. Gilbert, R. B. and Byrne, R. J. "Strain-Softening Behavior of Waste Containment System Interface," Geosynthetics International,3 (2), 1996,pp. 181-203. Giroud, I.P., Bachus, R.C., and Bonaparte, R. (1995). "Influence of Water Flow on the Stability of Geosynthetic-Soil Layered Systems on Slopes," Geosynthetics International, Vol. 2, No. 6, 1995,pp. 1149-1180. Koerner,G.R.and Narejo,D.(2005).'Direct Shear Database of Geosynthetic-to-Geosynthetic and Geosynthetic-to-Soil Interfaces." Geosynthetic Research Institute GRI Report#30. Matasovic, N. (1991). "Selection of Method for Seismic Slope Stability Analysis," Proc. of the 2nd International Conference on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics, (2), St. Louis, pp. 1057-1062. GW6489Ma -DRAFT Veneer atebihty APC Barry_EPA_000397 Geosyntec consultants Page 8 of 19 CP: TYE Date: 08/27/18 APC: GJR Date: 08/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project. Plant Barry Ash Pond Closure Project Project No: GW6089 United States Environmental Protection Agency(USEPA) (2015). Code of Federal Regulations (CFR)Title 40,Parts 257 and 261,Hazards and Solid Waste Management System;Disposal of Coal Combustion Residuals from Electric Utilities; Final Rule. WatershedGeo Unearthing Solutions(2017). "ClosureTurf Design Guidelines Manual" GW689Ma -DRAFT Veneer 8tebihty APC Barry_EPA_000398 Geosyntec° consultants Page 9 of 19 CP: TYE Date: 08/27/18 APC: GJR Date: 08/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project. Plant Bury Ash Pond Closure Project Project No: GW6489 TABLES GW689Ma -DRAFT Venm SB bility APC Barry_EPA_000399 Geosyntec° consultants Page 10 of 19 CP: TYE Date: 08/27/18 APC: GJR Date: 08/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Table 1.Back Calculation of Peak Interface Shear Strength Parameters for the ClosureTurf Cover System(Interface Adhesion Set to Zero) FSAbove GEOMEMBRANE Input Parameters: y,(Moist soil unit weight): 120 pcf yen (Saturated soil unit weight): 120 pcf y,,,(Unit wt of water): 62.4 per yb(Buoyant unit wt of soil): 57.6 pcf tw(water depth above critical interface): 0.042 It t* (water depth at slope toe): 0.042 ft 8(interface friction angle): 6.2 deg 4(soil internal friction angle): 30 deg a(interface adhesion intercept): 0.0 psf c(soil cohesion intercept): 0 psf h(vertical height of slope): 22 ft t (depth of cover soil above critical interface): 0.042 ft 9 (slope inclination): 2.00 deg FS: 1.50 FS Below GEOMEMBRANE Input Parameters.: y,(Moist soil unit weight): 120 pcf yem (Saturated soil unit weight): 120 pcf y (Unit wt of water): 62.4 pcf yb(Buoyant unit wt of soil): 57.6 pcf to(water depth above critical interface): 0.042 ft t* (water depth at slope toe): 0.042 ft S(interface friction angle): V 6.2 deg d(soil internal friction angle): V 30 deg *(interface adhesion intercept): 0.0 psf *(soil cohesion intercept): 0 psf h(vertical height of slope): 22 ft t (depth of cover soil above critical interface): V 0.042 ft (slope inclination): P 2.00 deg FS: 3.12 GW6489/Bavy-DRAFT Venm Subility APC Barry_EPA_000400 Geosyntec consultants Page 11 of 19 CP: TYE Date: 08/27/18 APC: GJR Date: 08/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project. Plant Barry Ash Pond Closure Project Project No: GW6489 Table 2. Back-Calculation of Residual Interface Shear Strength Parameters for the ClosureTurfe Cover System(Interface Adhesion Set to Zero) FSAbove GEOMEMBRANE Input Parameters: yt(Moist soil unit weight): 120 pcf y.(Saturated soil unit weight): 120 pef yw(Unit wt of water): 62.4 pcf yb (Buoyant unit wt of soil): 57.6 pet tw(water depth above critical interface): • 0.042 ft t• (water depth at slope toe): • 0.042 ft 8(interface friction angle): 5.0 deg 0(soil internal friction angle): 30 deg a(interface adhesion intercept): 0.0 psf c(soil cohesion intercept): 0 pef h(vertical height of slope): 22 ft t (depth of cover soil above critical interface):• 0.042 ft 9 (slope inclination): 2.00 deg IFS: F 1201. FS Below GEOMEMBRANE Input Parameters: y, (Moist soil unit weight): 120 pcf y.(Saturated soil unit weight): • 120 pcf yw(Unit wt of water): 62.4 pcf yb (Buoyant unit wt of soil): • 57.6 pcf 4.(water depth above critical interface): 0.042 fl t* (water depth at slope toe): 0.042 ft 8(interface friction angle): • 5.0 deg �(soil internal friction angle): • 30 deg *(interface adhesion intercept): • 0.0 psf *(soil cohesion intercept): • 0 psf It(vertical height of slope): • 22 ft t (depth of cover soil above critical interface):• 0.042 ft p (slope inclination): • 2.00 deg PS: F 2.49 GW6489,11 y-DRAFT Venw Sobility APC Barry_EPA_000401 Geosyntec consultants Page 12 of 19 CP: TYE Date: 08/27/18 APC: GJR Date: 08/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project. Plant Bury Ash Pond Closure Project Project No: GW6489 Table 3. Back-Calculation of Residual Interface Shear Strength Parameters for the ClosureTurf® Cover System under Seismic Loading(Interface Adhesion Set to Zero) Calculation of Factor of Safety Infinite Slope Conditions [Matasovic, 19911 FS = �Yea, u z ) +tan6(1 —Y- (z — d-)) — it, •tan(i •tan6 'z • cos Q Ysnt '7 ks +tang Input Parameters: y,pcf 120 z, ft 0.042 {3,degrees 2.0 yw,pcf 62.4 d,V, ft 0.0 ks, (-) 0.01 FS 0 120 . 0 042 )+tan(5.4) 1 — 62• 0) — _ (120 - 0.042 (cos(2.0))z) ( 0.01 tan(2.0) -tan(S.4) 0.01 + tan(2.0) FS=1.00 Minimum Residual Values from Veneer Static Stability: 8(deg) a(psf) 5.4 0 GW6489Ma -DRAFT Venw SB bihty APC Barry_EPA_000402 Geosyntec consultants Page 13 of 19 CP: TYE Date: 08/27/18 APC: GJR Date: 08/27/2018 CA: GJR Date: 08/27/2018 Client: APUSCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Table 4.Back-Calculation of Peak Interface Shear Strength Parameters along the GGRL— subgrade interface (Interface Adhesion Set to Zero) FS Below GEOMEMBRANE fn ut Parameters: yr(Moist soil unit weight): 120 pet y,a(Saturated soil unit weight): r 120 pet y (Unit wt of water): 62.4 pet yb(Buoyant unit wt of soo: 57.6 pet tw(water depth above critical interface): 0.000 ft t= (water depth at slope toe): 0.000 ft 8(interface fiction angle): 2.6 deg (soil internal friction angle): 30 deg a(interface adhesion intercept): 0.0 psf c(soil cohesion intercept): 0 psf h(vertical height of slope): 22 ft t (depth of cover soil above critical interface): r 0.542 ft 9 (slope inclination), F 2.00 deg FS: 1.50 Table 5. Back-Calculation of Residual Interface Shear Strength Parameters along the GGRL— subgrade interface (Interface Adhesion Set to Zero) FSBelow GEOMEMBRANE input Parameters: yt(Moist soil unit we gh[): 120 pet 1.(Saturated soil unit weight): 120 pet 1,,(Unit wt of water): 62.4 pet yb (Buoyant unit wt of soil): 57.6 pcf to(water depth above critical interface 0.000 ft t* (water depth at slope toe): 0.000 ft 8(interface friction angle): V 2.0 deg 0(soil internal friction angle): V 30 deg *(interface adhesion intercept): V 0.0 pat c(soil cohesion intercept): 0 psf It(vertical height of slope): 22 ft t (depth of cover soil above critical ine 0.542 ft 9 (slope inclination): 2.00 deg FS: F 1201. GW6489Bavy-DRAFT Veneer stability APC Barry_EPA_000403 Geosyntec consultants Page 14 of 19 CP: TYE Date: 08/27/18 APC: GJR Date: 08/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project. Plant Barry Ash Pond Closure Project Project No: GW6489 Table 6. Back-Calculation of Residual Interface Shear Strength Parameters along the GGRL- Subgrade Soil Interface under Seismic Loading(Interface Adhesion Set to Zero) Calculation of Factor of Safety Infinite Slope Conditions [Matasovic, 19911 FS = �Yea, u z ) +tan6(1 —Y- (z — d-)) — it, •tan(i •tan6 'Z • cos Q Ysnt 'Z ks +tang Input Parameters: y,pcf 120 z, ft 0.542 {3,degrees 2.0 yw,pcf 62.4 d,V, ft 0.542 ks, (-) 0.01 FS / 0 +tan(2.6) 1 — 62.4• (0.542 — 0.542) _ 0.01 -tan(2.0) tan(2.6) _ (120 - 0.542 2 (cos(2.0)57) ( 120 • 0.542 ) 0.01 +tan(2.0) FS=1.00 Minimum Residual Values from Veneer Static Stability: S(deg) a(pst) 2.6 0 GW6489Ma -DRAFT Venw SB bihty APC Barry_EPA_0004N Geosyntec consultants Page 15 of 19 CP: TYE Date: 08/27/18 APC: GJR Date: 08/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project. Plant Bury Ash Pond Closure Project Project No: GW6489 FIGURES GW689Ma -DRAFT Veneer Stability APC Barry_EPA_000405 Geosyntec consultants Page 16 of 19 CP: TYE Date: 08/27/18 APC: GJR Date: 08/27/2018 CA: GJR Date: 08/27/2018 Client APC/SCS Project. Plans Bury Ash Pond Closure Project Project No: GW6489 D Wedge 2 r � A Wedge 1 B- h r C � R Figure 1. Slope Geometry Used to Derive Finite Slope Equation for Static Veneer Stability [Giroud et al., 19951 GW6489Ma -DRAFT Veneer 6tebihty APC Barry_EPA_000406 Geosyntec consultants Page 17 of 19 CP: TYE Date: 08/27/18 APC: GJR Date: 08/27/2018 CA: GJR Date: 08/27/2018 Client APC/SCS Project. Plant Bury Ash Pond Closure Project Project No: GW6489 a �= 1 dw kA J Ham^ z O Gf h as ` �u KP Fm9 may * m IV � Umax i -Y - Ground Water Level N►- Seismic Exilalion ^ - Sleady Seepage Omv- Permanent DiSPlacement of MP - Sliding Surface sliding mass Figure 2. Slope Geometry Used to Derive Infinite Slope Equation for Seismic Veneer Stability [Matasovic, 19911 GW64891Ba -DRAFT Veneer Stability APC Barry_EPA_000407 Geosyntec consultants Page 1R of 19 CP: TYE Date: 08/27/18 APC: GJR Date: 08/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project. Plant Bury Ash Pond Closure Project Project No: GW6489 v � 4 2 degrees 22 ft Figure 3. Location and Cross Section of Selected Slope for Veneer Stability Analysis GW689Ma -DRAFT Veneer 8tebihty APC Barry_EPA_000408 Geosyntec° consultants Page 19 of 19 CP: TYE Date: 08/27/18 APC: GJR Date: 08/27/2018 CA: GJR Date: 08/27/2018 Client: APC/SCS Project. Plant Bury Ash Pond Closure Project Project No: GW6489 MIN 1? SAND LAYER ENGINEERED / SYNTHETIC TURF —PREPARED = - 6UBGRADE — b• CLOSURETURFm GEMOMPOSNE AGRU WMIL L-OPE — \ MICRODRAINa II — PREPARED suecanDE I GEOCOMPOSITE 6• CCR TT Figure 4. ClosI Cover System Detail for Plant Barry GW6 8911 v -DRAFT Venw SuIbility APC Barry_EPA_000409 Z%L APPENDIX C4 CLOSURE STABILITY ANALYSIS - LIQUEFACTION APC Barry_EPA_000410 Geosyntec° Consultants CALCULATION PACKAGE COVER SHEET Client: Alabama Power Company& Project: Plant Barry Ash Pond Closure Project#: GW6489 Southern Company Services Project TITLE OF PACKAGE: DRAFT CLOSURE STABILITY ANALYSIS—LIQUEFACTION t- CALCULATION PREPARED BY: Signature 27 August 2018 (Calculation Preparey CP) a. Name Clinton P.Carlson Date �a 6 ASSUMPTIONS&PROCEDURES Signaunc 27 August 2018 CHECKED BY: (Assumptions&Procedures Checker,APC) Name Sid Nadukura Date 3 Glenn J.Rix COMPUTATIONS CHECKED BY: Signanuc 27 August 2018 (Computation Checker,CC) Name M.Gizem Bozkurt Date BACK-CHECKED BY: Signature 27 August 2018 (Calculation Preparer,CP) U Name Clinton P.Carlson Date a m APPROVED BY: Signature 27 August 2018 a (Calculation Approver,CA) Name William Tanner Date REVISION HISTORY: NO. DESCRIPTION DATE CP APC CC CA A Draft Closure Design Calculation Package 08/27/2018 CPC SN/GJR NIGH WMT APC Barry_EPA_000411 Geosynte& consultants Page 1 of 27 CP: CPC Date: 08/27/18 APC: SN/GJR Date: 08/27/18 CA: WMT Date: 0827/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 CLOSURE STABILITY ANALYSIS—LIQUEFACTION PURPOSE This Draft Closure Stability Analysis—Liquefaction calculation package (Package) was prepared in support of the design to close the existing coal combustion residuals(CCR)ash pond at Alabama Power Company's (APC's) Plant Barry (Site), located in Bucks, Alabama. The ash pond will be closed using a"consolidate and cap-in-place" method whereby all CCR will be consolidated into an approximately 300-acre area (i.e., consolidated area) that will be constructed in the central portion of the ash pond using soil containment berms and a final cover system. The purpose of this Package is to present engineering calculations to evaluate the potential for triggering of liquefaction of materials encountered at the Site when subjected to the design earthquake. Specifically, this Package presents: (i) the earthquake hazard for the Site; (ii) results of screening-level analyses of materials encountered at the Site for susceptibility to liquefaction; and(iii)results of calculations for factors of safety against triggering of liquefaction based on in- situ tests (i.e., cone penetration tests)performed at the Site. The remainder of this Package is organized to present: (i) design criteria; (ii) analysis methodology; (iii) subsurface stratigmphy and design parameters; (iv) evaluation results; and (v) a summary with conclusions. DESIGN CRITERIA The liquefaction triggering evaluation presented in this Package was performed based on the following design criteria in accordance with the U.S.Environmental Protection Agency(USEPA) CCR Rule [2015]. Geosyntec [2018a] documents that the Site is considered to be located in a seismic impact zone (for the purposes of the calculations presented in the Draft Closure Stability Analysis — Seismic calculation package [Geosyntec, 2018a] and this Package) and discusses the basis for seismic stability design as follows: • Seismic stability evaluations of CCR impoundments should be performed based on ground motions from a seismic event with a 2 percent probability of exceedance (PE) in 50 years (i.e.,"probable earthquake within approximately 2,500 years") (Federal Register,Vol. 80, No. 74,p. 21316); and • Seismic design of existing CCR impoundments should be based on the"withstand without discharge" standard in accordance with the preamble of the USEPA CCR Rule. GW6 89/Bamy_100%Design_Lipefaction DRAFT2 APC Barry_EPA_000412 Geosynte& consultants Page 2 of 27 CP: CPC Date: 08/27/18 APC: SN/GJR Date: 08/27/18 CA: WMT Date: 0827/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 An additional design criterion applied to the proposed closure is that the calculated factor of safety against triggering of liquefaction should beat least 1.1 (i.e.,no expected triggering of liquefaction). If triggering of liquefaction is expected,a post-earthquake stability evaluation should be performed using reduced strengths. For the post-earthquake stability evaluation of the CCR surface impoundment,the minimum allowable calculated factor of safety is 1.2 based on the USEPA CCR Rule [2015]. ANALYSIS METHODOLOGY Liquefaction of soils is aphenomenon that may occur during seismic loading when loose,saturated materials experience loss of shear strength. The cyclic loading induced by an earthquake causes the loose soil skeleton to tend to collapse, shedding load from the soil particles to the incompressible water in the pore space between the particles. This decreases the effective stress in the soil, resulting in a decrease in soil shear strength and stiffness. If the pore-water pressure increases to approximately the total stress acting on the soil, the effective stress approaches zero and liquefaction is triggered. The current state-of-practice for evaluating liquefaction potential is empirical and based on case histories of occurrences and non-occurrences of liquefaction observed during past earthquakes. Occurrences (or non-occurrences) of liquefaction are determined by the presence (or absence) of surface manifestations of liquefaction such as sand boils, ground cracking, slope movements, and/or flow failures. Surface manifestations are generally present if high pore-water pressures were generated due to seismic loading and liquefaction was triggered. An initial step in performing a liquefaction triggering evaluation is the application of screening criteria (e.g., Bray and Sancio [2006], Boulanger and Idriss [2014]) to evaluate whether soils (or other granular-type materials such as CCR) are susceptible to liquefaction. Materials that are susceptible to liquefaction will not necessarily have liquefaction triggered during the design earthquake;however,further evaluation of these materials is warranted to identify the potential for strength loss during the design earthquake. For materials that are not susceptible to liquefaction, no further evaluation is needed. For the screening evaluation presented in this Package, the soil behavior type (SBT) index (I) estimated from cone penetration tests (CPT) was used to screen out clay-like materials, as noted in Boulanger and Idriss [2014]. h1 general, soils that exhibit clay-like behavior are not susceptible to liquefaction. An SBT index value of 2.5 was used as a threshold value between sand-like and clay-like materials in the interpretation of the subsurface stratigraphy to estimate the locations and elevations at which clay and sand layers were encountered across the Site. However, Boulanger GW6 89/Bao,_100%Design_laquefaction DRAFT2 APC Barry_EPA_000413 Geosynte& consultants Page 3 of 27 CP: CPC Date: 08/27/18 APC: SN/GJR Date: 08/27/18 CA: WMT Date: 0827/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 and Idriss [2014] recommend considering a range for the SBT index (e.g., 2.4 to 2.8) in the liquefaction susceptibility screening process to account for uncertainty in material response to earthquake shaking.An SBT index of 2.8 was conservatively selected for the screening evaluation presented in this Package to identify materials that are considered susceptible to liquefaction(i.e., SBT index values less than 2.8). For materials that are considered susceptible to liquefaction, predicting the potential for liquefaction triggering requires evaluation of both the seismic loading(i.e.,the demand,expressed in terms of the cyclic stress ratio [CSR]) and the soil resistance to the triggering of liquefaction (i.e., the resistance, expressed in terms of the cyclic resistance ratio [CRR]). Factors of safety against triggering ofliquefaction were calculated by taking the ratio of CRR to CSR.For calculated factors of safety against liquefaction less than 1.1, the subsurface material was considered to experience triggering of liquefaction. The CSR and CRR were calculated using the methodology presented below and in Attachment 1. Cyclic Stress Ratio As recommended by the National Academies of Sciences, Engineering, and Medicine [20161,the CSR was calculated using the simplified equation presented in Boulanger and Idriss [2014] to be consistent with the empirical data used to develop the equations for calculating CRR.The equation used to calculate CSR is the following: CSRMw.oy = 0.65 •QD •g— -rd (1) where: CSR�,de = CSR computed for a specific earthquake moment magnitude (M„,) and vertical effective stress(a'„); G„ = estimated vertical total stress (pounds per square foot [psf]); a',, = estimated vertical effective stress (pst); a, .Ig = maximum horizontal acceleration (as a fraction of the gravitational acceleration constant,g); and rd = shear stress reduction factor that accounts for the dynamic response of the soil profile. The vertical total and vertical effective stresses were estimated using the design unit weights (see the Draft Material Properties and Major Design Parameters calculation package [Data Package] [Geosyntec, 2018b]) and interpreted subsurface stratigraphy for the CPT soundings performed GW6 89/Bao,_100%Desiga_I.iquefaction DRAFT2 APC Barry_EPA_000414 Geosynte& consultants Page 4 or 27 CP: CPC Date: 08/27/18 APC: SN/GJR Date: 08/27/18 CA: WMT Date: 0827/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 during the pre-design field investigation (PDCPT) [Geosyntec, 2018c]. The maximum horizontal acceleration was approximated as the design surface spectral acceleration at a spectral period of 0.01 seconds calculated for the corresponding representative profile in the Draft Closure Stability Analysis—Seismic calculation package [Geosyntec, 2018a]. The shear stress reduction factor was calculated using the equations developed by Idriss [1999] presented below: rd = exp[a(z) +/3(z) • Mw] > 0.48 (2) a(z) = —1.012 — 1.126 • sin \L3 73 + 5.133) (3) (3(z) = 0.106 + 0.118 - sin(r12a2a + 5.142) (4) where: re = shear stress reduction factor that accounts for the dynamic response of the soil profile; M. = earthquake moment magnitude; and z = depth below the ground surface (meters [m]). Cyclic Resistance Ratio Results from in-situ tests performed at the Site were used to estimate the CRR for the materials encountered based on the methodology presented by Boulanger and Idriss [2014] and included in Attachment 1. It is noted that the liquefaction susceptibility of CCR is considered in industry practice to be similar to mineral soils; thus,the Boulanger and Idriss [2014] method is considered applicable to CCR. For the purposes of this Package, the calculations for CRR were performed using the Boulanger and Idriss [2014] method by computing an equivalent clean-sand cone tip resistance for the materials with SBT index values less than 2.8. SUBSURFACE STRATIGRAPHY AND DESIGN PARAMETERS Information required for the liquefaction triggering evaluation presented in this Package includes: • Design earthquake moment magnitude; • Subsurface stratigraphy ofthe consolidated area(both existing and post-closure elevations) and existing dikes and constructed containment berms; • Geotechnical parameters of the different materials encountered at the Site; • Results of available in-situ tests; and Gw6489/Bao,_100%Design_Li,eraction D12AFT2 APC Barry_EPA_000415 Geosynte& consultants Page 5 of 27 CP: CPC Date: 08/27/18 APC: SN/GJR Date: 08/27/18 CA: WMT Date: 0827/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 n Surface acceleration response spectra calculated by seismic site response analyses. Earthauake Hazard As presented in the Draft Closure Stability Analysis — Seismic calculation package [Geosyntec, 2018a], the 2014 model in the U.S. Geological Survey (USGS) hazard tool [USGS, 20141 was used to estimate the moment magnitude for a design earthquake at the Site. A design earthquake with a moment magnitude of 5.9 from the deaggregation of a seismic event with a 2 percent PE in 50 years for the peak ground acceleration was established for the Site. Figure 1 shows the design earthquake developed for the BC boundary (i.e., boundary between National Earthquake Hazard Reduction Program (NEHRP) site classes B and C with a mean shear wave velocity of 2,500 feet per second) from the USGS hazard tool [USGS, 20141 at free-field. The design earthquake corresponds to the mean earthquake event derived from the deaggregation. Subsurface Stratisraphv and Geotechnical Parameters The data used to develop the subsurface stratigraphy were obtained from field and laboratory investigations performed at the Site. These data are presented in the Data Package and pre-design field investigation report [Geosyntec, 2018b, 2018c]. Based on the available data sources, the subsurface stratigraphy at the Site primarily consists of(from top to bottom) existing CCR, Clay 1,Sand 1,Clay 2,and Sand 2.For the`consolidate and cap-m-place"method,CCR will be dredged and placed on top of existing CCR to consolidate into an approximately 300-acre area within the central portion of the Site(i.e., consolidated area). Dikes currently exist at the Site,but additional containment berms will be constructed around the consolidated area during closure. A total of 48 PDCPT were performed during the pre-design field investigation (PDCPT-0I to PDCPT-48) [Geosyntec, 2018c]. The locations of these tests are shown in Figure 2. For each PDCPT,the measured cone tip and sleeve resistances were used to estimate water table elevation and, in turn, SBT index values. As stated previously, an SBT index value of 2.5 was used as a threshold value in the interpretation of the subsurface stratigraphy to estimate the locations and elevations at which Clay 1,Sand 1,Clay 2,and Sand 2 were encountered across the Site. Generally across the Site,existing CCR was observed at elevations above 0 feet mean sea level(ft-msl),Clay 1 was observed between elevations 0 and-10 ft-msl, Sand 1 was observed between elevations -10 and -20 ft-msl, Clay 2 was observed between elevations -20 and -30 ft-msl, and Sand 2 was observed between elevations -30 and-50 ft-msl as detailed in the Draft Closure Stability Analysis — Seismic calculation package [Geosyntec, 2018a]. However, the interpreted subsurface stratigraphy for each PDCPT location was used in the screening evaluation and calculations of factors of safety against triggering of liquefaction. GW6 89/Bao,_100%Desig _Liquefaction DRAFT2 APC Barry_EPA_000416 Geosynte& consultants Page 6 of 27 CP: CPC Date: 08/27/18 APC: SN/GJR Date: 08/27/18 CA: WMT Date: 0827/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 As presented in the Data Package, the unit weights of the materials encountered across the Site vary by reach [Geosyntec, 2018b]. The boundaries for the different reaches are indicated by the solid black lines on Figure 2. The design unit weights were used in the screening evaluation and calculation of factors of safety against liquefaction. Figure 3 shows the fines contents measured during laboratory tests on samples of the materials encountered at the Site. The fines contents selected for the calculations of factors of safety against triggering of liquefaction presented in this Package are indicated by the dashed lines on Figure 3. A fines content of 60 percent is considered for the existing CCR. For the seams of sand-like material within Clay 1 and Clay 2, a selected fines content of 80 percent is used. Although the measured fines contents for Sand 1 and Sand 2 generally varied between 5 and 60 percent, conservative values of 10 and 0 percent, respectively, are used in the calculations of factors of safety against triggering of liquefaction. In-Situ Tests PDCPT-01,PDCPT-37 through PDCPT40,PDCPT42 through PDCPT-45, and PDCPT-48 were used in the screening evaluation and calculations of factors of safety against triggering of liquefaction for the materials encountered within the consolidated area. The existing ground surface elevations for PDCPT-01, PDCPT-39, and PDCPT42 approximately equal the post- closure elevations for the CCR closure indicated by the solid gray lines on Figure 2. Additional CCR placed on top of the existing CCR during the closure will have the following thicknesses for the other PDCPT within the consolidated area: (i) approximately 8 to 15 feet (ft) for PDCPT-38, PDCPT-44, PDCPT-45, and PDCPT-48; (ii) approximately 20 fit for PDCPT43; and (iii) approximately 30 It for PDCPT-37 and PDCPT40. PDCPT-02 through PDCPT-36, PDCPT-41, PDCPT-46, and PDCPT-47 were used in the screening evaluation and calculations of factors of safety against triggering of liquefaction for the materials encountered below the existing dikes and the containment berms that will be constructed around the consolidated area. As shown in Figure 2,many of these PDCPT were performed at the approximate toe of the existing dikes or the containment berms that will be constructed around the consolidated area. Therefore, for the calculations of the factors of safety against triggering of liquefaction,the overburden stresses of the existing CCR or dikes were conservatively neglected. Interpreted water table elevations from the PDCPT soundings were used in the calculation of the SBT index values.However,the water table elevations for post-closure conditions were considered in the calculations of factors of safety against triggering of liquefaction.The water table within the existing CCR is approximately at or above the existing ground surface and must be lowered to Gw6a89/Bao,_100%Desi,_laquefaction n12AFT2 APC Barry_EPA_000417 Geosynte& consultants Page 7 of 27 CP: CPC Date: 08/27/18 APC: SN/GJR Date: 08/27/18 CA: WMT Date: 0827/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 provide a more stable working platform prior to construction of the CCR closure. During and immediately after construction of the CCR closure (i.e., post-closure), the water table within the existing CCR was considered to be 2 ft below the top of the existing CCR.For long-term conditions (i.e., many years after closure), the water table elevation within the existing CCR is expected to approach an elevation of approximately 3 ft-msl. The water table elevation for post-closure conditions is conservatively considered for the PDCPT performed within the consolidated area in this Package. Prior to construction of the containment berms for the closure, the water table elevation will be drawn down to approximately 0 ft-msl(i.e., the bottom of the existing CCR)around the perimeter of the consolidated area. The water table elevation within the existing dikes is also considered to be at 0 ft msl for the purposes of this Package. For the calculations of the factors of safety against triggering of liquefaction for the materials encountered below the existing dikes and the containment berms that will be constructed during the CCR closure,the water table was considered to be at the post-closure ground surface (i.e., top of Clay 1 or Sand 1 layer or an approximate elevation of 0 ft-msl). For the PDCPT performed within the consolidated area, the following adjustments were made to the in-situ measurements prior to calculating the factors of safety against liquefaction: • Lower water table to 2 ft below the top of the existing CCR; • Adjust the depths of the sample measurements to include the thickness of the additional CCR placed on top of the existing CCR(if any) • Recalculate the vertical total stress to include the increase in stress induced by the placement of additional CCR(if any); and • Recalculate the vertical effective stress to account for the lower water table and increase in stresses induced by the placement of additional CCR. For the PDCPT performed along the dikes/containment berms, the following adjustments were made to the in-situ measurements prior to calculating factors of safety against liquefaction: • Lower water table to the post-closure ground surface elevation; • Adjust the depths ofthe sample measurements to reference the post-closure ground surface elevation as a depth of zero feet; • Recalculate the vertical total stress to remove the stresses induced by the existing CCR or embankment dikes; and GW6 89/Bao,_100%Design_Lipefaction DRAFT2 APC Barry_EPA_000418 Geosynte& consultants Page 8 of 27 CP: CPC Date: 08/27/18 APC: SN/GJR Date: 08/27/18 CA: WMT Date: 0827/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 • Recalculate the vertical effective stress to account for the lower water table and removal of stresses induced by the existing CCR or embankment dikes. Surface Acceleration Response Spectra Design surface acceleration response spectra were computed for profiles representative of the consolidated area for existing and post-closure elevations and the existing dikes and containment berms constructed during the closure in the Draft Closure Stability Analysis—Seismic calculation package [Geosyntec,2018a]. The calculated design surface acceleration response spectra from the seismic site response analyses for the design earthquake are shown in Figure 4. For PDCPT-01, PDCPT-39, and PDCPT-42 (i.e., PDCPT within the consolidated area where existing ground surface elevations are similar to the post-closure ground surface elevations),a maximum horizontal acceleration of approximately 0.08g, corresponding to the surface spectral acceleration calculated for the existing consolidated area profile at a period of 0.01 seconds, is used in Equation 1 to calculate the CSR profiles for these three PDCPT. A maximum horizontal acceleration of approximately 0.04g, which corresponds to the surface spectral acceleration calculated for the post-closure consolidated area profile (i.e., profile with additional CCR placed on top of the existing CCR) at a period of 0.01 seconds, is used to calculate the CSR profiles for the remaining PDCPT performed within the consolidated area. The calculated surface spectral acceleration at a period of 0.01 seconds for the dikes/containment berms representative profile is approximately 0.06g and is used in the calculation of the CSR profiles for the PDCPT performed along the existing dikes and the containment berms that will be constructed during closure. EVALUATION RESULTS Screening Results Figures 5 and 6 show the estimated SBT index values for materials encountered at the PDCPT performed within the consolidated area and along the dikes/containment berms, respectively. The sand layers are generally considered susceptible to liquefaction while the clay layers are generally not considered susceptible to liquefaction. However, there are seams of clay-like materials (i.e., SBT index values greater than 2.8) observed within the sand layers at some of the PDCPT locations. Including these seams of clay-like materials in the calculations of factors of safety against triggering of liquefaction is not practical as these materials are not considered susceptible to liquefaction. Similarly,there are seams of sand-like materials(i.e.,SBT index values less than 2.8) observed within the clay layers which would be considered susceptible to liquefaction. Therefore,factors of safety against triggering of liquefaction were only calculated for materials considered susceptible to liquefaction (i.e., materials with SBT index values less than Gw6489/Bao,_100%Desip_Lipefaction D12AFT2 APC Barry_EPA_000419 Geosynte& consultants Page 9 of 27 CP: CPC Date: 08/27/18 APC: SN/GJR Date: 08/27/18 CA: WMT Date: 0827/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 2.8). This encompasses a large portion of the existing CCR, a majority of the Sand 1 and Sand 2 layers, and some seams of sand-like material within the Clay 1 and Clay 2 layers. The dredged CCR placed on top of the existing CCR within the consolidated area and the existing dikes and containment berms that will be constructed during the closure will be above the water table elevation for post-closure conditions; thus, these materials are not considered susceptible to liquefaction and are not analyzed further. Cyclic Stress Ratios Figures 7 and 8 show the calculated CSR profiles for the PDCPT performed within the consolidated area and along the dikes/containment berms,respectively. The maximum calculated CSR values at PDCPT-01, PDCPT-39, and PDCPT-42 are approximately 0.12 and occur within the existing CCR. For the remaining PDCPT performed within the consolidated area, the calculated CSR values range from 0.02 to 0.04 and occur within the existing CCR as shown in Figure 7. The larger maximum calculated CSR values observed at PDCPT-01, PDCPT-39, and PDCPT-42 are the result of no additional CCR being placed at these locations and, in turn, the lower vertical stresses. As shown in Figure 8, the maximum calculated CSR values at the PDCPT performed along the existing dikes and containment berms constructed during the closure range from 0.09 to 0.13 and occur at the post-closure ground surface elevations. Factors of Safety Calculations The calculated factors of safety against triggering of liquefaction for the materials encountered within the consolidated area and below the dikes/containment berms are shown in Figures 9 and 10,respectively. For the materials encountered within the consolidated area,the calculated factors of safety against triggering of liquefaction are greater than 1.2. The lowest calculated factors of safety are observed within the materials encountered at PDCPT-01,PCDPT-39,and PDCPT-42 as a result of the larger calculated CSR values.The lowest calculated factors of safety for the materials encountered within the consolidated area are observed within the existing CCR(i.e.,elevations between approximately 0 and 20 ft-msl). The Sand 1 and Sand 2 layers encountered at the PDCPT performed within the consolidated area have minimum calculated factors of safety against triggering of liquefaction of approximately 1.4 and 1.7, respectively. Given the calculated factors of safety for the materials encountered within the consolidated area, liquefaction is not expected to be triggered within this area during the design earthquake. GW6 89/Bao,_100%Design_Lipefaction DRAFT2 APC Barry_EPA_000420 Geosynte& consultants Page 10 of 27 CP: CPC Date: 08/27/18 APC: SN/GJR Date: 08/27/18 CA: WMT Date: 0827/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 As shown in Figure 10, the calculated factors of safety against triggering of liquefaction for the materials encountered below the existing dikes and containment berms that will be constructed during the closure are generally greater than the target factor of safety of 1.1. There is one sample depth at one PDCPT(PDCPT-09)where the material encountered has a calculated factor of safety against triggering of liquefaction that is slightly less than 1.1.However,this layer is very thin(i.e., less than 0.2-ft thick)and is isolated, so it is not expected to impact the stability of the CCR closure should liquefaction be triggered during the design earthquake. The lowest calculated factors of safety for the materials encountered below the existing dikes and containment berms that will be constructed during the closure are observed within the Sand 1 layer or seams of sand-like material within the Clay 1 layer (i.e., elevations between approximately-6 and -20 ft-msl). The minimum calculated factors of safety against triggering of liquefaction for the Sand 2 layer and seams of sand-like materials within the Clay 2 layer(i.e., elevations between approximately-20 and-40 ft- msl) encountered below the dikes/containment berms is approximately 1.4. SUMMARY AND CONCLUSIONS A liquefaction triggering evaluation was performed based on the USEPA CCR Rule [2015] requirement for facilities in seismic impact zones,which the Site is considered to be within for the purposes of this Package, for the consideration of earthquake ground motions with a 2 percent probability of exceedance in 50 years for the design of CCR surface impoundments and associated structural components. The dredged CCR placed on top of the existing CCR within the consolidated area and the existing dikes and containment berms that will be constructed during the closure are not considered susceptible to liquefaction because these materials will be above the water table in the post-closure conditions. Results from PDCPT performed during a pre-design field investigation [Geosyntec, 2018c] were used to screen the materials encountered at the Site for susceptibility to liquefaction using the criterion noted by Boulanger and Idriss [2014].The materials encountered at the Site that screened as sand-like materials, including existing CCR, Sand 1, Sand 2, and some seams within Clay 1 and Clay 2, are considered potentially susceptible to liquefaction. Factors of safety against triggering of liquefaction for materials encountered at the Site that are considered susceptible to liquefaction were calculated using the Boulanger and Idriss [2014] method and the results of the PDCPT performed at the Site.The calculated factors of safety against the triggering of liquefaction for the materials encountered within the consolidated area are greater than 1.2. The materials encountered below the existing dikes and containment berms that will be constructed during the closure have calculated factors of safety against triggering of liquefaction greater than 1.1 except for a very thin(i.e.,less than 0.2-ft thick),isolated seam that is not expected GW6 89/Baoy_100%Design_Li,efaction DRAFT2 APC Barry_EPA_000421 Geosynte& consultants Page 11 of 27 CP: CPC Date: 08/27/18 APC: SN/GJR Date: 08/27/18 CA: WMT Date: 0827/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 to impact post-earthquake stability. Therefore, liquefaction is not expected to be triggered within the materials encountered within the consolidated area and not expected to impact the stability of the CCR closure and dikes/containment berms. REFERENCES Boulanger, R.W. and Idriss, I.M. (2014). "CPT and SPT Based Liquefaction Triggering Procedures," Report No. UCD/CGM-14/01, Center for Geotechnical Monitoring, University of California, Davis, CA. Bray, J.D. and Sancio, R.B. (2006). "Assessment of the Liquefaction Susceptibility of Fine- Grained Soil,"Journal of Geotechnical and Geoenvironmental Engineering,Vol. 132,No. 9,pp. 1165-1177. Geosyntec. (2018a). "Draft Closure Stability Analysis—Seismic," calculation package submitted to Alabama Power Company and Southern Company,August 2018. Geosyntec. (2018b). "Draft Material Properties and Major Design Parameters," calculation package submitted to Alabama Power Company and Southern Company, August 2018. Geosyntec. (2018c). "Draft Pre-Design Field Investigation Summary Report," submitted to Alabama Power Company, June 2018. Idriss, I.M. (1999). "An Update to the Seed-Idriss Simplified Procedure for Evaluating Liquefaction Potential," Proceedings, TRB Workshop on New Approaches to Liquefaction, Publication No. FHWA-RD-99-165, Federal Highway Administration, Washington,D.C. National Academies of Sciences,Engineering,and Medicine.(2016).State of the Art and Practice in the Assessment of Earthquake-Induced Soil Liquefaction and its Consequences, The National Academies Press, Washington,D.C. United States Environmental Protection Agency (USEPA). (2015). "40 CFR Parts 257 and 261: Hazardous and Solid Waste Management System; Disposal of Coal Combustion Residuals from Electric Utilities,"Federal Register,Vol. 80,No. 74. United States Geological Survey (USGS). (2014). "Dynamic: Conterminous U.S. 2014 (v4.1.1) Interactive Deaggregations,"<hqpsi//earthquake.usgs.gov/hazards/interactive GW6 89/Bao,_100%Desi,Liquefaction DRAFT2 APC Barry_EPA_000422 Geosyntec° comultBntS Page 12 of 27 CP: CPC Date: 08/27/18 APC: SN/GJR Date: 08/27/18 CA: WMT Date: 08/27/18 Client: APCISCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 FIGURES GWW9/Berry 100%Desigo_LigaeGUion_DR APC Barry_EPA_000423 Geosyntec° Consultants Page 13 of 27 CP: CPC Date: 0827/18 APC: SN/GJR Date: 0827/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 ■g=(b..-2.5) e=62.5..-2) ■e=62..-1.5) '5S 1.5..a) e ❑6=61..-0.5) a¢�3R�'�"` �5 e . cp ❑e-60s..D) n \Sp b5 Ooee 3 lbP ❑E=I0..0.5) OObo owe 15 tOsta L]c=I05. 1) r0 yam• yam.prP �e=I1..1.5) Roo/� ■e=I1.5..2) e=(2..2.5) s a. . e._ ■e=(2.5.. �1 l6 3zS � 65 PSt� qe 1ci a � st S pre ky Sr 6S¢���` b .tpa a/��/ aos b5t2,aQc pS 94s n smnmary statistics for,Deaggregation:Total Deaggregatientargein R¢Ryered targets TBti msen(farallsourcee) set..,i.d:1415yrs Retum Betled: 25205678M Binned: 100% n151E6km .edenwnte: 0.OW4.4.1' Oceedence rate:0A00396r36m yr' Ridden, O% m:593 R6Ggroundmodon: 0.04M83312g Tarn 2.M% me..B21. Figure 1. Deaggregation of 2 Percent Probability of Exceedance in 50 Years Earthquake Event for Peak Ground Acceleration at a BC Boundary at the Site(Obtained from USGS Hazard Tool [20141) GW6489/Bnry 100%Desigo_LiVeGUion_DItAFI2 APC Barry_EPA_000424 Geosynte& consultants Page 14 d 27 CP: CPC Date: 08/27/18 APC: SN/GJR Date: 08/27/18 CA: WMT Date: 0827/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 r-----------------------------T-----------------------------1 I I 1 55 Al 1 I 1 I I 1 •:l.\.;x'�ti .`- .. . me 1 1 � I l f L - - ---------------------------t -- ------ --- ------ --i I I I I I 1 I ^^ 1 I 1 + 1 Figure 2.Locations of Cone Penetration Tests Performed during the Pre-Design Field Investigation(PDCPT) [Geosyntec, 2018c] Notes: 'The circled PDCPT were used in the liquefaction triggering evaluation of the materials encountered within the consolidated area while the boxed PDCPT were used in the liquefaction triggering evaluation of the materials encountered below the dikes/containment berme. 'The solid black lines represent the boundaries of the different reaches presented in the Data Package [Geosyntec, 2018b]. 'The gray contour lines represent the proposed final elevations and grades of the closure. GW6489/na 100%Design Liquefaction DRAPr2 APC Barry_EPA_000425 Geosyntec° Consultants Page 15 of 27 CP: CPC Date: 0827/18 APC: SN/GJR Date: 0827/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 50 40 30 20 ' 10 ' • n ' �� •• Y o ' • • ' t � � • Clay 1 v 0 ♦ ♦ ♦ ♦ • • � r • • ♦Clay2 -10 ♦♦ ♦ ♦ e •• • • ♦ Sand 1 ♦• ♦♦ x Sand 2 -20 x I~ ♦♦4 : ♦ x 30 x x x x x 40 xX x X -50 x 0 20 40 60 80 100 Fines Content (%) Figure 3. Fines Contents Measured for Materials Encountered at the Site Note: 'The dashed lines represent the fines contents selected for the materials encountered at the Site and used in the calculations of factors of safety against triggering of liquefaction presented in this Package. GW6489uso, 100%Desigo_Li,efaawn_DItAFr2 APC Barry_EPA_000426 Geosyntec° Consultants Page 16 of 27 CP: CPC Date: 0827/I8 APC: SN/GJR Date: 0827/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 0.25 —Existing Consolidated Area —Post-Closure Consolidated Area 0.2 —Dikes/Containment Berms el —Input UHS 0.15 v U U Q 0.1 b N 0. rn 0.05 0 0.01 0.1 1 Period (see) Figure 4. Design Surface Acceleration Response Spectra Calculated for the Consolidated Area(Existing and Poet-Closure Elevations) and Dikes/Containment Berms Representative Profiles Notes: 'The input UHS represents the uniform hazard spectrum calculated for a seismic event with a 2 percent probability of exceedance in 50 years using the USGS hazard tool [USGS, 2014]. The UHS was used as input in the 1-D equivalent linear site response analyses. GW6489uso, 100%Desigo_LiVefaction_DItAFR APC Barry_EPA_000427 Geosyntec° Consultants Page 17 of 27 CP: CPC Date: 0827/18 APC: SN/GJR Date: 0827/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 Soil Behavior Type Index, Ic 0.0 1.0 2.0 3.0 4.0 50 o PDCPT-01 G PDCPT-37 Sand-Like Clay-Like 40 o PDCPT-38 0 PDCPT-39 30 x PDCPT-40 x PDCPT-42 +PDCPT-43 o M 20 o PDCPT-44 ° 0 0 o G PDCPT-45 g`� 0 o PDCPT-48 0 o 10 oXfib,$� o @6'�; o, o° 0 0 X w 1p � o0 -20 mho ® � o 0 K -30 � o �0 °W -40 CPO ° 40 0 -50 Figure 5.Estimated Soil Behavior Type(SBT)Index Values for Cone Penetration Tests (PDCPT)Performed within the Consolidated Area Note: 1A cut-off value of 2.8 was conservatively used for the SBT index to identify sand-like materials (i.e., less than 2.8) considered for the factor of safety calculation for triggering of liquefaction. 2SBT index values were calculated using the water table elevations estimated from measurements at the PDCPT. GW6489/Berry 100%Desigo_Liquefaction DRAFR APC Barry_EPA_000428 Geosynte& Consultants Page 18 of 27 CP: CPC Date: 08M/18 APC: SN/GJR Date: 08M/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Harry Ash Pond Closare Design Project No: GW6489 Soil Behavior Type Index, k Soil Behavior Type Index, 1, Sod Behav or Type Index, 1< Soil Behavior Type Index, L 0.0 1.0 2.0 3.0 4.0 0.0 1.0 2.0 3.0 4.0 0.0 1.0 2.0 3.0 4.0 0.0 1.0 2.0 3.0 4.0 50 50 50 50 o PDCPT-02 o PDCPT-12 4 o PDCPT-22 4 0 PDCPT-32 o PDCPT-03 Sand-Like Clay-Like o PDCPT-13 Sand-Like Clay-Like o PDCPT-23 Sand-Lice Clay-Lire o PDCPT-33 Sand-Like Clay-Like 40 -PDCPT-04 40 °PDCPT-14 o PDCPT-24 40 ,PDCPT-34 o PDCPT-05 °PDCPT-15 °PDCPT-25 °PDCPT-35 30 xPDCPT-06 30 xPDCPT-16 _ 30 x PDCPT-26 30 xPDCPT-36 x PDCPT-07 xPDCPT-17 xPDCPT-27 xPDCPT-41 +PDCPT-08 +PDCPT-18 +PDCPT-29 +PDCPT-46 20 -PDCPT-09 20 -PDCPT-19 20 oPDCPT-29 20 -PDCPT-47 o PDCPT-10 o PDCPT-20 o PDCPT-30 o PDCPT-11 o PDCPT-21 o PDCPT-31 10 10 10 l0 0 �a �Oo 0 ® �° °� i§e 0 to ° 0 ++ x X10 0 n -10 0o -10 -10o-20 0 -20 20 a� -20 +%+X �°R16 o 0 0 og o-30 + + + -30 $+ � -30 8 a16 °o 0 0 -30`d °� x ++ +4 o o°o o °°80 + oiQp -40 o ® x -00 co ® -00 rA cs� o -40 +# o°OSo 8 ° °mO -50 -50 -50 -50 Figure 6.Estimated Soil Behavior Type(SBT) Index Values for Cone Penetration Tests(PDCPT) Performed along the Dikes/Containment Berms Note: IA cut-off value of 2.8 was conservatively used for the SBT index to identify sand-like materials (i.e., less than 2.8)considered for the factor of safety calculation for triggering of liquefaction. 'SBT index values were calculated using the water table elevations estimated from measurements at the PDCPT. GW6489/11an, 100%Dwigo_LigaeWtion_DRAFr2 APC Barry_EPA_000429 Geosyntec° consultants Page 19 of 27 CP: CPC Date: 0827/I8 APC: SN/GJR Date: 0827/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 Cyclic Stress Ratio 0.00 0.05 0.10 0.15 50 40 — 30 20 10 w c y4 0 W 10 —PDCPT-01 -20 —PDCPT-37 —PDCPT-38 —PDCPT-39 -30 —PDCPT40 —PDCPT-42 -40 - —PDCPT43 —PDCPT44 —PDCPT-45 -50 —PDCPT48 Figure 7. Cyclic Stress Ratio(CSR)Profiles Calculated at the Cone Penetration Tests (PDCPT) Located witbin the Consolidated Area Note: 'The CSR profiles were calculated using the Boulanger and Idriss [2014] procedure and the post-closure stratigraphy and water table elevations (i.e., approximately 2 ft below the top of existing CCR). GW6489/Berry 100%De igo_LigaeGUion_DR APC Barry_EPA_000430 Geosyntec° Consultants Page 20 of 27 CP: CPC Date: 08M/18 APC: SN/GJR Date: 08M/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Harry Ash Pond Closure Design Project No: GW6489 Cyclic Stress Ratio Cyclic Stress patio Cyclic Stress Ratio Cyclic Stress Ratio 0.00 0.05 0.10 0.15 0.00 0.05 0.10 0.15 000 005 010 0.15 0.00 0.05 0.10 0.15 50 50 50 50 —PDCPT-02 —PDCPT-12 —PDCPT-22 —PDCPT-32 40 PDCPT-03 —PDCPT-13 —PDCPT-23 —PDCPT-33 —PDCPT-04 40 —PDCPT-14 40 —PDCPT-24 40 —PDCPT-05 —PDCPT-15 —PDCPT-25 —PDCPT-34 30 —PDCPT-06 30 —PDCPT-16 30 —PDCPT-26 30 —PDCPT-35 —PDCPT-07 —PDCPT-17 —PDCPT-27 —PDCPT-36 —PDCPT-08 —PDCPT-18 —PDCPT-28 —PDCPTAI 20 —PDCPT-09 20 —PDCPT-19 20 —PDCPT-29 20 _PDCPT-46 —PDCPT-10 —PDCPT-20 —PDCPT-30 —PDCPT-11 —PDCPT-21 —PDCPT-31 —PDCPT-47 10 10 10 10 c g a o 0 0 u� -10 -10 -10 .10 -20 -20 20 -20 -30 -30 -30 -30 -40 -40 40 — -40 -50 .50 -50 -50 Figure 8. Cyclic Stress Ratio(CSR)Profiles Calculated at the Cone Penetration Tests(PDCPT) Located along the Dikes/Containment Berms Note: 'The CSR profiles were calculated using the Boulanger and Idriss [2014] procedure and the post-closure stratigraphy and water table elevations (i.e.,post-closure ground surface elevation). GW6489/Bany 100%Dwi, Li,eWtion—DRAFP2 APC Barry_EPA_000431 Geosyntec° consultants Page 21 of 29 CP: CPC Date: 08n7/18 APC: awG,m Date: 08n7/18 CA: WMT Date: 08r27n8 Client: APCISCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 Calculated FS Agautst Liquefaction 0.00 0.50 1.00 1.50 2.00 50 o PDCPT-01 D PDCPT-37 40 -PDCPT-38 o PDCPT-39 30 xPDCPT-40 x PDCPT-42 +PDCPT43 ** x 20 oPDCPT-44 x ❑PDCPT-45 AA LA o PDCPT-48 10 o � C � 0 Ox Wo * 0 -10 �* Doi ®o 0 -20 x 0 -30 -40 -50 Figure 9. Calculated Factors of Safety(FS)Against Triggering of Liquefaction for Materials Encountered at Cone Penetration Tests (PDCPT) Located within the Consolidated Area Note: 'Factors of safety against triggering of liquefaction were only calculated for materials with estimated SBT index values less than 2.8 (i.e., materials potentially susceptible to liquefaction). 'The calculations were performed using the post-closure stratigraphy and water table elevations (i.e., approximately 2 ft below the top of existing CCR). GW6489uso, 100%Deign Liquefaction DRAFT2 APC Barry_EPA_000432 Geosynte& consultants Page 22 of 27 CP: CPC Date: 0827/18 APC: SN/GJR Date: 0827/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Harry Ash Pond Closure Design Project No: GW6489 Calculated FS Against Liquefaction Calculated FS Against Liquefaction Calculated FS Against Liquefaction Calculated FS Against Liquefaction 0.00 0.50 1.00 1.50 2.00 0.00 0.50 1.00 1.50 2.00 0.00 0.50 1.00 1.50 2.00 0.00 0.50 1.00 1.50 2.00 50 50 50 50 o PDCPT-02 .PDCPT-12 -PDCPT-22 oPDCPT-32 -PDCPT-03 -PDCPT-13 -PDCPT-23 cPDCPT-33 40 -PDCPT-04 40 ,PDCPT-14 40 1PDCPT-24 40 °PDCPT-34 &PDCPT-05 &PDCPT-15 °PDCPT-25 &PDCPT-35 30 xPDCPT-06 30 xPDCPT-16 30 xPDCPT-26 30 xPDCPT-36 x PDCPT-07 x PDCPT-17 x PDCPT-27 x PDCPT-41 +PDCPT-08 tPDCPT-18 +PDCPT-28 +PDCPT-46 20 -PDCPT-09 20 oPDCPT-19 20 .PDCPT-29 20 oPDCPT47 o PDCPT-10 oPDCPT-20 -PDCPT-30 o PDCPT-11 -PDCPT-21 -PDCPT-31 10 10 10 10 m M 0 x 0 &In 0 X'cf 0 y + W o x o � & 40 M + o x6%� + o o W -10 + * k �V.°� -10 0 0 0 0 0 -]0 + ,," ,- - 0g2 -20 °To+'Qo �'b -20 -20 ° 80 ° - -20 + + xSax-rx o d9 x ox & ° x x fix*' IT ++ ao o °®oo x ° -30 - +++ +o -30 && ++ & -30 x -30 + b ® + * x -40 1 * -00 -40 -40 00 -50 r -50 r -50 -50 Figure 10. Calculated Factors of Safety(FS)Against Triggering of Liquefaction for Materials Encountered at Cone Penetration Tests (PDCPT)Located along the Dikes/Containment Berms Note: 'Factors of safety against triggering of liquefaction were only calculated for materials with estimated SBT index values less than 2.8 (i.e., materials potentially susceptible to liquefaction). 'The calculations were performed using the post-closure stratigraphy and water table elevations(i.e., approximately 2 ft below the top of existing CCR). GW6489/Bart, 100%Desigo_LiqueWtion_DRAFT2 APC Barry_EPA_000433 Geosyntec° comultBnts Page 23 of 27 CP: CPC Date: 08/27/18 APC: SN/GJR Date: 08/27/18 CA: WMT Date: 08/27/18 Client: APCISCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 ATTACHMENT 1 BOULANGER AND IDRISS [20141 METHOD GW6489/Berry 100%Desigo_LigaeGUion_DR APC Barry_EPA_0004M Geosyntec° Consultants Page 24 of 27 CP: CPC Date: 0827/I8 APC: SN/GJR Date: 0827/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 BOULANGER AND IDRISS METHOD Corrected Cone Tip Resistance Cone tip resistances measured during the CPT(qn)were corrected for unequal end area effects [Campanella et al., 1982] using the following equation: qt = qc + (1— ar)u2 (1) where: qt = corrected cone tip resistance(psf); q, = cone tip resistance measured during CPT sounding(psf); al = area ratio for the cone tip; and tee = pore pressure measured behind the cone tip (psf). The corrected cone tip resistances were reported for the CPT soundings performed at the Site during the pre-design investigation [Geosyntec,20181. Overburden Correction Factors The corrected cone tip resistances were also corrected for the overburden stresses encountered at the depth of the measurements. The correction factor for overburden stress was calculated using the following equations: m CN = (o°) < 1.7 (2) v m = 1.338 — 0.249(gtrNrs)0.264 (3) where: CN = overburden stress correction factor; Po = atmospheric pressure=2,116.2 psf; n'a = estimated vertical effective stress at depth of CPT measurement (psf); and gtwes = equivalent clean-sand corrected cone tip resistance normalized for overburden stress. In Equation 3, the equivalent clean-sand corrected cone tip resistance normalized for overburden stress was limited to values between 21 and 254. GW6489uso, 100%Doigo_Li,eGUion_DItAFP2 APC Barry_EPA_000435 Geosyntec° Consultants Page 25 of 27 CP: CPC Date: 0827/I8 APC: SN/GJR Date: 0827/18 CA: WMT Date: 08/27/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 The corrected cone tip resistances normalized for overburden stress were then calculated using the following equation: gt1N = CN Pt (4) a where: qnN = corrected cone tip resistance normalized for overburden stress. The overburden correction factor was iteratively calculated using the calculated equivalent clean-sand corrected cone tip resistances. In addition to the overburden correction factors applied to the cone tip resistances, an overburden correction factor for the CRR was also calculated using the equations below: Ko = 1 — Cn In leal < 1.1 (5) _ ( ) Cn 37.3-8.27(gtrNCS)ossl 0.3 6 where: Ka = overburden correction factor for CRR. Equivalent Clean-Sand Correction A correction factor accounting for the fines content of the materials encountered at the Site was added to the corrected normalized cone tip resistances to calculate equivalent clean-sand values. The correction factor accounting for the fines content was calculated using: rr (/ 57 l AgtIN = (11.9 + 9t,N\14.6)exp 11.63 — ec+z - (71 +z/2] (7) where: LLLLLL AgnN = equivalent clean-sand correction factor for cone tip resistance; and FC = fines content considered for the encountered material(percent). These correction factors were added to the corrected normalized cone tip resistances to calculate equivalent clean-sand corrected cone tip resistances using the equation below: gt,Ncs = gt1N +Agt1N (8) GW6489/Berry 100%Dwigo_LigaeGUion_DItAFI2 APC Barry_EPA_000436 Geosyntec° consultants Page 26 of 27 CP: CPC Date: 08/27/18 APC: SN/GJR Date: 08/27/18 CA: WMT Date: 08/27/18 Client: APCISCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 Magnitude Scaling Factor A magnitude scaling factor was used to adjust the calculated CRR for the design earthquake event at the Site. The magnitude scaling factor was calculated using: MSF = 6.9 • exp(m-) — 0.058 < 1.8 (9) where: MSF = magnitude scaling factor; and M. = moment magnitude for the design earthquake event. Cyclic Resistance Ratio The CRR for a reference moment magnitude of 7.5 and vertical effective stress of 1 atmosphere (CRRm-7.5,d,=1 aan)was calculated using the following equation: QLINCS 1/QrIN,S 2 1/QLINCS 3 I/9[INCS 4 llII CRRM=7s,av=tatm = exP[ 113 + \ 3000 ) — \ 140 ) + \ 137 ) — 2.81 (10) The reference CRR was then adjusted to the design earthquake for the Site and the vertical effective stress for the depth of the cone tip resistance measurement using the equation below: CRRM oe = Ka • MSF • CRRM=7.5,o„=1atm (11) where: CRRm,,aro = site-adjusted CRR. The reference and site-adjusted CRR were limited to values of 100 in the calculations. Factor of Safety Against Liquefaction The factor of safety against the triggering of liquefaction (FSN) was calculated using the following equation: CRRM o F$li0 = CSR v (20) where: CSR = cyclic stress ratio calculated at the depth of the cone tip resistance measurement for the corresponding representative profile. GW6489/11erry 100%Desigo_LiVeGUion_DR APC Barry_EPA_000437 Geosyntec° Consultants Page 27 of 27 CP: CPC Date: 08/27/18 APC: SN/GJR Date: 08/27/18 CA: WMT Date: 08/27/18 Client: APCISCS Project: Plant Barry Ash Pond Closure Design Project No: GW6489 Calculated factors of safety greater than 2.0 were reported as 2.0. Factor of safety calculations were only performed for measurements below the water table and for materials with SBT index values less than 2.8. REFERENCES Boulanger, R.W. and Idriss, I.M. (2014). "CPT and SPT Based Liquefaction Triggering Procedures," Report No. UCD/CGM-14/O1, Center for Geotechnical Monitoring, University of California, Davis, CA. Campanella, R.G., Gillespie, D. and Robertson, P.K. (1982). `Pore Pressures during Cone Penetration Testing," Proceedings of the 2nd European Symposium on Penetration Testing,ESPOT II, A.A. Balkema,Amsterdam, The Netherlands,pp. 507-512. Geosyntec. (2018). "Draft Pre-Design Field Investigation Summary Report," submitted to Alabama Power Company, June 2018. GW6489/11erry 100%De igo_LigaeGUion_DR APC Barry_EPA_000438 APPENDIX C5 INTERIM CONDITIONS SLOPE STABILITY ANALYSIS APC Barry_EPA_000439 Geosyntec° consultants CALCULATION PACKAGE COVER SHEET Client: Alabama Power Company & Project: Plant Barry Ash Pond Closure Project#: GW6489 Southern Company Services Project TITLE OF PACKAGE: DRAFT INTERIM CONDITIONS SLOPE STABILITY ANALYSIS o Signature 27 August 2018 P CALCULATION PREPARED BY: (Calculation Preparer,CP) � Name David Rein/Lucas P. Can Date ASSUMPTIONS&PROCEDURES Signature 27 August 2018 CHECKED BY: (Assumptions&Procedures Checker,APC) Name Jim Hansen Date 3 COMPUTATIONS CHECKED BY: Signa. 27 August 2018 (Computation Checker,CC) Name Rachel Thompson Dare BACK-CHECKED BY: Signature 27 August 2018 (Calculation Preparer,CP) Name David Rem/Lucas P. Carr Dare APPROVED BY: Signature 27 August 2018 0 m (Calculation Approver,CA) Name William Tanner,P.E. Date REVISION HISTORY: NO. DESCRIPTION DATE CP APC CC CA A Draft Closure Design Calculation Package 8/27/2018 DK/LPC DW RLT WT APC Barry_EPA_0004 O Geosyntec consultants Page 1 of 55 CP: DK/LPC Date: 07/19/18 APC: JB Date: 8/22/18 CC: RLT Date: 8/22/18 Client BCB Project: Plant Barry Project No: GW6489 DRAFT INTERIM CONDITIONS SLOPE STABILITY ANALYSIS PURPOSE This Draft Interim Conditions Closure Slope Stability Analysis calculation package (Package)was prepared to in support of the design to close the existing coal combustion residuals (CCR) ash pond at Alabama Power Company's Plant Barry (Site), located in Bucks, Alabama. The Site will be closed using a "consolidate and cap-jn-place" method whereby CCR will be excavated from southern parts of the Site (Closure by Removal Area) and all CCR consolidated into an approximately 300-acre area that will be constructed in the central portion of the ash pond using soil containment berms and with a final cover system. This Package presents the results of preliminary engineering calculations to evaluate the temporary stability of cut CCR slopes within the footprint of the Closure by Removal Area, during closure construction when CCR is actively being excavated. Currently, this Package presents CCR cut slope stability at two cross-sections for the purposes of selecting design bench widths,heights, and inter-bench slopes for CCR excavation areas. This Package is organized to present: (i) design criteria; (ii) analysis methodology; (iii) subsurface stratigraphy and design parameters;(iv) cross sections and cases analyzed;(v) analysis results; and(vi) conclusions. This Package will be updated prior to the Final submittal to provide a comprehensive evaluation of interim closure construction stability, including adding: (i) analysis of additional cross-sections;(ii)analysis of the stability of the existing dikes during closure- by-removal excavation, Mobile River flooding conditions, and construction traffic loading; (iii) interim slope stability analyses for new soil containment berms that will be constructed within the Closure by Removal Area, and (iv) end-of-construction slope stability analyses for both the soil containment berm and the final configuration of the Consolidated Area. DESIGN CRITERIA The closure design at Plant Barry will be performed in accordance with the provisions of the United States Environmental Protection Agency's (USEPA's) federal CCR Rule contained in 40 CFR §257 (and 40 CFR §261 by reference), as amended (United States Environmental Protection Agency, 2015), (United States Environmental Protection GW6089IBury_Intmm Slope Stability-50%Design 20180827 APC Barry_EPA_000441 Geosynte& consultants Page 2 of 55 CP: DK/LPC Date: 07/19/18 APC: JH Date: 8/22/18 CC: RLT Date: 8/22/18 Client BCB Project: Plant Barry Project No: GW6489 Agency, 2016). The USEPA federal CCR Rule do not include design criteria for interim construction conditions for CCR surface impoundment closures.However,the CCR Rule does include end-of-construction design criteria for the lateral expansion and new construction of CCR surface impoundments. In the absence of design criteria for interim conditions at existing CCR surface impoundments, the design criteria for lateral expansion and new construction of surface impoundments were used for this project. The stated criteria listed in 40 CFR 257.74 are: • The calculated static factor of safety (FS) under the end-of-construction conditions must equal or exceed 1.30. ANALYSIS METHODOLOGY Slope stability analyses were performed using Spencer's method of analysis (Spencer, 1973), as implemented in the computer program SLIDE,version 8.016(Rocscience,Inc., 2018). The SLIDE program generates potential slip surfaces, calculates the FS for each of these surfaces, and identifies the slip surface with the lowest FS (i.e., the critical slip surface).Non-circular and block-type slip surfaces were analyzed in SLIDE. Searches for the critical slip surface in SLIDE were performed with the optimization feature enabled. SUBSURFACE STRATIGRAPHY AND DESIGN PARAMETERS Information required for the slope stability analyses includes: • Representative subsurface stratigraphy beneath the Site; • Unit weights and shear strengths of different subsurface units and materials encountered at the Site; • Water table elevations; and • Geometric details for the cut slope and excavations. Subsurface Stratigraohv and Geotechnical Parameters The data used to develop the design subsurface stratigraphy and the geotechnical parameters were obtained from field and laboratory investigations at the Site. These data are presented in the Draft Material Properties and Major Design Parameters(Geosyntec Consultants, 2018)package (Data Package). Based on the Data Package, the subsurface GW6089IBury_Intmm Slope Stability-50%Design 20180827 APC Barry_EPA_000442 Geosyntec° consultants Page 3 of 55 CP: DK/LPC Date: 07/19/18 APC: JB Date: 8/22/18 CC: RLT Date: 8/22/18 Client BCB Project: Plant Barry Project No: GW6489 stratigraphy at the Site primarily consists, from top to bottom,of five units;existing CCR, Clay 1, Sand 1, Clay 2 and Sand 2. Due to the spatial variability in stress history and undrained shear strength parameters for the foundation soils, especially for Clay 1 and Clay 2,the Site was divided into a total of 10 design reaches(Reaches 1, 2A, 213, 2C, 3A, 3B, 3C, 4, 5A and 5B) with each reach having a unique set of material parameters. Discussion on the development of these reaches and associated design parameters are provided in the Data Package. Tables 1 and 2 provide a summary of design reach parameters considered for interim construction conditions. Interim construction loading conditions are short-tern in nature; occurring only between the excavation of CCR and backfill of the area with clean fill;the excavation is expected to be at its maximum depth for only a day or two. Therefore, undrained conditions were assumed in cohesive materials (Clay 1 and Clay 2), because excess pore pressures induced by construction loading will take a few months to a few years to dissipate in these low-permeability materials. Undrained conditions are expected to be more critical than drained conditions, as the cohesive materials will consolidate,and gain strength as excess pore pressures dissipate. For the final version of this Package, additional analyses will be performed with drained conditions in the cohesive materials to assess potential conditions that may develop if the excavations progress slower than anticipated. Drained conditions were assumed in CCR, Sand 1, and Sand 2 because these are free-draining materials where excess pore pressures are not expected to develop during construction loading. Undrained strengths for Clay 1 and Clay 2 were modeled using a function of undrained shear strength versus elevation, with a minimum undrained shear strength assigned using a separate material type, as documented in the Data Package. Water Level Elevations The Data Package identifies two distinct water levels at the Site: (i) an upper, perched water level within the CCR and Clay 1 (referred to as Upper WL) located at a depth between 3 feet above and 3 feet below top of existing CCR; and (ii) a potentiometric water level for the Sand 1, Clay 2, and Sand 2 layers generally corresponding to the pool level in the adjacent Mobile River(referred to as Lower WU. During closure construction, the Upper WL was assumed to remain unaltered at the existing ground surface within the CCR Consolidation Area. Within the Closure by GW6089IBury_Intenm Slope Stability-50%Design 20180827 APC Barry_EPA_000443 Geosyntec consultants Page 4 of 55 CP: DK/LPC Date: 07/19/18 APC: JB Date: 8/22/18 CC: RLT Date: 8/22/18 Client BCB Project: Plant Barry Project No: GW6489 Removal Area, the Upper WL was assumed to follow the interim excavation ground surface, as the area will have free water removed through unwatering during construction. Within the temporary cut slope between the CCR Consolidation Area and the Closure by Removal Area, the Upper WL was assumed to be three feet beneath the bottom of each bench; this corresponds to the depth of temporary dewatering ditches to be installed during closure construction. Pore water from the CCR will flow into these ditches, resulting in gravity dewatering of the CCR. The Lower WL was assumed to be at elevation' 3 ft for closure stability analyses; this corresponds to the normal pool level in the Mobile River. The effects of Mobile River flooding on interim closure construction seepage and slope stability, including existing dikes, cut slopes, and the new soil containment berms, will be evaluated in the final version of this calculation package. CROSS SECTIONS AND CASES ANALYZED Selection of Cross Sections Two cross-sections (B-B' and D-D') were selected for interim conditions slope stability analyses of the CCR cut slopes. The selected cross-sections were analyzed for CCR cut slope stability at the lowest and highest design strength reaches of the Site, to aid in evaluating ranges in CCR cut slope benching requirements. The locations of the selected cross sections are shown in Figure 1 along with the proposed interim CCR excavation plan and design reaches. Figure 2 shows the location of the selected cross sections on isopachs of Clay 1 thickness. Cross-section designations and locations presented in this Package are the same as the cross-sections presented in the Draft Closure Slope Stability Analysis calculation package (Geosyntec Consultants, 2018). Cross-section B-B' was selected to evaluate the required CCR cut slope geometry over a low-strength zone of Clay 1. This cross-section is in Reach 3A and has the lowest design undrajned shear strengths in Clay 1 and Clay 2 out of the design reaches at the Site.Within Reach 3A, cross-section B-B' corresponds to a CCR cut slope height of 24 ft, an ' All elevations presented in this Package are based on North American Vertical Datum of 1988 (NAVD88). GW6489IBury_Intenm Slope Stability-50%Design 20180827 APC Barry_EPA_000444 Geosyntec° consultants Page 5 of 55 CP: DK/LPC Date: 07/19/18 APC: JB Date: 8/22/18 CC: RLT Date: 8/22/18 Client BCB project: Plant Barry Project No: GW6489 excavation design bottom elevation of-2.0 ft, and a Clay 1 thickness of 16 ft. This geometry corresponds to critical geometric conditions within Reach 3A for the southern CCR cut slope area. Cross-section D-D' was selected to evaluate the required CCR cut slope geometry over a relatively higher-strength zone of Clay 1. This cross-section is primarily located in Reach 5A, but also crosses a section of Reach 5B. Reach 5A has the highest design undrained shear strengths for Clay 1 and Clay 2 out of the ten reaches at the Site, and Reach 5B has the third-highest undrained shear strength out of the ten reaches.Within Reach 5A,cross- section D-D' corresponds to a CCR cut slope height of 24 ft, an excavation bottom elevation of 1.25 ft,and a Clay 1 thickness of 12 ft. These correspond to critical geometric conditions within Reach 5A for the northeastern CCR cut slope area. Additional cross-sections will be analyzed for the final version of this Package to further optimize the total volume of CCR excavation required to maintain stable CCR cut slopes. Cut Slope Geometry and Surcharge Loading Multiple cut slope geometries were evaluated at each cross-section, to aid in selecting a cost-effective cut slope geometry for use at the Site. Cut slope geometries included bench heights of 5, 7, and 10 feet. Each bench height was analyzed with inter-bench slopes of 2H:1 V, 3H:1 V, and 4H:1 V. These cut slope geometries were selected based on conversations between Geosyntec, Southern Company Services, and Trans-Ash. Construction surcharge loads of 500 pounds per square foot (pst) with a width of 20 ft were applied to each bench to represent construction equipment and/or temporary material stockpiles. This surcharge magnitude and width are intended to represent typical earthwork equipment (i.e. midsized trackhoes, wheel loaders, and dump trucks) and construction stockpiles(i.e. a 6-ft high stockpile of 92 pcf CCR). Surcharge loads will be limited to a maximum width of 20 ft during construction. Up to four benches are present at each cross-section, and construction surcharge loads on combinations of multiple benches were also considered in the analysis. Load combinations were selected to evaluate critical combinations of equipment on multiple benches, and are summarized in Table 3. Slope stability analyses were performed with surcharge loads located at both the outer and inner edges of the bench. GW6089IBury_Intenm Slope Stability-50%Design 20180827 APC Barry_EPA_000445 Geosyntec° consultants Page 6 of 55 CP: DK/LPC Date: 07/19/18 APC: JB Date: 8/22/18 CC: RLT Date: 8/22/18 Client BCB Project: Plant Barry Project No: GW6489 Slope stability analyses were performed for each of the bench height and slope geometry, and a minimum bench width of 20 ft.The width of the benches and/or the minimum offset between construction surcharge loads and the outer edge of the bench were increased, if necessary to obtain a factor of safety of 1.30 during construction loading conditions. The required excavator reach to excavate material 25 ft past the toe of the CCR cut slope was also calculated for each slope stability analysis. The conceptual geometry of the CCR cut slope geometry is provided in Figure 3. A summary of the evaluated cut slope geometry and surcharge loading combinations is provided in Table 3. Slip Surfaces For both cross-sections, the following potential slip surfaces were considered: • Global slip surfaces encompassing the entire CCR cut slope: A failure along this type of slip surface would be large-scale and potentially cause significant disruptions and/or health and safety issues during construction. • Local slip surfaces encompassing the toe and lower bench of the CCR cut slope: A failure along this type of slip surface would be small-scale, and potentially result in a health and safety issue if construction equipment is present on the lower bench but would not be anticipated to cause significant construction disruptions or affect the remainder of the CCR cut slope. ANALYSIS RESULTS A summary of calculated FS for critical slip surfaces, corresponding CCR cut slope geometry, and estimated volume of cut slope excavation per linear foot of a 25-ft high cut slope is presented in Table 4. The results of the slope stability analyses for the critical global slip surfaces are presented in Attachment 1,while the results for local slip surfaces are presented in Attachment 2. Cross-Section B-B' (Low-Strength Foundation) For cross-section B-B', minimum FS of 1.30 for both local and global slip surfaces were used to estimate bench geometry and construction surcharge loading for each cut slope scenario. The resulting design bench widths ranged from 25 ft (5 ft bench height with GW6089IBarry_Intmm Slope Stability-50%Design 20180827 APC Barry_EPA_000446 Geosyntec° consultants Page 7 of 55 CP: DK/LPC Date: 07/19/18 APC: JB Date: 8/22/18 CC: RLT Date: 8/22/18 Client SCS Project: Plant Barry Project No: GW6489 4H:1V inter-bench slopes) to 65 ft (10 ft bench height, 2H:1V inter-bench slopes). Excavator reach lengths ranged from 40 ft (5 ft bench heights with 2H:1 V and 3H:1 V inter-bench slopes) to 75 ft (10 ft bench heights with 3H:1V and 4H:1V inter-bench slopes). Construction loading minimum offsets ranged from 0 ft(5 ft bench heights with 3H:1 V and 4H:1 V inter-bench slopes) to 25 It (10 ft bench heights with 2H:1 V inter- bench slopes). Estimated excavation volumes ranged from 72 cubic yards per foot(10 ft bench heights with 2H:1 V inter-bench slopes) to 98 cubic yards per foot (5 ft bench heights with 2H:1 V inter-bench slopes). This indicates that a 5 It bench height and either 2H:1 V or 3H:1 V inter-bench slope is appropriate for the low-strength portions of the Site and will provide the required slope stability FS while limiting excavator reach. Cross Section D-D' (Higher-Strength Foundation) For cross-section D-D', minimum FS of 1.39 and 1.59 were obtained for global and local slip surfaces, respectively, for each bench geometry and construction surcharge loading scenario with the minimum bench width of 20 ft. Wider benches were not required to meet the design criteria for minimum FS of 1.30. Excavator reach lengths range from 35 ft (5 ft bench height with 2H:1V inter-bench slopes) to 65 ft (10 ft bench heights with 4H:1 V inter-bench slopes). Construction loading minimum offsets were 0 ft each analyzed case. Excavation volumes ranged from 38 cubic yards per foot (10 ft bench heights with 2H:1 V inter-bench slopes)to 84 cubic yards per foot(5 ft bench slopes with 4H:1 V inter-bench slopes). This indicates 10 ft bench heights and either 2H:1 V or 3H:1 V inter-bench slopes are appropriate for the higher strength portions of the site and will provide the required slope stability factor of safety while limiting excavator reach and the total volume of excavated CCR. CONCLUSIONS Interim CCR cut slope stability analyses were performed for two cross-sections, one representing the lowest design strengths for the cohesive foundation soils(i.e.,Clay 1 and Clay 2) and one representing the highest design foundation soil strengths at the Site. Multiple cut slope bench widths, heights, and inter-bench slopes were evaluated for each cross-section to evaluate the relative constructability and cost-effectiveness of varying cut slope geometries. Based on the analyses results, 3H:1V inter-bench slopes are recommended for the Site. Inter-bench slopes should be limited to 5 ft in height for portions of the Site with low design strength foundation soils (Reaches 1, 3A, 313, and GW6089IBury_Intenm Slope Stability-50%Design 20180827 APC Barry_EPA_000447 Geosyntec consultants Page 8 of 55 CP: DK/LPC Date: 07/19/18 APC: JB Date: 8/22/18 CC: RLT Date: 8/22/18 Client BCB project: Plant Barry Project No: GW6489 3C), while bench heights of up to 10 ff are appropriate for the highest design strength foundation soils at the Site (Reach 5A). Intermediate bench heights and/or widths will likely be appropriate for the reaches with intermediate soil strengths (Reach 2A, 213, 2C, 4, and 5B). These analyses will continue to be refined as the Design progresses, including analyzing CCR cut slopes in intermediate reaches. REFERENCES Geosyntec Consultants. (2018). Draft Closure Slope Stability Analysis, Alabama Power Company, Plant Barry Closure Design. Geosyntec Consultants. (2018). Draft Material Properties and Major Design Parameters, Alabama Power Company, Plant Barry Closure Design. Rocscience, Inc. (2018, July). SLIDE v8. Tornoto, Ontario, Canada. Spencer, E. (1973). Thrust Line Criterion in Embankment Stability Analysis. Geotechnigue, 85-100. United States Environmental Protection Agency. (2015). Code of Federal Regulations (CFR) Title 40, Parts 257 and 261, Hazardous and Solid Waste Management System; Disposal of Coal Combustion Residuals from Electric Utilities; Final Rule. United States Environmental Protection Agency. (2016). Code of Federal Regulations (CFR) Title 40, Parts 257 and 261, Hazardous and Solid Waste Management System: Disposal of Coal Combustion Residuals from Electric Utilities; Extension of Compliance Deadliens for Certain Inactive Surface Impoundments; Respons. GW6089IBury_Intmm Slope stability-50%Design 20180827 APC Barry_EPA_000448 Geosyntec° consultants Page 9 of 55 CP: DK/LPC Date: 07/19/18 APC: JB Date: 8/22/18 CC: RLT Date: 8/22/18 Client SCS Project: Plant Barry Project No: GW6489 TABLES GW6089IBury_Intenm Slope Stability-50%Design 20180827 APC Barry_EPA_000449 Geosyntec° consultants Page 10 of 55 CP: naI6PC Date: 07/19/18 APC: In Date: 8/22118 CC: PLT Date: 8/22/18 Client: SCS Project: Plant Barry Project No: GW6489 Table 1. Summary of Material Properties for CCR, Sand 1, and Sand 2 Drained Shear Strength Friction Angle, Cohesion, Unit Weight,y, 41 C, Material (pct) (deg) (PSO Existing CCR 92 36 0 Sand 1 115 (Reach 3A)/ 110(Reach 5A)/ 110(Reach 5B) 35 0 Sand 120 38 0 Notes: 'Design unit weights for Clay 1, Sand 1,and Clay 2 vary by design reach.The design unit weights for these materials are listed in Table 2. GW6489IBarry_Intenm Slope Stability-50%Design 20180827 APC Barry_EPA_000450 Geosyntec° consultants Page 11 of 55 CP: aRI6PC Date: 07/19/18 APC: Stt Date: 8/22118 CC: PLT Date: 8/22/18 Client: SCS Project: Plant Barry Project No: GW6489 Table 2. Summary of Material for Clay land Clay 2 Clay 1 Clay 2 Undrained Maintain Shear Undrained Shear Strength Strength',S. Increase with Undrained Shear Design Unit Weight,yt (pst) Depth,AS./Az Unit Weight,y, Strength',S. Reach (pet) and Datum(z) (psftft) (pct) (psf) 3A 95 200 psf at El. 0 ft 8.4 102 S,Ja',.e=0.258, Min. S.=500 psf 5A 1A: 110 1A: 550 1A: 0 1B: 105 1B: 420 at El. Oft 1B: 11.6 Not Present 5B 105 375 at El. 2 ft 10.5 Notes: 'The undrained shear strengths for Clay 2 is defined as the maximum of the SHANSEP strength(S,/a'-=0.258)and a specified minimum shear strength value. GWW9IBarry_Inteam Slope Stability-50%Design 20180827 APC Barry_EPA_000451 Geosyntec° consultants Page 12 of 55 CP: DKI PC Date: 07/19/18 APC: SB Date: 8/22118 CC: PLT Date: 8/22/18 Client: SCS Project: Plant Barry Project No: GW6489 Table 3. Evaluated CCR Cut Slope Geometries and Load Combinations' Bench 2H:1V,3H:1V,and 4H:1V Cut Slopes' Height Number of Benches where (Bn) Benches and Construction Loads (It) Designations were Considered (Load Combinations) 5 4: A, B, C,D A AB CD ABC BCD ABCD 7 3: A, B, C A AB BC ABC 10 2: A, B A B AB Notes: 1. A conceptual cross-section ofbench geometry is provided in Figure 3 2. All load combinations were checked separately with loads at the outer edge and inner edge of the benches. GWW9IBarry_Intmm Slope Stability-50%Design 20180827 APC Barry_EPA_000452 Geosyntec consultants Page 13 of 55 CP: nnI6PC Date: 07/19/18 APC: SH Date: 8/22118 CC: RLT Date: 8/22/18 Client: SCS Project: Plant Barry Project No: GW6489 Table 4. Summary of Analysis Results Cross- Bench 2H:1V Cut Slo a Cs 3H:1V Cut Slope Cs 4H:1V Cut Slope Cs Section Height Volume of Minimum Minimum Minimum Minimum Required Volume of Minimum Minimum Minimum Minimum Required Volume of Minimum Minimum Minimum Minimum Required (Hn) Excavation Global Local Bench Excavator Excavator Excavation Global Local Bench Excavator Excavator Excavation Global Local Bench Excavator Excavator (ft) (VE) Factor of Factor of Width Offset Reach (VE) Factor of Factor of Width Offset Reach (VE) Factor of Factor of Width Offset Reach (CY/ft) Safety' Safety' (Wn) (OE) (RE) (CY/ft) Safety' Safety' (Wn) (OE) (RE) (CY/ft) Safety' Safety' (Wn) (OE) (RE) Sc E ft ft n Sc E ft ft ft FSc E ft ft ft 5 98 1.39 1.30 40 5 40 91 1.31 1.32 30 0 40 93 1.34 1.44 25 0 45 ......... ....... ... ......... ......... ........ ........ ........ .................................... B-B' 7 85 1.36 1.33 50 10 49 84 1.34 1.30 40 5 51 83 1.31 1.33 30 0 53 10 72 1.30 1.31 65 25 70 76 1.31 1.35 55 20 75 80 1.30 1.34 45 10 75 5 61 1.70 1.59 20 0 35 72 1.86 1.95 20 0 40 84 2.01 2.32 20 0 45 D-D' 7 48_. 1.57 2.09 20 0 39 60 1.76 2.11 20.. 0____- 46 71 1.92 ,... 2.38 20 0 --53 10 38 1.39 1.76 20 0 45 1 50 1.59 1.99 20 0____ 55 1 62 1.80 2.20 20 0 65 Note: 1. Minimum factors of safety refer to the lowest computed factor of safety for all evaluated load combinations and slip surface types for bench height and cut slope.Minimum factors of safety are presented separately for local and global slip surfaces. GW6089IBury_Interie Slope stability-50%Design 20180827 APC Barry_EPA_000453 Geosynte& consultants Page 14 of 55 CP: DKI PC Date: 07/19/18 APC: SB Date: 8/22118 CC: PLT Date: 8/22/18 Client: SCS Project: Plant Barry Project No: GW6489 FIGURES GW6489IBury_Interie Slope Stability-50%Design 20180827 APC Barry_EPA_000454 Geosynte& consultants Page 15 of 55 CP: DRI6PC Date: 07/19/18 APC: 2H Date: 8/22118 CC: RLT Date: 8/22/18 Client: SCS Project: Plant Barry Project No: GW6489 D' Reach 5A Reach5B," .. Reach 4,., Reach 3k , .. `�aem y/ Rea Reath 2C .,... each 3B \ Reach each 3A x° Figure 1. Selected Cross Sections and Interim CCR Excavation Plan GW6089IBury_Interim Slope Stability-50%Design 20180827 APC Barry_EPA_000455 Geosynte& consultants Page 16 of 55 CP: DKI PC Date: 07/19/18 APC: 3H Date: 8/22118 CC: RLT Date: 8/22/18 Client: SCSI Project: Plant Barry Project No: GW6489 D' ach 5 ieach 5B t each 4 ach 3A Reach 1 Reach 2C v. Br 'r �cbj0 Reach 3B .a \ Reach 2B ti Reach 3A ti Figure 2. Selected Cross Sections and Clay 1 Isopach GW6089IBury_Interim Slope Stability-50%Design 20180827 APC Barry_EPA_000456 Geosyntec consultants Page 17 of 55 CP: DKI PC Date: 07/19/18 APC: SB Date: 8/22118 CC: RLT Date: 8/22/18 Client: SCS Project: Plant Barry Project No: GW6489 Existing Grade �l_._._._._._.___._._._._._._._._.___._._._._._._._._._._._._._._._._' B _._._-_BENCX D_.___._._.___._._._._.___._._._BEtl-a _._.___._._._._.___._._._._._._BE _._.___._.___._._._._. BENCH IH C. We B. Cs We 1 Ba Excavator Rs C. We 1� BT OE CCR c, We t Bi z[--25R� Clay 1 Design Excavation Bottom Elevabon jim Figure 3. Conceptual CCR Cut Slope Geometry GW5089IBury_Intenm Slope Stability-50%Design 20180827 APC Barry_EPA_000457 Geosynte& consultants Page Is of 55 CP: UKI PC Date: 07/19/18 APC: SH Date: 8/22118 CC: PLT Date: 8/22/18 Client: SCS Project: Plaatllarry Project No: GW6489 ATTACHMENT 1 SLOPE STABILITY ANALYSIS OUTPUT-GLOBAL SLIP SURFACES GW6089IBury_Interie Slope Stability-50%Design 20180827 APC Barry_EPA_000458 Cohesion Vertical Minimum Unit Weight Cohesion Phi Cohesion n Datum Material Name Color Qbs/k3) Strength Type (psf) (deg) Type Change (R) Strength Shear Strength Water Surface (psf/R) Ratio (psf) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(113A D) ® 95 Undrained 200 FDatum 8.4 0 Piezometric Line Sand 1(R3A D) ■ 115 Mohr-Coulomb 0 35 Piezometric Line Clay 2(113A D) ® 102 Vertical Stress Ratio 0.258 S00 Piezometric Line Sand 2(R3A D) ■ 120 Mohr-Coulomb 0 38 PiezometricU I Clay 1(R3A Up) ■ 95 Undrained 200 Constant Piezometric Line 2 Spencer 1.39 Existing Ground loom iavaz Surface ♦ z sm.00 immz o q 0 CCR a z ♦ z .Cl a_ 1 R3A D Clay 1 (R3A UD) Sand 1 (R3A D) . . Sand 2(R3A D) Clay 2 (R3A D) 1550 tsoo lsso noo nso laoo laso P,,gin Geosyntec° Plant Barry 50%Closure Design consultants °� Section B. 2H:1V Slope. 5 Pt Bench Height n,y I .onNeOesAY David Kein Southern Company Dee, 8/16/2018 — 1:400 "` B-B_Interim_2Hto1V_5ft_Bench.slmd APC Bany_EPA_000459 Cohesion Vertical Minimum Unit Weight Cohesion phi Cohesion n Datum Material Name Color Qbs/k3) Strength Type (psf) (deg) Type Change (R) Strength Shear Strength Water Surface (psf/R) Ratio (psf) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(113A D) ® 95 Undrained 200 FDatum 8.4 0 Piezometric Line Sand 1(R3A D) ■ 115 Mohr-Coulomb 0 35 Piezometric Line Clay 2(113A D) ® 102 Vertical Stress Ratio 0.258 500 Piezometric Line Sand 2(R3A D) ■ 120 Mohr-Coulomb 0 38 Piezometric Line Clay 1(R3A UD) ■ 95 Undrained 200 Constant Piezometric Line 2 Spencer 1.36 500.00 Rt2 Existing Ground 2 500.W Ibsift2 Surface • CC R 10. 2 .'-cla 1 R3A D / Y-� --- � 'CIay1 (R3A UD) �. Sand 1 (R3A D) . . . . . . . . . ;;�Y///l�%IYY.r/l/l/�%l////l /l/r7r//////i/.J: Sand 2(R3A D) Clay 2(R3A D) 1550 1600 1650 1700 1]50 1900 1850 A,*. Geosyntec° Plant Barry 50%Closure Design consultants °� Section B. 2H:1V Slope. 7 Pt Bench Height i,s I �on David Kein Southem Company 8/17/2018 '�` 1:400 B-B_Interim_2Hto1V_7ft_Bench.slmd APC Bany_EPA_00000 Cohesion Vertical Minimum Unit Weight Cohesion Phi Coheslon Datum Material Name Color (lbs/h3) Strength Type (psf) (deg) Type Change (ft) Strength Shear Strength Water Surface (psf/R) Ratio (psf) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(113A D) ® 95 Undrained 200 FDatum 8.4 0 Piezometric Line Sand 1(R3A D) ■ 115 Mohr-Coulomb 0 35 Piezometric Line Clay 2(113A D) ® 102 Vertical Stress Ratio 0.258 500 Piezometric Line Sand 2(R3A D) ■ 120 Mohr-Coulomb 0 38 Piezometric Line Clay 1(R3A UD) ■ 95 Undrained 200 Constant Piezometric Line 2 Spencer 1.30 500.00 Ibs/82 Existing Ground 2 Surface . 2 500.00 Ibs/It2 a 4.0 CCRT 10.0 2 _ 0.0 CIay1 (R3AD) CIay1 (R3A UD) TT 0 Sand 1 (R3AD) . . :%'q4./ . . . . . . �. . . . _ . . . . . . . . . . .. . , .... .. . ... . Sand 2(R3AD) Clay 2(R3AD) 1550 1600 1650 1700 1750 1800 1850 Geosyntec° Plant Barry 50%Closure Design consultants °� Section B.21-1:1V Slope. 10 Pt Bench Height i,s I �on David Kein Southern Company 8/17/2018 '�` 1:400 B-B_Interim_2Hto1V_lOR_Bench.slmd APC Bany_EPA_000481 Cohesion Vertical Minimum Unit Weight Cohesion phi Cohesion n Datum Material Name Color Qbs/k3) Strength Type (psf) (deg) Type Change (R) Strength Shear Strength Water Surface (psf/R) Ratio (psf) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(113A D) ® 95 Undrained 200 FDatum 8.4 0 Piezometric Line Sand 1(R3A D) ■ 115 Mohr-Coulomb 0 35 Piezometric Line Clay 2(113A D) ® 102 Vertical Stress Ratio 0.258 500 Piezometric Linel Sand 2(R3A D) ■ 120 Mohr-Coulomb 0 38 Piezometric Line Clay 1(R3A UD) ■ 95 Undrained 200 Constant Piezometric Line 2 Spencer 1.31 soo.00 IbsHt2 Existing Ground Surface z 500.00 ibem2 • 4. 30. 3 T 3 CCM11 I 1 g 3 1 A D) Clay 1 (R3A UD) . . Sand 1 (R3A D) . . . . Sand 2(R3A D) Clay 2(R3A D) 1550 1600 1(160 1700 1750 1801 1850 PAcAAo Geosyntec° Plant Barry 50%Closure Design consultants °� Section B.3H:1V Slope. 5 Pt Bench Height n,y I .onNeOesAY David Kein Southern Company Dee, 8/17/2018 '�` 1:400 B-B_Interim_3Hto1V_Sft_Bench.slmd APC Bany_EPA_000462 Unit WeightCohesion phi [ n Cohesion Datum Material Name Color Qbs/k3) Strength Type (psf) (deg) Type Vertical Minimum Type Change (R) Strength Shear Strength Water Surface (psf/R) Ratio (psf) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(113A D) ® 95 Undrained 200 FDatum 8.4 0 Piezometric Line Sand 1(R3A D) ■ 115 Mohr-Coulomb 0 35 Piezometric Line Clay 2(113A D) ® 102 Vertical Stress Ratio 0.258 500 Piezometric Line Sand 2(R3A D) ■ 120 Mohr-Coulomb 0438 LlbsM2 Piezometric LineI Clay 1(R3A UD) ■ 95 Undrained ConstPiezometric Line 2 Spencer 1.34 1 500.00 Ibsm2 Existing Ground 2 T 5 Surface 5 00.00 Ibsm2 CCR 2 Clay 1 (R3A(R3A UD) Sand 1 (R3A D) . . . .c,/l//l//Y '/l/ . . . . . _ . ,%<{;t',tCSh44C�,<4$',�; Sand 2(R3A D) Clay 2(R3A D) 1550 1600 1650 1700 1750 1800 1850 vi lar Geosyntec° Plant Barry 50%Closure Design °� Section B. 3H:1V. 7 Fit Bench Height Consultants �,.I won David Kein — Southern Company inn � 8/17/2018 ' 1:400 � B-B_Inberim_3Hto1V_7ft_Bench.slmd APC Bany_EPA_00003 Unit WeightCohesion Vertical Minimum Cohesion Phi Cohesion Datum Material Name Color Qbs/k3) Strength Type (psf) (deg) Type Change (R) Strength Shear Strength Water Surface (psf/R) Ratio (psf) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(113A D) ® 95 Undrained 200 FDatum 8.4 0 Piezometric Line Sand 1(R3A D) ■ 115 Mohr-Coulomb 0 35 Piezometric Line Clay 2(113A D) ® 102 Vertical Stress Ratio 0.258 500 Piezometric Line Sand 2(R3A D) ■ 120 Mohr-Coulomb 0 38 Piezometric Line Clay (113A Up) ■ 95 Undrained 200 Constant Piezometric Line Spencer 1.31 500.00 Ibs/R2 Existing Ground 2 Surface • CCR . 3 Clay 1 (R3A D) Cluy 1 (R3A UD) Sand 1 (R3A D) . . . . . »»iz'r? ,. ./4' '.' :: . . % ;�////.%%Y/,�// �%/11�544�YYk444+ <: //lhlll '; Sand 2(R3A D) Clay 2(R3A D) 1550 1600 1650 1T00 1750 181 1850 PAyAo Geosyntec° Plant Barry 50%Closure Design consultants °� Section B 3H:1V Slope. 10 R Bench Height i,s I �on David Kein Southern Company 8/17/2018 '�` 1:400 �"` B-B_Interim_3Hto1V_lOR_Bench.slmd APC Bany_EPA_000469 ■■ 11 11 a aaaaaa . III II II II II f li III li li ♦ ��� ------------ Plant Barry 1 •11 1 II 1 :II 1 1' Closure Design 1 1 � 11 I I1.. Unit WeightCohesion Vertical Minimum Cohesion Phi Cohesion Datum Material Name Color Qbs/k3) Strength Type (psf) (deg) Type Change (R) Strength Shear Strength Water Surface (psf/R) Ratio (psf) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(113A D) ® 95 Undrained 200 FDatum 8.4 0 Piezometric Line Sand 1(R3A D) ■ 115 Mohr-Coulomb 0 35 Piezometric Line Clay 2(113A D) ® 102 Vertical Stress Ratio 0.258 500 Piezometric Line Sand 2(R3A D) ■ 120 Mohr-Coulomb 0 38 Piezometric Line Clay 1(R3A UD) ■ 95 Undrained 200 Constant Piezometric Line 2 Spencer 1.31 Existing Ground Surface 500.00 Ibs/ft2 2 500.00 Ibs/ft2 500.00 Ibs/ft2 4 CCR q 4 DIay1 (R3L GIay1 (R3A UD) Sand 1 (R3A D) 'i . . . . . . . . . . . . . . . . . . . . . . . . Sand2(R3A D) GIay2 (R3A D) 1550 1600 1650 1700 1750 1900 1650 vrojer Geosyntec° Plant Barry 50%Closure Design consultants Section B.4H:1V Slope. 7 Pt Benrh Height n,y I .on David Kein Southern Company Dee, 8/17/2018 '�` 1:400 B-B_Interim_4Hto1V_7ft_Bench.slmd APC Bany_EPA_000466 Cohesion Vertical Minimum Unit Weight Cohesion phi Cohesion n Datum Material Name Color Qbs/k3) Strength Type (psf) (deg) Type Change (R) Strength Shear Strength Water Surface (psf/R) Ratio (psf) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(113A D) ® 95 Undrained 200 FDatum 8.4 0 Piezometric Line Sand 1(R3A D) ■ 115 Mohr-Coulomb 0 35 Piezometric Line Clay 2(113A D) ® 102 Vertical Stress Ratio 0.258 500 Piezometric Line Sand 2(R3A D) ■ 120 Mohr-Coulomb 0 38 Piezometric Line Clay 1(R3A UD) ■ 95 Undrained 200 Constant Piezometric Line 2 Spencer 1.30 Existing Ground Surface 500.001 2 2 10.0 4 CCR . 4 let 45.0 Clay 1 (R3A D) Clay 1 (R3A UD) se Sand 1 (R3A D) sand 2(R3A D) clay 2 (R3A D) . � . 1sso 1600 1650 no11 o nso leoo laso vrojer Geosyntec° Plant Barry 50%Closure Design consultants Section B.4H:1V Slope. 10 R Bench Height n,y I .on David Kein Southem Company Dee, 8/17/2018 — 1:400 "` B-B_Interim_4Hto1V_lOR_Bench.slmd APC 3any_EPA_000467 sion Material N...e Color Unit Weight Strength Cohe th Type Cohesion Cohesion Change Datum Water Surtace gbs/ft31 IPsfl (deg) ) Type (Psf/R) (R) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay I(RSA D) ® 105 Undrained 420 FDatum 11.6 0 Piezometric line 2 Sand I(115A D) ■ 110 Mohr-Coulomb 0 35 Piezometric line 1 Clay IA(RSA UD) ■ 110 Undrained 550 Constant Piezometric Line Sand 2(115A D) ■ 120 Mohr-Coulomb 0 38 Piezometric line 1 Clay I Me UD) ® 105 Undrained 375 FDatum 10.5 2 Piezometric line 2 Sand 1(R58 D) ■ 115 Mohr-Coulomb 1 0 1 35 1 1 1 1 Piezometric line 1 Existing Ground 500.00 Ibs/fl2 Surface 500.00 Ibs/R2 Spencer 1.70 2 2 3 CCR 2 2 1 Clay 1 (R5B UD) Clay 1 (R5A D) Clay 1A(R5A UD) Sand 1 (R5A D) Sand 2 Sand 1 (R5B D) 1440 1460 1480 1500 1520 1540 1560 1560 1600 1620 1640 1660 1680 vrojes Geosyntec° Plant Barry 50% Closure Design Constiltants °a�Ov' Section D.2H:1V Slope. 5 R Bench Height David Kein ,e i moo+oon 8/22/2018 �` 1:300 D-D_Interim_2Hto1V_5ft_Bench.slmd APC Barry_EPA_000468 Unit Weigh[ Cohesion Phi Cohesion Cohesion Datum Material Name Color (Ibs/11:3) Strength Type ( ) (dog) Type Change (ft) Water Surface (psf/ft) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(115A DI ® 105 Undained 420 FDatum 11.6 0 Piezometric Une 2 Sand 1(R5A DI 110 Mohr-Coulomb 0 35 Piezometric Une 1 Clay 1A(R5A UD) ■ 110 Undained 550 Constant Piezometric Une2 Sand 2(R5A DI 120 Mohr-Coulomb 0 38 Piezometric Une 1 Clay 1(R58 UD) ® 105 Undained 375 FDatum 10.5 2 Piezometric Une 2 Sand 1(R5B D) ■ 115 Mohr-Coulomb 0 35 Piezometric Une 1 Spencer Existing Ground 500.00 IbsM 1.57 Surface 500.00 IbsRt2 2 2 3 CCR 2 1 Clay 1 (R5B UD) Clay 1 (RSA D) Clay 1A(R5A UD) Sand 1 (R5A D) Sand 1 (R56 D) Sand 2 1440 1460 1480 1500 1520 1540 1560 1580 1600 1620 1640 140 1680 vrojes Geosynte& Plant Barry 50%Closure Design consultants Section D.2H:1V Slope. 7 R Beni Height n,y I .on � David Kam � Southern Company Des, 8/22/2018 '�` 1:300 D-D_Interim_2Hto1V_7ft_Bench.slmd APC Bany_EPA_000469 Unit Weigh[ Cohesion Phi Cohesion Cohesion Datum Material Name Color (Ibs/ft3) Strength Type ( ) (deg) type Change (ft) Water Surface (psf/ft) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(115A D) ® 105 Undained 420 FDatum 11.6 0 Piezometric Une 2 Sand 1(R5A D) 110 Mohr-Coulomb 0 35 Piezometric Une 1 Clay 1A(R5A UD) ■ 110 Undained 550 Constant Piezometric Une2 Sand 2(R5A D) 120 Mohr-Coulomb 0 38 Piezometric Une 1 Clay 1(R58 UD) ® 105 Undained 375 FDatum 10.5 2 Piezometric Une 2 Sand 1(R5B D) ■ 115 Mohr-Coulomb 0 35 Piezometric Une 1 Spencer 500.00 Ibs/1112 1.39 Existing Ground Surface 2 2 CCR 3 1 10.0 Clay 1 (R5B UD) Clay 1 (R5A D) Clay 1A(RSA UD) Sand 1 (R5B D) Sand 1 (R5A D) Sand 2 . . , . . . , . . . , . . . , . . . , . . . , . . . , 1440 1460 1480 1500 1520 1540 1560 1580 1600 1620 1640 1660 1680 vrojes Geosyntec° Plant Barry 50%Closure Design consultants Section D.21-1:1V Slope. 10 R Bench Height n,,I .on � David Kein ! Southern Company Des, 8/21/2018 '�` 1:300 aex D-D_Interim_2Hto1V_101t_Bench.slmd APC Bany_EPA_000470 sion Material rvame Color Unit Weight Strength Cohe th Type Cohesion Cohesion Change Datum Water Surtace fibs/ft31 IPsfl (deg) ) Type IPsf/R) (R) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay IRSA D) ® 105 Undrained 420 FDatum 11.6 0 Piezometric Line Sand I(R5A D) ■ 110 Mohr-Coulomb 0 35 Piezometric tine 1 Clay IA IR$A UD) ■ 110 Undrained 550 Constant Piezometric Line Sand 21R5A D) ■ 120 Mohr-Coulomb 0 38 Piezometric tine 1 Clay 11R5B JD) ® 105 Undrained 375 FDatum 10.5 2 Piezometric Line Sand 1(R5B D) ■ 115 Mohr-Coulomb 1 0 1 35 1 1 1 1 Piezometric tine 1 Existing Ground 500.00 Ibs/112 Spencer Surface 500.00 Rossi .86 3 3 --_ 3 3 1 CCR 5. 3 j Clay 1 (RSB UD) �Clay 1 (R5A D) Clay 1A(R5A JD) Sand 1 (R5AD) Santl 2 Sand 1 (RSB D) 1440 1460 1480 1S00 1520 1S40 1560 1580 1600 1620 1640 1660 1680 vroj- Geosyntec° Plant Barry 50%Closure Design consultants °� Section D.31-1:1V Slope. 5 R Bench Height by David Kein ! Southern Company ..oioor�xlll on' 8/21/2018 . 1:300 �,e.� D-D_Interim_3Hto1V_5R_Bench.slmd APC Barry_BPA_000471 Unit Weigh[ Cohesion Phi Cohesion Cohesion Datum Material Name Color (Ibs/ft3) Strength Type ( ) (deg) type Change (ft) Water Surface (psf/ft) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(115A DI ® 105 Undained 420 FDatum 11.6 0 Piezometric Une 2 Sand 1(R5A DI 110 Mohr-Coulomb 0 35 Piezometric Une 1 Clay 1A(R5A UD) ■ 110 Undained 550 Constant Piezometric Une2 Sand 2(R5A DI 120 Mohr-Coulomb 0 38 Piezometric Une 1 Clay 1(R58 UD) ® 105 Undained 375 FDatum 10.5 2 Piezometric Une 2 Sand 1(R5B D) ■ 115 Mohr-Coulomb 0 35 Piezometric Une 1 Spencer 500.00 lbslfi2 1.76 Existing Ground Surface 3 500.00 Ibs1f12 0 3 3 CCR 1 200 B 1 Clay 1 (R5B UD) Cley 1 (R5A D) Clay to(R5A UD) Sand 1 (R5B D) Sand 1 (R5A D) Sand 2 1440 1460 1480 1500 1520 1S40 1560 1560 1600 1620 1640 1660 1680 vrojes Geosynte& Plant Barry 50%Closure Design consultants Section D. 31-1:1V Slope. 7 Pt Benrh Height. n.,I .— ar David Kein �,r Southern Company Des, 8/21/2018 '�` 1:300 D-D_Interim_3Hto1V_7ft_Bench.slmd APC Bany_EPA_000472 Unit Weigh[ Cohesion Phi Cohesion Cohesion Datum Material Name Color (Ibs/ft3) Strength Type ( ) (dog) Type Change (ft) Water Surface (psf/ft) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(115A DI ® 105 Undained 420 FDatum 11.6 0 Piezometric Une 2 Sand 1(R5A DI 110 Mohr-Coulomb 0 35 Piezometric Une 1 Clay 1A(R5A UD) ■ 110 Undained 550 Constant Piezometric Una Sand 2(R5A DI 120 Mohr-Coulomb 0 38 Piezometric Une 1 Clay 1(R58 UD) ® 105 Undained 375 FDatum 10.5 2 Piezometric Une 2 Sand 1(R5B D) ■ 115 Mohr-Coulomb 0 35 Piezometric Une 1 Spencer 500.00 Ibs/1112 1.59 1 Existing Ground Surface 3 500.00 Ibs/fl2 3 3 CCR 2 .0 3 1 Clay 1 (R5B UD) Glay 1 (R5A D) Clay 1A(R5A UD) Sand 1 (R5B D) Sand 1 (R5A D) Sand 2 1440 1460 1480 1500 1520 1640 1560 1580 1600 1620 1640 1660 1680 vrojes Geosynte& Plant Barry 50%Closure Design consultants Section D.3H:1V Slope. 10 R Benrh Height n,y I .on A, David Kam � Southern Company Des, 8/22/2018 '�` 1:300 D-D_Intenn_3Hto1V_10ft_Bench.slmd APC Bany_EPA_000473 Cohesion Unit Weight Cohesion Phi Cohesion Datum Material Name Color (lbs/k3) Strength Type (psf) (deg) Type Change (it) Water Surface (psf/k) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line 2 Clay 1(R5A D) ® 105 Undrained 420 FDatum 11.6 0 Piezometric Line 2 Sand 1(R5A D) ■ 110 Mohr-Coulomb 0 35 Piezometric Line 1 Clay 1A(R5A UD) ■ 110 Undrained 550 Constant Piezometric Line Sand 2(115A D) ■ 120 Mohr-Coulomb 0 38 Piezometric Line 1 Clay I(RSB UD) ® 105 Undrained 375 FDatum 10.5 2 Piezometric Line 2 Sand 1(R5B D) ■ 115 Mohr-Coulomb 0 35 Piezometric Line 1 Spencer Existing Ground 5000oimm 2.01 Surface 500a0ll 0 4 --71 0 0 4 111MCCR zoo 5.0 2]0 � 4 Clay 1 (R5B UD) Clay 1 (R5A D) , , Clay 1A(R5A UD) Sand 1 (R5B D) IS!Idl (R5AD) Sand 2 1425 1450 1475 1500 7525 15W 1575 1600 1625 1650 16]5 is, GeosynLec Plant Barry 50%Closure Design Consultants °'�Oo' Section!.4H:1V Slope. 5 Pt Benrh Heigh 1,y I -non David Kein r Southern Company � 8/21/2018 '� 1:300 �� D-D_Interim_4Hto1V_5ft_Bench.slmd APC Bany_EPA_000474 Unit Weigh[ Cohesion Phi Cohesion Cohesion Datum Material Name Color (Ibs/ft3) Strength Type ( ) (deg) type Change (ft) Water Surface (psf/ft) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(115A DI ® 105 Undained 420 FDatum 11.6 0 Piezometric Une 2 Sand 1(R5A DI 110 Mohr-Coulomb 0 35 Piezometric Une 1 Clay 1A(R5A UD) ■ 110 Undained 550 Constant Piezometric Une2 Sand 2(R5A DI 120 Mohr-Coulomb 0 38 Piezometric Une 1 Clay 1(R58 UD) ® 105 Undained 375 FDatum 10.5 2 Piezometric Une 2 Sand 1(R5B D) ■ 115 Mohr-Coulomb 0 35 Piezometric Une 1 Spencer 1.92 500.00 Ibs1f12 Existing Ground Surface 4 500.00 Ibs1f12 2 .0 3 4 CCR 2 0 4 Clay 1 (R5B UD) Clay 1 (RSA D) . . . . . . _ .... Clay 1A(R5A UD) > Sand 1 (R5B D) Sand 1 (R5A D) Sand 2 . I 1440 1460 1480 1500 1520 1540 1560 1580 1600 1620 1640 1660 1680 vrojex Geosyntec° Plant Barry 50%Closure Design consultants Section D.4H:1V Slope. 7 R Beni Height Ne I .— � David Kein �,r Southern Company Des, 8/21/2018 '�` 1:300 D-D_Interim_4Hto1V_7ft_Bench.slmd APC Bany_EPA_000475 Unit Weigh[ Cohesion phi Cohesion Cohesion Datum Material Name Color (Ibs/ft3) Strength Type ( ) (dog) Type Change (ft) Water Surface (psf/ft) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(115A DI ® 105 Undained 420 FDatum 11.6 0 Piezometric Une 2 Sand 1(R5A DI 110 Mohr-Coulomb 0 35 Piezometric Une 1 Clay 1A(R5A UD) ■ 110 Undained 550 Constant Piezometric Une2 Sand 2(R5A DI 120 Mohr-Coulomb 0 38 Piezometric Une 1 Clay 1(R58 UD) ® 305 Undained 3]5 FDatum 10.5 2 Piezometric Une 2 Sand 1(R5B D) ■ 115 Mohr-Coulomb 0 35 Piezometric Une 1 Spencer 500.00 Ibs/%2 1.80 z17- Existing Ground Surface 4 TT 2 .0 4 3 CCR 0 4 1 0.0 IL Clay 1 (R513 UD)] Olay 1 (RM D)� Clay 1A(R5A UD) Sand 1 (R5B D) Santl 1 (R5A D) Sand 2 1440 1460 1480 1500 1520 1540 1560 1580 1600 1620 1640 1660 1680 vrojex Geosyntec° Plant Barry 50%Closure Design consultants Section D.4H:1V Slope. 10 Ft Bench Height. n,y I .on � David Kein � Southern Company Des, 8/22/2018 — 1:300 D-D_Interim_4Hto1V_101t_Bench.slmd APC Bany_EPA_000476 Geosynte& consultants Page 37 of 55 CP: UKI PC Date: 07/19/18 APC: SH Date: 8/22118 CC: PLT Date: 8/22/18 Client: SCS Project: Ptaatliarry Project No: GW6489 ATTACHMENT 2 SLOPE STABILITY ANALYSIS OUTPUT-LOCAL SLIP SURFACES GW6089IBury_Interie Slope Stability-50%Design 20180827 APC Barry_EPA_000477 Cohesion Vertical Minimum Unit Weight Cohesion Phi Cohesion n Datum Material Name Color Qbs/k3) Strength Type (psf) (deg) Type Change (R) Strength Shear Strength Water Surface (psf/R) Ratio (psf) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(113A D) ® 95 Undrained 200 FDatum 8.4 0 Piezometric Line Sand 1(R3A D) ■ 115 Mohr-Coulomb 0 35 Piezometric Line Clay 2(113A D) ® 102 Vertical Stress Ratio 0.258 500 Piezometric Line Sand 2(R3A D) ■ 120 Mohr-Coulomb 0 38 Piezometric Lin Clay 1(R3A Up) ■ 95 Undrained 200 Constant Piezometric Line 2 Spencer 1.30 Existing Ground 500,00 ll�= Surface spo.po iearnz ♦ soo0o m 0 2 o z CCR 4 z So 40.0 2 Clay 1 (R3AUD) . . . . . . .,.,.,.. Sand 1 (R3A D) ..... ��c _ _ . . . . . . . . /l//.'NYC: . . _ . . . . . ,%Xt;t,t4S�S�h<r5�t{�'✓; . . Sand 2(R3A D) Clay 2(R3A D) 1550 1600 1650 1700 1750 1800 1850 PAcAAo Geosyntec° Plant Barry 50%Closure Design consultants °emktan Section B. 2H:1V Slope. 5 Pt Bench Height i,s I �onNeOesAY David Kein Southem Company Dee, 8/16/2018 — 1:400 "` B-B_Interim_2Hto1V_5ft_Bench.slmd APC Bany_EPA_000478 Cohesion Vertical Minimum Unit Weight Cohesion Phi Cohesion n Datum Material Name Color Qbs/k3) Strength Type (psf) (deg) Type Change (R) Strength Shear Strength Water Surface (psf/R) Ratio (psf) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(113A D) ® 95 Undrained 200 FDatum 8.4 0 Piezometric Line Sand 1(R3A D) ■ 115 Mohr-Coulomb 0 35 Piezometric Line Clay 2(113A D) ® 102 Vertical Stress Ratio 0.258 500 Piezometric Line Sand 2(R3A D) ■ 120 Mohr-Coulomb 0 38 Piezometric Lin Clay 1(R3A Up) ■ 95 Undrained 200 Constant Piezometric Line 2 Existing Groiund Surface Spencer 500.00 Ibs/R2 1.33 2 500.00 Ibs/R2 . 2 500.00 Ibs 2 40.0 1 7.0 10.0� EC CR v 2 10.0� 17.0 n 2 Cla D 3t (Y _.Y 1 (R3A_) Clay 1 (R3AUD) Sand 1 (R3A D) Sand 2(R3A D) Clay 2(R3A D) 1550 1600 1651 1700 1750 1801 1851 PAcAAo Geosyntec° Plant Barry 50%Closure Design consultants °� Section B. 2H:1V Slope. 7 Pt Bench Height i,s I �onNeOes A, David Kein Southern Company Dee, 8/17/2018 — 1:400 "` B-B_Interim_2Hto1V_7ft_Bench.slmd APC 3any_EPA_000479 Cohesion Vertical Minimum Unit Weight Cohesion phi Cohesion n Datum Material Name Color Qbs/k3) Strength Type (psf) (deg) Type Change (R) Strength Shear Strength Water Surface (psf/R) Ratio (psf) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(113A D) ® 95 Undrained 200 FDatum 8.4 0 Piezometric Line Sand 1(R3A D) ■ 115 Mohr-Coulomb 0 35 Piezometric Line Clay 2(113A D) ® 102 Vertical Stress Ratio 0.258 500 Piezometric Line Sand 2(R3A D) ■ 120 Mohr-Coulomb 0 38 Piezometric Line Clay 1(R3A UD) ■ 95 Undrained 200 Constant Piezometric Line 2 Existing Ground Spencer Surface 1.31 2 saot;r, R,dl) 1 - - Z - - - - - — - CCR 10. 25 Clay 1 (R3A D) ------------ --- Clay I (R3A UD)', Sand 1 (R3A D) Sand2 (R3A D) CIay2(R3A D) 1550 1600 1650 1T00 1T50 18)0 1850 vrojeY Geosyntec° Plant Barry 50%Closure Design consultants °'�Oo' Section B.21-1:1V Slope. 10 Pit Bench Height I �on David Kein innr ,r Southern Company 8/17/2018 '�` 1:400 B-B_Interim_2Hto1V_lOR_Bench.slmd APC Bany_EPA_000480 Cohesion Vertical Minimum Unit Weight Cohesion phi Cohesion n Datum Material Name Color Qbs/k3) Strength Type (psf) (deg) Type Change (R) Strength Shear Strength Water Surface (psf/R) Ratio (psf) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(113A D) ® 95 Undrained 200 FDatum 8.4 0 Piezometric Line Sand 1(R3A D) ■ 115 Mohr-Coulomb 0 35 Piezometric Line Clay 2(113A D) ® 102 Vertical Stress Ratio 0.258 500 Piezometric Line Sand 2(R3A D) ■ 120 Mohr-Coulomb 0 38 Piezometric Lin Clay I(113A Up) ■ 95 Undrained 200 Constant Piezometric Line2 Existing Ground Surface 2 500.00 Ibs/ft2 500.00 Ibs/H2 A pe S 500.00Ibs/ft2 ncer 3 pe .30. C 5. 1 3 . 3 32 1 MI L 7,7 , Clay 1 (R3A D) Clay 1 (R3A UD) Sand 1 (R3A D) ..... <�/> _ _ . . . . . . . . /l//.'NYC: . . _ . . . . ,%Xt;t,t4S�S�h<r5�t{�'✓; . . Sand 2(R3A D) Clay 2(R3A D) 1550 1600 1650 1T00 1T50 1800 1850 PAcAAa Geosyntec° Plant Barry 50%Closure Design consultants °emktan Section B.3H:1V Slope. 5 Pt Bench Height n,y I .onNeOesAY David Kein — Southem Company Dee, 8/17/2018 — 1:400 ae ° B-B_Inberim_3Hto1V_5ft_Bench.slmd APC 3any_EPA_000481 Cohesion Vertical Minimum Unit Weight Cohesion phi Cohesion n Datum Material Name Color Qbs/k3) Strength Type (psf) (deg) Type Change (R) Strength Shear Strength Water Surface (psf/R) Ratio (psf) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(113A D) ® 95 Undrained 200 FDatum 8.4 0 Piezometric Line Sand 1(R3A D) ■ 115 Mohr-Coulomb 0 35 Piezometric Line Clay 2(113A D) ® 102 Vertical Stress Ratio 0.258 500 Piezometric Line Sand 2(R3A D) ■ 120 Mohr-Coulomb 0 38 Piezometric Lin Clay I(113A UD) ■ 95 Undrained 200 Constant Piezometric Line2 Spencer 1.30 500.00 Ibs/ft2 Existing Ground 2 500.00 lb 2 1 Surface CCR 3 2 Clay 1 (R3A D) Clay 1 (R3A UD) Sand 1 (R3A D) Sand 2(R3A D) Clay 2(R3A D) 1550 1000 1ri50 170o 1i 18)0 1850 Geosyntec° Plant Barry 50%Closure Design consultants °� Section B. 31-1:1V. 7 R Bench Height n,y I .onNeOesAY David Kein Southern Company Dee, 8/17/2018 — 1:400 '" B-B_Interim_3Hto1V_7ft_Bench.slmd APC Bany_EPA_000482 Cohesion Vertical Minimum Unit Weight Cohesion Phi Cohesion n Datum Material Name Color Qbs/k3) Strength Type (psf) (deg) Type Change (R) Strength Shear Strength Water Surface (psf/R) Ratio (psf) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(113A D) ® 95 Undrained 200 FDatum 8.4 0 Piezometric Line Sand 1(R3A D) ■ 115 Mohr-Coulomb 0 35 Piezometric Line Clay 2(113A D) ® 102 Vertical Stress Ratio 0.258 500 Piezometric Line Sand 2(R3A D) ■ 120 Mohr-Coulomb 0 38 Piezometric Line Clay (R3A Up) ■ 95 Undrained 200 Constant Piezometric Line Spencer 1.35 Existing Ground Surface 2 . 3 500.001 /R2 3 CCR 5 1 20.0 . 3 Clay 1 (R3A C) Cluy 1 (R3AUD) Send 1 (R3A D) . : :Cdl'YX�yyii1J1J11J'J'�'1'JJJff/,Fr,'>' '.�:: . . . . . . ,. �X -? ; ,i445tu4'SY,24Kti4C� . ? i h4��,<444ift✓k{4594445t4SkSiR4' Sand 2(R3A D) Clay 2(R3A D) 1 s50 1600 1650 1TOo 1150 180o 1850 Geosyntec° Plant Barry 50%Closure Design consultants °� Section B 3H:1V Slope. 10 R Bench Height i,s I �onNeOes A, David Kein Southern Company Dee, 8/17/2018 — 1:400 "` B-B_Interim_3Hto1V_lOR_Bench.slmd APC Bany_EPA_000483 Cohesion Vertical Minimum Unit Weight Cohesion Phi Cohesion n Datum Material Name Color Qbs/k3) Strength Type (psf) (deg) Type Change (R) Strength Shear Strength Water Surface (psf/R) Ratio (psf) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1)113A D) ® 95 Undrained 200 FDatum 8.4 0 Piezometric Line Sand 1)R3A D) ■ 115 Mohr-Coulomb 0 35 Piezometric Line Clay 2)113A D) ® 102 Vertical Stress Ratio 0.258 500 Piezometric Line Sand 2)R3A D) ■ 120 Mohr-Coulomb 0 38 Piezometric Lin Clay I(113A UD) ■ 95 Undrained 200 Constant Piezometric Line2 Existing Ground Surface 2 Spencer . 1.44 4 500.00Ibs CCR 25.0 4 5.0 0 4 4 :K�y - - - - - -ay 1 (R3A UD) 2. . . : . . . .ia Clay 2(R3A D) 1550 1600 1650 1700 1750 1800 1850 PAcAAo Geosyntec° Plant Barry 50%Closure Design consultants °� Section B.41-1:1V Slope. 5 R Bench Height i,s I �onNeOesAY David Kein Southern Company Dee, 8/17/2018 — 1:400 '" B-B_Interim_4Hto1V_5ft_Bench.slmd APC 3any_EPA_000484 Cohesion Vertical Minimum Unit Weight Cohesion Phi Cohesion n Datum Material Name Color Qbs/k3) Strength Type (psf) (deg) Type Change (R) Strength Shear Strength Water Surface (psf/R) Ratio (psf) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(113A D) ® 95 Undrained 200 FDatum 8.4 0 Piezometric Line Sand 1(R3A D) ■ 115 Mohr-Coulomb 0 35 Piezometric Line Clay 2(113A D) ® 102 Vertical Stress Ratio 0.258 500 Piezometric Line Sand 2(R3A D) ■ 120 Mohr-Coulomb 0 38 Piezometric Lin Clay I(113A Up) ■ 95 Undrained 200 Constant Piezometric Line2 Existing Ground Spencer Surface 1.33 2 500.00 Ibs/112 . 4 500.00 lb 4 CCR 4 4 Clay 1 (R3A D) _ _ GIay1 (R3A UD) ...,Sand1 (R3A D) . . . . Sand 2(R3A D) >; . . . . . . . . . . . . . . . . Glay2 (R3A D) .: . . . . 1550 1600 1650 1700 1750 1800 1850 PAcAAo Geosyntec° Plant Barry 50%Closure Design consultants °� Section B.4H:1V Slope. 7 Pt Bench Height n,y I .onNeOesAY David Kein Southern Company Dee, 8/17/2018 — 1:400 "` B-B_Interim_4Hto1V_7ft_Bench.slmd APC Bany_EPA_000485 Cohesion Vertical Minimum Unit Weight Cohesion Phi Cohesion Datum Material Name Color (lb./�) Strength Type (psf) (deg) Type Change (k) Strength Shear Strength Water Surface (psf/k) Ratio (psf) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay I(R3A D) ® 95 Undmined 200 FDatum 8.4 0 Piezometric Line 2 Sand I(R3A D) 115 Mohr-Coulomb 0 35 Piezometric Line 1 Clay 2(R3A D) ® 102 Vertical Stress Ratio 0.258 500 Piezometric Line Sand 2(R3A D) ❑ 120 Mohr-Coulomb 0 38 Piezometric Line 1 Clay 1(R3A UD) ■ 95 Undmined 200 Constant Piezometric Line 2 Spencer 1.34 ExisBng Ground Surface 2 500-001 /f@ • 4 7D� 10.0 100 4 Clay 1 Clay 1 (R3A UD) Sand 1 (R3A D) Sand 2(R3A D) Clay 2 (R3A D) 1550 1600 1650 1T00 1T50 1800 1850 vmp Geosyntec° Plant Barry 50%Closure Design consultants °� Section B.4H:1V Slope. 10 Pt Bench Height & David Kein �,r SouNem Company 8/17/2018 '�` 1:400 B-B_Interim_4Hto1V_lOR_Bench.slmd APC Bany_EPA_000486 Material sion rvame Color Unit Weight Strength Cohe th Type Cohesion Cohesion Change Datum Water Surtace (Ibs/ft31 IPsfl (deg) ) Type (Psf/R) (R) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay I(RSA D) ® 105 Undrained 420 FDatum 11.6 0 Piezometric Line 2 Sand I(115A D) ■ 110 Mohr-Coulomb 0 35 Piezometric Line 1 Clay IA(RSA UD) ■ 110 Undrained 550 Constant Piezometric Line Sand 2(115A D) ■ 120 Mohr-Coulomb 0 38 Piezometric Line 1 Clay 1(R5B UD) ® 105 Undrained 375 FDatum 10.5 2 Piezometric Line 2 Sand 1(R5B D) ■ 115 Mohr-Coulomb 0 35 Piezometric Line 1 Existing Ground 500.00 Ibs/ft2 Surface 500.00 Ibs/R2 2 Spencer _ 4 1 1.59 2 3 CCR 2 5.0 2 1 Cla 1 R 11 CIay1 (R56 UD) 5AD y ( ) (Clay 1A(RSAUD) � Sand 1 (R5B D) Sand 1 (R5A D) Sand 2 1440 1460 1480 1500 1520 1540 1560 1580 1600 1620 1640 1660 1680 v j- Geosyntec° Plant Barry 50%Closure Design Coll °ate""' Section D. 2H:1V Slope. 5 FtBenrh Height ,,��nu i moo+amn a,y,:,a, David Kein Southern Company Pam 8/22/2018 �` 1:300 D-D_Interim_2Hto1V_5ft_Bench.slmd APC Barry_EPA_000487 Unit Weigh[ Cohesion Phi Cohesion Cohesion Datum Material Name Color (Ibs/ft3) Strength Type (�) (dog) Type Change (ft) Water Surface (psf/ft) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(115A DI ® 105 Undained 420 FDatum 11.6 0 Piezometric Une 2 Sand 1(R5A DI 110 Mohr-Coulomb 0 35 Piezometric Une 1 Clay 1A(R5A UD) ■ 110 Undained 550 Constant Piezometric Une2 Sand 2(R5A DI 120 Mohr-Coulomb 0 38 Piezometric Une 1 Clay 1(R58 UD) ® 105 Undained 375 FDatum 10.5 2 Piezometric Une 2 Sand 1(R5B D) ■ 115 Mohr-Coulomb 0 35 Piezometric Une 1 Existing Ground Surface Spencer 2.09 2 2 CCR 3 2 Clay 1 (R5B UD) Clay 1 (RSA D) Clay 1 A(R5A UD) Sand 1 (R5B D) Santl 1 (R5A D) Sand 2 1440 1460 1480 1500 1520 1540 1560 1560 1600 1620 1640 1660 1660 vrojes Geosyntec° Plant Barry 50%Closure Design consultants Section D.2H:1V Slope. 7 R Beni Height n,y I .onMc6s&A, David Kam � Southern Company Des, 8/22/2018 — 1:300 D-D_Interim_2Hto1V_7ft_Bench.slmd APC Bany_EPA_000488 Unit Weigh[ Cohesion Phi Cohesion Cohesion m Datu Material Name Color (Ibs/ft3) Strength Type (�) (deg) type Change (ft) Water Surface (psr/ft) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(115A DI ® 105 Undained 420 FDatum 11.6 0 Piezometric Une 2 Sand 11R5A DI 110 Mohr-Coulomb 0 35 Piezometric Une 1 Clay 1A(R5A UD) ■ 110 Undained 550 Constant Piezometric Una Sand 21R5A DI 120 Mohr-Coulomb 0 38 Piezometric Une 1 Clay 1(R58 UD) ® 105 Undained 375 FDatum 10.5 2 Piezometric Une 2 Sand 1(R5B D) ■ 115 Mohr-Coulomb 0 35 Piezometric Une 1 Spencer 1.76 Existing Ground Surface 2 500.00 Ibs/ft 2 CCR 3 0 1 2 10.0 Clay 1 (R5B UD) . Clay 1 (R5A D) Clay 1A(R5A UD) Sand 1 (R5B D) Sand 2 Sand 1 (RSA D) 1440 1460 1480 1500 1520 1540 1560 1560 1600 1620 1640 1660 1680 vrojes Geosynte& Plant Barry 50%Closure Design consultants Section D.21-1:1V Slope. 10 R Bench Height n,,I .on � David Kam � Southern Company Des, 8/21/2018 '�` 1:300 D-D_Interim_2Hto1V_101t_Bench.slmd APC Bany_EPA_000489 sion Material rvame Color U Weight Strength Cohe th Type Cohesion Cohesion Change Datum Water Surtace gb (Is/ft31 IPsfl (deg) ) Type (Psf/R) (R) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay(RSA D) ® 105 Undrained 420 FDatum 11.6 0 Piezometric Line Sand I(115A D) ■ 110 Mohr-Coulomb 0 35 Piezometric line 1 Clay IA(RSA UD) ■ 110 Undrained 550 Constant Piezometric Line Sand 2(115A D) ■ 120 Mohr-Coulomb 0 38 Piezometric line 1 Clay 1(R5B UD) ® 105 Undrained 375 FDatum 10.5 2 Piezometric line 2 Sand 1(R5B D) ■ 115 Mohr-Coulomb 0 35 Piezometric line 1 Existing Ground Surface 500.00 Ibs/R2 Spencer 3 1.95 0 Ibs/112 Ibs/R2 3 3 CCR 3 Cla 1 R5AD , 11 CIay1 (R56 UD) y ( ) -Clay 1A(RSAUD) Sand 1 (R5B D) Sand 1 (R5A D) Sand 2 1440 1460 1480 1500 1520 1540 1560 1560 1600 1620 1640 1660 1680 v j- Geosyntec° Plant Barry 50%Closure Design consultants °� Section D.3H:1V Slope. 5 R Beni Height n,y I .on � David Kein � Southern Company 8/21/2018 '�` 1:300 D-D_Interim_3Hto1V_5R_Bench.slmd APC Barry_EPA_000490 ----------------- .................... ............ ....... . -.- ............................................ ..e.-.-.-.-.-................... ---- . . . . . . . . . �j- PlantBarry50% Design Unit Weigh[ Cohesion Phi Cohesion Cohesion m Datu Material Name Color (Ibs/ft3) Strength Type (�) (dog) Type Change (ft) Water Surface (psr/ft) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1(115A DI ® 105 Undained 420 FDatum 11.6 0 Piezometric Une 2 Sand 1(R5A DI 110 Mohr-Coulomb 0 35 Piezometric Une 1 Clay 1A(R5A UD) ■ 110 Undained 550 Constant Piezometric Une2 Sand 2(R5A DI 120 Mohr-Coulomb 0 38 Piezometric Une 1 Clay 1(R58 UD) ® 105 Undained 375 FDatum 10.5 2 Piezometric Une 2 Sand 1(R5B D) ■ 115 Mohr-Coulomb 0 35 Piezometric Une 1 Spencer 1.99 Existing Ground Surface 3 500.00 s/ft2 10. 3 CCR � 2 .0 3 Clay 1 (R5B UD) Clay 1 (RSA D) Clay 1A(RSA UD) Sand 2 Sand 1 (R5B D) Sand 1 (R5A D) 1440 1460 1480 1500 1520 1540 1560 1560 1600 1620 1640 1660 1660 vrojas Geosyntec° Plant Barry 50%Closure Design °'�Oo�' Section D.3H:1V Slope. 10 FtBenrh Height Consultants I Inn-non David Kein —,e Southern Company 8/22/2018 ' 1:300 D-D_Intenn_3Hto1V_SOIt_Bench.slmd APC Bany_EPA_000492 sion Material rvame Color Unit Weight Strength Cohe th Type Cohesion Cohesion Change Datum Water Surtace (Ibs/ft31 IPsfl (deg) ) Type (Psf/R) (R) CCR ■ 92 Mohr-Coulomb 0 36 Piezometric Line Clay I(RSA D) ® 105 Undrained 420 FDatum 11.6 0 Piezometric line 2 Sand I(115A D) ■ 110 Mohr-Coulomb 0 35 Piezometric line 1 Clay IA(RSA UD) ■ 110 Undrained 550 Constant Piezometric Line Sand 2(115A D) ■ 120 Mohr-Coulomb 0 38 Piezometric line 1 Clay 1(R5B JD) ® 105 Undrained 375 FDatum 10.5 2 Piezometric line 2 Sand 1(R5B D) ■ 115 Mohr-Coulomb 0 35 Piezometric line 1 ExisBng Ground Surface Spencer 2.32 - - - - - - _ — 500.00Ibs/fl2 4 _ - - 5.0 1 0.0 �y 500.001 - 3 5.0 CCR 5.0 4 4 Clay 1 (R5B JD) Clay 1 (R.AD) Clay 1A(R5AUD) S Sand 1 (R5B D) Sand 1 (R5A D) Sand 2 . . 1440 1460 1480 1500 1520 1540 1560 1560 1600 1620 1640 1660 1680 v j- Geosyntec° Plant Barry 50%Closure Design consultants °� SectionD.4H:1V Slope. 5 Pt Benrh Height n,,I .on � David Kein � Southern Company 8/21/2018 '�` 1:300 D-D_Interim_4Hto1V_5ft_Bench.slmd APC Barry_EPA_000493 OVA ,: : ----.-.-.-.-.-.. . . ----:.:.:.:.:.:.:. ---------------------------------- UMMUNUMN ................NONE............JMI........� ............................................ ....................................................::: ............................. . • De :::::::::::::mmiU iiiiiiiii�::::::::::Tii .: .•.•....•:� ��+: �::: •.•: �s: �:: •: :; MUMM 00000000i�io� •f•••••. .....••:' .%:::':ii`= :�J_::::::::}}:':�!••':�Ci':':i•:':':':'i i00000•:OOOOi i::::::::iiiiiii :!:!:!:!:!:!:!:!:•.:!:::�:!:!:!:!:!:!:!.........................•__._._._._._._._._._.____________._.____________.!. . � • , %Closure Design APPENDIX C6 SEEPAGE ANALYSES AND MITIGATION DESIGN APC Barry_EPA_000496 Geosyntec consultants CALCULATION PACKAGE COVER SHEET Client: Alabama Power and Southern Project: Plant Bany Ash Pond Closure Project N: GW6489 Company Services Project TITLE OF PACKAGE: DRAFT SEEPAGE ANALYSES AND MITIGATION DESIGN F CALCULATION PREPARED BY: Signature gg (Calculation Preparey CP) 24 August 2018 i Name Jim Hansen Dare �a a ASSUMPTIONS&PROCEDURES Signature CHECKED BY: 24 August 2018 (Assumptions&Procedures Checker,APT) Name Daniel Woeste Date 3 �a COMPUTATIONS CHECKED BY: Signature (Computation Checker,CC) 24 August 2018 Name Daniel Woeste Date Y s BACK-CHECKED BY: S'gnam'" 24 August 2018 ly (Calculation Preparer,CP) Name Jim Hansen Date APPROVED BY: Signature 26 August 2018 a (Calculation Approver,CA) 8� Name William Tanner,PE Date REVISION HISTORY: NO. DESCRIPTION DATE CP APC CC CA A Draft Seepage Analyses&Mitigation Dsgn. 27 August 2018 JRH DJW DJW APC Barry_EPA_000497 Geosyntec consultants Page 1 of 28 CP: JRH Date: 8/17/2018 APC: D.FW Date: 8/23/2018 CA: Date: Client: sCs Project Plant Barry Closure Design Project No: GW6489 DRAFT SEEPAGE ANALYSES AND MITIGATION DESIGN INTRODUCTION This Seepage Analyses and Mitigation Design package(herein referred to as the Seepage Package) was prepared in support of the design to close the existing coal combustion residuals (CCR) ash pond at Alabama Power Company's(AFC's)Plant Barry (Site), located in Bucks,Alabama. The ash pond will be closed using a`consolidate and cap-in-place" method whereby all CCR will be consolidated into an approximately 300-acre area that will be constructed in the central portion of the ash pond using soil containment berms and with a final cover system. The southern portion of the side will be closed using a `closure-by-removal" method by excavating the ash. Figure 1 presents the proposed bottom elevation for the excavation,which varies from-3 to+3.25 feet and is generally between elevation-2.0 and-0.5 feet. If a flood event on the Mobile River were to occur during construction, the potential exists for seepage-related instability(i.e.piping and heave)to occur,both of which may damage the existing perimeter dikes at the Site. This Seepage Package provides a preliminary evaluation of seepage- related issues for the proposed excavation, including: (i) potential for piping and heave; (ii) mitigation using seepage berms; and (iii) estimated flow rates, based on simplified calculations. Seepage berms were selected as the preferred mitigation method based on discussions with Southern Company Services. This Seepage Package will be updated prior to the final submittal to include a comprehensive evaluation of seepage-related issues at the site,using a three-dimensional groundwater model that is currently in development for the Site. The model is currently being developed using MODFLOW (U.S. Geological Survey, 2017) that will incorporate three-dimensional effects, variability in soil unit layers, and transient groundwater effects related to the relatively short duration flood events. SUBSURFACE STRATIGRAPHY The subsurface stratigraphy at the Site is described in detail in the Ash Pond Closure Feasibility Study,Phase 1 Summary Report(Geosymec Consultants,2017)and Material Properties and Major Design Parameters (Geosyntec Consultants, 2018). A brief description of the subsurface stratigraphy, as related to this Seepage Package, is described below. n Coal Combustion Residuals (CCR) are at the ground surface and will be excavated from the areas where seepage is a potential concern. GW"89/DItAFT SEEPAGE ANALYSES AND MITIGATION DESIGN AEC Barry_EPA_000498 Geosyntec consultants Page 2 of 28 CP: dREI Date: 8/17/2018 APC: D.FW Date: 8/23/2018 CA: Date: Client: sCs Project Plant Barry Closure Design Project No: GW6489 • Clay 1 underlies the CCR and is a laterally-extensive layer of organic silt and organic clay that acts as an impervious barrier for seepage pressures developing beneath. Figure 2 presents the clay thickness after excavation, which varies from about 3 to 25 feet. • Sand 1 underlies Clay 1 and consists of interbedded lenses of loose to medium dense, sand, silty sand, clayey sand, and sandy clay. This unit is not laterally continuous and, where present, is up to approximately 30 feet thick. • Clay 2 underlies Sand 1 and consists of soft to stiff, medium to high plasticity clay. This unit is not laterally continuous and, where present,is up to approximately 20 feet thick. • Sand 2 underlies Clay 2 and consists of poorly graded,medium dense, alluvial fine-grained sand. This unit is highly permeable relative to the other soil units. The total thickness of the Sand 2 unit at the Site is unknown,but it was present in borings advanced to 100 feet below grade. Figure 3 presents subsurface profiles at several cross-sections. Seepage is generally governed by the most permeable and/or continuous soil units,as seepage flows can be transmitted readily through such soil units.However,seepage may be limited by the presence of relatively impervious soil units. Due to the discontinuity of the Sand 1 and Clay 2 layers, the analyses in this package are based on a two-layer subsurface profile consisting of Clay (based on Clay 1) overlying Sand (based on Sand 2). This assumption is conservative because it effectively reduces the thickness of Clay 1. TOPOGRAPHIC AND HYDRAULIC CONDITIONS The Site is bounded by an existing dike that isolates the Ash Pond from the surrounding Mobile River floodplain. During closure construction, the existing dike will function as a levee and will protect the closure-by-removal portions of the Ash Pond from inflows of water from the Mobile River. The analyses in this Seepage package consider the 100-year flood event of the Mobile River, this is considered to be the design flood event for the purposes of design. Figure 4 indicates that the river level for the design event (100-year flood) is elevation' +16 feet and the typical river level for design is elevation+3 feet. ' All elevations listed in this report are in the North American Vertical Datmn of 1988(NAVD88) GW"8%DItAFT SEEPAGE ANALYSES AND MITIGATION DESIGN AEC Barry_EPA_000499 Geosyntec consultants Page 3 of 28 CP: JRH Date: 8/17/2018 APC: D.FW Date: 8/23/2018 CA: Date: Client: sCs Project Plant Barry Closure Design Project No: GW6089 Figure 3 shows the existing and proposed ground surface at several cross-sections. Based on these cross-sections,the following design assumptions were used for the seepage analyses: • The top of dike is at elevation+20 feet, • The bottom of the dike is 100 feet wide after CCR excavation, and • The near shore of the river is about 150 feet from the waterside toe of the dike. IIYDROGEOLOGIC CONDITIONS Monitoring wells were installed along the dike to measure groundwater constituents in Sand 1 and Sand 2 in the sand layer. Monitoring well installation details are provided in the Draft Pre-Design Field Investigation Summary Report (Geosyntec Consultants,2018). Figure 5 presents a Site Plan with the monitoring well locations. Figure 6 presents the river elevation as a function of time and the observed range of water pressures from the monitoring wells at specific reading times. Based on the data presented in Figure 6, it appears that the water pressures in the sand are approximately equal to those in the river. Continuous monitoring of the monitoring wells is planned prior to construction to better evaluate the response of sand water pressures to river elevation. The interior of Site currently has two pools at operational elevations +15 and+18 feet, as shown in Figure 4. The proposed excavation plan is based on a unwatered excavation, which means that the water level during pond closure will be equal to the excavated grades that are shown in Figure 1. Therefore, the water levels inside the excavation (typically elevation -2.0 to -0.5 feet) will be lower than those in the river, resulting in seepage into the excavation and the potential for heave or piping to occur during a flood event. During a flood event, it is likely that the total head in the pervious Sand 1 will increase to approximately the same elevation as the Mobile River. The presence of the relatively impervious Clay 1 barrier over the top of Sand 1 will limit seepage flow into the closure-by-removal area. This may result in excess pore pressures developing at the top of Sand 1 /bottom of Clay 1; such pore pressures may lead to the development of high exit gradients and/or the presence of sand boils that could undermine the existing dike. Based on the data provided in Figure 6,the seepage analyses consider two different hydrogeologic conditions: 1. Constant head—Water pressures in the entire sand layer are equal to the river level. This condition assumes that Clay 1 is impervious, resulting in no leakage into the Closure by GW"89/DI2AFT SEEPAGE ANALYSES AND MITIGATION DESIGN AEC Barry_EPA_000W0 Geosyntec consultants Page 4 of 28 CP: JRH Date: 8/17/2018 APC: D.1W Date: 8/23/2018 CA: Date: Client: SCS Project Plant Barry Closure Design Project No: GW6489 Removal area, and no corresponding reductions in water pressure in Sand 1. This assumption is conservative, as some amount of leakage and corresponding reduction in head will occur during a flood event. 2. Decreasing head—Water pressures in the sand layer decrease towards the interior of the Site. This condition assumes that some amount of leakage occurs through Clay 1,reducing water pressures in Sand 1. This assumption is slightly less conservative; however, it will require more advanced seepage analyses to confirm. SOIL PARAMETERS The primary soil parameter required for the seepage analysis is unit weight. Unit weights were calculated in the Material Properties and Major Design Parameters (Geosyntec Consultants, 2018) and are summarized in Table 1. The area of CCR excavation includes design reaches 2A, 2B,2C, 3A,and 3B.For these reaches,the unit weight of Clay 1 varies from 92 to 100 pounds per cubic foot(pcf). The unit weight for seepage berm fill, which may include different soil types, is assumed to be 115 pcf This assumption should be reevaluated when the type of berm fill is selected. Hydraulic conductivity is also required to estimate excavation inflow rates during a flood event. Hydraulic conductivity was estimated as 1 x 10' cm/sec for Sand 1 and 1 x 10-6 cm/sec for Clay 1. These numbers are preliminary estimates based on Geosyntec's experience and will be updated as part of the final design. SEEPAGE ANALYSES AND SEEPAGE BERM DESIGN Seepage analyses were conducted based on guidelines provided in the U.S. Army Corps of Engineers (USACE) Design and Construction of Levees Engineer Manual No. 1110-2-1913 (United States Army Corps of Engineers, 2000) and the USACE Hurricane and Storm Damage Risk Reduction System Design Guidelines (HSDRRG) (United States Army Corps of Engineers, 2012). Both references utilize the effective stress method to calculate seepage factors of safety during a flood event. The effective stress (i.e. piping) method calculates a critical hydraulic gradient for a soil,and compares the critical gradient to the expected gradient during a flood event to calculate a factor of safety following Equation 1: FS = ya` (Equation 1) yw•ho Mere: GW6489/DRAFT SEEPAGE ANALYSES AND MITIGATION DESIGN APC Barry_EPA_000W1 Geosyntec consultants Page 5 of 28 CP: JRH Date: 8/17/2018 APC: D.1W Date: 8/23/2018 CA: Date: Client: SCS Project Plant Barry Closure Design Project No: GW6089 y' = Effective unit weight of blanket(pcj) yw = Unit weight ofwater= 62.4pcf zr = Clay 1 thickness ha = Excess head at the bottom of Clay 1 (feet) The minimum design factor of safety criteria was taken from seepage berm design guidance criteria presented in the HSDRRG (USACE, 2016). The criteria provides minimum factors of safety against underseepage for seepage berms at various distances from the dike toe. Table 2 presents the target factors of safety against underseepage versus distance from the dike toe. Appendix A presents spreadsheet calculations for underseepage at various distances from the dike toe. The calculations are performed for both constant head and decreasing head conditions. A base case scenario was performed based on typical conditions across the excavation.Then,a parametric study was performed to document the effect of changes in each variable to the resulting factor of safety. The parameters analyzed are summarized in Table 3. The spreadsheet calculates the amount of overburden that is required on top of the Clay l to meet the required minimum FS. Based on the required overburden, a thickness of seepage blanket at each distance and total volume of seepage blanket are also calculated based on Equation 1. Prior to final design, this calculation package will be updated to also include a calculation of seepage factors of safety based on total stress (i.e. heave)criteria. DECREASING HEAD ANALYSIS For the decreasing head condition, simplified equations are used based on Appendix C of the USACE Design and Construction of Levees manual (United States Army Corps of Engineers, 2000). A more precise MODFLOW model that captures 3-dimensional effects and variable Site conditions is currently being performed to improve on the assumptions made in this Seepage Package. The decreasing head condition is based on the following hydrogeologic assumptions: • The river is hydraulically connected to the sand layer at the river shore, • The clay layer acts as an impervious blanket between the dike and the river, and • Leakage through Clay 1 reduces the total head in Clay 1. Figure B-5 in the USACE Design and Construction of Levees manual (United States Army Corps of Engineers, 2000) presents the following equations for estimating decreasing water pressures beneath a dike: GW"99MD T SEEPAGE ANALYSES AND MITIGATION DESIGN APC Barry_EPA_000W2 Geosyntec consultants Page 6 of 28 CP: JR6 Date: 8/17/2018 APC: D.FW Date: 8/23/2018 CA: Date: Client: scs Project: Plant Barry Closure Design Project No: GW6489 b. CASE 2 - Impervious topstratoa both riverside and landsfde e t - • L tr1 . M :• y.. � titt f d ho • H �LT t L3 3, \ L x hit . ho X. for x < L3 3 hx . 0 for x > L3 SEEPAGE PER UNIT LENGTH OF LEVEE . . . . . . . . . . . . . . QS ; kfH Where: Li = Distance from seepage entry to riverside dike toe; Lz = Width of dike; L3 = Distance from landside dike toe to seepage exit; ha = Head beneath top stratum at landside dike toe; & = Head beneath top stratum at distance x from landside levee toe; $ = Shape factor for use in seepage equation; and d = Thickness ofseepage layer. Li and L2 are assumed to be 150 and 100 feet, respectively, as described previously. There is not a distinct seepage exit point from which to define L3; however, the maximum possible length is the distance from the dike to the center of the excavation, which is about 2,000 feet. For this calculation,L3 is assumed to be 600 feet. This value was chosen because it corresponds to a FS of approximately 1.0 at the toe of the seepage berm, 16H away from the dike. The thickness of the sand layer is unknown and likely exceeds 100 feet. However, seepage flow likely does not occur GW"89/DRAFT SEEPAGE ANALYSES AND MITIGATION DESIGN AEC Barry_EPA_000W3 Geosyntec consultants Page 7 of 28 CP: JRH Date: 8/17/2018 APC: D.1W Date: 8/23/2018 CA: Date: Client: SCS Project Plant Barry Closure Design Project No: GW6489 throughout the entire layer so, d is assumed to be 50 feet. The forthcoming MODFLOW analyses will be used to assess the validity of these assumptions. RESULTS AND CONCLUSIONS The results of the parametric seepage analyses for the constant head and decreasing head conditions are summarized in Tables 4 and 5,respectively. Results of the seepage analyses indicate that the required seepage berm dimensions are highly sensitive to the porewater pressure assumptions in the sand layer. The constant head condition is conservative because no reduction in porewater pressures due to leakage through Clay 1 is assumed in the central portions of the closure by removal area. . Some amount of leakage will occur through Clay 1, as it is not a truly impervious material. Therefore, it is our opinion that the decreasing head condition is expected to be more representative of the site conditions and appropriate for the preliminary design of a seepage berm. However, the MODFLOW analyses should be conducted to confirm the accuracy of these assumptions. Results of the decreasing head condition analyses indicate the required seepage berm volume ranges from about 460 to 1,650 cubic feet per linear foot of dike. Where unfavorable conditions coincide (i.e. low weight clay, thin clay, and/or low toe elevations), the required volume may be greater than 1,650 cubic feet per foot. For cost estimating purposes, we recommend assuming an average seepage bean volume equal to 1,000 to 1,500 cubic feet per foot of dike. Total seepage flow during the 100-year flood event is estimated to be 30 cubic feet per day per foot of dike, or approximately 1,500 gallons per minute for the entire Closure by Removal area. This value is considered a preliminary order of magnitude estimate. GW6489/DRAFT SEEPAGE ANALYSES AND MITIGATION DESIGN APC Barry_EPA_000504 Geosyntec consultants Page 8 of 28 CP: JRH Date: 8/17/2018 APC: D.rW Date: 8/23/2018 CA: Date: Client: SCS Project Plant Barry Closure Design Project No: GW6089 REFERENCES Geosyntec Consultants. (2017).Ash Pond Closure Feasibility Study, Phase 1 Summary Report, Alabama Power Company Plant Barry, Bucks, Alabama. Kennesaw, Georgia. Geosyntec Consultants. (2018).Draft Pre-Design Field Investigation Summary Report,Alabama Power Company Plant Barry, Bucks,Alabama. Kennesaw,Georgia. Geosyntec Consultants. (2018).Material Properties and Major Design Parameters, Alabama Power Company Plant Barry, Bucks,Alabama. U.S. Geological Survey. (2017).MODFLOW 6. United States Army Corps of Engineers. (2000).Design and Construction of Levees. Washington,D.C.: United States Army Corp of Engineers. United States Army Corps of Engineers. (2012).Hurricane and Storm Damage Risk Reduction System Design Guidelines (Interim). New Orleans, Louisiana: New Orleans District Engineering Division. GW"89/DI2AFT SEEPAGE ANALYSES AND MITIGATION DESIGN APC Barry_EPA_000505 Geosyntec consultants Page 9 of 28 CP: Jan Date: 8/17/2018 APC: DJW Date: 8/23/2018 CA: Date: Client: SCS Project Plant Barry Closure Design Project No: GW6489 Table 1 - Summary of Clay 1 Design Unit Weights Design Clay 1 Design Unit Weight,yt Reach (PC') 1 94 2A 92 2B 97 2C 100 3A 95 3B 95 3C 100 4 105 5A IA: 110 1B: 105 5B 105 GW"89/DI2AFT SEEPAGE ANALYSES AND MITIGATION DESIGN APC Barry_EPA_000506 Geosyntec consultants Page 10 of 28 CP: dRH Date: 8/17/2018 APC: D.TW Date: 8/23/2018 CA: Date: Client: SCS Project: Plant Barry Closure Design Project No: GW6489 Table 2—Target Factors of Safety Against Underseepage Distance from Dike Toe Minimum Factor of Divided by Height of Dike' Safetye 0 1.6 4 1.5 8 1.3 12 1.1 16 or more 1.0 1. Dike height is defined as the difference in elevation between Project Grade(top of dike)and the prevailing ground surface elevation in the vicinity of the landside dike toe. 2. The minimum design factor of safety criteria was taken from seepage berm design guidance criteria presented in the HSDRRG(USACE,2016). GW"89MItAPT SEEPAGE ANALYSES AND MITIGATION DESIGN APC Barry_EPA_000W] Geosyntec consultants Page 11 of 28 CP: JRH Date: 8/17/2018 APC: D.1W Date: 8/23/2018 CA: Date: Client: SCS Project Plant Barry Closure Design Project No: GW6089 Table 3—Parametric Study Variables Input Parameter Typical Value Low Value High Value Clay 1 Unit Weight(pcf) 95 92 100 Dike Toe Elevation(feet) -1 -3 +1 Clay Thickness(feet) 10 5 20 GW"89/DI2AFT SEEPAGE ANALYSES AND MITIGATION DESIGN APC Barry_EPA_000W8 Geosyntec consultants Page 12 of 28 CP: dRH Date: 8/17/2018 APC: D.TW Date: 8/23/2018 CA: Date: Client: SCS Project Plant Barry Closure Design Project No: GW6489 Table 4-Constant Head Results Required Berm Thickness at Distance from Dike Toe(feet) Total Dike Toe 4H 8H 12H 16H Berm (Target (Target (Target (Target (Target Volume FS at Case Analyzed FS=1.6) FS=1.5) FS=13) FS=1.1) FS=1.0) (f alft) Berm Toe Typical Conditions 11.9 11.0 9.2 7.3 6.4 3077 0.31 Low Unit Weight 12.2 11.3 9A 7.6 6.7 3164 0.28 (y=92 pcf) High Unit Weigh[(y= 100 pct) 11.5 10.6 8.7 6.9 6.0 2931 0.35 Low Toe Elevation(-3 feet) 13.7 12.6 10.6 8.5 7.5 3889 0.27 High Toe 10.2 9.4 7.7 6.1 5.3 2355 0.35 Elevation(+1 feet) Tltin Clay 13.3 12.4 10.6 8.7 7.8 3553 0.15 (zt=5 feet) Thick Clay 9.1 8.2 6.3 4.5 3.6 2124 0.61 (z[=20 feet) GW6489MuAFT SEEPAGE ANALYSES AND MITIGATION DESIGN APC Barry_EPA_000W9 Geosyntec consultants Page 13 of 28 Cp: 4RH Date: 8/17/2018 APC: D.TW Date: 8/23/2018 CA: Date: Client: SCS Project: Plant Barry Closure Design Project No: GW6489 Table 5-Decreasing Head Results Required Berm Thickness at Distance from Dike Toe(feet) Total Dike Toe 4H 8H 12H 16H Berm (Target (Target (Target (Target (Target Volume FS at Case Analyzed FS=1.6) FS=1.5) FS=13) FS=1.1) FS=1.0) (Waft) Berm Toe Typical Values 7.6 5.6 3.3 1.3 0.0 1172 0.99 Low Unit Weight 78 5.8 3.5 1.6 0.3 1260 0.90 (y=92 pcf) High Unit Weight 7.1 5.1 2.8 0.9 0 1043 1.14 (y= 100 pcf) Low Toe Elevation(-3 feet) 8.8 6.4 3.7 LS 0 1474 1.01 High Toe 6.4 4.7 2.7 1.1 0 889 1.00 Elevation(+1 feet) Tltin Clay 9.0 7.0 4.7 2.7 1.4 I648 0.49 (zt=5 feet) Thick Clay 4.7 2.7 0.4 0 0 464 1.98 (z[=20 feet) GW6489/DI2AFT SEEPAGE ANALYSES AND MITIGATION DESIGN APC Barry_EPA_000510 Geosyntec l" consultants Page 14 of 28 CP: JRH Date: 9/17/2018 APC: DJW Date: 8/23/2018 CA: Date: Clie.l SCS Project. Plant Barry Closure Design Project No: GW6489 Xr x, p a x,n j \ x. % X a ^ +� xa v z, / wm /x— xwo Xua X %ora ' Eno ° x x X xan x.,a xir x< %m x xam x X xaa x,m xna .fe .r Xa X x x. x m x.rm waa X— Figure 1 —Site Plan with Proposed Excavation Elevation GW6189MIIAFT SEEPAGE ANALYSES AND MITIGATION DESIGN AEG Barry_EPA_000511 Geosyntec l" consultants Page 15 of 28 CP: JRH Date: 9/17/2018 APC: DJW Date: 8/23/2018 CA: Date: Clie.l SCS Project. Plant Barry Closure Design Project No: GW6489 ELEVATiMr LE ■ ■ m i Figure 2—Remaining Clay Thickness After Excavation GW6189MIIAFT SEEPAGE ANALYSES AND MITIGATION DESIGN AEG Barry_EPA_000512 Geosyntec° consultants Page 16 of 38 CP: JRH Date: 8/17/2018 APC: DJW Dare: 8/23/2018 CA: Date: Client: sCs Project: Plant Barry Closure Design Project No: GW6489 i r. i .1 5 � t d _ I A _ 6Eu C etir�o GW6489MItAFT SEEPAGE ANALYSES — ox NotoORcefora+wixc p, xmroacoxsmuttiou ,,,, qpC Barry_EPA_000513 Geosynte& consultants P., 17 ae 1s CP: JRH Date: 8/17/2018 APC: DJW Date: 8/23/2018 CA: Date: Client: SCS Project: Plant Barry Closure Design Project No: GW6489 14 \T 1 1 h wmwx...m C xo.FOR caNs•aocriox Figure 3—Cross Sections ~89MItAFT SEEPAGE ANALYSES AND MITIGATION DESIGN AEG Barry_EPA_000514 Geosyntec consultants Page 18 of 28 CP: JRH Date: 9/17/2018 APC: DJW Date: 8/23/2018 CA: Date: Clime SCS Project. Plant Barry Closure Design Project No: GW6489 Lia Ob ,Till i IIII ; IIIL �,\ � JJI 'f wllDiln yl'.yl �.i_ L. i c Figure 4—Existing Site Conditions GW6189MII AFT SEEPAGE ANALYSES AND MITIGATION DESIGN AEG Barry_EPA_000515 Geosyntec° comilltant5 Page 19 of 28 CP: JRH Date: 8/17/2018 APC: DJW Date: 8/23/2019 CA: Date: Cheat: SCS Project: Plaat Barry Closure Dear Project No: GW6489 REACH 5B LEGEND @ SCS HISTORICAL BORING REACH SA 2013 SCS PIEZOMETER F MOBILE RIVER - � 2015 SCS MONITORING WELL �a t ] 2017 SPT BORING REACH 4 O 2016$PT BORINRG X 201E CPT — — APPROXIMATE LIMITS OF CCR APPROXIMATE LIMITS OF rs DESIGN REACH NOTES: REACH 1 ' t. APPROXIMATE CCR LIMITS AS REACH 11 DEFINES IN THE SUPPLIED JII 3695aA G'VOLUME FROM EXTRACTED FROM 7-28-09'AND EXTRACTED FROM THE PERIMETER BERM 2. REACH BOUNDARIES WERE C REACH 2C DEVELOPED USING SUBSURFACE EXPLORATION DATA AND .tea �� REACH 3B INTERPRETATION OF HISTORIC REACH 2A AERIAL IMAGERY,AND SHOULD k - BE CONSIDERED APPROXIMATE. REACH BOUNDARIES LOCATED C e I SUBSURFACE EXCAVA IO REACH 3A SUBSURFACE EXCAVATIONS MAY VARY FROM THOSE SHOWN ON 1 LL REACH 3E I THIS DRAWING. \ I i — I SCALE IN FEET PLANT BARRY COOLING WATER DISCHARGE CANAL t\ DESIGN REACHES WITH AERIAL f AND BORINGS REACH 2B :,.\ CeoWnwl> FIGURE — REACH 3A cobras 1 F"'ECTNO: GWate9 I AUGUST wig Figure 5—Monitoring Well Locations GW6189/DRAPT SEEPAGE ANALYSES AND MITIGATION DESIGN APC Barry_EPA_000516 Geosyntec° consultants Page 20 of 28 CP: JRH Date: 8/17/2018 APC: DJW Date: 8/23/2019 CA: Date: Cheat: sCs Project: Plaat Barry Closure Dear Project No: GW6489 16 River Elevation (USGS) MW-1 through MW-16 12 J 1n C O aQi 4 w 0 -4 12/14/15 2/29/16 4/18/16 6/7/16 8/30/16 10/17/16 Figure 6—River Elevation and Monitoring Well Data GWW9MItAFT SEEPAGE ANALYSES AND MITIGATION DESIGN AEG Barry_EPA_000517 Geosynte& ODDSIIItantB Page 21 of 45 CP: LPC Date: 7/31/2018 APC: Date: CA: Date: Client: tics Project: Plant Barry Closure Design Project No: GW6489 APPENDIX A - SEEPAGE SPREADSHEET CALCULATIONS GW6a89M11AFT SEEPAGE ANALYSES AND MITIGATION DESIGN AEG Barry_EPA_000518 Casel Typical Conditions INPUTS Design Water Level 16 feet Levee Height 21 feet For Reference Levee Top EL 20 feet Head Differential (DWSE), HI 17 feet Reach I Clay Unit Weight(pcf) Levee Sot EL -1 feet 2A 92 Clay Thickness,z, 30 feet Head at Levee Toe(DWSE), ho 12.0 feet 2B 97 Inside Water Level -1 feet 2C 100 Clay Unit Weight,y 95 pcf Sand layer thickness, d 50 feet 3A 95 Water Unit Weight 62.4 pcf Seepage Shape Factor,5 0.059 3B 95 Berm Unit Weight 115 pcf Sand Permeability, k1 0.01 cm/sec Distance from Levee to Seepage Entry, Lr 150 feet Sand Permeability, k, 28.3 ft/day QS kfH Width of Levee, Li 100 feet Seepage per Unit Length 28.3 ft3/ft/day Distance from Levee to Seepage Exit, L3 600 feet Seepage for South Area(`30,000 feet) 1473 gal/min With Head Loss(see Case 2 figure to right) gmtn = FS* (Yw *h:) -Y' *zt Head at bottom Required Berm b. rside and landside CASE 2 - Impervious topstratut e Distance from Levee Toe of Clay 1,h„ Required Effective Thickness,tm;n FS = y, *z1 both riv Divided by Levee Height feet Minimum FS (feet) Overburden, qm;,,(psf) (feet) Y. *ho 0 0 1.6 12.0 872 7.6 FS at Berm Toe 0.99 2IL 4 84 1.5 10.3 640 5.6 Volume of Berm (ft'/ft) 11728 168 1.3 8.6 375 3.3 12 252 1.1 7.0 152 1.34j7 t y 16 336 1 1.0 1 5.3 1 3 1 0.0 -' d Without Head Loss 1-1 + + Head at bottom Required Berm Distance from Levee Toe of Clay 1,h„ Required Effective Thickness,tm;n Divided by Levee Height feet Minimum FS (feet) Overburden, qm;,,(psf) (feet) hD ` t{ Li + + 3 0 0 1.6 17.0 1371 11.9 FS at Berm Toe 0.31 4 84 1.5 17.0 1265 11.0 Volume of Berm (ft'/ft) 3077 /L3 - X 8 168 1.3 17.0 1053 9.2 hx . ho tt\ L ') for x < L3 12 252 1.1 17.0 841 7.3 3 16 336 1.0 17.0 735 6.4 hx s 0 for x > L3 Notes: 1) Design is based on Tables 3.4 and 3.5 from USACE New Orleans District Hurricane and Storm Damage Risk Reduction System Guidelines(2012) APC Barry_EPA_000519 Casel Low Unit Weight INPUTS Design Water Level 16 feet Levee Height 21 feet For Reference Levee Top EL 20 feet Head Differential (DWSE), HI 17 feet Reach I Clay Unit Weight(pcf) Levee Sot EL -1 feet 2A 92 Clay Thickness,z, 30 feet Head at Levee Toe(DWSE), ho 12.0 feet 2B 97 Inside Water Level -1 feet 2C 100 Clay Unit Weight,y 92 pcf Sand layer thickness, d 50 feet 3A 95 Water Unit Weight 62.4 pcf Seepage Shape Factor,5 0.059 3B 95 Berm Unit Weight 115 pcf Sand Permeability, k, 0.01 cm/sec Distance from Levee to Seepage Entry, Li 150 feet Sand Permeability, k, 28.3 ft/day QS kfH Width of Levee, Li 100 feet Seepage per Unit Length 28.3 ft3/ft/day Distance from Levee to Seepage Exit, L3 600 feet Seepage for South Area(`30,000 feet) 1473 gal/min With Head Loss(see Case 2 figure to right) gmtn = FS* (Yw *h:) -Y' *zt Head at bottom Required Berm b. rside and landside CASE 2 - Impervious topstratua e Distance from Levee Toe of Clay 1,h„ Required Effective Thickness,tm;n FS = y, *Zt both riv Divided by Levee Height feet Minimum FS (feet) Overburden, qm;,,(psf) (feet) Y. *ho 0 0 1.6 12.0 902 7.8 FS at Berm Toe 0.90 2IL 4 84 1.5 10.3 670 5.8 Volume of Berm (ft'/ft) 1260 4j7 x 8 168 1.3 8.6 405 3.5 12 252 1.1 7.0 182 1.6 t y 16 336 1 1.0 1 5.3 1 33 0.3 -' d Without Head Loss 1-1 + + Head at bottom Required Berm Distance from Levee Toe of Clay 1,h„ Required Effective Thickness,tm;,, Divided by Levee Height feet Minimum FS (feet) Overburden, qm;,,(psf) (feet) hD ` t{ Li + + 3 0 0 1.6 17.0 1401 12.2 FS at Berm Toe 0.28 4 84 1.5 17.0 1295 11.3 Volume of Berm (ft'/ft) 3164 /L3 - x 8 168 1.3 17.0 1083 9.4 hx . ho tt\ L for x < L3 12 252 1.1 17.0 871 7.6 3 16 336 1.0 17.0 765 6.7 hx s 0 for x > L3 Notes: 1) Design is based on Tables 3.4 and 3.5 from USACE New Orleans District Hurricane and Storm Damage Risk Reduction System Guidelines(2012) APC Barry_EPA_000520 Casel High Unit Weight INPUTS Design Water Level 16 feet Levee Height 21 feet For Reference Levee Top EL 20 feet Head Differential (DWSE), HI 17 feet Reach I Clay Unit Weight(pcf) Levee Sot EL -1 feet 2A 92 Clay Thickness,z, 30 feet Head at Levee Toe(DWSE), ho 12.0 feet 2B 97 Inside Water Level -1 feet 2C 100 Clay Unit Weight,y 100 pcf Sand layer thickness,d 50 feet 3A 95 Water Unit Weight 62.4 pcf Seepage Shape Factor,5 0.059 3B 95 Berm Unit Weight 115 pcf Sand Permeability, k, 0.01 cm/sec Distance from Levee to Seepage Entry, Li 150 feet Sand Permeability, k, 28.3 ft/day QS kfH Width of Levee, Li 100 feet Seepage per Unit Length 28.3 ft3/ft/day Distance from Levee to Seepage Exit, L3 600 feet Seepage for South Area(`30,000 feet) 1473 gal/min With Head Loss(see Case 2 figure to right) gmtn = FS* (Yw *h:) -Y' *zt Head at bottom Required Berm b. rside and landside CASE 2 - Impervious topstratut e Distance from Levee Toe of Clay 1,h„ Required Effective Thickness,tm;n FS = y, *Zt both riv Divided by Levee Height feet Minimum FS (feet) Overburden, qm;,,(psf) (feet) Y. *ho 0 0 1.6 12.0 822 7.1 FS at Berm Toe 1.14 L2 IL 4 84 1.5 10.3 590 5.1 Volume of Berm (ft'/ft) 10434j7 8 168 1.3 8.6 325 2.8 12 252 1.1 7.0 102 0.9 t y 16 336 1 1.0 1 5.3 1 -47 1 0.0 -' d Without Head Loss 1-1 + + Head at bottom Required Berm Distance from Levee Toe of Clay 1,h„ Required Effective Thickness,tm;n Divided by Levee Height feet Minimum FS (feet) Overburden, qm;,,(psf) (feet) hD ` t{ Li + + 3 0 0 1.6 17.0 1321 11.5 FS at Berm Toe 0.35 4 84 1.5 17.0 1215 10.6 Volume of Berm (ft'/ft) 2931 /L3 - X 8 168 1.3 17.0 1003 8.7 hx . ho tt\ L ') for x < L3 12 252 1.1 17.0 791 6.9 3 16 336 1.0 17.0 685 6.0 hx s 0 for x > L3 Notes: 1) Design is based on Tables 3.4 and 3.5 from USACE New Orleans District Hurricane and Storm Damage Risk Reduction System Guidelines(2012) APC Barry_EPA_000521 Casel Low Toe Elevation INPUTS Design Water Level 16 feet Levee Height 23 feet For Reference Levee Top EL 20 feet Head Differential (DWSE), HI 19 feet Reach I Clay Unit Weight(pcf) Levee Sot EL -3 feet 2A 92 Clay Thickness,z, 30 feet Head at Levee Toe(DWSE), ho 13.4 feet 2B 97 Inside Water Level -3 feet 2C 100 Clay Unit Weight,y 95 pcf Sand layer thickness, d 50 feet 3A 95 Water Unit Weight 62.4 pcf Seepage Shape Factor,5 0.059 3B 95 Berm Unit Weight 115 pcf Sand Permeability, k, 0.01 cm/sec Distance from Levee to Seepage Entry, Li 150 feet Sand Permeability, kr 28.3 ft/day QS kfH Width of Levee, Li 100 feet Seepage per Unit Length 31.7 ft3/ft/day Distance from Levee to Seepage Exit, L3 600 feet Seepage for South Area(`30,000 feet) 1646 gal/min With Head Loss(see Case 2 figure to right) 9mtn = FS* (Yw *h:) -Y' *zt Head at bottom Required Berm b. rside and landside CASE 2 - Impervious topstratua e Distance from Levee Toe of Clay 1,h„ Required Effective Thickness,tm;n FS = y, *Zt both riv Divided by Levee Height feet Minimum FS (feet) Overburden, qm;,,(psf) (feet) Y. *ho 0 0 1.6 13.4 1013 8.8 FS at Berm Toe 1.01 4ji-,t-L2 L3 4 92 1.5 11.4 737 6.4 Volume of Berm (ft'/ft) 1474 x 8 184 1.3 9.3 428 3.712 276 1.1 7.2 171 1.5 ' t y 16 368 1 1.0 1 5.2 1 -2 1 0.0 -' d Without Head Loss L, + + Head at bottom Required Berm Distance from Levee Toe of Clay 1,h„ Required Effective Thickness,tm;,, L3 Divided by Levee Height feet Minimum FS (feet) Overburden, qm;,,(psf) (feet) hD ` t{ Li + + 3 0 0 1.6 19.0 1571 13.7 FS at Berm Toe 0.27 4 92 1.5 19.0 1452 12.6 Volume of Berm (ft'/ft) 3889 /L3 - x 8 184 1.3 19.0 1215 10.6 hx . ho tt\ L for x < L3 12 276 1.1 19.0 978 8.5 3 16 368 1.0 19.0 860 7.5 hx s 0 for x > L3 Notes: 1) Design is based on Tables 3.4 and 3.5 from USACE New Orleans District Hurricane and Storm Damage Risk Reduction System Guidelines(2012) APC Barry_EPA_000522 Casel High Toe Elevation INPUTS Design Water Level 16 feet Levee Height 19 feet For Reference Levee Top EL 20 feet Head Differential (DWSE), HI 15 feet Reach I Clay Unit Weight(pcf) Levee Sot EL 1 feet 2A 92 Clay Thickness,z, 30 feet Head at Levee Toe(DWSE), ho 30.6 feet 2B 97 Inside Water Level 1 feet 2C 100 Clay Unit Weight,y 95 pcf Sand layer thickness, d 50 feet 3A 95 Water Unit Weight 62.4 pcf Seepage Shape Factor,5 0.059 3B 95 Berm Unit Weight 115 pcf Sand Permeability, k, 0.01 cm/sec Distance from Levee to Seepage Entry, Li 150 feet Sand Permeability, kr 28.3 ft/day QS kfH Width of Levee, Li 100 feet Seepage per Unit Length 25.0 ft3/ft/day Distance from Levee to Seepage Exit, L3 600 feet Seepage for South Area(`30,000 feet) 1299 gal/min With Head Loss(see Case 2 figure to right) 9mtn = FS* (Yw *h:) -Y' *zt Head at bottom Required Berm b. rside and landside CASE 2 - Impervious topstratut e Distance from Levee Toe of Clay 1,h„ Required Effective Thickness,tm;n FS = y, *Zt both riv Divided by Levee Height feet Minimum FS (feet) Overburden, qm;,,(psf) (feet) Y. *ho 0 0 1.6 10.6 731 6.4 FS at Berm Toe 1.00 2IL 4 76 1.5 9.2 540 4.7 Volume of Berm (ft'/ft) 8898 152 1.3 7.9 315 2.7 12 228 1.1 6.6 125 1.14j7 t y 16 304 1 1.0 1 5.2 1 0 1 0.0 -' d Without Head Loss 1-1 + + Head at bottom Required Berm Distance from Levee Toe of Clay 1,h„ Required Effective Thickness,tm;,, Divided by Levee Height feet Minimum FS (feet) Overburden, qm;,,(psf) (feet) hD ` t{ Li + + 3 0 0 1.6 15.0 1172 10.2 FS at Berm Toe 0.35 4 76 1.5 15.0 1078 9.4 Volume of Berm (ft'/ft) 2355 /L3 - X 8 152 1.3 15.0 891 7.7 hx . ho tt\ L ') for x < L3 12 228 1.1 15.0 704 16 304 1 1.0 1 15.0 1 610 5.3 hx s 0 for x > L3 Notes: 1) Design is based on Tables 3.4 and 3.5 from USACE New Orleans District Hurricane and Storm Damage Risk Reduction System Guidelines(2012) APC Barry_EPA_000523 Casel Thin Clay INPUTS Design Water Level 16 feet Levee Height 21 feet For Reference Levee Top EL 20 feet Head Differential (DWSE), HI 17 feet Reach I Clay Unit Weight(pcf) Levee Sot EL -1 feet 2A 92 Clay Thickness,z, 5 feet Head at Levee Toe(DWSE), ho 12.0 feet 2B 97 Inside Water Level -1 feet 2C 100 Clay Unit Weight,y 95 pcf Sand layer thickness, d 50 feet 3A 95 Water Unit Weight 62.4 pcf Seepage Shape Factor,5 0.059 3B 95 Berm Unit Weight 115 pcf Sand Permeability, k, 0.01 cm/sec Distance from Levee to Seepage Entry, Li 150 feet Sand Permeability, k, 28.3 ft/day QS kfH Width of Levee, Li 100 feet Seepage per Unit Length 28.3 ft3/ft/day Distance from Levee to Seepage Exit, L3 600 feet Seepage for South Area(`30,000 feet) 1473 gal/min With Head Loss(see Case 2 figure to right) gmtn = FS* (Yw *h:) -Y' *zt Head at bottom Required Berm b. rside and landside CASE 2 - Impervious topstratua e Distance from Levee Toe of Clay 1,h„ Required Effective Thickness,tm;n FS = y, *Zt both riv Divided by Levee Height feet Minimum FS (feet) Overburden, qm;,,(psf) (feet) Y. *ho 0 0 1.6 12.0 1035 9.0 FS at Berm Toe 0.49 2 IL 4 84 1.5 10.3 803 7.0 Volume of Berm (ft'/ft) 16488 168 1.3 8.6 538 4.7 12 252 1.1 7.0 315 2.74j7 t y 16 336 1 1.0 1 5.3 1 166 1 1.4 d Without Head Loss 1-1 + + Head at bottom Required Berm Distance from Levee Toe of Clay 1,h„ Required Effective Thickness,tm;n Divided by Levee Height feet Minimum FS (feet) Overburden, qm;,,(psf) (feet) hD ` t{ Li + + 3 0 0 1.6 17.0 1534 13.3 FS at Berm Toe 0.15 4 84 1.5 17.0 1428 12.4 Volume of Berm (ft'/ft) 3553 /L3 - X 8 168 1.3 17.0 1216 10.6 hx . ho tt\ L ') for x < L3 12 252 1.1 17.0 1004 16 336 1.0 17.0 898 7.8 hx 0 for K > L3 Notes: 1) Design is based on Tables 3.4 and 3.5 from USACE New Orleans District Hurricane and Storm Damage Risk Reduction System Guidelines(2012) APC Barry_EPA_000524 Casel Thick Clay INPUTS Design Water Level 16 feet Levee Height 21 feet For Reference Levee Top EL 20 feet Head Differential (DWSE), HI 17 feet Reach I Clay Unit Weight(pcf) Levee Sot EL -1 feet 2A 92 Clay Thickness,z, 20 feet Head at Levee Toe(DWSE), ho 12.0 feet 2B 97 Inside Water Level -1 feet 2C 100 Clay Unit Weight,y 95 pcf Sand layer thickness, d 50 feet 3A 95 Water Unit Weight 62.4 pcf Seepage Shape Factor,5 0.059 3B 95 Berm Unit Weight 115 pcf Sand Permeability, k, 0.01 cm/sec Distance from Levee to Seepage Entry, Li 150 feet Sand Permeability, k, 28.3 ft/day QS kfH Width of Levee, Li 100 feet Seepage per Unit Length 28.3 ft3/ft/day Distance from Levee to Seepage Exit, L3 600 feet Seepage for South Area(`30,000 feet) 1473 gal/min With Head Loss(see Case 2 figure to right) gmtn = FS* (Yw *h:) -Y' *zt Head at bottom Required Berm b. rside and landside CASE 2 - Impervious topstratua e Distance from Levee Toe of Clay 1,h„ Required Effective Thickness,tm;n FS = y, *Zt both riv Divided by Levee Height feet Minimum FS (feet) Overburden, qm;,,(psf) (feet) Y. *ho 0 0 1.6 12.0 546 4.7 FS at Berm Toe 1.98 2IL 4 84 1.5 10.3 314 2.7 Volume of Berm (ft'/ft) 464 x 8 168 1.3 8.6 49 0.4 12 252 1.1 7.0 -174 0.04j7 t y 16 336 1 1.0 1 5.3 1 -323 1 0.0 -' d Without Head Loss 1-1 + + Head at bottom Required Berm Distance from Levee Toe of Clay 1,h„ Required Effective Thickness,tm;,, Divided by Levee Height feet Minimum FS (feet) Overburden, qm;,,(psf) (feet) hD ` t{ Li + + 3 0 0 1.6 17.0 1045 9.1 FS at Berm Toe 0.61 4 84 1.5 17.0 939 8.2 Volume of Berm (ft'/ft) 2124 /L3 - X 8 168 1.3 17.0 727 6.3 hx . ho tt\ L ') for x < L3 12 252 1.1 17.0 515 4.5 3 16 336 1 1.0 1 17.0 1 409 3.6 hx s 0 for x > L3 Notes: 1) Design is based on Tables 3.4 and 3.5 from USACE New Orleans District Hurricane and Storm Damage Risk Reduction System Guidelines(2012) APC Barry_EPA_000525 4� APPENDIX D VOLUMETRIC REDUCTION OF COAL COMBUSTION RESIDUALS APC Barry_EPA_000526 Geosynte& consultants CALCULATION PACKAGE COVER SHEET Client: Alabama Power Company&Southern Project: Plant Barry Ash Pond Project#: GW6489 Company Services Closure Project TITLE OF PACKAGE: DRAFT-VOLUMETRIC REDUCTION OF COAL COMBUSTION RESIDUALS f CALCULATION PREPARED BY: Signature August 24,2018 (Calculation Preparer,CP) p Name Maria F.Limas Date o, ASSUMPTIONS&PROCEDURES Sipe August 24,2018 CHECKED BY: (Assumptions&Procedures Checker,APC) Name Clinton P. Carlson Daw 3 COMPUTATIONS CHECKED BY: Signature August 24,2018 (Computation Checker,CC) Name Clinton P.Carlson Daw Wu BACK-CHECKED BY: Signature August 24,2018 Y (Calculation Preparey CP) Name Maria F.Limas Date a m APPROVED BY: Signature August 24,2018 $ (Calculation Approver,CA) d Name William Tanner Daw a REVISION HISTORY: NO. DESCRIPTION DATE CP APC CC CA A Draft Closure Design Calculation Package 08/27/2018 MFL CPC CPC WT APC Barry_EPA_000527 Geosyntec° consultants Page 1 of 11 CP: MFL Date: 08UM APC: CPC Date: 0824/18 CA: WT Daze: 0824/18 Client: APOSCS Project: Plant Berry Ash Pond Closure Project Project No: GW6489 DRAFT-VOLUMETRIC REDUCTION OF COAL COMBUSTION RESIDUALS INTRODUCTION This Draft Volumetric Reduction of Coal Combustion Residuals calculation package (Package) was prepared in support of the design to close the existing coal combustion residuals (CCR) ash pond at Alabama Power Company's (APC's)Plant Barry (Site), located in Bucks,Alabama. The ash pond will be closed using a"consolidate and cap-in-place" method whereby all CCR will be consolidated into an approximately 300-acre area that will be constructed in the central portion of the ash pond using soil containment berms and with a final cover system. As part of the closure of the Plant Barry ash pond, a portion of the existing CCR will be dredged and consolidated within a new containment structure before placing a final cover system. Compaction of the CCR placed in the consolidation area, and dewatering of the CCR during compaction, will cause a reduction in volume of the CCR from in-situ sluiced conditions. This Package presents an estimate of the reduction in volume of the CCR during compaction based on available field and laboratory data. AVAILABLE DATA SOURCES Based on discussions with the client, Geosyntec understands that the Site is composed predominantly of fine-grained CCR(i.e., fly ash),with a small percentage of coarse-grained CCR (i.e.,bottom ash). Site characterization efforts consisted of two field investigations and laboratory testing programs led by Geosyntec in 2017 and 2018: (i) the Ash Pond Closure Feasibility Study Phase II Summary Report as detailed in Appendix A of Geosyntec(2017); and(ii)the Pre-design Field Investigation Summary Report(Geosyntec, 2018). Shelby tube, split-spoon, grab, and bulk samples of CCR were collected during the 2017 and 2018 field investigations. The data from these two investigations and lab programs were utilized to understand the volumetric change of the CCR materials from in-situ to final placement using compaction and moisture conditioning. METHODOLOGY To calculate fill volumes for the ash pond closure, it was necessary to estimate the reduction in volume of the CCR as a result of dredging, dewatering and compaction. The reduction in volume is defined by the following shrinkage factor: Shrinkage Factor = =° x 100% (1) a Plant Barry AP Volumetric Reduction DRAFT APC Barry_EPA_000528 Geosyntec° consultants Page 2 of 11 CP: MFL Date: 88/24/18 APC CPC Date: 0824/18 CA: WT Daze: 0824/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 where: Vf c = total volume of compacted CCR[cubic feet(ft;)]; and Vt t = total volume of in-situ CCR [ff;]. For a sample of a geotechnical material,the dry unit weight is calculated as follows: —W' 2 1d — Vt ( ) where: yd = dry unit weight of geotechnical material [pounds per cubic foot(ft)]; Ws = weight of solids of geotechnical material [pounds (lb)]; and Vt = total volume of geotechnical material [ft']. Therefore, the total volume of in-situ CCR(Vt_;) and compacted CCR(Vt e) can be calculated as follows: VCi = WW, (3) Yd i V = u='°` (4) Ydc where: yd t = dry unit weight of in-situ CCR [pcf]; yd e = dry unit weight of compacted CCR [pcf]; Ws ; = weight of solids of in-situ CCR [lb]; and Ws r = weight of solids of compacted CCR [lb]. The weight of solids of CCR will remain constant after excavation and compaction,which means W, ; and W,r are equal. Therefore,the shrinkage factor can be calculated as follows: Shrinkage Factor = Yd` x 100% (5) Yd C Shelby tube samples from the 2017 and 2018 investigations were used to measure the moisture content and dry unit weight of in-situ CCR(yd 1)via laboratory tests. These samples were assumed to contain a mix of fly and bottom ash representative of the ash pond composition. Plant Ba AP Volumetric Reduction_DRAFT APC Barry_EPA_000529 Geosyntec° consultants Page 3 of 11 CP: MFL Date: MUM APC: CPC Date: 08/24/18 CA: WT Date: 0824/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 In addition, standard Proctor tests were conducted per ASTM D698 (Method B) on bulk samples of fly ash from the 2017 investigation and a mix of fly and bottom ash from the 2018 investigation to estimate the optimum moisture content and maximum dry unit weight of CCR after compaction (y, r). Values of dry unit weight of compacted CCR (y, r) were obtained using the standard Proctor tests for relative compactions of 90 and 95 percent, which are expected to be achieved in the field. Average values of dry unit weight of in-situ CCR(yd 1) and compacted CCR(yd t,)were then used for the calculation of shrinkage factors. CALCULATIONS AND RESULTS Twenty Shelby tube samples from the 2017 and 2018 laboratory testing programs (Geosyntec, 2017;Geosyntec,2018)were used to estimate the dry unit weight of the in-situ CCR.The collected Shelby tube samples and the laboratory testing results used for the calculations in this Package are provided in Table land Figure 1. The maximum, minimum, and average in-situ dry unit weights of the samples tested are approximately 73, 52, and 57 pcf,respectively. The results from standard Proctor tests used for the calculations in this Package are provided in Table 2. Figure 2 presents compaction curves for the six samples of fly ash tested. The average maximum dry unit weight and optimum moisture content obtained from standard Proctor tests are 78 pcf and 32 percent, respectively. Table 3 presents calculated average values of dry unit weight for relative compactions of 90 and 95 percent for the standard Proctor tests. The average dry unit weight measured for in-situ CCR (i.e., 57 pcf) was used to calculate shrinkage factors for the two different levels of compaction using Equation 5. For relative compactions of 90 and 95 percent, the calculated shrinkage factors of the CCR are 82 and 78 percent,respectively. The calculation results are provided in Table 3. SUMMARY AND CONCLUSIONS This Package presented calculations for shrinkage factors for the estimation of the reduction in volume of the CCR after dredging and compaction as part of the closure of the Site. For a relative density of 90 and 95 percent of the average maximum dry density, the calculated shrinkage factor varies from 78 to 82 percent, which corresponds to an average reduction in volume of approximately 20 percent. The 20 percent reduction in volume is used to calculate the volume of the compacted CCR for the purposes of civil design of the Site. Plant Barry AP Volumetric Reduction DRAFT APC Barry_EPA_000530 Geosyntec° consultants Page 4 of 11 CP: MFL Date: 88/24/18 AM CPC Date: 0824/18 CA: WT Daze: 0824/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 REFERENCES Geosyntec. (2017). "Draft Ash Pond Closure Feasibility Study Phase H Summary Report", calculation package submitted to Alabama Power Company, September 2017. Geosymec. (2018). "Draft Pre-Design Field Investigation Summary Report," submitted to Alabama Power Company, June 2018. Plant Barry AP Volumetric Reduction DRAFT APC Barry_EPA_000531 Geosyntec° co=ltants Page 5 of 11 CP: MPL Date: 88/24/18 APC: CPC Date: 0824/18 CA: WT Daze: 0824/18 Client: APC/SCS Project: Plant Barry Ash Pond Closore Project Project No: GW6489 TABLES Plant Barry AP Volumetric Reduction DRAFT APC Barry_EPA_000532 Geosyntec° consultants Page 6 of 11 CP: MFL Date: 08/24/18 APC: CPC Date: 08/24/18 CA: WT Date: O11/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Table 1.Results of Tests for Dry Unit Weight on Shelby Tube Samples of CCR Average Average Dry Unit Moisture Sample ID Sample Sample Weight Content(%) Source Laboratory Teat Depth(ft) Elevation(it) (pct) GSB-3D, 10-12' 11.0 19.5 57.8 58.2 Geos tec 2017 unit weight ASTM D2937 GSB-7D,6-8' 7.0 16.4 57.0 54.5 Geos tec 2017 unit weight ASTM D2937 PDS-03 11-13 12.0 6.4 46.6 89.0 Geos tec 2018 unit weight ASTM D2937 PDS-I1D 8-10 9.0 13.6 60.7 54.3 Geos tec 2018 unit weight ASTM D2937 GSB-1D,9-1l' 10.0 14.0 63.3 53.1 Geos tec 2017 Consolidated Undrained Triaxial ASTM 134767 GSB-1D, 12.5-14.5' 13.5 10.5 56.3 58.75 Geos tec 2017 Consolidated Undrained Trfaxial ASTM D4767 PDS-01B 2-4 3.0 18.1 54.2 71.6 Geos tec 2018 Consolidated Undrained Trfaxial ASTM D4767 PDS-07 7-9 8.0 11.2 52.7 64.1 Geos tec 2018 Consolidated Undrained Trfaxial ASTM D4767 PDS-09D 9-11 10.0 10.5 51.2 73.8 Geos tec 2018 Consolidated Undrained Trfaxial ASTM D4767 PDS-25B 10-12 11.0 8.1 32.8 144.4 Geos tec 2018 Consolidated Undrained Trimial ASTM D4767 GSB-1D, 12.5-14.5' 13.5 10.5 60.3 57.7 Geos tec 2017 Hydraulic Conductivity ASTM D5084 PDS-10 8-10 9.0 12.6 62.9 53.4 Geos tec 2018 Hydraulic Conductivity ASTM D5084 PDS-13B 6-8 7.0 13.9 63.4 52.5 Geos tec 2018 Hydraulic Conductivity ASTM D5084 PDS-15B 10-12 11.0 9.7 47.6 90.1 Geos tec 2018 Hydraulic Conductivity ASTM D5084 PDS-I6 5-7 6.0 17.3 68.4 48.0 Geos tec 2018 Hydraulic Conductivity ASTM D5084 GSB-3D 10-12' 11.0 19.5 57.5 62.6 Geos tec 2017 One-Dimensional Consolidation(ASTM D2435 GSB-7D 6-8' 7.0 16.4 52.1 72.9 Geos tec 2017 One-Dimensional Consolidation ASTM D2435 PDS-13B 6-8 7.0 13.9 73.0 41.9 Geos tec 2018 One-Dimensional Consolidation ASTM D2435 PDS-15B 10-12 11.0 1 9.7 61.7 50.4 Geos tec 2018 One-Dimensional Consolidation ASTM D2435 PDS-I6 5-7 6.0 17.3 65.9 49.1 Geos tec 2018 One-Dimensional Consolidation ASTM D2435 Plant Bart AP Volumetric Reductioa_DRAFT APC Barry_EPA_000533 Geosyntec° consultants Page 9 of 11 CP: MFI, Date: 0824/18 APC: CPC Date: 0824/18 CA: WT Daze: 0824/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Table 2. Standard Proctor Tests Results of Fly Ash Samples Average Average Maximum Dry Optimum Sample ID Sample Sample Unit Weight Moisture Source Depth(it) Elevation(ft) (pco Content(%) BS-7D-FA(1) N/A N/A 77.9 31.2 Geosyntec(2017) BS-7D-FA(2) N/A N/A 76.0 32.9 Geosyntec(2017) BS-7D-FA-Mix N/A N/A 77.1 32.5 Geosyntec(2017) PDS-04 4"-14" 0.75 18.6 79.3 32.2 Geosyntec(2018) PDS-06 4"-14" 0.75 18.1 76.8 31.4 Geosyntec(2018) APT-02 0-20 10.0 14.0 78.4 29.0 Geosyntec(2018) Plant Barry AP Volumetric Reduction DRAFT APC Barry_EPA_0005M Geosyntec° consultants Page 8 of 11 CP: MITI, Date: 8824/18 APC: CPC Date: 0824/18 CA: WT Daze: 0824/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Table 3. Calculated Shrinkage Factor of CCR for Different Levels of Compaction Relative Dry Unit Weight of Dry Unit Weight of Compaction Irl Compacted CCR 121 In-Situ CCR IJI Shrinkage Factor M (pcf) (Pcf) M 95 74 58 77 90 70 58 81 Notes: 1. Percentage ratio of the dry unit weight of CCR compacted in the field to the maximum dry unit weight obtained from standard Proctor test. 2. Average values of dry unit weight obtained from standard Proctor tests on fine-gained CCR(i.e,Fly ash). 3. Average value of dry unit weight measured from laboratory tests on Shelby tube samples. Plant Barry AP Volumetric Reduction DRAFT APC Barry_EPA_000535 Geosyntec° co=ltants Page 9 of 11 CP: MFL Date: O8/24/18 APC: CPC Date: 08/24/18 CA: WT Date: 0824/18 Client: APC/SCS Project: Plant Barry Ash Pond Closare Project Project No: GW6489 FIGURES Plant Barry AP Volumetric Reduction DRAFT APC Barry_EPA_000536 Geosyntec° consultants Page 10 of 11 CP: MFL Date: 0824/18 APC: CPC Date: 08/24/18 CA: WT Date: 0824/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 22 I From Dry Unit Weight Tests 20 From CU Triaxial Tests ■ From Hydraulic Conductiviry Tests ; • From 1-D Consolidation Tests 18 AL I I •■ I 16 • I Average Td ee 57 P f I 14 I c I LL e � ■ 12 w I 1a ■ I • B I I I 6 I 4 0 10 20 30 40 50 60 70 8o Dry Unit Weight, yd(pcq Legend: ft-MSL-feet above mean sea level pat-pounds per cubic toot Figure 1. Dry Unit Weight of In-Situ CCR from Laboratory Tests on Shelby Tube Samples Plant Barry AP Volumetric Reduction DRAFT APC Barry_EPA_000537 GeosynteO' consultants Page 11 of 11 CP: MFL Date: O8/24/18 APC: CPC Date: 08/24/18 CA: WT Date: 0824/18 Client: APC/SCS Project: Plant Barry Ash Pond Clesure Project Project No: GW6489 86 I 84 ♦ PDs-044•-14- ♦ B8-7D-FA(l) ♦ PDs 66 4^-14^ ♦ Bs-7D-FA(2) ♦ APT-020-20 ♦ B3-7D-FAMix 82 I I 80 u Averag a yams 78 pc 78 76 IC=951 ye= 7 Pcf ;I r I , 72 RC=90 L,yd= 7 D pcf 1 1 70 1 68 Av ge e, = 32 ° I I I 66 0 5 10 15 20 25 30 35 40 45 50 Moisture Content, Legend: RC- Relative Compaction pcf-pounds per cubic foot %-percent Figure 2. Standard Proctor Testa on CCR Samples Plant Barry AP Volumetric Reduction DRAFT APC Barry_EPA_000538 Z N& APPENDIX E HYDROLOGIC EVALUATION OF COVER PERFORMANCE APC Barry_EPA_000539 Geosyntec consultants CALCULATION PACKAGE COVER SHEET Client: APC&SCS Project: Plant Bany Ash Pond Closure Project Project#: GW6489 TITLE OF PACKAGE: DRAFT HYDROLOGIC EVALUATION OF COVER PERFORMANCE z F CALCULATION PREPARED BY: Signature August 27,2018 (Calculation Preparer,CP) Name Melissa C. Setz Dare a ASSUMPTIONS&PROCEDURES Signature August 27,2018 CHECKED BY: (Assumptions&Procedures Checker,APC) Name Clinton P.Carlson Date 3 m S ignore Au COMPUTATIONS CHECKED BY: S gust 27,2018 (Computation Checker,CC) Name Clinton P.Carlson Date u BACK-CHECKED BY: Signature August 27,2018 � x 4 (Calculation Preparer,CP) Name Melissa C. Setz Dart a m APPROVED BY: Signature August 27,2018 (Calculation Approver,CA) Name Ali Ebrahimi,Ph.D.,P.E.(GA) Date REVISION HISTORY: NO. DESCRIPTION DATE CP APC CC CA A Draft Closure Design Calculation Package 08/27/2018 MCS CPC CPC AE APC Barry_EPA_000W Geosyntec consultants Page 1 of 21 CP: MCS Date: 8127118 APC: CPC Date: 8/27/18 CA: AE Date: 8127118 Client: APCS Project. Plant Bury Ash Pond Closure Project No: GW6489 DRAFT HYDROLOGIC EVALUATION OF COVER PERFORMANCE PURPOSE This Draft Hydrologic Evaluation of Cover Performance calculation package (Package) was prepared in support of the design to close the existing coal combustion residuals (CCR) ash pond at Alabama Power Company's (APC's) Plant Barry (Site), located in Bucks, Alabama. The ash pond will be closed using a "consolidate and cap-in-place" method whereby all CCR will be consolidated into an approximately 300-acre area that will be constructed in the central portion of the ash pond using soil containment berms and with a final cover system. This Package presents engineering calculations for the final cover system of the Site to: (i) estimate infiltration rates through the prescriptive final cover system described in the U.S. Environmental Protection Agency (USEPA) CCR Rule [USEPA, 2015] and the ClosureTurf'e final cover system proposed for the closure (Figure 1); (ii) evaluate the equivalencies of the final cover system in minimizing infiltration by comparing the annual rate of infiltration through the final cover system with the rate of infiltration through the prescriptive final cover system; (iii)estimate the hydraulic heads on the cover geomembrane of the proposed final cover system; and (iv) calculate the total infiltration rates (i.e., for the entire closure area) for the prescriptive cover system and the ClosureTurf'final cover system. The remainder of this Package is organized to present: (i) final cover system details; (ii) evaluation methodologies; (iii) analyzed scenarios; (iv) evaluation results; and (v) summary and conclusions. FINAL COVER SYSTEM DETAILS Two cover systems were evaluated as part of this Package: • prescriptive final cover system; and • a ClosureTurf® final cover system. The prescriptive cover system was used as the baseline against the ClosureTurfe final cover system for comparison. According to Section 257.102(d)(3)(i)of the USEPA CCR GW6489/13 yAP Closure Design HELP AEC Barry_EPA_000541 Geosyntec consultants Page 2 of 21 CP: MCS Date: 8127118 APC: CPC Date: 8/27/18 CA: AE Date: 8127118 Client: APCS Project: Plant Bury Ash Pond Closure Project No: GW6489 Rule [USEPA, 2015],the prescriptive cover system for in-place closures must satisfy the following minimum criteria: • The permeability of the final cover system must be less than or equal to the permeability of any bottom liner system or natural subsoils present, or a permeability no greater than I x 10-5 cm/sec, whichever is less; • The infiltration of liquids through the closed CCR unit must be minimized by the use of an infiltration layer that contains a minimum of 18 inches of earthen material; • The erosion of the final cover system must be minimized by the use ofan erosion layer that contains a minimum ofsix inches ofearthen material that is capable of sustaining native plant growth. For the current conditions at the Site, where no liner system is present, the prescriptive cover system would consist of the following layers (from top to bottom): • 0.5-foot(1t)thick layer of vegetative cover(for erosion protection); and • 1.5-$thick infiltration layer(for infiltration reduction). The proposed ClosureTurf final cover system is shown in Figure 1 and consists of the following layers (from top to bottom): • 0.5-inch(in.)thick(minimum) sand infill and engineered turf; • two(2)woven geotextile backing layers; • studded drainage layer that is part of the linear low-density polyethylene(LLDPE) MicroDrain®product; and • 50-mil (minimum) thick textured geomembmne with spike down that is part of the LLDPE MicroDrain®product. For the proposed ClosureTurf® final cover system, a geocomposite and 6 in. of prepared subgrade will be placed below the textured geomembrane to assist potential gas generation to migrate to high points, as shown in Figure 1. GW6589Barty AP Closure Design HELP APC Barry_EPA_0005 2 Geosyntec consultants Page 3 of 21 CP: MCS Date: 8127118 APC: CPC Date: 8/27/18 CA: AE Date: 8127118 Client: APCS Project: Plant Barry Ash Pond Closure Project No: GW6489 METHODOLOGY The hydrologic evaluation of the cover systems presented in this package was modeled using the Hydrologic Evaluation of Landfill Performance(HELP)software,Version 3.07, developed for the USEPA [Schroeder et al., 1994a and 1994b]. The HELP program is a quasi-two-dimensional hydrologic model of water movement across, into, through, and out of waste disposal facilities, and the components of waste disposal facilities such as liner systems and cover systems. The program accepts climate, soil, and design input data, and uses a solution technique that accounts for the effects of surface storage, runoff, infiltration, percolation, evaporation, soil moisture storage, and lateral drainage. The remainder of this section discusses the development and selection of the input data required for the HELP analyses of the cover systems evaluated in this Package. Evapotranspiration Data The evaporative zone depth is defined as the maximum depth from which water may be removed by evapotranspiration. This depth affects the storage of water near the surface and directly impacts the computations for evapotranspiration and runoff[Schroeder et al., 1994a and 1994b]. For vegetated surfaces,the evaporative zone depth should be equal to the expected average depth of root penetration. The evaporative zone depth for the prescriptive cover system was selected as 22 in.using the HELP model default value for vegetated areas (i.e., vegetative cover) near Mobile, AL. The evaporative zone depth was selected as 0.6 in. for the ClosureTurfs' final cover system because that is the approximate thickness of the system (i.e., the thickness of the synthetic turf, sand infill, and woven geotextile layers). Precipitation Data Synthetic daily precipitation data for a 100-year modeling period for Mobile, AL was generated using the synthetic weather generator in the HELP model. These synthetic daily precipitation were used for the Site location. The 100-year precipitation data were GW6489Barty AP Closure Design HELP AEC Barry_EPA_0005t3 Geosyntec consultants Page 4 of 21 CP: MCS Date: 8127118 APC: CPC Date: 8/27/18 CA: AE Date: 8127118 Client: APCS Project: Plant Bury Ash Pond Closure Project No: GW6489 generated for the post-closure stage (i.e., with final cover) in the evaluation of the prescriptive cover system and the ClosureTurf"final cover system. Per the recommendation of Schroeder et al. [1994 a, b], because the Site is located approximately 25 miles from Mobile (the closest available default location in the HELP model) and the land use and topography varies between the Site and the city, the normal mean monthly precipitation values between 1981 and 2018 for the closest weather station to the Site (i.e. Bay Minette, Weather Station ID: USC00010583) were calculated and entered into the HELP model to improve the statistical characteristics of the resulting daily values. The calculated monthly values were obtained from the National Center for Environmental Information(NOAA)data center. The synthetic daily precipitation values generated in the HELP model will vary from month to month and from year to year and will not equal the normal values entered. The comparison between the default and calculated mean monthly precipitation for the Site is listed in Table 1. The 100-year,24-hour storm event for a 100-year modeling period was used for the HELP model runs.Per the recommendation of Schroeder et al. [1994 a,b],the peak daily rainfall value in the synthetically generated precipitation data was manually adjusted to model the 100-year,24-hour stone event for the Site with a peak daily rainfall depth of 14.0 in. for the post-closure condition,as provided in the Draft Final Cover System Surface Water Management Design [Geosyntec, 2018a]. This calculated peak daily rainfall depth replaced the maximum daily rainfall value that was synthetically generated for the 100- year modeling period. Temperature Data Synthetic daily temperature data was generated for Mobile using the synthetic weather generator in the HELP model over a 100-year modeling period. For sites that are located more than 100 miles away from or have elevation differences greater than 500 R from the default locations available in HELP, Schroeder et al. [1994a and 1994b] recommends using available site-specific temperature data to improve the statistical characteristics of the resulting daily temperature values. Because the Site is less than 100 miles from Mobile and the elevation difference between the Site and city is less than 500 ft, the default temperature values generated by HELP for the Mobile station were representative of the Site and were used in the model. GW6489Barty AP Closure Design HELP APC Barry_EPA_0005 Geosyntec consultants Page 5 of 21 CP: MCS Date: 8127118 APC: CPC Date: 8/27/18 CA: AE Date: 8127118 Client: APCS Project: Plant Bury Ash Pond Closure Project No: GW6489 Solar Radiation and Relative Humiditv Data Solar radiation and relative humidity data for a 100-year modeling period were developed using the synthetic weather generator in HELP for the Mobile station. Final Cover System Table 2 shows the cover system components for the prescriptive cover system and the proposed ClosureTurf's final cover system, along with material properties used in the HELP model. Unless noted in Table 2,the default properties from the HELP model built- in database were used for soil texture,porosity,field capacity,wilting point,and saturated hydraulic conductivity of the different layers. Geomembrane Laver Data The geomembrane component of the ClosureTurf® final cover system was modeled to contain one small hole per acre and have good installation quality (HELP Placement Quality equal to 3) that can be achieved with third-party construction quality assurance (CQA) and testing. The hole sizes were modeled to be 0.16 square inches (in')in area as recommended by Giroud and Bonaparte [19891 for design purposes. A geomembrane hydraulic conductivity(vapor diffusivity)of 2.0 x 10-13 centimeters per second(cm/sec) was selected. The two woven geotextile backing layers for the ClosureTurfs final cover system were not modeled as layers in the HELP analyses due to the relatively small thickness of the geotextiles and their high permeability. Lateral Drainaee Laver Data The hydrologic evaluation of the final cover system is divided into three portions for the Site based on the final cover grading plan as shown in Figure 2: (i) a top deck; (ii) a middle portion; and(iii)a lower portion. The drainage paths for each section of the cover system were designed with slopes of 3.5 percent, but post-settlement slopes of 3 percent were used in the analyses to represent long-term conditions. The selected critical drainage paths for the top deck, middle, and lower portions have lengths of approximately 525 ft, 630 ft, and 615 ft,respectively, as shown on Figure 2. The drainage paths illustrate flow GW65891Ba AP Closure Design HELP AEC Barry_EPA_000545 Geosyntec consultants Page 6 of 21 CP: MCS Date: 8127118 APC: CPC Date: 8/27/18 CA: AE Date: 8127118 Client: APCS Project: Plant Bury Ash Pond Closure Project No: GW6489 conveyance from on the top deck or along the side slopes into the benches and perimeter drainage channels of the final cover system. Hydraulic Conductivity of Drainage Lavers in Cover System Table 2 shows the initial(i.e.,"as manufactured")hydraulic conductivities of the drainage layers within the cover system used in the HELP model. This table also lists reduced hydraulic conductivities of the drainage layers under long-term field conditions, as described in Attachment 1. The final cover system will experience only a low normal stress during construction and post-closure conditions, so a reduction factor(i.e.,partial factor of safety)of 1.0 was used for both the immediate compression and immediate geotextile intrusion correction factors. For the ClosureTurt®cover system(see Figure 1)a geomembrane will be placed below the studded drainage layer, so only infiltrating surface water is expected to flow through the drainage layer. Therefore, chemical degradation and chemical clogging of drainage layers will be negligible, and reduction factors of 1.0 were used for these corrections. Creep, delayed intrusion,and particulate clogging are expected to happen to a limited degree for the drainage layer(selected reduction factors of 1.1 for each factor); some biological clogging is also expected to occur (selected reduction factor of 1.2). These reduction factors were obtained from several sources available in the technical literature [Giroud et al.,2000;GRI-GC8, 2001;Koerner, 1998] and are further defined in Attachment 1. An overall reduction factor (RF) of 2.4 (including an overall factor of safety of 1.5) was applied to the hydraulic conductivity of the drainage layer. Table 2 includes the initial and reduced hydraulic conductivity for the drainage layer in the final cover system. Hvdraulic Conductivity of Placed CCR For the HELP model runs, the hydraulic conductivity of CCR was selected to be 2.1 x 10-5 cm/sec. The thickness of CCR placed within the closure area will vary across the Site.An average CCR thickness of 35 ft,20 ft,and 10 ft was selected for the top deck, middle portion, and lower portion,respectively, for the HELP analyses. GW6489Ma AP Closure Design HELP APC Barry_EPA_000546 Geosyntec consultants Page 7 of 21 CP: MCS Date: 8127118 APC: CPC Date: 8/27/18 CA: AE Date: 8127118 Client: APCS Project: Plant Bury Ash Pond Closure Project No: GW6489 Surface Conditions and Runoff The final cover system was modeled as allowing runoff from 100 percent of the covered area, with fair vegetation for the prescriptive cover and engineered turf for the ClosureTurf®final cover system. For the calculation of total infiltration rate for the entire closed area,the total surface area of the Site is approximately 300 acres. ANALYZED SCENARIOS HELP model runs were performed for the prescriptive cover system and the ClosureTurf® final cover system for different portions of the Site (i.e., top deck, middle portion, and lower portion), using long-term conditions with reduced sloped and reduced hydraulic conductivities for the drainage layers. Infiltration rates through the cover system and hydraulic heads on the geomembrane were estimated from the HELP model output for a unit area of 1 acre. Average annual infiltration rates were estimated for the modeling period. Average and maximum hydraulic heads on the geomembrane were estimated for the peak daily rainfall event. Total annual infiltration volumes(e.g.,gallons per year[gal/yr])through the cover system were approximated by multiplying the estimated average daily infiltration rates through the top deck, middle portion, and lower portion by the surface area of the Site and then converting them to annual rates. The ratio(as a percentage)of the annual infiltration through the ClosureTurf®final cover system compared to the prescriptive cover system was calculated as follows: Annual""E"nn through aosureTurf Final Caver System Percent Reduction of Annual Infiltration=(1- Annual lnmimnon lhrvagh Pmscriptive Co',,rysem ) x100 (1) RESULTS The results of the HELP model runs are presented in Table 3, and the complete output files are included in Attachment 2. GW6589Msuy AP Closure Design HELP AEC Barry_EPA_000W Geosyntec consultants Page 8 of 21 CP: MCS Date: 8127118 APC: CPC Date: 8/27/18 CA: AE Date: 8127118 Client: APCS Project. Plant Bury Ash Pond Closure Project No: GW6489 Maximum and Averase Hydraulic Heads The estimated maximum and average hydraulic heads on the geomembrane for the peak daily storm event(i.e., 100-year,24-hour)for the ClosureTurt®final cover system are 0.9 and 0.5 in, respectively, and are presented in Table 3. The maximum hydraulic head estimate of 0.9 in.is greater than the thickness of the ClosureTurf®cover system drainage layer(i.e.,0.6 in). This finding indicates that water flow during a peak daily storm event (i.e., 100-year, 24-hour) is expected to be handled through the drainage layer and some surface flow. The erosion protection of ClosureTurf due to surface flow is discussed in Draft ClosureTurf® Cover System Design Package [Geosyntec,2018b]. Infiltration Rates As listed in Table 3 for the prescriptive cover system, the estimated average daily infiltration rate is approximately 0.041 inches per acre per day(in./ac/day),which is equal to approximately 1,100 gallons/acre/day(gpad). The HELP model results in Table 3 show that the ClosureTurf® final cover system reduces the calculated infiltration rates by 99.997 percent compared to that of the prescriptive cover system. For the ClosureTurf® final cover system, the estimated average daily infiltration rate is about 1.1 x 10-6 in./ac/day,or approximately 0.03 gpad. Total Infiltration As listed in Table 3,the total annual infiltration through the prescriptive cover system is calculated to be about 123 million gallons per year(gal/yr) (based on average infiltration and 3 percent post-settlement slopes). The calculated total annual infiltration through the ClosureTurf' final cover system is approximately 3,300 gal/yr (based on average infiltration and 3 percent post-settlement slopes). The calculated annual infiltration for the ClosureTure final cover system is approximately 0.003 percent of the calculated annual infiltration for the prescriptive cover system (Table 3). Stated differently, the ClosureTurf® final cover system was calculated to reduce the total annual infiltration rate through the cover system by over 99.99 percent when compared to the prescriptive cover system. GW6489Barty AP Closure Design HELP AEC Barry_EPA_000548 Geosyntec consultants Page 9 of 21 CP: MCS Date: 8127118 APC: CPC Date: 8/27/18 CA: AE Date: 8127118 Client: APCS Project: Plant Bury Ash Pond Closure Project No: GW6489 SUMMARY AND CONCLUSIONS The prescriptive cover system was modeled as a 6-in. thick vegetative cover layer underlain by an 18-in. thick infiltration layer with a hydraulic conductivity equal to that reported in Section 257.102 (d)(3)(i)(A) of the USEPA CCR rule [USEPA, 2015]. The modeled final cover system considered in this Package was a ClosureTurfe final cover system. The reduction in infiltration through the ClosureTurf final cover system was evaluated by comparing the average calculated rate of infiltration through the ClosureTurf®final cover system to that through the prescriptive cover system for post-settlement slopes of 3 percent and the critical drainage path lengths shown in Figure 2. The total estimated annual infiltration through the prescriptive cover was 123 million gal/yr. The total estimated annual infiltration through the ClosureTurf" final cover system was approximately 3,300 gal/yr. The ClosureTurf® final cover system was calculated to reduce the total annual infiltration through the cover system by over 99.99 percent when compared to the prescriptive cover system. Therefore, the proposed ClosureTurf®final cover system is demonstrated to be equivalent (and superior) to the prescriptive cover system. GW6589Ma AP Closure Design HELP AEC Barry_EPA_000519 Geosyntec consultants Page 10 of 21 CP: MCS Date: 8127118 APC: CPC Date: 8/27/18 CA: AE Date: 8127118 Client: APCS Project: Plant Bury Ash Pond Closure Project No: GW6489 REFERENCES Geosyntee (2018a). "Draft Final Cover System Surface Water Management Design," calculation package submitted to APC and SCS,August 2018. Geosyntec (2018b). "Draft ClosureTurA Cover System Design Package," calculation package submitted to APC and SCS,August 2018. Giroud, J.P. and Bonaparte, R. (1989). "Leakage Through Liners Constructed with Geomembranes, Part I: Geomembrane Liners," Geotextiles and Geomembranes, Vol. 8,No. 1,pp. 27-67. Giroud, J.P., Zomberg, J.G., and Zhao, A. (2000). "Hydraulic Design of Geosynthetic and Granular Liquid Collection Layers,"Geosynthetics International,Vol. 7,Nos.4- 6. GRI-GC8 (2001). "Determination of the Allowable Flow Rate of a Drainage Geocomposite," Standard Guide, Geosynthetic Research Institute. Koerner,R.M. (1998). "Designing with Geosynthetics,"Third Ed.,Prentice Hall,pp. 302 —304. Schroeder, P.R., Lloyd, C.M., and Zappi, P.A. (1994a). "The Hydrologic Evaluation of Landfill Performance (HELP) Model, User's Guide for Version 3," U.S. Environmental Protection Agency, Office of Research and Development Washington,D.C., Report No. EPA/600/R094/168a. Schroeder, P.R., Dozier, T.S.,Zappi, P.A., McEnme, B.M., Sjostrom,J.W., and Peyton, R.L. (1994b). `The Hydrologic Evaluation of Landfill Performance (HELP) Model Engineering Documentation for Version 3,"U.S. Environmental Protection Agency, Office of Research and Development, Washington, D.C., Report No. EPA/600/R- 94/168b,pp. 116. United States Environmental Protection Agency (USEPA). (2015). "40 CFR Parts 257 and 261: Hazardous and Solid Waste Management System; Disposal of Coal Combustion Residuals from Electric Utilities,"Federal Register,Vol. 80(74),April. GW6489Barty AP Closure Design HELP AEC Barry_EPA_000550 Geosyntec consultants Page 11 of 21 CP: MCS Date: 8/27/18 APC: CPC Date: 8/27/18 CA: AIR Date: 8/27/18 Client APC Project: Plant Barry Ash Pond Closure Project No: GW6489 SCS TABLES GW6 Mavy AP Closurellesip HELP APC Barry_EPA_000551 Geosyntec consultants Page 12 of 21 CP: MCS Date: 8/27/18 APC: CPC Date: 8/27/18 CA: AIR Date: 8/27/18 Client APC Project: Plant Barry Ash Pond Closure Project No: GW6489 SCS Table 1. Comparison between Mean Monthly Precipitation Data at Mobile,AL from Default Values in the HELP Model and Calculated Mean Monthly Precipitation Data from the Nearby Weather Station at Bay Minette,AL Default Monthly Precipitation Calculated Monthly Month Precipitation from in HELP for Mobile,AL (in') NOAA Weather Station in. 0) January 4.59 5.76 February 4.91 5.23 March 6.48 5.46 April 5.35 4.93 May 5.46 5.82 June 5.07 7.07 July 7.74 7.63 August 6.75 6.42 September 6.56 5.52 October 2.62 3.32 November 3.67 4.77 December 5.44 5.74 Total 64.64 67.67 Note: The normal mean monthly precipitation values were calculated based on data from the NOAA data center for the daily Precipitation between 1981 and 2018 for the closest weather station to the Site(i.e.,Bay Minene, AL, Weather Station ID: USC00010583) and entered in the HELP model to improve the statistical characteristics ofthe resulting daily values. GW618ouavy AP Closure Desip HELP APC Barry_EPA_000552 Geosyntec° consultants Page 13 of 21 CP: MCS Date: 8/27/18 APO CPC Data: 8/27/18 CA: AE Date: 8/27/18 Client: A3C3 Project Plant Barry Ash Pond Closure Project No: GW6489 Table 2. Material Properties Used in the HELP Model for Prescriptive Cover and ClosureTurl®Final Cover System ClosureTurf®Final Total Field Willing Hydraulic Saturated Hydraulic HELP Material Component Prescriptive Cover Cover System Porosity 0) Capacity 0) Point 0) Transmissivity,0 Conductivity,k Texture#0) System Thicknesses Thicknesses (m2/sec) (cm/sec) Vegetative Cover Layer 6 in. 0.471 0.342 0.210 - 1.0 x 104(2) 12 Infiltration Soil Layer 18 in. 0.471 0.342 0.210 - 1.0 x 10-50) 12 Engineered Turf 0.5 in.)6) 0.437 0.062 0.024 - 2.5 x 100 2 Studded Drainage Layer for MicroDraina 130 mil(3.3 main) 0.850 0.010 0.005 2.5 x IW 75.76(31.57)(4) 20 50-mil(min)LLDPE MicmIhainn 50 mil 0 0 0 - 2.0 x 10'1315) 35 Prepared Subgrade 6 in. 0.427 0.418 0.367 - 5.0 x 10'(3) 16 Double-Sided Geocrmposite Drainage Layer 200 mil(5.1 man) 0.850 0.010 0.005 1.0 a 104 1.96(0.82)(4) 20 Placed CCR Varies from 10 to 35 ft(a) 0.541 0.187 0.047 - 2.1 x 10-'(9) 30 Notes: 1. The values shown for total porosity,field capacity,and wilting point correspond to the default values for the selected HELP material texture number. 2. The hydraulic conductivity values for the vegetative cover and protective soil layers were selected based on typical values of sandy and silty loam. 3. The hydraulic conductivity value for the infiltration soil layer of the prescriptive cover system was selected m the smaller value of the hydraulic conductivity of the natural subsoils,estimated to be 1.1 x 10-5 cm/sec,or 1.0 x 10-5 cm/sec,as required by Section 257.102(d)(3)(i)(A)of the USEPA CCR rule[USEPA,2015]. 4. The hydraulic conductivities of drainage layers were calculated by dividing typical in-plane hydraulic transmissivity values from manufacturers by the thickness of the layer(e.g., 1.0 x 10-3 m2/sec/5.1 mm= 1.96 cm/sec for 200-mil geocomposite drainage layer). The calculated hydraulic conductivities were then reduced by a factor of 2.4 to represent the hydraulic conductivities expected for long-term conditions(e.g., 1.96/2.4=0.82 cm/sec for 200-mil geocomposite drainage layer). The reduced hydraulic conductivities are shown in parentheses. 5. The hydraulic conductivity value for the geomembrane was selected based on typical values from manufacturers. 6. The thickness for the engineered turf layer represents the combined thickness of the synthetic turf,sand infill,and woven geotextile. 7. The hydraulic conductivity of the engineered turf layer was selected based on the manufacturers design guidelines. 8. The thickness of CCR to be placed above the existing CCR to reach final grades varies across the Site. CCR thickness of 35 ft,20 ft,and 10 R was selected for the top deck,middle portion,and lower portion,respectively,for the HELP models. 9. The hydraulic conductivity selected for the CCR is based on Geosyntec experience at CCR sites. GW6489Bany AP Closurellesip HELP AEC Barry_EPA_000553 Geosyntec° consultants Page 14 of 21 CP: MCS Date: 8127/18 APC: CPC Date: 8/27/18 CA: AE Date: 8127/18 Ghent. SCS Project: Plant Barry Ash Pond Closure Project No: GW6489 Table 3. Results of HELP Analyses for Prescriptive Cover System and ClosureTurt®Final Cover System Infiltration Rate Hydraulic Head on Cover Percent Reduction through Final Cover Geomembrane on Peak Rainfall of Annual Post- Thickness it Total Annual Drainage (in./acre/day) Infiltration Rate Day(in.)I>I Infiltration through Final Cover Settlement (t) Granage aye Infiltration through HELP Model Portion of Site Length throw Final Cover Final Cover System System III Drainage ft (2) Drainage Layer (gal/acre/day) Final Cover Compared to File Name I� Slope(%) O (mil) Average x 10's Maximum Average (gaVyr)(o Prescriptive Cover (%)(5) Top Deck 525 41,200 1,100 - - TD_PRESC Prescriptive 3 Middle Portion 630 - 41,600 1,100 - - 123,290,000 - M_PRESC Lower Portion 615 41,600 1,100 - - L PRESC Top Deck 525 0.90 0.02 0.89 0.52 TD_CLSTF ClosurcTurfit Final Cover 3 Middle Portion 630 130 1.23 0.03 0.91 0.52 3,300 99.997 M_CLSTF System lu•(') Lower Portion 615 1.18 0.03 0.89 0.52 L CLSTF Notes: 1. All analyses consider long-term conditions for the final cover system(i.e., 100 year,24-hour storm event; 100 percent of Site allowing runoff;post-settlement drainage slopes of 3 percent;reduced hydraulic conductivity of drainage layers). 2. The top deck,middle portion,and lower portion of the Site's final cover grading and its drainage lengths are shown in Figure 2. 3. Maximum and average liquid heads were estimated for the peak daily rainfall event. The average liquid head is the average head over the drainage length at the peak daily rainfall over a period of 24 hours. 4. The area of the Site used in the calculation of tout infiltration through the final cover is 300 acres. 5. Reduction Ratio of infiltration rates through cover=(1-annual infiltration through the ClosureTurf final cover system/annual infiltration through the prescriptive cover system) x 100. 6. The complete HELP output files are included in Attachment 2. 7. Details for ClosureTurfa final cover system is shown in Figure 1. 8. A curve number of 93 was manually input for the HELP model of ClosureTurlle final cover system based on the manufacturers design guidelines. GW6489IEao,AP_Closwe Design HELP APC Barry_EPA_00055,1 Geosyntec consultants Page 15 of 21 CP: MCS Date: 8/27/18 APC: CPC Date: 8/27/18 CA: AE Date: 8/27/18 Client APC Project: Plant Barry Ash Pond Closure Project No: GW6489 SCS FIGURES GW6 Marry AP Closurellesip HELP APC Barry_EPA_000555 Geosyntec consultants Page 16 of 21 CP: MCS Date: 8/27/18 APC: CPC Date: 8/27/18 CA: AE Date: 8/27/18 Client APC Project: Plant Barry Ash Pond Closure Project No: GW6489 scs MIN ln' SAND LAYER ENGINEERED SYNTHETIC TURF PREPARED_ _ r =SUBGRADE _ III—II III 6"CLOSURETURF8 — II 1 II GEOCOMPOSITE CCR AGRU 50MIL LLDPE MICRODRAINO t — T = PREPARED SUBGRADE t= III _ GEOCOMPOSITE =`11-11 s" CCR Figure 1. Proposed ClosureTurf Final Cover System(Not to Scale) GW6489,Cavy AP Closure Desip HELP APC Barry_EPA_000556 Geosyntec° consultants Page 17 of 21 CP: MCS Date: 8/27/18 APC: CPC Date: 8/27/18 CA: AE Date: 8/27/18 Client: ASCS& Project: Plant Barry Ash Pond Closure Project No: GW6489 Final Cover Maximum Drainage Lengths* t r Legend: r 0 Top Deck a 0 Middle Portion '� r 0 Lower Portion -( - - - - Bench _ -----------=,---+--- 5 eft --- --�- 1 -�_ _ .. . Drainage Channel J 1 " Drainage Path Length rt - LL*Negligible difference between plan view and •��• - - slope length because of very shallow slope Figure 2. Grading for Top of ClosureTurf Final Cover System and Selected Critical Drainage Paths for the Top Deck,Middle Portion, and Lower Portion of the Cover System GW6689Bavy AP Closure Desigv_HELP AEC Barry_EPA_000557 Geosyntecc" Consultants Page 18 of 21 CP: MCS Date: 8/27/18 APC: CPC Date: 8/27/18 CA: AE Date: 8/27/18 Client: APCS Project: Plant Bury Ash Pond Closure Project No: GW6489 ATTACHMENT Reduction in Hydraulic Conductivity of Drainage Layers GW6589,13 yAP Closure Design_HELP APC Barry_EPA_000558 Geosyntecc" consultants Page 19 of 21 CP: MCS Date: 8/27/18 APC: CPC Date: 8/27/18 CA: AB Date: 8/27/18 Client: APCS Project: Plant Bury Ash Pond Closure Project No: GW6489 Reduction in Hydraulic Conductivity and Flow Capacity of Drainase Lavers The long-term, field flow capacity of drainage layers is influenced by several factors that can cause the capacity to vary from the "as manufactured" value. Typically, the flow capacity is described with hydraulic conductivity(k) for natural drainage layers and with the term in-plane hydraulic transmissivity (0) for geosynthetic materials. Hydraulic conductivity is related to the hydraulic transmissivity and the thickness of the drainage layer(t) and can be calculated for geosynthetic materials using: k = a (1) where: k = hydraulic conductivity (cm/sec); B = hydraulic transmissivity (square centimeters per second [cm2/sec]); and t = drainage layer thickness(centimeters [cm]). Design flow capacity (hydraulic conductivity or transmissivity) of the drainage layers was calculated by applying reduction factors (RFs) for conditions that affect drainage layers on a long-tern basis in the field. The following equations proposed by Giroud et al. [2000] were used to estimate the long-term design hydraulic conductivity or transmissivity for the drainage layers. Rme.,ed BLr - RFrwCOZRFrnrrrvxRFCRXRFINXRFCDKRFpCXRFCCXRFRC (2) Bdesi = OLr (3) gn FS where: 0 = hydraulic transmissivity or hydraulic conductivity; OLT = long-term Q B„ren,...ed = Omeasured in the laboratory; GW6589Ma AP Closure Design_HELP APC Barry_EPA_000559 Geosyntecc" consultants Page 20 of 21 CP: MCS Date: 8/27/18 APC: CPC Date: 8/27/18 CA: AB Date: 8/27/18 Client: APCS Project: Plant Bury Ash Pond Closure Project No: GW6489 RF for immediate compression under normal stress (mostly applicable for RFrMco = geosynthetics; can be negligible based on the test conditions under which the data is generated); RF for immediate geotextile intrusion under normal stress (applicable for RFIMIN = geosynthetics; can be negligible based on the test conditions under which the data is generated); RF,, = RF for time-dependent creep (mostly applicable for geosynthetics); RFIN = RF for delayed geotextile intrusion(applicable for geosynthetics); RF for chemical degradation of the polymer compounds used in the RF,, = geocomposites(applicable for geosynthetics; can be negligible based on the anticipated field conditions); RFPc = RF for particulate clogging; RFcc = RF for chemical clogging; RFac = RF for biological clogging; edeeign = B appropriate for use in design; and FS = FS to account for uncertainties. GW6589Ma AP Closure Design HELP APC Barry_EPA_000560 Geosyntecc" consultants Page 21 of 21 CP: MCS Date: 8/27/18 APC: CPC Date: 8/27/18 CA: AE Date: 8/27/18 Client: APCS Project: Plant Bury Ash Pond Closure Project No: GW6489 ATTACHMENT HELP Model Output Files GW6589,13 yAP Closure Design HELP APC Barry_EPA_000561 ...... mELXXE., ALL .=, wL wL HYDROLOGIC EVALUATION OF wL wL IGHT N�GUURHF HG�P MODEL VERSION E.Q;,PIwE:..�� DEESEING SAT. NOR. DON. = D.9999999,ED9aE 04 CR/EEL EVELOPED AS ENVIRONMENTAL HADERENTERY HERE IN CARMAYS 'CIIIIAGET STATION FOR U5EPA RISK REDUCTION ENGINEERING LIFORATOW .............................................................................. TYPE 3 . VERTICAL IRRADIATION LAYER �:GCIFCTFATIGOM DAIS FILE: X-PRECIP.DA YCYD X TEMA.D, wL,wL SOLAR RANCYCLATION.FILE: ..D.DL9 wL/wL DE3 YC SOL OF L ON 3�VUEFAETRFFN:��ATDOI DATALE: LiD_A E.<.DIA FFECTIVE SENT. MEAD. D.99999993EDXaE DEN LM/=EL DXmD DATA FILE. )TD_PREST.CXT FOR: IA.,, DATE. 11./31FI, SOIL .............................................................................. mEC%ME99 MATERIAL TEXTURE a,ME:A.D EXEXEE wL,wL TL.LE. MARRY ASH Paw- PRE,mE�EVE LwER, TRY DEER OR SLOPES YO= M. .............................................................................. NO ML EFFECTIVE CULT. Mw. E.X,CORAL NOTE: INDICES MOISTURE DEATERRO OF THE LAYERS AND GREEN WATER W RE COMPUTED AS NEARLY STEADY STATE VALUES BY THE PROGRAM .A I TYPE I -VERTICAL PERCOLATION LAYER GO IS TER NE.-VER sia � Y C.L I LAVE. PD .I, 4370 wLML Page F Eye 3 EZELO fPPKIry TO PRESC RD PRESS ::4 wL/wL TIED PC wL/wL INITIAL AD L WATER CFEMENT wL/WL WiE. XPiIM DFPJ'1 EFf Et*IVE Sa, HAD LEND. - 0.E9999990,BWE AA WSE[ SERIES ALA. SEASONGOAL ON LARLITUDE 38.4� WAR AN LEAF AREA INDIA A CRAFT OF FISHING pX LATE) AERATES Tux puLIAX MATE) zT QAV N.0 I WWINDD n[uDDxvE arS0xry = MATERIAL REQUIRE NUMBS A =M AND Qwni[n n[uixvE xnx0xry 00% TILDIDGES1 AT:ON INCHES PERNAGE I. puARTER REuirvE xni0in ee% wL/wL AVERAGE am puAFTER RELATIVE HUMIDITY - /i.00% wVwI wV,H wVwL EFFECTIVE Li. M➢. L.O. 0.3onssssBceaE-W WSEL MORE. IN DATA HAS LLY GENERATED 111 AL XDwaLLMEAN FORMERLY PPRECIPITATION (ENERGY. ,PH/NL EEE/w0 MAP/SEP APR/OCi LAY/XW ]DX/DGC GENERAL DESIGN AND GONE DATA NOTE: YEA EIGHT(AREA FORMER MAE LGANOTED FROM DEFAULT WHY PAROF BASE USING WILL TERTIARY#12 WITH A AND A SLOPE LENGTH OF 525. FEET. MORE: TIME,FATURF DATA,NQ SYNTHETICALLY GENERATED ISING 1.1 IFRMALDMEAXLMMIMLY TEMPS MIRE (DEGREES FAXREXMEIT) AREA PRO ECTED DIN EVAPORATIVE GORE DEPTH 22.. CNC�::AL Pu ,PHbDL FEE/AIR MAR/ESP PPP/OCR MAY/XW ]DX/DEC A LIMIT OF EVAPORATIVE STORAGE 11*16, :1 RE ED DO G ED 74.90 No.,. LOAD LIMIT OF EYANSINTIVE ARCHAIC I:. I.:EN RES. IPLIA ".I. T AL WATER IN LARTER FE— io, IN TIAL MARTER EXFLWMAiERULS .L B.w IXd 21YEAR MORE: ICALLY E APC Barry_EPA_000W2 ............................................................................... (INCHES) ANNAGE NONTHLY VALUES IN INCHES FOR YEARS I THROUGH D. 3.N/=.L 11N. wEEl AFP/. FAY/F. SDN/DEL DAILY AYARAEI 11 AD ON TO I OF LAYER A mrnLS ,.1i6 ..IS, ..wz e.n5 E.El. 1.3ee Ls 6(Sn. oEn vLsl sa YEAS 1.3,9 F.93, ,.AY, 6.,33 ,."31 I.,. INE.S SEE, 1I.EF, EDAOTRANSFI..T30F - -- 9PECI9I,.,,m 63.PP ( 9.56.1 u6366.e fea.A ,DTAL6 RUNOFF N.19. ( 5.ISN) � AE.65 19.96E .3 3.551 3.EE6 3.3,E 3.31F E9APOTRA1YRATIDN ...61E ( 5.E., o. 9D.i3O .3 6.96E 6.639 S.". F.=. nD./LEAF.6E,NNU6" 15.955,9 ( ..15A1» �53. 9 12.13147 PERRII Avi ON/LE.RAE iW AYES I . u E, AYEFF6E HEAD ON T� ".F56 ( F.—) 1L..121 I.FNIS .,A ,.,IRA ,.691R ,.6,19 3.,AY " ; ; �E N.D6P u..9D,5 ( ..,9,6» 53599. E I.IENI 0. ro. D�A„ 5 NOS 6.993D 1.�63 D.W D.9935 1..90 E"3N'WA,FR5T E CHAND ON/LEANA6E,a�LAYER 5 wuT - --- ..............................................................................CA 0 Sm. —ATIvrs 6.47[e a 781 —185 Fs916 0.E— D-46 A 5 vage s FEAR DAILY VALUES FOR YEARS 1 UHFWG" ISO - (ONCHE51 (CU. P 0. = a A„M W 11-111 /LEARARE,PUGP LAYER 3 1.393576 FE 4A93.95335 AYERADE HEAD ON TOY'OF FEPCMA„M/LEAKAGE UNROUGH"LAYER 5 ..16,943 S0.. 17 FNIPUF VEG. SOIL W,EP (WL/WL) "..LO F,FInuF YEA. SOIL WATER (YOL/roq ".1633 ...............................e........................................... .....................m......................................m............ - FINAL NATEP STM.6E AT EMU OF YEAR IN Loi IIFaFS) (wL/wL) APC Barry_EPA_000W3 .............................................................................. THTLRxERR v.L T TD.E�RssD R, HER PART ITY NO/B L A BUD CAPABILITY 0.34S NO wL ODE LANDFILL :..�s; PE P 0.2667 wL ODE HG�P WERE VERSION E..IOTIVE E.T. HAD. . . _ O.DDDDDPD,EE.RE-D.CRESSO LEREOPED BY ENVIRONMENTAL LABORATORY .............................................................................. rvPE, .VERTICAL PER LATE x LAYER FREC[P.DE MATERIAL FEATURE_ wtYS ,.-,EM.W wLLODE %I .LLVO �w.DII EDL,WE BULL ,RESL.DID FEITIVE SENT. :AD. w. - D.RRRRRRR,ED�E 01 IHLSIL DDTP�DATA FTLF. FRESL.D:NT TAP 3 BARRIER SOIL .................................................E.........E.................. TH[<RxISI MATERIAL TRUSTEES a:RRa°OR D INERES NO I'LL .[.LE. DMav ASH PDW PRESCRIPTIVE LIVER. FUDDLE A SUITESITT.1EARRATELITY R.EEG: ME IMF .............................................................................. ENFELT�E IL ART.WATER TER. ss%%H,ENO VEL TWIRL -BI GORE: EB�TIAL MOISTURE OANTEENT OF THE LAYERS AND ANEW DATE WERE OMPLITED AS NEARLY STEADY STATE VALUES BY THE PROGRAM. LAYER A LAYER I TYPE I -VERTICAL PEALUMATIGH LAYER TYPE,.YERTTL T LAYER PDDR.TTY AE,0 DEC w s*:. L Page L HERE i FZELO GPKIry x_PABOO X_PALSO BA38O wLLODE FEAR A' I wL/wL wL/YOL NOTE. LIALOT ASPIRATION DATA WAS OBTAINED FROM EFEELLERE S.i. HYD USED. - O.RREARR987000E BE WSEC NESTLE ALA. 51TAT ON LATITUDE 30.4� WAR HIM LEAF AREA INGELK a OD ,EI eLES SEASONSTART OF GROWING ssa 1EILIAN DATA)l REST BY FARE EARGUAL z,QUARTeERR RELATIVE arRmiry m,ERZu TERROR NUMBER o BY w END QUARTER RELATIVE xnmiry 72 00% I.puu,[a n[urnE:Pnmxry 00% Z. AVERAGE am NU=A a[wirvE:En[oin ,S.Oe% I I.LAPATITY USED w4VOL WELTENA POINT ...'A wVw wVWUL EFFELTERE ART. DID. USED. e.EesvnsseeeaE-es CAISEC NOTE. SYNTHETICALLY GENERATED D C E LA AL NORMAL MEAN MONTHLY PRECIPE,A,Iw (INCHES) NE� vR/zUL FEE/LAG wx/zEP mRIOC, :av/xw ZUx/LAC GENERAL DEGERN AND E..�G ME NOTE: SRE5 UNITE CJRVIS�BURGER WAS LORETTO FROM DEFAULT ASE L DATA EASE FELLA SELL TEXPURE RIS WILD A SLOPE LE�RAEEA, A SURFAIE SLOPE OF FIE GTH OF BIG. FEET. NOTE: TERM RATURE DATA WAS SAAMETTICALLY GENERATED USING LA AL. ION OF AREA BE LOADING TRADER EAA.G DERCENT mFAREDHEAR CMON HLY,ExPEParv[RE (DEGREES FAHRENHEIT) ARE AROEEETED ON AE Pu - IANN/IUL FEE/LAG nw/zEP mRI.ET Nwv/xw EUx/LAC AL WATER IN LAYER 11.AAG U.El TOTAL zUTOTALITLEAESUR WA IMF LOW TER O.eD THCXES/YEAR NOTE. xGLLv C APC Barry_EPA_0005 ............................................................................... �5 (INCHES) AVERAGE NAMELY VALUES IN DECLINES FOR YEARS I THROUGH IN 3,N,ICL IWADS EEl .HEY/E. I"./DEL DAILY ADERAE1 11 AD ON TO I OF LAYER A NLFLS 1.16F 6.N1 6.939 A.K9 6.6.3 1.3I5 LS 6(Sn. uEV3.,=vL5( Fn YEARS ARO W 3P, ,Io" I."1 ".933 1..EA A." 1.",E I."I I.r.= �. FEE, PEAREM P"ECIPI,.,,m HE.A. ( 9.36.) u6366.9 ,fifi.m 1. WAEFF 43793.44 IN9 3. 6 3.EE7 3.3,E 3.3„ EVAPO..aEPEAR.I. ...636 ( 3.6"61) 1a,..,.IS 59..57 1*111 THE "W Ai,� IN5 ,. 5 >.� ".E. ..3. ININ,LEARARE INARU6H .......I , ..I.E) 55""".199 33.35EM WTui I,LE..a6E LAVE. 3 CA,, 3 .................................... .VEiu6E HEM ON=w 0.057 ( ...IF) 1.8 .SHI .74M IN.LS I.13AA ,..n9 6.,E,. ,.WA, 3.,533 "REEFLUN; ; ARE..IlH IN.9"6,9 ( .. u67) 2S.EYIEE 44 1 ro. "ERED 31E3 ..96ra ,."IIN .."1"3 ".9961 1.47,. E"3NIN,F6 STORAGE CHANES ON/LEAW6E INMAN.15 wu. --- --- --- ............................................................................... IN 0 Sm. LEV=alvLs 0.4991 0.6597 5597 e.sies e.m95 0-6 O—C A vage s FEAR DAILY VALUES FOR YEARS 1 T REAW USE (INCHES) (CU. P0. 1 a A„M/LEUFAME,XW 3W6 06X LAYER 3 1.0 "PE 52..61639 LAYERACERANHE HEAD ON TOY'OF PE"CM M A,I /LEAKAGE 3HARU6HLAVE" 5 USMIAO 76.AE693 Y."IPuw VEG. SOIL W,E" (WL/WL) "..LJ F,mnux YEA. FEEL FETE" (VOL/Wq ".1633 ...............................e........................................... .....................m......................................m............ - FINAL NITERSiM.6E a EMU OF YEAR 1W (,.IS) (wL/wL) 'PACH WATER RARE APC Barry_EPA_000555 DO NO SC .............................................................................. TREIRxERR .F�BssB B, RER PART ITY NO/L L A GOD CAPACITY 0.34S NO wL wI 0.2667 wL wI ING POINT ..GROW HG�P WERE VERSION E..I;,FILAR :..�BSE,E CTrvE E.T. HAS. CONGO. _ B.BBBBBBB,EE.GE-D.CHISHO LEVELOPED BY ENVIRONMENTAL LABORATORY A MUSK REDUCTION ENGINEERING LABORATORY .............................................................................. rvPE, .VERTICAL PERCOLATION LAYER PRECIP.DE MATERIAL FEATURE_ wt,C, ME RAUTD; CARTA FILE: ,0-,EM.W wLLOCI AD.DIB .LIVE �w.DIE EDL,WE SALE ,RE,E.DEB FICTIVE SUN. HAD. MA. - B.BBBBBBB,E�BE DR IRL=IC DDTP:rt DATA FILE. —REST.OUT IT:.. IB.E, D.TE. IAGVGGEB TAP 3 BARRIER SOIL .................................................E.........E.................. T ICINIEE MATERIAL TRUSTEES aRBa B ONTO, ITT.CARNALITY R.EEG:NO I'LL ARMEDTITLE. BARRY.SUS PD PRESCRIPTEw ONCE. L�A B%SLOPE, MI IMF GHT M.El. .............................................................................. EFFE<TI E IL MAT. TER CDw. . B. BBBBB,ENO EVEL CHIRAL -Gl GORE: ED�TIAL MOISTURE EINTEENT OF THE LAYERS AND SHOW DATE WERE ONPLTED AS NEARLY STEADY STATE VALUES BY THE PROGRAM. LAYER A LAYER I TYPE I -VERTICAL PERCOLATION LAYER THICKNES DO TYPE E.YEN w s*:.L T LAYER PDRO.TTY .E,B VOLML Page L HERE i EZELD GPKIry LTAEEC L_FALSE BA300 wLLOCI FEAR A' I wL/wL wL/YOL NOTE. EVALOT ASPIRATION DATA WA5 OBTAINED FROM EFFECTIVE S.i. HYD CMD. - B.OB93ERE87A00E BE CT/SEC NESTLE ALA. 51TAT ON LATITUDE 30.4� WAR HIM LEAF AREA ING" a OD ,EILAVER I MI OR BEGRAN'. BCFS SEASONSTART OF GROWING sux 1EILI.x ml REST AV FACE EARGUAL WAR z,puAFTeERR RELATIVE UrNmiry MATERIAL RECORDER NUMBER 0 AV= EON puARTER RELATIVE xnmiry 00% THICKNESEG IS:GO INCHES .,A., I.puuT[a n[urnE xnmxry 00% wLLOCI .,A.,am"NATEa a[wirvE:En[oin ,T.Oe% w4BOL wVDR wL RUL FFFFCTwE CRT. WHO. CUD. e.Eesvnss0ee0E-Bs CAISEC NOTE. SYNTHETICALLY GENERATED USING D C E LA AL NORMAL MEAN HOURLY PRECIPITATION (INCHES) MA� ERR/IDL FEB/w0 wx/zEP MARIOCT MAY/xw Zux/LAC GENERAL DEGERN AND ENDS.�E ME NOTE: SEEi UNITE CURVE NUMBER NEWS COMPUTED FROM DEFAULT AS L D—BASE FERNS SELL TEXPURE RIS WILD A SLOPE LE�RAEEA, A SURFACE SLOPE OF FIE GTH OF 615. FEET. NOTE: TERM HATURE DATA,WASS SHATHETICALLY GENERATED UNINE IENTS 1.1 LA AL. ION OF AREA AL LOWING TRADER EAA.G DERCENT mwMEDHEAR CMON MONTHLY TExPEParvIRE (DEGREES FAHRENHEIT) ARE FROOEITED ON nI ILANG - IUN/IDL FEB/LAG nw/zEP MARI.CT MAY/xw EDx/LAC AL MULTER IN LAYER TOTAL SUTOTALITIAECUR AWA TER ExFLwMAhDTAw 0.00 TRCX4111 ES/HERE NOTE. ALL HADEATION DARER LANE SYNTHETICALLY GENERATED USING COAFF TENTS FOR MABER LA AL ANDERNE AND STATION LATITUDE � 3B.41 DECADES ENNOPOTRUEASPIANATION AND WHETHER DATA APC Barry_EPA_000%6 ............................................................................... �5 (INCHES) ANERAGE NONTHLY VALUES IN INCIMES FOR YEARS I INFIDEL IN IAD/5NL IWADS EEl ARP, FAY/N. INN/DEL DAILY ADERAE1 11 AD ON TO I OF LAYER A NLFLS 1.16F 6.N1 .NETS A.K9 E.E. 1.371 LS 6(Sn. uEVi.nvLS( Fn YEARS ARO ADRF, T3NF I."I F.F33 1.NEH A." I.N,E I."I IDES �. FEE, AEARENT >PECI.I,.,,m 6,.PP ( O.3P.) u6366.e I... ADNOFF 437s3.44 17.14 E6 3. 6 3.EE7 3.3,E 3.31 EVAPOTRNF,ARTI. ...636 ( 3.6"61) 1a.AD,.IS IS..E, THE "�Ai,� OF5 N. 5 >. D.E. F.=. nH./LEAA.6E ADADU6H .......I , ..I.A) 551A.'I.F 33.35.7 ui NF,LE.YA.E TARN„LAYER 5 u EP , .................................... .VExwE HEAD ON=w 6.657 ( ..ea„ AD.LS LESS. ,HER», 6.,I14 ,.�„ 3.,IRS " ; ; ADE NAR 6P ,E.",», ( 4.33062 w . 3 3,. 333 ro. oR A„aa 31E3 ...84 ,..1AD ".8185 0.9961 1.4774 F"3H'WA,FR 5T E ..57 ON,LEAYARE,a�LAYFR 5 ADUT — --- ..............................................................................IN 0 Sm. LE-ATIVLS 6.smi a 7SO —315 —UN 0.71" D-6 N vage s FEE,5 FEAR DAILY VALUES FOR YEARS 1 TIPW6N USE (INCHES) (CU. P0. 1 a A„MEA PW 3WS/LNARE, 06P LAYER 3 1.0O FE 52..616El ACERADE HEAD ON TOY'OF El FEPCOLA„M/LEAKAGE THROUGH" 1 LAVER 5 .... O75.68111 NAYIPUF VEG. SOIL W,EP (VUL/VOL) "..LJ F,mnuN YEA. SOIL WATER (VOL/roq ".I633 ...............................e........................................... .....................m......................................m............ - FINAL LUTE"STM.6E AT EMU OF YEAR IFF (,.IS) (wL/wL) WATER ..RARE APC Barry_EPA_000W7 exxxxxxxxexxxxxxxxxexxxxx.xxexxxxxxxxexxxxxxxxexxxxxxxxxxxxx F:nreusL i K/wI x MIIXNE53 0.50 Z"L WE TING FIDGET A A'. Vw HYDROLEDIC EVALUATION OF LL WVwL ] (]FRNENBEPM199])E EFFECTIVE SR. FAR. CUO. B.35B000X.lI 01 IN/SEE FOR U5E�SAE TUNDRAS EXPERIFEENT STATION A DISK REDUCTION ENGINEERING LAWflATRY .............................xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx..x TYPE 3 - IT.MGSXWE L1YE0. \B-PPECIP.W MATEPI1Li - =. WP:RAFJR;DATA FILE: \B-TEXR.W WLryOL :FLAP RADIATION DATA FILE: \B-ND.M3 ED= \B-EVM.ULL WLryOL SOIL ANNFIL \T(K STF.01B I FEITEVE.. HAD. 11,11111. CM /SEC CUTINCT—FILE. \i(:_CLlTI.W( T➢N: 1].3] N]E ]/30/301B .xxn.m.xxxx....xxxxxx......... .........xn.m.........x.........x........ TYPE C- FLEXIBLE MEMBRANE LINER M E0.IPL i TITLE. BMgY ASH FUNDR4SMENPF EWES, CUP BECK IN 5LWES THRUCKNISES :::I ...........m................................................m.......m... w/wL /wL INITIAL SOIL WATER CONTENT E AGERE WL/v0L 3 Cg3EC ENCTIXL MUCESTURE CONTENT OF THE LAYERS AND GROW AFTE WERE AMC FINLIKE DENSITY AC - ALES/ACRE MNIEO AS NEARLY STEADY-STATE VALUES BY THE FROGPAY. INSTALLATION �S LES/ACRE FNL PLEXEIRQUALIIY 3-GRES LAYER I TYPE I-RREATICAL PEX :AnM(AYES l ...vue.3 MTESUJ iE MTESIAL TEXTURE- ..11L wL/w .GEM Z. W f/OL wL/VOI EFFERIVE EXT. WID. (TM. 0.309999998000E-06 WSEC EFFERIVE SAT. MD. E.G. 019M939P7BBBE-W WSEC TYPE - LATERAL TRALLEARE LAAER WITTE4 GTE NUMERIC CURVE"YER WAS WEER-SPECIFIED. NATESIu iE wL/VOL GENT IN OF AREA ALLOSIONER RUNOFF I... 'GTE. AREA RKYFC7ED ON HSLIODECIALL PLANE WL WL/WLNIT AL LATER IN SAT. M. CMG. M/SEC - I. INCHES SLOTS LOWE LEENCIT OF EVAPORATIVE STROKES ...II ENIE.EA DRAINAGE LIN. I'.. FEET CAN IDL SNOW LATER 8 NOR t=�5 TTLL SUBSURFACE INFLWRATESIFLS B.w INCHES/YEAR A EXACT A SOIL LINER EY4POTRANSPIRATCURN AND WEATHER ENTA M]EPYlTEXTUREEGA _ ..XI INIG.LA wL/WL RATE. PAiIM GFWI VAL/wL ICBILE FLA. W�D EA CITY 8.187E AL I WATER IT FRUIT .11wLI.L EFFECT rvI SXT. (Sn. CO:O. B.IYm99980—SUC cWSE[ NAI M LEAF AREA x (3ULIM GATE) END OF CORNING s5w (Iu IAH CATE( LUMTER RE CRT Q LATIVE HUMIDITY - ----- SW QUARTER RELATIVE MINORITY = AVERAGES 3M QOMTEA RELATIVE HUMIDITY ]].00 N APC Barry_EPA_000M8 TOC AVERAGE.M w.B<ER RELATIVE H-RG,n . 73.R g NOTE FRIO PETRUTION CATA HALF ANATHETICALLY GENERATED USING CONCERN �FRU;` Eµ'RONmLY PRECIPITATICH (INCHES)" I.9EBI.REA .III I.BB. ..GO, E.IRSE.EII I.,R WELL I,,/w, wa/SOB LAB/BR xeY/xw 3W/BEG ITT. BEVurIGxs ROTE: TURN RATHER DYTA WELL SYNTHETICALLY GENERATED USING E " : � ;E E : DEVIATIONS B. R <11 ..I9. ..All ..I. NORMAL L: roE ;E (DEGREES FLAREi, wx[- -----CEEB E---un i EMILIE EWALD MAR/Ill ux/BRR 3 ,BE- -- -------- ER 1. 1.4929 NOTE. SYNTHETICALLY ION/LFRRE THROUGH LAYER, S.,B,3 1.19., S.BB,B ,.R ,.SB,1 AND SIRETTEN LATITUDE - 38.41 DEGREES TOTALS ::::,.o N,U G.", LITIGANT DANCING COLLECTED FOUR LAYER I AVENUES PENNEY VALUES IN INCHES FER YEARS I THROUGH IN TOTTA LI A.ANAL, „ ,ID- FE.,NN HARSE1 RR,R RAY,w ,-R,R- STD. DEFFArIRE RR B.DDR B.BDDD B.RDO ENT D I.OFFEED I.DIED IFECTIETATION nW/LEARRE THROUGH LAYER B 313 69age s s.n I AT < 7 s.x3 e.eea, O.0.eUNITue B B.eeHE e.BOee e.BBOO -.wee iD_[LSiF EVP ,R9I ,IW Le.I'O CLIFF PoN6M I. .,) 3937B.H 15.930 SN. -EVICTIONS B.BaOO B.BBBO B.BBBO B.WH 0.O%V B.00WLATERAL DRAINAGE COLLECTED 9.EGII.( 4.11111) 11 ..ERA ss JB3]B EUAui xW/LE.x.GE TW¢TH une 3 I.LAYER 1 ------- --------��................ vExEELmw/LEumE THROUGHe.e0033 ( e.aOee.) ,.,vx ,m.LS B.0VER ...00 I.GRAND N.eH9 G.eeW Y.G. —A 3 w 8.0111 8.001) AVINANCE A.ON SN. OEVI1i1w5 8.000] B.BOO] OF LPYE0. 3 1..1 1.REGRAND O.BW1 O.BBB1LATERAL DFAINARE --ERFB B.0000B( B.00OBB) B.GRAGE B.%9OB RR04 LAYER 5 ACHING OF MURPHEY AVERAGED RALLY HOLDS (m.") iIIN/LEAKNE THROUGH B.BBO33 ( B.RUNG) 1..1 ., .A 4VEP 6AD ON w ...A. l ..00O, mLY RETRACE HEAD M,w OF FAVOR 3 OF LAYER s B.BSn B.B131 B.BH3 B.B,B3 O.B,13 1.8,9 1VEPIBES ILA/LEAF---THROUGH 8.00033 8.CAI ( 000,6) ,.,91 ...ASN. DEFECTIONS 0.01.0 B.BiH ...ED I.BB]9 O.BHN 0.01.3 CHANGE IB WIFR-,RAGE ...DO ( B.197B1 -..I, I.ON .....r RALLY AVERAGE REM ON RP OF LAYER 6 n..................«««««........ ...... AFT. INVENTION GVU 0.6000 ...A, B.ANA A.ANA A.GRAND O.BBBB g,AA DAILY VLLRS PoR YENS ,M.dpl ,BB- ............................................................................... (IRXES) (w. FT.) .««......««.«.....r«««.....r«.........«...................................... nu OFF II.BIl .BWG.131B TOTALS A jsx Ws) FOR COLLECTED FROM LAYER x ,.,WSS .ESS.xen, .FORME.ANNUAL 3M. D. oEYr.3x R YF.R ,xxRWw See CAN, E c .....................................3NGURIS ........CU...................... D. FEET BR ERr BEuoFA3xDH/--.RAGE iXRm LAYER 3 e.RR31 e.v.,B BRSR9lrnnw AEERAGE xFm w mg OF uvsR 3 B.1,9 RBx-FF Is.1R j E..IlA) GR7I.14 SE.ln MAY I.READ ON mB OF LAYER I R.Rs APC Barry_EPA_000W9 FAR PER IAD �TION OF.P<E A.PP.TIN L IE g TO.,FEE, ..ED. G.P�P °:< ;, ;; :wE1.�s"`.YEP P <:aaa�. ;: ss; P A.NNE. ...I. FAILERM HEAD ON TOY OF LkYER —INN I .P PR IN L..EP . .<EEPap Rg.... ................... ....................................................... gEP<GL.,IGP,LF.gANE,PRILGH LAYER , RgPP,P, ,.g,,,, .............................................................................. ruxvwx YLG. SOZL ru*LP (wLML) ..sgzx �Pr. P YLG. SOIL WATER (NIUVOL) ++ WL.m heads arc mmputM ...ME,p—a egm"FAE. ++ hree WE.0 .rxnnuxxxxn...rxxxxn....T...................E.....r IT.......xxxxn.. ............................................................................. FlX MIEP STORAGE AT END OF YEAR IN LAYER (I.ES) (.LML) wge s vage IP APC Barry_EPA_000570 exxxxxxrrexxxxxxrrxexxxxx.rxexxxxxxrrexxxxxxrrexxxxxxrxxxxxx F:niwsL i K/wI x MIIXNE55 0.50 Z"L WE TING POINT A A'. Vw HYDROLOGIC EVALUATION OF LL WVwL ] (]FRNENBEPM199])E EFFECTIVE ER. FAR. CUE. B.35BOO000 lI 01 fN/SEE FOR U5E�SAE TEGRAYS EXPERIMENT STATION A DISK REDUCTION ENGINEERING LARAWALLORY .............................xxxxxxrxxxxxxxxxrrxxxxxxxxxrxxxxxxxxrxxxxxxxxx..x ryPE 3 - IT.MGSXWE L1YE0. \B-PPECIP.DG MATERIAL TEXTURE ED= TO RAID; OXIDE FILE: \B-iEW.W WLryOL \B-PM.M3 WE INA DO I MY I.E.ED= \B-EVM.OLL VO ry L GAILFIL : \gRSif.O1B SPY. HAD. CW. CX/SEC WTWf—FILE. ICLIif.Wf DRAINAGE LENTICH I IT TI:4. IS:59 N]1: ]/SB/3OIN .xnnmxxxxx....rxx.. ........xx....rrx........r.........r.............. ... TYPE C- FLEXIBLE MEMBRANE LINER MATERIAL Y TITLE. BMPY ASH MENDR45BPETBRF EWES, MIDDLE PLOTTED 3%SLOPES THURFUNIIS :::I IVALL ...........m................................................................ w/wL W=WL/wL F�;TAI SOIL WATER CONTENT GAGNER 3 CgSEC NttF. - ALES/ACRE CMNTEE 0.5 NEARLY STEADY STATE VALUES PV ME PPOGPM. LFS/ACRE AMC PLACEXEMIQUALITY�S 3-WER LAYER I TYPE 1-RRENTICAL PEX :Anw LAYER l ...vue.3 MATERIAL iE MATERIAL TEXTURE INCHES WL/VDL THICKNESS :p. w/WL ED.L wyw .GEM Z. W fVOL wL/WI EFFERIVE EXT. HYD. USAGE. 0.30999999PBBBEO6 WSEC EFFERIVE Sii. MD. E.G. O.09M939PJBBBE-W CHISEC TYPE - LATERAL WFUNINATE LAYER WITTE4 GTE DIRECT CURVE NUMBER MAKE5 REER-SPECIFIED. NATER3u iE wL/WL GENT IN OF AREA ALLOWING RUNOFF I... 'GTE. AREA RDYFC7ED ON HSLIORENTARL PC WL L/ L NIT AL LATER IN EVAPORATING DOME GUY A SPi W . MD. CMD. N/EC - I. INI.Es XLEFE COME LIMIT DF EVAPORATIVE STROKES ...II INIE.EA DRAINAGE LIN. A... FEET CAN CAL SNOW LATER 8 YNN �=�G INFLOW FICA INITIAL LATER A7.111 INIDE, TOTAL SUBSURFACE INFL L.N@ INCHES/YEAR A EXACT A SIDE. LINER EVAPOTINAVISPIRATNIN AND WEATHER DRECA, MA]EPYl EGA _ WL/WL NOTE: EVAPOIL MiIM DFWI WL/WL HKAILE FLA. W�D EX CITY 8.187E wLI.L EFFE[Try I SAT. :YD CO:O, B.20ANDE9998OO SUC CN/5E[ MAXI N LEAF AREA x (3ULDAN DATE) END OF CORNING sRw (ILA IAH DATE( E'APSE FIVE SOME LW MR.PTER RE CRT Q LATIVE HEREDITY - ----- SW QUARTER RELATIVE HEREDITY = AVERAGES SM QUARTER RELATIVE MINORITY DRAG R APC Barry_EPA_000571 IT AVERAGE.M M.THER RELATIVE HCHIGHLY . 73.M g NOTE FRIO PITRUTION NOTA NVEN SYNTHETICALLY GENERATED USING RUNOFF E`RFUL Eµ'gRTHLY PRECIPITATICH (INCHES.. 1.BBB I.,,. 1.GA< ..I'. I..EI ,..I WELL I,,/NG ./I,, NIL/¢ HLY/.DY ]M,DIE STD. REVLATIMS ROTE: TURN RATHER DATA HELL SYNTHETICALLY GENERATED USING xMroL`DnEnx" nLv�iEwEwrunE (DEGREES FgxRExuiEIT) s,o. ow,Arxoxz e.241 G3. B.BBB Il a.an ..19, I.I. ..IS, EMILIE EWALD ./SE. ux/GR u-ER-L -------- COLLECTED---- --Egm unx I M ]M,DEE COLLECT - 1. FOR VA.ED AN I�UGANFEF .2 AN NOTE. SYNTHETICALLY ION/LEARNE THROUGH p3 1.,,,. 1.I,,. 1...,, 1.13.8 ,.3I<B YER 3 LATERAL DRAINAGE COLLECTED FOUR LAYER I AVENUES MONTHLY VALUES IN INCHES NEIL YEARS I THROUGH IN LI AA, A.ANAL, „ ,IDL FE.,«w HAUSLE1 APR,. Y/. ,GA/El STD. DEVIATIONS M .ADD B..DDD I.RN IIECTIETATION nM/LEARNE THROUGH LAYER G ]11 GPage s s.n 3.0 I. 8.13 e.eea, O.PeGREG,ue a e.eeHE e.eaee e.88aO I.-A H_gLSiF EVAPo,RN6P,M,IM U.,,6 CL(iF1JO99) 39„1.83 11.BH ST . DEVIATIONS B.BaOO ...080 ...BBO B.WH 0.O%V ..00W ATERAL INCIDENCE COLLECTED 37.074N ( 4.18111) I.VION sOALBe EXM LANE U I Aui xON/LuuGE THROUGH unx ] x PExEDLmONM1EumE THROUGH 6.09O45 ( 6.NAVY) s.Gs1 B.ONaGG mr.6 0.0VER ...O, I.ereE N.Rare O.00ON 0.00w unx 3 ON 0.018 ( I.0031 ANINGF HEAD ON sN. 0EVI1i1M5 8.000] B..aa, A..1 A..1 U.BONI O.BBB, LATERAL DEADLINE OF uvE0. 3 LEERED B.aOOOB( B.00OBB) I.ON B.%9OB R RON AVERAGOES OF FORTHLY AVERAGED RALLY FADS (IIgIES) CL N'TCON/LEAKE THROUGH "ORG5 1 I.ERROR) ,.GSl I. I, unx 6AD ON ON ...A. 1 ..DR.l Om LY AVERAGE HEAD M TM OF unx 3 OF LAYER e B. 6) B.01,3 B.BIDi B.B6, B.B,N B.BIaz 1.113.1VEPIGES IMRFAFLOE THROUGH 8.0O0M ( 0.000111 1.6I.." dtl CAI SN. DEVIATIONS 0.0196 8.099 B.Bl.9 ...111 O.BI66 O.OIBs CHANGE IB WTFR STORAGE ...DO ( B.I0I31 -..I, I.NO .1 INS I.NOR D.DOOR O�GUUGF O�0122 .....r RALLY AVERAGE REM ON RP OF LAYER6 n..................«««««......IF .....uw AVERECDC, :.I N I.HAVER Al EVER, A.ANDUAL 0.0000 ...A, B.CAN A.ANG A.GRAND 0.OFOR - P,AA DAILY VLLUES FOR YEYS 1 Tgdpl 1. ............................................................................... (INCHES) (CU. FT.) .««.....«««.«.....r«««.....r«.........«............................a......... nuxOFF IS.ON ..G17..115 TOTALS A Isx Ms) FOR w E COLLECTED FROM LAYER 1 A.Hw .Ez]] 55.7.41.z1 ..ERNE ANNUAL ROTA D. oEYiix R YFLLL. 1 xHRwaR 1.e O .....................................iNKILIS ........CU...................... D. FEET PER Exr PEuouixOH/LE.R.eE TXRAA«LAYER 3 R.RR.R32 0.]1NG PRSRPIrnnM .].ea 1 9.s..) I..3ee.e 1w.ee nYEucE xFm M raP OF uvSR 3 B.su GEN." 2..NO 1 ..ONES) n.E..E I9.5O4 MAY I.READ ON rM OF LAYER I D.9B. APC Barry_EPA_000572 FAR PER IAD �TION OF.P<E A.PP.TIN L IE g I,.,FEE, RED. END FARIERM HEAD ON TOY OF LkYER 6 —INN I .<E EPa GP..., L EP . Rg SEE. D. .EP .Y.«.PR PEm .. .............................................................................. gEP<GL.,IGP,LF.gANE,PRILGH LAYER , RgPP,P. ,.gg,g, .............................................................................. ruxvwx YLG. SOZL ru*LP (wLML) ..'III �Pr. P YLG. SOIL WATER (NAIL/VOL) ++ WL.m.cads arc mmputM ring ME,p—x egmtlem. ++ hree WE.0 .rrnnu...............urrrrn...............E.....r........rrrrn.. ............................................................................. FlW MIEP STORAGE AT END OF YEAR IN LAYER (I.ES) (.LML) wge s vage IP APC Barry_EPA_000573 exxxxxx..exxxxxxx.r.xxxxxxx.rexxxxxx.rexxxxxx.rexxxxxxxrr.xxx nnreusL i D I I r MIIXNE55 0.50 ZY'L WE TING FIDGET A A'. Vw ] (]FRLL WVwL NENBEPM199])E EFFECTIVE SR. FAR. CUO. B.15B00000aW0F 01 fN/SEE FRIELODED BY EXAFFIRIGNMENTAL LABORATORY A DISK REDUCTION ENGINEERING CARNALITY .............................xxxxxxxr..xxxxxxx...xxxxxxx.r.xxxxxxxxr.rxxxxx..r TYPE 3 - IT.MGSXWE L1YE0. \B-PPEEIP.W MATEPI1Li - =. IT RAID; DATA FILE: \B-iEW.O] WLryOL :OL" CARECRATION DATA FILE: \B-PPD.013 WE INA IN I BY I.E.ED= \B-EVM.OLL WLryOL GAIL A. FIL \L RSif.OIB S1i. HAD. RM. EX/SEC WTWf DATA FILE. \L_aSif.OUR i➢4. 30.35 NTE. ]/IS/30IB .xnn..rxxx.x....rxxxxx.........x....rr.........r.........r..............x... TYPE 4- FLEXIBLE MEMBRANE LINER M E0.IPL i TITLE. BARRY ASH FUNDROSOPENPF EWES, ALLEN 3%SLOPES THRUCINIIES :::I ...........m................................................m............. w/wL WRITE"N.C. AW= INITIAL SOIL WATER CONTENT B AGANG WL.L 3 ENIXIE ENETIXL MUCESTURE CONTENT OF THE LAYERS AKD SLASH AFTE WERE AMC FINLIKE DENSITY - FLEE/ACRE MNTEO AS NEARLY STEADY-STATE VPLOES BY THE FROGPAY. I RS LEE/ACRE FNL PVtEXENT QU ALITY TY 3-WO> LAYER I TYPE 1-RREATICAL PEE FILL LAYER t ...vue.3 MTEPUJ iE MTESIAL TEXTURE INCHES OWE 11 WL/VDL THICKNESS :p. w/WL ED.L wyw VO/M wVwL wL/wL wL/WI EFFERIVE EXT. RID. GYM. A.30999999PBBBEOA WSEI EFFERIVE SAT. .. E.G. 0.4999939P]BBBE-041 WSEE TYPE - LATERAL TRALLEARE LADDE WLTE4 ITS RUBRIC CURVE NUIRGER WOU5 REER-SPECIFIED. THICKNESS ::' INCHES �CS TOO I CURVE BUNMER A'.. NATERTu iE wL/WL GENT IN OF AREA ALLOSIONER RUNOFF ING.. 'GTE. LI CAPACITY ::N. wL/WL AL PLANE L/WL L/WLIT AL LATER IN EVAPORATIVE GONE e GET A SAT. M. EMU. EN/SEE - I. INCHES SLOTS LIKE LEENCIT OF EVAPORATIVE STRIKES ...11 ENIE.EA DRAINAGE LIN. 1".. FEET INCE UAL SNOW LATER 8 ENG �=�5 CARL I WATER IN LAYER RATESIFLS A SIR FICA INITIAL LATER GAINER INIRE, TOTAL SUBSURFACE INFLOWB.DA INCHES/YEAR A EXACT A SOIL LINER EVUXETRANSPIRATCURN AND WEATHER DATA M]EPYlTEXTUREEGA _ ..XI INIG.LA WL/WL NOTE: EVAJOHIL MiIM OBTAINED FROM VASE COL ICOILE FLA. W�D EA CITY BASTE IF I WATER IT FRUIT .11wLI.L EFFECT rvI SAT, INTO CO:O, 0.109YE99980—GKI IN/SC[ MAl M LEAF AREA x (3ULIM OATC) END OF CORNING s5w (ILA IAH DATE( LW WN.PTER RE CRT Q LATIVE HUMIDITY - ----- ll0 QUARTER RELATIVE HUMIDITY = AVERAGE 3M QUARTER RELATIVE HIrtDITY ]].00 N APC Barry_EPA_000574 LCL AVERAGE.M BwP<ER RELATIVE HBRDTn . 73.R g NOTE FRIO PETRUTION NOTA NVEN SYNTHETICALLY GENERATED USING CONCERN �RTUAL Eµ'g�MLY HOLDER (INCHES)" 3.RB I.,R 1..IIIR9 I..I, I.R9 WELL I,,/wG ./I,, LAB/BR my/xw ]W/BEc ITT. BEVuiICAl ROTE: TURN RATHER DUTY FEEL SYNTHETICALLY GENERATED USING xRroL`DnEnx" nlvRiEwEwrunE (ORPEES FwRExuiEET) VA.ED s,o. owlPrxoxz e.63. e.6R a.an ..3B, B.I.1520E B.IE3 EMILIE EWALD wa/SE, ux/rci ui[--- -------- -----CEEB Exw unx 3 IA W ]W,BEE IO - LALLY w,L RRE TOUGH 61 RH„"61 1.114 1.I7A3 I.B650 1.1447 ,.536E AND SIRETTEN LATITUDE - 38.41 DEGREES TOTALS ::::,.e U G.", LITIGANT DRAINAGE COLLECTED FOUR LAYER E AVENUES MAINLY VALUES IN INCHES FER YEARS I THROUGH IN TOTTA Ll A.ANAL, W HEARUSGI APR,. Y,w ,DR,Wg STS. DEYLArIRE ..DDR B..DDD ENT D.DI.NEED O I.DIED IFECTIETATION nW/LEMPGE THROUGH LAYER 6 313 69age s s.n 3.0 -7 6.x3 e.eea, a.aG 6 B.eeHE e.BOee e.BBOO I.-A FIRE L_[LSiF EVPPo,RN691M,IW Le. FL(rFI. .,) 3B13B.9B IE.Y3 STUD. DEVIATIONS B.OaOO B.BBBO ...BBO B.WH 0.O%V B.00WLATERAL DRAINAGE COLLECTED n.3B577 ( 4.33196) 135056.953 SO.B475 'HER LAYER I E.Wui EON/LE.x.GE iW0.TH unx ] ....... ........ ��................ 9ELAYEmw/LEumE THROUGH e.eaeo3 ( e.aOee6) ].56] 6 mr. B LAYERGVER ...O, I.ereD N. G. O.BBBi x 3 w B.017 ( 8.003) AVINANCE A.ON SN. OEVI1i1w5 8.000] B.BOO] B.EAYE0. 3 A.RO1 A..1 O.BON1 O.0BB1LATERAL DEACHARE LEERED B.aOOOB( B.00OBB) I.NO B.Mtla RRM LAYER 5 AVERNSES OF MURPHEY AVERAGED RALLY FADS (IIgIES) TEW/LEAFAGE THROUGH "Do", 1 B.ERROR) 1.56] BT.C.4 unx 6AD ON w ...GO 1 ..ROO1 Dm LY RETRACE HEAD M TON OF unx 3 DE LAYER 6 B.0165 B.B3,3 B.B60 B.B6. O.B]]1 1.1210 1VEPIBES Iw/EFAF THROUGH DGX 8.00067 ( 8. 0B9) ].]B3 A.ANSI SN. 0.010 8.091 .. ...IBI6B 0.O19s IN DEVIPi1WE . . . O. CHANGE WTFR STORAGE ...DO ( B.IO13) -B.39 I.ON RALLY AVERAGE HEAD ON RP OF LAYER 6 .....rn..................«««««............... AFT. INVENTION GVV 0.0000 .."OO B.L9Oa A.ANA A.GRAND O.BBBB 9Gx WRY VLLRS PoR YA. 1 Tgdpl 1OB- ............................................................................... (1YFXES) (w. FT.) .««.....«««.«.....r«««.....r«.........«............................a......... nu OFF IS.Ssa .71.2116 TOTALS A (STIFF DEVIATIONS) FOR COLLECTED FROM LAYER z B.99B5] E595.].ue AVERAGE ANNUAL ioi. D. oEYiix R YF.R ]xxRWw x.e THE E c .....................................3NGURIS ........CU...................... D. FEET .R Exr .EuoLAixDH/LE.RxE THROUGH LAYER 3 B.RR32 B.v.66 9RSR9Irnnw 6].R 1 9.seal I.63...e ER.eB PEEWBE xFm w ra9 OF uvsR 3 B.su GEN." IS.LAND 1 4.R.1) n19..AG ..IR MAY I.FRED ON rR OF LAYER I D.AN APC Barry_EPA_000575 FAR PER IAD �TION OF.P<E A.PP.TIN L LE g Ig.P FEE, ..ED. END °:< ;, ;; :wE1.�s"`.YEA P <:aaaLMU�. P ..PP,P ...I. FARIERM HEAD ON TOY OF LkYER 6 ..'A, —INN I Y.«PR Em.; ,..EP . .<EEPaREAD. Rg.... .............................................................................. gEP<GL.,IGP,LF.gANE,PRILGH LAYER , RgPP,.g gG .............................................................................. ruxvwx YLG. SOZL ru*LP (wLML) ..ggzx �Pr. P YLG. SOIL WATER (NAIL/VOL) ++ WL.m.cads arc mmputM ring ME,p—x egmtlem. ++ hree WExU .rrnnu...............urrrrn...............E.....r........rrrrn.. ............................................................................. FlW MIEP STORAGE AT END OF YEAR IN LAYER (I.ES) (.LML) wge s vage IP APC Barry_EPA_000576 APPENDIX F ClosureTurf' Cover System Design APC Barry_EPA_000577 Geosyntec consultants CALCULATION PACKAGE COVER SHEET Client: Alabama Power Company & Project: Plant Barry Ash Pond Closure Project#: GW6489 Southern Company Services Project TITLE OF PACKAGE: DRAFT CLOSURETURr COVER SYSTEM DESIGN PACKAGE B CALCULATION PREPARED BY: sip 24 August 2018 r (Calculation Prepares,CP) d Name Maria F.Limas Date d ASSUMPTIONS&PROCEDURES Signature 24 August 2018 CHECKED BY: (Assumptions&Procedures Checker,APC) Name M.Gizem Bozkurt Date 3 24 Au COMPUTATIONS CHECKED BY: Signature gust 2018 (Computation Checker,CC) Name M.Gizem Bozkurt Date cYi BACK-CHECKED BY: Signature 24 August 2018 (Calculation Preparer,CP) Q Names Maria F.Limas Dare a m APPROVED BY: Signature 24 August 2018 (Calculation Approves,CA) Name Glenn J.Rix Date REVISION HISTORY: NO. DESCRIPTION DATE CP APC CC CA A Draft Closure Design Calculation Package 08/27/2018 MFL MGB MGB G.IR APC Barry_EPA_000578 Geosynte& consultants Page 1 or 19 CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Projea No: GW6489 DRAFT-CLOSURETURF®COVER SYSTEM DESIGN PACKAGE INTRODUCTION &PURPOSE ClosureTurf®Cover System(ClosureTurf®) is an engineered cover system that may be used as an alternative to the prescriptive, multi-component soil cover system defined in the United States Environmental Protection Agency (USEPA) Subtitle D regulations [Watershed Geosynthetics (WatershedGeo), Summary of Benefits of ClosureTurA. Recent developments and applications of engineered turf as a final cover system make it a viable alternative to traditional soil covers, particularly for Coal Combustion Residuals(CCR)facility closures. Owners of CCR facilities may not have a soil borrow source as readily available as an owner of a landfill,which has a continuous demand for borrow soil for applications such as daily/intermediate cover. ClosureTurf" is a three-component system (Figure 1) comprising: (i) a structured geomembrane (i.e., SuperCrripnet®, MicroSpike®, or MicroDrain�); (ii) an engineered turf protective layer consisting of high-density polyethylene (HDPE) grass blades adhered to woven geotextiles; and (iii) a thin layer [minimum of 0.5 inches(in.)thick] of specified infill, which is primarily used for ballasting, and is usually clean sand. In areas of high water flows where sand infill alone may be erodible [i.e.,velocities between 4 and 10 feet per second (fps)], ArmorFill® infill can be used. ArmorFill® infill is a polymer emulsion that is a mixture of six-parts water to one-part concentrated ArmorFill®. The emulsion is sprayed onto previously placed sand infill to improve erosion resistance. If flow velocities exceed 10 fps, the sand can be mixed with cement to provide even greater erosion resistance; the sand/cement infill is referred to as HydroBinder®. The mix design used in HydroBinder® has a typical compressive strength of 5,000 pounds per square foot (psf). When using HydroBinder®, ArmorFill® is typically applied to form a transition zone between areas of sand infill and areas of HydroBinder® infill [WatershedGeo, 2018a]. ClosureTurf®, ArmorFill®, and HydroBinder® are manufactured by WatershedGeo. This Draft ClosureTurf Cover System design package (Package) was prepared in support of the design to close the existing coal combustion residuals (CCR) ash pond at Alabama Power Company's (APC's) Plant Barry (Site), located in Bucks, Alabama. The ash pond will be closed using a "consolidate and cap-in-place" method whereby all CCR will be consolidated into an approximately 300-acre area that will be constructed in the central portion of the ash pond using soil containment berms and with a final cover system. The Package presents a review of literature and design calculations related to the following performance aspects of ClosureTurf®, using 50- mil MicroDmin® (herein refereed to as MicroDrain®) as the structured geomembrane and sand as the infill: GW6489/13arry_50%Design Closurerurr Draft APC Barry_EPA_000579 Geosynte& consultants Page 2 of 17 CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 • erosion resistance; • burrowing animals; • wind uplift resistance; • resistance to ultra-violet(LTV) light; • thermal exposure effects; and • vehicle trafficking. A hydrologic evaluation and veneer stability analyses were also completed for the ClosureTurf® product as part of the detail design package and can be found in the Draft Hydrologic Evaluation of Cover Performance [Geosyntec,2018a] and the Draft Veneer Stability Analysis for Final Cover Design [Geosyntec,2018b] calculation packages,respectively. CLOSURETURF®PERFORMANCE ASPECTS Erosion Resistance TRI/Environmental Inc. performed a series of tests in 2010 and 2013 in accordance with ASTM D6459 [Standard Test Method for Determination of Rolled Erosion Control Product (RECP) Performance in Protecting Hillslopes from Rainfall-Induced Erosion]and ASTM D6460 [Standard Test Method for Determination of Rolled Erosion Control Product (RECP) Performance in Protecting Earthen Channels from Stormwater-Induced Erosion] for the purpose of estimating the erosion resistance of ClosureTurf®with a 0.5-in.thick sand infill(Attachment 1). For the hillslopes erosion tests(i.e.,ASTM 136459),three rainfall intensities were tested(i.e.,2,4,and 6 in.per hour) on a 3 horizontal to 1 vertical(3H:IV) sloped test strip that was 8-feet(ft) wide by 40-11 long. Of the rain events tested,the 6 in.per hour rainfall intensity test resulted in the greatest sediment yield per acre(i.e.,loss of sand infill),with a calculated rainfall-induced sand infill erosion volume being 0.04 percent of the total sand volume per hour. For the channels erosion tests(i.e.,ASTM D6460), five different flow depths were tested on a trapezoidal channel (i.e., 2-11 wide by 40-ft long with 2H:1 V side slopes)with a 5-percent bed slope.The minimum flow depth tested was 1.72 in.,which correspond to a maximum bed shear stress of 0.45 psf and resulted in a soil loss of 0.03 in. The maximum tested flow depth was 6.15 in., which corresponds to a maximum bed shear stress of 1.60 psf and resulted in loss of 0.5 in. of sand infill. According to the precipitation frequency estimate for Bucks, Alabama (i.e., for the Site), the average 100-year, 24-hour storm precipitation is 14.0 in. (Attachment 2). The peak rainfall in the GW6489/Barry_50I,DesignClosureTurf Draft APC Barry_EPA_000580 Geosynte& consultants Page 3 of 17 CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 100-year,24-hour hydrograph was calculated to be approximately 6.0 in.per hour(Attachment 2), equal to the highest rain intensity used for the erosion resistance tests performed by TRI/Environmental. Because the steepness of Site slopes (approximately 3.5-percent pre- settlement slope) are substantially flatter than the 3H:1 V slopes evaluated by TRI/Environmental, sand infill erosion under Site conditions is expected to be substantially less than 0.04 percent of the total infill sand volume per hour under the 100-year, 24-hour storm event. However, if significant levels of sand erosion are observed at the Site during the post-closure period,periodic maintenance would need to be performed to augment the sand infill thickness. Infill inspection and maintenance should be addressed in the routine inspection program for the final cover system. WatershedGeo developed a chart, presented in Figure 3, to determine the maximum allowable drainage lengths between drainage benches based on the hydraulic transmissivity (i.e., in-plane flow capacity) of the SuperGripneto geomembrane and the limiting tractive shear stress on the sand infill due to surface runoff flowing over it According to the manufacturer product data sheets included in the ClosureTurf®Design Guidelines Manual [WatershedGeo, 2018a- Attachment 81, the SuperGripnee provides the same drainage capacity as the MicroDraino; therefore,the chart is considered applicable to ClosureTurf® systems with MicroDrain®. For the calculation of the maximum allowable drainage lengths shown in the chart,the limiting shear stress on the sand infill was selected as 0.2 psf based on the results from the erosion tests (i.e., ASTM D6460)performed by TRI/Environmental Inc. on a trapezoidal channel with a 5-percent bed slope lined with ClosureTurf®. Based on the extrapolation of the tests results, a bed shear stress of 0.2 psf results in a loss of sand infill thickness of less than 0.02 in, as shown in Attachment 1. The maximum drainage length between benches at the Site is 630 ft for pre-settlement slopes of 3.5 percent, as shown in Figure 2. The chart presented in Figure 3 was used to evaluate the Site's maximum allowable drainage lengths based on the ClosureTurf® Design Guidelines Manual [WatershedGeo, 2018a— Attachment 81. For the estimation of the maximum allowable drainage length at the Site, the curve for a rainfall intensity of 6 in. per hour (i.e., calculated peak rainfall intensity for the 100-year, 24-hour storm at the Site) was evaluated for the slopes at the Site, as shown in Figure 3. The maximum allowable drainage length was estimated as 690 ft for the pre- settlement slope of 3.5 percent Because the design maximum drainage length (i.e., 630 feet) is less than the maximum allowable drainage length calculated for the design rainfall intensity and slopes at the Site, erosion of the sand infill material is expected to be less than 0.02 in . Burrowing Animals Burrowing animal (e.g., rodent) activity can be an issue for the integrity and performance of conventional soil or soil-geosynthetic final cover systems [Lutton et al., 19791. ClosureTurf has no soil layer; therefore, there is no effective habitat for a burrowing animal to live. Also, due to GW6489/Bany_50%r sign_CloaureTurf_Ere APC Barry_EPA_000581 Geosynte& consultants Page 4 of 17 CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APO/9C8 Project: Plant Barry Ash Pond Closure Project Project No: GW6489 the exposed nature of the product, a ClosureTurf® system does not provide an effective cover and/or shielding for borrowing animals from predators(i.e., birds of prey). Representatives at WatershedGeo have indicated (via email communications) that in their experience to date,with data from more than 1,000 acres of ClosureTurfx installed across multiple climate zones,no evidence of burrowing animal activity has been reported. Wind Uplift Resistance The uplift of an exposed geomembrane due to the wind-induced suction force can be a potential failure mechanism. While ClosureTurf® is not an exposed geomembrane, it nonetheless will experience aerodynamic forces. In the preparation of this Package, conventional exposed geomembrane wind uplift analyses (i.e., Giroud et al. [19951 and Botelho et al. [2014]) were considered for the evaluation of the uplift potential of ClosureTurf®; however, the wind flow mechanisms for exposed geomembranes and ClosureTurf® materials are quite different, mainly due to the ballasting and wind-breaking effects of engineered turf blades and sand infill layer. Therefore, performing wind uplift calculations for the ClosureTurf® system using an exposed geomembrane methodology was judged to be overly conservative. Computational modeling of the ClosureTurf® system was also considered; however, due to the complexity of modelling the engineered turf blade's three-dimensional structure, it was decided to use experimental data available from wind tunnel testing results for the evaluation of ClosureTurf®'s wind uplift potential. Georgia Tech Research Institute (GTRI) conducted wind tunnel testing in 2010 that was used to evaluate the forces generated at the surface of the ClosureTurf® engineered turf system [GTRI, 2010] (Attachment 3). Testing was performed on a flat, level surface, with wind speeds ranging from 7 to 120 miles per hour (mph). Measurements were taken with sustained wind velocities; dynamic effects, such as wind gusts,were not studied. The purpose of the testing was to evaluate the required depth of sand infill to provide sufficient ballasting to counteract the impacts of wind. The wind tunnel testing showed low uplift pressures (i.e., 0.12 psf) on the engineered turf component of the ClosureTurf®system when exposed to 120 mph winds[GTRI,2010].The design of the ClosureTurt®system specifies a minimum 0.5-inch thick sand infill layer,with an estimated sand unit weight of 110 pounds per cubic foot, corresponding to a ballasting effect of 4.58 psf. Therefore, for sustained wind speeds up to 120 mph on a flat, level surface,the engineered turf of the ClosureTurf® system is considered stable as the ballasting effect of sand infill (i.e., 4.58 psf) is substantially greater than the expected uplift(i.e., 0.12 psf). GW6489/Barry_50%DesignClosureTurf Draft APC Barry_EPA_000582 Geosynte& consultants Page 5 or 17 CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/9C8 Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Wind data for the Site was evaluated from multiple sources for comparison to the wind speeds evaluated in the wind tunnel testing. Climatic wind data collected between 1972 and 2015 for Mobile, Alabama (approximately 25 miles south of the Site) reported that the maximum wind speed for the city was 97 mph(Attachment 4) [National Climatic Data Center,2015]. Historically, the state of Alabama has also experienced tornados and thunderstorms with increased wind speeds. The National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Information Storm Events Database was queried for various event types (e.g., strong winds,thunderstorm winds,hurricanes,and tornados)between 1 January 1950 and 18 April 2018 in Baldwin and Mobile Counties, Alabama(Attachment 5). The two highest estimated wind gusts from the query were 120 mph on 27 March 2009 from a thunderstorm wind in Robertsdale, approximately 50 miles southeast of the Site, and 101 mph on 26 January 2009 from a thunderstorm in Creola,approximately 10 miles south of the Site.This last event can be considered as the maximum local historical wind speed due to its proximity to the site. The database query results also included multiple tornadoes that ranged between category Fl to F3. From NOAA's website, category Fl three-second gust speeds can range from 79 to 117 mph, and category F3 three-second gust speeds can range from 162 to 209 mph, as shown in Attachment 6. Wind speeds associated with a tornado of category F3 were registered on 21 November 1997 in Saraland, Alabama, approximately 14 miles south of the Site. The ClosureTurf system was only tested for sustained wind speeds up to 120 mph on a flat,level surface. From the available wind tunnel test results, it is expected that ClosureTurf® at the Site's shallow slopes(i.e., 3.5-percent)will be stable with respect to the maximum local historical wind speed of 101 mph,however no data is available to evaluate uplift performance of the ClosureTurf for wind speeds higher than 120 mph to represent tornadoes of category F2 and F3 that have historically occurred in the proximity of the Site. While available testing methods and results appear to be reasonable, field conditions and slope inclinations could alter the expected ClosureTurf® system wind uplift performance. WatershedGeo is scheduled to perform additional wind testing of the ClosureTurf®system in 2018 related to inclined surfaces and wind gust speeds mimicking tornado gust characteristics. As part of the 100 percent detailed design, the findings of this testing will be reviewed and the conclusions of this Package along with any design considerations will be updated.As necessary,the detailed design of the ClosureTurf®cover system could be augmented through the use of anchor trenches and/or supplemental ballasting (e.g., placement of concrete blocks at slope crests),which would improve the wind uplift resistance. It is noted that the wind uplift evaluation discussed in this section assumes that no additional features are installed on the ClosureTurf® cover system (e.g., solar panels). If additional features are installed on the cover in the future, additional evaluations should be performed. GW6489/Barry_50I,resign_Closurclu Draft APC Barry_EPA_000583 Geosyntec"' consultants Page 6 of 17 CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APO/9C3 Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Resistance to UV Lieht ClosureTurf®has elements that are permanently exposed to UV radiation when installed as a final cover system (e.g., the HDPE grass blades comprising the "engineered turf'). Geosyntec performed a literature review related to turf longevity in 2015 [Geosyntec, 2015]. The results of this review are summarized below. Data and results from a field test facility in New River,Arizona,in which HDPE grass blades were evaluated after 1, 5, 7, and 10 years of exposure, were reviewed. Extrapolation of this data by WatershedGeo[2014]resulted in a prediction of 65 percent retained tensile strength after 100 years of service, and a half-life (i.e., 50 percent retained tensile strength) of 216 years. Additionally, Richgels et al. [2015] published half-life predictions of exposed HDPE grass blades using 2013 laboratory data from the Geosynthetics Research Institute (GRI) on HDPE geomembrane strips exposed to UV lamp irradiation. Richgels et al. [2015] reported upper-bound and lower-bound half-life predictions of 247 years and 176 years,respectively. The HDPE grass blades of the ClosureTurf® system are manufactured using yam with a tensile strength of 15 pounds (lb). In comparison, the tensile strength requirements of the HDPE grass blades of the ClosureTurf®system vary between 2.5 and 3.5 lb based on applied loads of pull-out forces from equipment operation and water runoff forces [Diguilo, 2013]; this required tensile strength is approximately 16.7 percent to 23.3 percent of the manufactured strength capacity. Because the required tensile strength is approximately 16.7 percent to 23.3 percent of the manufactured strength capacity, and the reviewed studies indicate that the estimated half-life of the HDPE grass blades ranges from 176 to 247 years (when the product is expected to retain 50 percent of the manufactured strength capacity,which is greater than the required tensile strength), WatershedGeo states in the Summary of Benefits of ClosureTurf document that the engineered turf will have a 100+year functional longevity(Attachment 7). Thermal Exposure Effects As a final cover system, ClosureTurf® will be exposed to a range of temperatures. Large temperature differentials over a short period of time can cause stress cracks (i.e., external or internal cracks in a plastic caused by tensile stresses less than its short-term mechanical strength) within the ClosureTurf®geomembrane(i.e.,MicroDrame). Stress cracking can be evaluated using the Standard Test Method for Evaluation of Stress Crack Resistance of Polyolefin Geomembranes Using Notched Constant Tensile Load (NCTL) Test (ASTM D5397). In this accelerated aging index test,specimens are: (i)loaded at 20 to 50 percent of the tensile yield strength of the material; (ii) notched 20 percent of their overall thickness; and (iii) placed in a bath containing 10 percent surfactant at 50 degrees Celsius(°C). The time to failure is then measured. GW6489/Barry_50'/Design_CloaureTurf_Draft APC Barry_EPA_00058,t Geosynte& consultants Page ] of 17 CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Per GRI-GM13 [GSI, 2016], the minimum acceptable stress crack resistance time for a HDPE geomembrane tested using ASTM D5397 is 500 hours. Manufacturer product data sheets for the 50-mil HDPE MicroDrain®report that the materials,tested via ASTM D5397, have a stress crack resistance time of at least 500 hours [WatershedGeo, 2018a] (Attachment 8),which meets current industry standards. LLDPE geomembranes exhibit more ductile behavior, and thus they are less susceptible to stress-cracking than HDPE geomembranes. LLDPE geomembranes only suffer stress cracking after oxidation caused by external agents [Peggs,2003]. For potential cyclic thermal behavior (i.e., freeze-thaw effects), WatersbedGeo refers to a study completed by the USEPA [Comer et al., 19961 where very-low-density polyethylene (VLDPE) and high-density polyethylene(HDPE)liners and seams were tested for freeze-thaw cycles ranging from -200C to 300C. Testing results indicated "neither geomembrane sheets nor their associated seams are adversely affected" by the freeze-thaw testing performed [Comer et al., 1996]. It is reasonable to consider the freeze-thaw effects on ClosureTurf "s MicroDrain®would be similar to the geomembranes studied in Comer et al. [1996]. Further, the sand infill layer may provide an additional insulating effect on the MicroDraino from the ambient temperature fluctuation. It is noted that installation is acceptable during ambient temperatures above 400F and below 1040F, but it should be demonstrated during installation that these potentially adverse weather conditions do not affect the integrity of the installed liner [USBR, 2014]. Particular care should be given when installing HDPE geomembranes because they have a higher coefficient of thermal expansion than linear low-density polyethylene (LLDPE) [Schein, 2009], and undesirable wrinkles could form during installation. Manufacturer's guidelines (Attachment 9) should be followed during installation [WatershedGeo, 2018b]. Temperature changes after installation of the ClosureTurf®cover system may induce contraction and tensile stresses. Analyses were conducted to evaluate whether these stresses could be large enough to pull out the MicroDrain®anchors. The pull-out resistance was evaluated for two cases of anchorage: (i) MicroDmin®runout beneath a riprap channel and (ii) an anchor trench. The calculations of pull-out resistance for the MicroDmin®are provided in Attachment 11. Tensile forces induced by temperature change were calculated using the coefficient of thermal expansion obtained from ASTM D696 testing on a 40-mil HDPE geomembrane (Attachment 10) and the tensile yield strength and yield strain provided in the manufacturer product data sheet for HDPE MicroDrain® (Attachment 8). The LLDPE MicroDrain® is expected to have lower coefficient of expansion and lower elasticity modulus; therefore, the tensile forces induced by temperature changes will be smaller. For a 700C temperature differential,pull-out stresses in the HDPE MicroDraino were calculated to be less than 10 percent of the manufactured tensile yield GW6489/Barry_50%Design_ClosureTurf Draft APC Barry_EPA_000585 Geosynte& consultants Page 8 or 17 CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APO/9C8 Project: Plant Barry Ash Pond Closure Project Project No: GW6489 strength. It is noted that pull-out stresses will reduce as the ambient temperature returns to the temperature at which the MicroDmin® was installed. The minimum MicroDrain®ronout length required to resist the pull-out forces induced by thermal contraction was calculated as 1.3 feet for a 1.0-ft thick riprap lining and a factor of safety of 1.5. A plot of calculated minimum MicroDrain" mount lengths versus riprap thicknesses is provided in Figure A.11-2 (Attachment 11). The factor of safety against pull-out induced by thermal contraction of the MicroDrain"for a proposed 2-ft deep and 2-fit wide anchor trench was calculated as 8.2. The factor of safety for the LLDPE MicroDrain" is expected to be higher due to the lower tensile forces induced by temperature change on LLDPE. Vehicle Trafficldna Traffic loading evaluations are appropriate for ClosureTurf" as vehicles may be needed during routine inspections or maintenance periods. WatershedGeo recommends that travel speeds for vehicles on the ClosureTurf" system be limited to 15 mph or less [WatershedGeo, 2018a]. Additionally, to reduce the potential for sand infill erosion and/or rutting, WatershedGeo recommends that vehicles should limit the number of passes on the final cover system and avoid driving over the same area repeatedly. Furthermore, WatershedGeo indicates that if specific areas experience high traffic, the sand infill should be placed at the full height of the engineered turf [WatershedGeo,2018b]. Tensile testing (ASTM D4595) and static puncture (California Bearing Ratio) testing (ASTM D6241) on the engineered turf was performed by SGI Testing in 2013. Results from these tests were used by WatershedGeo to evaluate the puncture resistance of the ClosureTurf"system under fire pressure loading, as described in the Design Guidelines Manual [WatershedGeo, 2018a] (Attachment 8). Puncture resistance was calculated by WatershedGeo as the product of the tensile strength and the circumference of an equivalent circular area of a tire, considering no ground support beneath the ClosureTurf". For a standard pick-up truck with an estimated contact pressure of 32 pounds per square inch(psi)for each tire(i.e.,a vehicle weight equal to 2,000 lb per tire and a contact tire area per tire approximately equivalent to a 9 in. diameter circular area), the calculations show that the ClosureTurf" system has an acceptable puncture resistance. Calculations provided in the Design Guidelines Manual [WatershedGeo, 2018a] (Attachment 8) were also performed to evaluate damage resistance of ClosureTurf" based on traffic speed for vehicle weights equivalent to fire trucks (contact tire pressure of approximately 120 psi). The Installation Guidelines Manual [WatershedGeo, 2018b] (Attachment 9), states the following related to the engineered turf drivability: GW6489/Barry_50%resiga_Closurclu Draft APC Barry_EPA_000586 Geosynte& consultants Page 9 of 17 CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Projea No: GW6489 • No equipment will be allowed on slopes exceeding 15 percent until sand infill is in place. On slopes less than 15 percent, prior to infill placement, all-termin vehicle (ATV) type vehicles me allowed if rubber tire or track pressure is less than 5 psi; • Post-construction (i.e., full specified sand infill thickness) drivability tire pressures on slopes greater than 10 percent should be limited to less than 35 psi; and • Post-construction allowable rubber fire or track pressures on top decks (i.e., slopes less than 5 percent)may increase to as much as 120 psi,if sustained traffic load is not expected. Although WatershedGeo's Design and Installation Manuals [WatershedGeo, 2018a and 2018b] indicate that post-construction tire pressures as high as 120 psi are suitable to drive on the ClosureTurf® system if slopes are less than 5 percent, Geosymec recommends that industry standard practices for geomembranes be implemented such that: • Traffic will be limited to vehicles less than 35 psi in designated "roadways"to be built on the ClosureTurf*system; and • Roadways will include (from top to bottom): a minimum of 1-ft aggregate of base layer, a 20-ounce(oz) gemextile cushion layer, and the ClosureTurf® system. SUMMARY AND CONCLUSIONS The review of ClosureTurf® manufacturer information, technical literature, Site design, and Site conditions provided in this Package indicate that: • Erosion Resistance: Based on ASTM D6459 testing of ClosureTurf®, a rainfall-induced sand infill erosion volume of 0.04 percent of the total sand volume per hour for a 6 in.per hour rain was estimated. Because the site-specific rainfall intensity for the 100-year, 24- hour storm is approximately 6 in. per hour and the steepness of designed slopes (i.e., 3.5 percent pre-settlement) are significantly less than the testing configuration of 3H:1 V, the sand infill erosion is expected to be substantially less than 0.04 percent of the total sand volume per hour under the design storm event. Based on the hydraulic transmittivity of the MicroDrain® and limiting shear stresses on the sand infill, the maximum allowable drainage length between benches for the designed slopes was calculated as 690 ft, which is greater than the design maximum drainage length(i.e.,630 feet);therefore,no significant erosion of the sand infill is expected. If significant sand erosion is observed at the Site, maintenance should be performed. GW6489/Barry_50I,DesignClosureTu Draft APC Barry_EPA_00058] Geosynte& consultants Page 10 of 17 CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 • Burrowine Animals: With the lack of soil in the ClosureTurf®system, no effective habitat for a burrowing animal exists.Also,due to the exposed nature of the product,ClosureTurf® system does not provide an effective cover and/or shielding for borrowing animals from predators. • Wind Uplift: Experimental data from GTRI wind tunnel testing was used to evaluate wind uplift potential [GTRI, 2010]. Based on the results of this testing, a ClosureTu& system with 0.5-inch thick sand infill layer should have sufficient ballasting to counteract small uplift forces that may result from winds of up to 120 mph (i.e., 0.12 psf). In general, maximum local historical wind speeds(approximately 101 mph)are less than that modeled during the testing. However, tornados of category F3,which have historically occurred in the proximity of the Site, can generate wind speeds of up to 209 mph. Furthermore, WatershedGeo is scheduled to perform additional wind testing of the ClosureTurf®system for different field conditions,slope inclinations,and wind gust speeds in 2018.The findings of this testing will be reviewed and the conclusions of this Package along with design considerations will be updated,if necessary. • Resistance to UV Light: Based on literature review,test results, and evaluations completed by Geosyntec and WatershedGeo, the engineered turf will have a 100+ year functional longevity(Attachment 6). • Thermal Effects:Based on a HDPE freeze-thaw cycle study completed by USEPA[Comer et al., 19961, neither the MicroDrain® geomembrane sheets nor their associated seams would be expected to be adversely affected due to the freeze-thaw cycles. The sand infill layer may provide additional insulation for the MicroDrain®from the ambient temperature fluctuation.Product data sheets for the HDPE MicroDmino report that the materials,tested via ASTM D5397,have a stress crack resistance time of at least 500 hours[WatershedGeo, 2018a] (Attachment 8), which meet current industry standards. The LLDPE MicroDrain® is expected to have a higher stress crack resistance. The calculated minimum length of MicroDrain®runout under a riprap channel required to resist the pull-out forces induced by thermal contraction of the HDPE MicroDrain® is presented in Figure A.11-2 (Attachment 11) for varying riprap thicknesses. Additionally, the factor of safety against pull-out forces induced by thermal contraction of the MicroDrain® for a 2-foot deep and 2-foot wide anchor trench proposed by the final cover system design was estimated to be 8.2 (Attachment 11). The LLDPE MicroDmin® is expected to have a higher factor of safety against pull-out. GW6489/Barry_50%Desiga_ClosureTurf Draft APC Barry_EPA_000588 Geosynte& consultants Page 11 of 17 CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Projea No: GW6489 Vehicle Trafftckine: WatershedGeo's Design and Installation Manuals [WatershedGeo, 2018a and 2018b] indicate that post-constmctjon tire pressures as high as 120 psi are suitable to drive on the ClosureTurf°'system.However,Geosyntec recommends that traffic be limited to specified roadway corridors to be installed on the ClosureTurf® system, and industry standard practices for vehicle trafficking for HDPE geomembranes (i.e., use of a geotextile cushion layer and a minimum 1-fit of base aggregate layer between the ClosureTurf®and a light-weigbt vehicle tire) are followed at the Site. GW6489/Barry_50%DesignClosurclu Draft APC Barry_EPA_000589 Geosynte& consultants Page 12 of 17 CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APCISCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 REFERENCES Botelho, K.J., Heynes O., Giroud, J.P. (2014). "Evaluating Wind Uplift for Exposed Geomembranes Using Computer Modeling," Proceedings of Geo-Congress 2014, Atlanta, Georgia,Vol. 3,No. 234,pp. 2513-2522. Comer,M.L. Sculli,and Y.G.Hsuan(1996)."Freeze-Thaw Cycling and Cold Temperature Effects on Geomembrane Sheets and Seams,"A.I. EPA/600/5-96/004. Diguilo,D. (2013). "ClosureTurf®—The Next Generation Closure System".Northern New England SWANA Conference,Lebanon,New Hampshire, September 25, 2013. Geosyntec (2015). "Literature Review and Assessment of ClosureTurf UV Longevity,"prepared for Watershed Geosynthetics,Atlanta, GA. Geosyntec (2018a). "Draft Hydrologic Evaluation of Cover Performance;' calculation package submitted to Alabama Power Company and Southern Company Services,August 2018. Geosyntec(2018b)."Draft Veneer Stability Analysis for Final Cover Design,"calculation package submitted to Alabama Power Company and Southern.Company Services,August 2018. Giroud, J.P., Pelte, T., and Bathurst, R.J. (1995). "Uplift of Geomembranes by Wind," Geosynthetics International, Vol. 2,No.69 pp. 897-952. GRI (2014). "Exposed Lifetime Predictions of 19-Difference Geosynthetics in the Laboratory and in Phoenix,Arizona,"GRI Report#44, December 16. GSI (2016). "Test Methods, Test Properties and Testing Frequency for High Density Polyethylene (HDPE) Smooth and Textured Geomembranes,"Revision 14,January 6. GTRI (2010). "Aerodynamic Evaluations of Closure Turf Ground Cover Materials," Report by Georgia Tech Research Institute,July 8. Koerner,R.M. (1999). "Designing with Geosynthetics"0 Edition. Prentice-Hall Inc. Lorton, R.J., Regan, G.L., Jones, L.W. (1979). "Design and Construction of Covers for Solid Waste Landfills," Volume I, Section 20, pp. 226-227. USEPA, Office of Research and Development, Municipal Environmental Research Laboratory,January 1. National Climatic Data Center(2015). "Comparative Climatic Data for the United States Through 2015,"Asheville,North Carolina. GW6489/Barty_50%Desiga_ClosureTurf Draft APC Barry_EPA_000590 Geosynte& consultants Page 13 of 17 CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/9C8 Project: Plant Barry Ash Pond Closure Project Project No: GW6489 National Oceanic and Atmospheric Administration (NOAA) (2017). NOAA Atlas 14 Point Precipitation Frequency Estimates. Silver Springs, MD. htti)s://hdsc.nws.noaa.eov/hdsc/nfds/nfds man cont.html, accessed 6 December 2017. NOAA (2017). Storm Events Database. httos://www.ncdc.nom.2ov/stolmevents/, accessed 12 December 2017. See Attachment 5. NOAA(2017).Enhanced F Scale for Tornado Damage.hus://www.spc.noaa. oe v/faq/tomado/ef- scale/ accessed 12 December 2017. See Attachment 6. Peggs, I. D. (2003). "Geomembrane liner durability: contributing factors and the status quo." lst United Mngdom Geosynthetics Symposium,UK Chapter of IGS, June 2003. Richgels, C., Ayers, M., and Urmtia, J. (2015). "Estimation of Geographic Ultraviolet Radiation Levels and Impact on Geosynthetic Cover Systems," Proceedings of Geosynthetics 2015, Portland,Oregon,February 15-18. Scheirs,J.(2009)."A Guide to Polymetric Geomembranes:A Practical Approach,"Chapter 12,p. 200, August. United States Bureau of Reclamation (USBR) (2014). "Design Standard No. 13 Embankment Dams, Chapter 20: Geomembranes,"Phase 4(Final), March. USEPA (1993). "Solid Waste Disposal Facility Criteria," Document No. EPA 530-R-93-017, United States Environmental Protection Agency,November. WatershedGeo (2017). "Summary of Benefits of ClosureTurf,"Accessed 12 December 2017. WatershedGeo(2014)."Technical Submittal for ClosureTurf1T4—Alternative Final Cover,Closure of Municipal Solid Waste Landfill Units,"December 2. WatershedGeo (2018a). "ClosureTurf Design Guidelines Manual,"January. WatershedGeo (2018b). "ClosurcTu f Installation Guidelines Manual,"January. GW6489/Barry_50I,DesignClosurclu Draft APC Barry_EPA_000591 Geosynte& consultants Page 14 of 17 CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 FIGURES GW6489/Barry_50%Design_ClosumTurf Draft APC Barry_EPA_000592 Geosynte& consultants Page 15 of 17 CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 MIN Ir SAND DYER ENGINEERED SYNTHETIC TURF PREPARED SVBGRADE RRR 6, CLOSURETUW r GEDCGMPCSITEAGRU MICRO 0 AINL PE MIGRODRAIN' - 1 PREPARED SUBGRADE I GEOCOMPOSITE `CCR Figure 1. ClosureTurf® System with Sand Infill Placed on Top of Prepared Subgrade GW6489/Berry_50I,4sign_ClosureTurf DrnR APC Barry_EPA_000593 Geosyntec° consultants Page 16 or 11 Cp: MFL Date: 09/24/18 APC: MGB Date: 08/24/18 CA: GSR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 V. Final Cover Maximum Drainage _ i�� t Lengths* 615 fitI 1 - � Y __ _Pig - �y • V ' .v°�'w Legend: �, _ Top Deck Middle Portion Lower Portion _____ _ — — _ Bench — • — Drainage Channel Drainage Path Length .� ;-\ ' � � r 'Negligible difference between plan view and AA - ,j slope length because of very shallow slope Figure 2. Maximum Drainage Lengths of the Slopes at the Site GW6489nB y 50%Dasiga_ClosureTurf_DraO APC Barry_EPA_000594 Geosyntec° consultants Page 1] of 17 CP: MFL Date: 09/24/18 APC: MGB Date: 08/24/18 CA: GSR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Closure Turf Maximum Drainage Length(with Sand Ballast) 1000 p1 Use chartto determine the maximum drainage Watershed lengths between damage benches or discharge 900 �1I ' Geosynthetics- wales. oeedand Flaw distance is calculated with hydraulic shear of 0.2 paf in the ballast sand. 11 i 800 De Rainfall Intensity Intensity tti m ]00 - - - - - - —2in/hr d 1 � •••••••3in/hr O. O G 600 .1 , ----4 in/hr E I - - 5in/hr E 500 K - e -6in/hr f tt`tt 40U x a — • ]in/hr .� .... ........4..y.. 300 l7 �` — _ 100 Pr Sanlaman Slope=3.5 0 0% 5% 10% 15% 20% 25% 30% 35% 10% 45% 50% Gradient(slope) Figure 3. ClosureTurt®Maximum Drainage Length for Peak Rainfall Intensity for the 100-year,24-Hour Storm at the Site GW6489/14my_50%Dasigo_Closuretarf_Draft APC Barry_EPA_000595 Geosynte& consultants CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 ATTACHMENT GW6489/Barry_50%Design ClosumTurt Draft APC Barry_EPA_000596 TRUENVIRONMENTAL,INC. A Texas Research Imemaa'onal Company Project: ASTM D 6459 Client: RPH Test Date: 4/26/2010 Rainfall Rates: 2,4,6 in/hr(target);20 minutes at each intensity(60 min.total) Bed Size&Slope: 8-ft wide x 40-ft long;3H:1 V Sand Ballast Layer,Ids: 1130 (approximately 1/2-inch thick,hand spread) Intensity Runoff Cannot. Soil[,osa Sediment %of Ballast in Plot (in/hr) (gallons) R-Factor (Ibs/slope) tons/acre Runoff/Seepage 2.36 93 13.13 0.00 0.00 ClosureTurf 4.65 258 97.99 0.00 0.00 0.04% 6.57 360 1 292.43 0.41 1 0.03 Time Carl Cumm. Peak Rational (min) Rainfall(in) Runoff(in) Runoff(CES)i Chi "C"r 20 0.79 0.46 0.013 96.2 0.74 40 2.34 1.76 0.026 94.5 0.76 60 4.53 1 3.50 0.038 1 91.3 0.78 Soil Loss vs RUSLE R-Factor Slopel-O/rl/I10-CbaueTuf —Pdy.(Slapet-0a/27/10-CbwroTurt) 0.030 y=5E-M2-5EOSx R•=0.f)B84 0.025 0.020 a 0.015 N C 0.010 N N O Me 0.005 O !A 0.--- 0 50 100 150 200 250 300 350 RUBLE R-Factor 1.Theeffective numffcurvenumber wasdetennincil MsolvingforS in theequation Q=[(P-0.2SW(P 8S)l wbchsQothedepth.f..ff(i.)and Pis theminfalidepth(inl Thcn,CN=1000/(S-l0). 2Themtimal-C"coefficientwasd�incdbysolvingfo Cin Q=C[AwhereQisthepeekdischargerate(cfs),Iisthepeekrainfallintensity(iN ) and A is thedoure a area(acre% NMe;ThetestingisbaseduponacceptedindusuypmeticeaswellasthetestmeNodiiMed. Teslresulure,.nNhereindowtapplytosemplesotherthan those tested TRl neither accepts responsibility for nor makes claim u to the final use and puryose CIS 5/5110 Quality Review/Date 9063 Bee Caves Road/Austin,Texas 78733/ph:$12 263 2101/fax:512 263 2558/snvw.GeosyntheticTesling.com APC Barry_EPA_000597 TRUENVIRONMENTAL,INC. A Texas Research International Company i c. 1.. Test Slope Prepared and Liner Installed Synthetic Turf Deployed and Sand Ballast Layer Hand Applied r � . e,4,and 6 innrc Rainfall Applied in Succession and Substantial In-Plane Drainage Observed 9063 Bee Caves Road/Austin,Texas 78733/ph:512 263 2101/fax:512 263 2558/y .GeosyntheticTesting.wm APC Barry_EPA_000598 TRVENVIRONMENTAL,INC. ATexas Resea muemational Company !j I/r Bodle Grab Samples and Flow Rate Measurements Taken During Testing d y.. 1 Only Small Amounts of Sand Migrated Within the Drainage Layer and Little Sand Movement Was Observed On Surface 1? Typical Unprotected!Slope Erosion from Testing Protocol(2 imhr on led;6 inlhr on right) 9063 Bee Caves Road/Austin,Texas 78733/ph:512 263 2101 /fax:512 263 2558/www.GeoaynthetbTesgng,wm APC Barry_EPA_000599 TRUENVIRONMENTAL,INC. A Texas Research International Company APPENDIX-DATA 9063 Bee Caves Road/Austin,Texas 78733/ph: 512 263 21011 fax:512 263 2556/w .GeosyntheticTesling.i o n APC Barry_EPA_000600 DDRF Rainfall Testing Sediment Concentration Grab Samples Followed by Runoff Rate Slope p: 1 Target Rain:2 in/hr Measurements is Time Date: 4/26/2010 Start Rairt 1225 PM End Rain: 12:45 PM 1 1228 miipiiiig interval: 003 End Runoff. 12:47 PM 2 12.31 Rain Time(min): 20_00 rest Time(min): 22_00 3 12:34 Product ClosureTurt Desoc. Membrane and Synthetic Turf Capping System 4 12:37 Lot#: Na Artchont. Sand Anchorage: t/2-inch Thick 5 1240 TOP OF SLOPE 6 12:43 v+m= 177% (circle'a'for open valves) Set valves to 9 Psi. 7 tl= 23 ram x x x % 8 — 2J2 imhr P— 9 Psi 9 A 10 x 11 x P= 9 psi B 12 x 13 x C P= 9 Psi x 14 x x 15 X P= 9 psi D x 12 % x 13 % E P= 9 psi % 14 % x 15 % P= 9 psi F O x x x Runoff Rate Measurements x G P= 9 pal x # Time Gallon,seconds x % 1 2 180 x P= 9 psi H x 2 6 31 x x 3 10 15 x I P= 9 psi x 4 14 10 x 5 18 10 x P= 9 psi J X 6 20 9 x 7 x 6 tl= 18 m 9 2.13 inlhr Temp. 78 deg 10 w41= 17.4% Hum. 78 % 0= 19 ram 2 im 2.24 inthr Avenge Depth: 20.00 mm 13 n'�= 18.6% Asa Rainfall Intensity: 236 INhr 14 15 Notes: 2 0 mph breeze. 13 Approx 92 gal collected. 14 15 1 APC Barry-EPA-000601 DORF Ralnrau Tesi Sediment Concentration Grab Samples Followed by Runoff Rate Slope X: 1 Tisirglilt Rain:4 inliir Measurements a Time Date: 4126/2010 Start Reim 12:53 PM End Rain: 1:13 PM 1 12:55 anipinig interval: 0:02 End Runoff: 1:17PM 2 12:57 Rain Time(min): 2000 rest Time(min): 24_00 3 12:59 Product: Clostai Descn. Membrane and Synthetic Turf Capping System 4 13:01 Lot 9: We Anchors: Sand Anchorage: 112-inch Thick 5 13.03 TOP OF SLOPE Set valves to 9 psi. 6 13:05 wd= 17M X X x x 1 13:07 a= 42 mm P= 9 psi 8 13:09 4S I., A 9 13:11 X 10 13:13 X P= 9 psi B 11 x z 12 x C P= 9 psi X 13 X O x 14 X P= 9 psi D x 15 x X /2 E P= 9 psi X 13 x x 14 X IF 9 psi F x 15 X x x G P= 9 psi X RunoRRatBMeasuremenb x X a rmn Gsor,air-nd• x P= 9 psi H x 1 2 8 X O x 2 4 6 X I P= 9 psi X 3 6 6 z X 4 B 6 X P= 9 psi J X 5 10 6 x 6 12 6 x ] 14 5 d= 39 min 8 16 5 i= 4.61 inlhr 9 18 5 wd= 11.4% Temp. n deg 10 20 5 d• 3] nm Hum. 86 % 11 i= 4.31 /hr 12 wq= 18.6% Average Depth: 39.33 mm t3 Avg Rainfall Intensity: 4.65 inlhr 14 15 Notes: 12 0 mph breeze. 3 Approx 260 gal collected. 14 15 APC Barry_EPA_0n0602 DDRF Rainfall Testing Sediment Concentration Grab Samples Followed by Runoff Rate Slope#: 1 Target Rain: 6 Whir Measurements # Time Date: 4I 2010 Start Rain: 12:53 PM End Rail 1:13 PM 1 12:55 iinPuny mscin it 0:02 End Runoff: 1:17 PM 2 12:57 Rain Time(min): 20.00 Pest Time(min): 24.00 3 12:59 Product ClosureTurt Del Membrzneand Synthetic Turt Capping System 4 13:01 Lot#: Na Anchors: Send Anchorage: 112-inch Thick 5U13:1 TOP OF SLOPE 6 "InX (circle'e for open vati Set valves to 9 psi. ] d= 57 min z X X % 8 i= 6.23 inter P= 9 psi 9A 10 x 11 X P= 9 psi B 12 x X 13 C P= 9 psi X 14 X X 15 X P= 9 psi D x 12 x % 13 E P= 9 psi X 14 x X 15 x P= 9 j/hAvemi F x x x Runoff Rats Measurements x G P= 9 psi X # i canon,secones x X 1 2 4 X P= 9 % 2 4 4 x X 3 6 4 X P= 9 psi X q g q X X 5 10 4 X P= 9 X 6 12 4 X T 14 4 % 8 18 4 tl= 58 9 18 4 Tem0. 69 deg 10 20 4 ww= 17.4% Hum. 88 % 11 d= 52 12 i= 6,14 Depth: 55.67 man 13 wm= 18.6% Avg Rainfall Intensity: 6.57 inter 14 15 Notes: 12 0 mph breeze. 3 Approx 360 gal collected. 14 15 APC Barry_EPA_000603 OJanAO Slope#1 Time per Collection Runoff Sample Too Time Interval Total Time, Associated Counted. Gallon, Mid-Time, Rate, Number Uwe No Time,min min min gallmiI Runoff,gal Runoff,gal 2.35 mom 2 0.00 0 0.00 0.00 0.00 0,00 0.00 0.00 2-1 2.00 160 5.00 5.00 3.50 0.33 1.67 1.67 2-2 spit 31 1.52 6.52 6.26 1.94 294 4.60 24) 10.00 15 3.73 10.25 10.13 400 14.93 19.54 24 14.00 10 3.92 14.17 28.17 6.00 23,50 43.04 24 18.00 10 4.00 18.17 36.17 6.00 24.00 li 24 20.00 9 1.98 "As 40.16 6.67 13.22 son tend 22.00 1 85 22.00 12.33 92.59 Total Collected Runoff(appm) 4.65 inlbr 4 a 0 0.00 0.00 0.00 0.00 0.00 0.00 4-1 2 8 2.13 2.13 2.07 7.50 16.00 18.00 4-2 4 6 1.97 4.10 4.05 10.00 1967. 35.67 4-3 6 6 2.00 6.10 6.05 10.00 20.09 55.67 44 8 6 2.00 6.10 8.05 10,00 2000. 75.67 4-5 10 6 2.00 10.10 10.08 10.00 20.00 0.67 44 12 6 2.00 12.10 12.05 10.00 20.00 115.67 4-7 14 5 1.98 14.06 14.04 12.00 231 139.47 44 16 5 2.00 16.08 16.00 12.00 24.00 163.47 49 18 5 2.00 18.08 18.04 12.00 24.00 167.47 4.10 20 5 2.00 20.08 20.04 1200 24.00 211.47 fiend 24.00 3.92 24.00 47.00 2611,47 Tool Collected Runoff(approa) 5.90 i1 6 0 0 0.00 0.00 0,00 0.00 0.00 0.00 &1 2 4 2.07 2.07 203 15,00 31.00 31.00 6­2 4 4 200 4.07 4.03 15.00 30.00 61.00 85 6 4 2.00 6.07 6103 15.00 31 91.00 BI 8 4 2.00 8.07 8.03 15.00 31 121.00 6-5 10 4 zoo 10.07 10.03 15.00 Dow 151.00 64 12 4 2.00 12.07 12.03 15.00 30.00 181.00 62 14 4 IN 14.07 14.03 15.00 30.00 211.00 6.8 16 4 2.00 11 16.03 15.00 woo 241.00 1 18 4 2.00 16.07 18.03 15.00 30.00 271.00 6.10 20 4 2.00 20.07 20.03 15.00 30.00 301.00 6en0 24.00 3.0 24.00 $9.00 360.00 Total Collected Runoff(approa) O m im v io m g Slope#1 -Sediment Concentration rest Tula) Taal Sediment Furofi rmelo AseweR /vv oted A lad semoie Tme Toal Oemmea ory Some Orysedimenl CWttad Collected Coneentindun. 6em01lrq Collect 1 d Runoff. Sediment settle Loss. Numde` mmNes Weight, wei,%ii Weight Weight Weight m9 Wher Wt.,0 Volume el m41 Time gel gal cons.lryn be mter,I 414DIVI01 Mr .sy 6JemW 2.1 303 303.51 32.92 32.a2 3292 am 287.59 0.22 0.00 2.011 IN 1.67 Oln am 2.2 am 31076 32.92 32.92 32.92 a. 2]].04 0.28 0.00 am 31 2m OW am 2-3 am 3MA3 3292 3292 32.92 O.W 9221 022 am 10.00 15 1993 O.W am H 12.00 311.55 32.92 32.92 KA2 am 278.64 0.28 0.03 1400 10 23W 0.03 am 24 15M 299.63 32.92 32.92 32.92 0m 265.71 on am 10W 10 24W am am 2.6 10.0] 304.77 3292 32.W 3292 DM 27185 022 am 2003 9 1. 0co am AW am 22. 0 12M am am 4240Mr sp Taal Solids Ln am 1115=09 41 2W 311.17 32.92 32.92 3292 am 278.25 020 0m 2M a 16.W ... am 42 Aw 308.34 32.92 3292 3292 am MAP 0n am 4.03 6 199T am am 4J am 293.5fi 32.92 W92 32.92 0.00 29M 0.28 0.00 am 6 what O.W 0.00 44 a 313.40 32.92 32.92 32.92 0m 203A8 028 0.03 am a 2000 am Om 45 10.00 313.35 32.92 3292 3292 0m M.,cl 0n OW lom 6 20.00 am 0.00 48 1200 310.89 32.92 32.92 32.92 am 217.97 0.28 am 12M 6 2000 am 0.00 47 14.00 314.63 W92 32.92 32.92 0.0] 281.71 0.28 O.W 14W 5 2380 0.00 0m " 16.00 317.22 32.92 W.92 32.92 0.0] M M 028 am 16I00 5 24 W am am a9 10A0 315.58 32.92 32.92 3282 am 29260 028 000 1OW 5 2400 am 0.00 410 20.00 313.9 3292 U. 32.92 0.0] 263.95 0w 0.0] 20M 5 2400 am am MVO= am 24A0 0 4760 am am 5.90 i"r -4 Total Solids LaN: 0.00 611142009 &1 2.00 317.68 32.02 3292 32.92 am 284.76 029 am 2M 4W 31A0 am am 6­2 4CU 315.42 32.92 32.92 32.92 am 2a250 028 am 4A0 4,00 30.00 0.0 000 68 6. 314.60 3292 MM 32.92 0m 28176 028 am 6M 4.00 30.w am 000 6-0 BW 31269 3292 3292 32.92 0.0] 279.97 028 0.03 8.0] 4. wall 000 am 85 low313,42 32.92 32.92 .32 am 20J.50 am am law 4M 30A0 0.[0 000 8$ 12. 3W.16 3292 32.93 3292 0.m 276.24 am am 12M 4M ..00 0.w 000 &7 14.03 31341 W92 3292 W.92 am203.49 028 am1400 4. woo 000 am " 16.00 315.77 3292 3292 3292 am 282.85 am am 16.00 4L0 Pom am 0.00 &9 law mall 3292 32M 3392 0.00 276.77 am am 19.00 4.00 wall am O.W 6_10 20M 310.70 32.92 3292 32.92 0m 277.78 028 0.03 20.00 4. Pam am 003 AVG= 010 24.00 O.W saw am am Twalleolids LOsm CA t O OI lm v to m 0 SLOPE 91 -Sediment Weights Total Dry Sediments: 0.00 2 irdhr Collected Typ.TSS in Wt.Of pan +wet soil,g 0 Decanted Collected Wt. Of pan +dry soil, 9 0 Runoff, Wt. Of pan.g 0 lb/gal Wt. Of dry soil, g 0 0 Wt. Of water, Water Content,w% Collected Runoff,gal Total Wet Sediments, %dry solids, 92.6 Dry Collected Sediments,g 0.00 0.00 Total Dry Sediments: 0.00 4 in/hr Collected Typ.TSS in Wt.Of pan +wet soil,g 0 Decanted Collected Wt. Of pan+dry soil, g 0 Runoff, Wt. Of pan, d 0 lb/gal Wt. Of dry soil, g 0 0 Wt, Of water, g Collected Water Content, w% Runoff,gal Total Wet Sediments, %dry solitls 258.5 Dry Collected Sediments, g 0.00 0.00 Total Dry Sediments, Ibs: 0.41 6 in/hr Collected Typ.TSS in Wt. Of pan +wet soil,g 402.35 Decanted Collected Wt. Of pan+dry soil, g 400.76 Runoff, _ Wt. Of pan,g 216.31 Ib/gal Wt. Of dry soil,g 184.45 0 Wt. Of water, g 1459 Collected Water Content,w% 0.9 Runoff,gal Total Wet Sediments, %dry solids 360.0 Dry Collected Sediments,g 184.45 0.00 APC Barry_EPA_000606 . A Texas VIRONMENTAL,INC. A Taxes Research NTM.tlonal Company Projeet ASTM D 6460:large-scale Channel Testing(Single Replicate Results) Client: Clo ificTurf Test Date: 5/9/2013 Shear Range: 0.5-2.0 p if(tmget) Flume Size&Slope: Trapezoidal 2-ft wide botere x 40-ft long;2:1 Side Slopes;5°o Bed Slope Event: 30 minutes at each shear Shear Flow depth Flow Manning's Max Bed velocity cutrun. Level (in) (fps) Plow(afs) roughness, She(par) Strass CSLI(in) CSLI,(in) is 1 1.72 2.22 0.64 0.041 0.45 0.03 OA3 2 2.62 3.14 1.37 0.031 0.68 0.06 0.09 3 318 4.21 2.23 OA33 0.83 OD6 OA5 4 3S3 1 4.86 3.10 0.032 1 0.99 0.05 0.20 5 6.15 8.24 9.44 0.026 1 1.60 0.31 O.S1 Limiting Shear via ASTM D 6460 CiosureTurf 0.70 y=0.2024xrtva Re=0.9923 0.60 Dmong Shear=1.52 Pat 0.50 ................. ............. .. ............... .9........ ............. ............ ......... c w 0.40 is 0 0.30 0 y 0.20 11 as E 0.10 E ca 0.00 Otto 1.00 2.00 3.00 Shear,psf The reading is based upon accepted mdnsnr assame as well as the ion m float listed. Tut reaulas reported mein do not apply to aamplu othu rhm Nae tested TRl neither accepts responsibility for nor makes claim as to the final use and puryose CIS 5/17/13 Quality Review/Date 9063 Bee Caves Read/Austin,Texas 78733/ph:512 263 2101 /fax:512 263 2558/www.GeosyntheticTesting.com APC Barry_EPA_000607 . A Texas VIi intTAL,INC. A Taxes Research lntem INC.Company ClosureTurf Installed 8 Close,Before Start of Flows Low and Medium Low,Shear Flows Medium-High Shear Flow and Retained Sand In-fill 7 ;Qe i Highest Flow and Final Channel Condition after Testing(moat sand removed) 9063 Bee Caves Read/Ami Texas 78733/ph:512 263 2101 /lax:512 263 2558/..GeosyntheticTesting.com AIaC Barry_BPA_000608 . A Texas esesmhIENTAL,INC. A Taxes VIRONMENT ,INC.gonat Company APPENDIX-DATA 9063 Bee Caves Road/Auslin,Texas 78733/ph:512 263 2101 /lax:512 263 2558/w .GeosyntheticTesting.com APC Barry_EPA_0D0609 CHANNEL I-SHEAR USERS Deb: SB113 6mrlTlre: 11]O PM E.11—. ii WAM swf. Loom I.,RRf E..'"'1'. hpn v u A., 3 Outlelwelr CNnnel Ter h 110 FLOW a rOepM,In •IWwllnA a rVebdp.M pn c o o opp A 5 cm.¢Wxnl[RI c ler sin rm Taro so E 612 w¢I6em.[m o 5 on w.mr 0 - aoar De cmea.. 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Ekµ cm It I It V 000 Cblpr Sall Loze A BnLoulGeln,b n C OrOSOII Lou,ln 000 onl —In _ .11 n APC Barry_EPA_000614 TRI/Environmental, Inc. 5/17/2013 A Texas Research International Company Limiting Shear via ASTM D 6460 ClosureTurf 0.70 y=0.2024xz 1 R'= 0.9923 0.60 Limiting Shear=1.52 psf \ 0.50 . .................................................................................. .............:`.. c N 0.40 U_ N N O 0.30 0 N 0.20 E E 0 E U 0.10 $ 0.00 N 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 Shear, psf im n N 9063 Bee Caves Road / Austin,TX 78733 / 512-263-2101 1 FAX 263-2558 / 800-880-TEST TRI/Environmental, Inc. 5/17/2013 A Texas Research International Company Limiting Velocity via ASTM D 6460 ClosureTurf 0.70 y= 0.0075x2 e531 R'=0.9849 0.60 Limiting Shear=7.7 psf \ 0.50 . .................................................................................. c N 0.40 U_ N N O 0.30 0 N 0.20 g E / E E U 0.10 O% $ 0.00 N 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 6.00 6.50 7.00 7.50 8.00 8.50 9.00 9.50 10.00 Velocity, ft/sec im v io m 9063 Bee Caves Road / Austin,TX 78733 / 512-263-2101 1 FAX 263-2558 / 800-880-TEST Manning's n vs. Water Depth Vegetated TRMs 0.050 0.040 O O O 0.030 y=0.0517xo.31. W=0.953 c m m c c '.k 020 0.010 0.000 n 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 mWater Depth,in v io m Energy Grade Lines -All Shear Levels ClosureTurf 200.00 Shear Level 5 y'-0.0497x+198.48 Shear Level 4 y=-0.0494x+197.62 199.00 Shear Level Y'-0.0507x+197.51 -------------- Shear Level Y=-0.0515x+197.36 ____ t Sh 0_______ ear Lovell y=-0.0522x+197.22 E198.00 L U C d m O m m 197.00 ° C O q 7 m w 196.00 195.00 op1i 0 2 4 6 8 10 12 14 16 18 20 im XSection(ft along test reach) v io m Geosynte& consultants CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 ATTACHMENT GW6489/Barry_50%Design ClosumTurt Draft APC Barry_EPA_000619 4/13/2018 Precipitation Frequency Data Server t NO"Atlas 14,Volume 9,Version 2 'l Location name:Axis,Alabama,USA' z)Le ' Latitude:31.0014°,Longi[utle:-87.8958° p IVA Elevation:13.85 R" ! rce'�ESRI Maps ou :u8G5 POINT PRECIPITATION FREQUENCY ESTIMATES Santa Perks,Deborah Malin,Sandra Pavlovk, chem Roy,Michael SL Laurent,Can Tryyeluk,Dale Unruh Mcheal yenta,Gedi Bonnin NOM,National Wester Service,Silver Spring,Maryland PF tabular I PF_gCt hp ical I Mips & aerials PF tabular PDS-based point precipitation frequency estimates with 90%confidence intervals(in inches�l Average recurrence interval(years) °°DODOOODD�O 1 2 5 10 25 50 100 200 500 1000 Smin 0468-0]30 0.530A.82] 0.631-0991 0.]49513 0.810-5.5 0.882-'.53) 0.943-19.]2) 0.94--1.92) 1.07-22..20 1.132.41 10-min 0.68&1.07 O.775�1.21 0.924-5.45 1.05-311.66 1.19-1999 1.292.23 1.382951 1.46-2.82) 1.5]3.2) 1.66--3..52 15-min 0.83&414.30 0.90-8.48 1.13- ]] 1.2]2002 1.45242 1.82]3 1.88300] 1.]8-e�3.43 1.91392 2.024.30 30-min 1.51 172F 2.07 2.31 2.78 3.10 3.42 F 3.75 7F420 4.54 1.22-1.90) 1 (1.392.1]) 11 (1.66-2.61) (1.89-2.9) (2.15-3.60) (2.44.05) (2.514.5)11(2.64-5.11) (2.85-5.84) (3.00-6.39) 60-min 2.01 2.29 2.77 3.18 3.79 4.29 4.81 5.36 6.13 6.74 1.62-2.53) (L842.88 2.22-3.40) (2.544.02) (2.954.94) (3.26-5.64) (3.53-6.44) (3.787.33) (4.17-8.55) (4.46-9.40) 2•hr 2.51 2.86 3.46 4.00 4.81 5.48 6.20 6.97 8.06 8.93 (2.04-3.14) 1 (2.31-3.5) 11 (2.79-4.33) (3.21-5.02) (3.77-6.25) (4.19-7.16) (4.59-8.27) (4.96-9.49) (5.2-11.2) (5.95-12.5) 3-hr 2.31353) 2.62d.01 3:7A.88 3.6]-5..70 4.38-77..22 4.91893] 5.439]4 5.9&1111.3 6.]013.5 7.8015.2 6-hr 2.81--44.25 3:91.82 3.885892 4.556?9 5.549503 6.28-10a ].03-312.5 ].7-14.8 8.89-0.] 9.74-20.1 12-hf 3.36-5.01 3.84-5.73 4.]41912 5.598A6 68&151a 7.82-13.0 8.78--15.4 9:4-18.1 11282.0 12325.0 24-hr 4.15 5.50 8.80 8.22 10.3 12.1 14.0 16.2 19.3 21.9 3.93-5.70) 1 (4.546.70) 11 (5.68-8.42) (6.74-10.1) (8.30-13.2) (9.4]-15.6) (10.7-18.4)11(11.&21.7) (13.6-26.3) (14.9-29.9) 2-day 5.44 6.35 8.02 9.59 12.0 14.1 16.3 18.8 22.4 25.3 6.53-6.58) 1 (5.2&7.68) 11 (6.65-9.72) (TW11.7) (9.73-15.3) (11.1-18.0) (12.5-21.3) (13.8-25.0) (15.8-30.3) (174-34.3) 5.92 6.88 8.63 10.3 12.8 15.0 17.4 19.9 23.1 26.7 3•day (6.95-7.13) 1 (5.746.28) 11 (7.18-10.4) (8.50-12.4) (10.4-16.2) 1(11.9-19.1) (13.3-22.5) (14.7-26.4) (16.8-31.9) (18.4-36.1) 79 4day 5.32-]563 6.11-8.78 7.5640.9) 8.90-13.0 10816.8 123g19.] 1338--23.2 1522].1 1732.8) 19.03.0 I F 7-day 6.328.98 7.0-10.0 8.4112.1 9.78-14.1 11.7-17.9 13220.8 14624.3 16.028.3 18.2-34.0 198-38.3 10d8y 7:5-10.1 ].92111.2 9.33-13.2 10.6-15.2 125-19.0 14.10-21.9 15.4-5.3 18]9.3 1898 5.D 2 59 9.2 11.0 12.2 14.3 16.1 18.8 21.0 23.4 25.9 29.3 32.1 20-0ry 9.36-13.0) 1 (10.4-14.4) 11 (12.1-16.9) (13.6-19.1) (15.4-23.1) (16.9-26.0) (18.2-29.5) (19.3-33.3) (21.2-38.6) (22.542.6) 30-daY 13.2 14.7 17.2 19.3 22.2 TA.S 26.9 29.3 32.6 35.1 (11.&15.5) 1 (12&17.3) 11 (14.6-20.2) (16.2-22.8) 1(18.226.9)11(19.730.0) (20.9-33.6) (21.9-37.4) (23.542.5) (24.746.4) 45•day 13848.9 15.4-21.1 1]9'4.6) 198-2].6 219-32.1 8�5.5 246'9.2 256A3.2 2]0A8.3 28.052.2 60-day 164689) 1Z&24.4 0�18.4) 23.0-31.] 2525.6) (268?04) 28044.4 28948.5 8853.8) 312-6.8 1 Precipurfon frequency(PF)estimates in this table ere based on frequency analysis of partial duration series(PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of rile 90%confidence interval.The probability at precipitation kequency estimates(for a given duration and average recurrence interval)will be greater than the upper bound(or less than the lower bound is 5°/a.Es6meone at upper bounds are not checked against probable maximum precipitation(PMP)estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top PF graphical APC Sal_000620 hfps://hdsc.nm.noaa.gov/hdsctpfds/pfds_pdntpege.htm171et=31.001481on=-87.9958&data=depth&units=english&sedes=pds 1/4 4/13/2018 Precipitation Frequency Data Server PD5-based depth-duration-frequency(DDF)curves Latitude: 31.0014". Longitude: -87.9958- 45 Aceragerecunance I-- ----------- - -`--, -----:--:--. Interval c a25 __,- - -__ _•-_ - -_-, - — b [ — 10 p c — b0 y 15 .. ..:. .;....C 100 c 10 200 500 1000 0 T T T T T T T T T N E E E E Nr1, L e aaa as as cc Duration 45 35 ......!...........:........:...........L........'.... ....... ...... r -- -- Durettin y — 6-min — 2Aay a 25 - ---- . - ---'- - c — 1Dmin — 3Say p +`1 — 30min — 1Eay n C — 2+r — 2"ay 5 — Bar — 4".y - -. _. - — 12-Or — 50-0ey 0 — 2"r 1 2 5 10 25 50 100 200 500 1000 Average recurrence interval (years) NOAAAdas 14,Volume 9,Version 2 Created(CMT). Fn Apr 13 1525 15 2018 Back to Top Maps & aerials Small scale terrain APC Barry_EPA_000621 hops://hdsc.nm.noaa.gov/hdsctpfdslpfds_pdntpege.html7let=31.0014&lon=-87.9958&data=depth&units=english&sedes=pds 2/4 4/13/2018 Precipitation Frequency Data Server k A' 3hm 3mi Large scale terrain 1 Monlgomery"� ALABAMA nmies5urg' � A Mdhue Bllorci +�I Gklfport }- s peusacola 1� L ., ;.1• _. IUD` a• 06km COrai Large scale map arc J Hattiecbur0 ® I obile GUI1Cotl�IlpxL Pensacda + .. 100km Li Large scale aerial APC Barry_EPA_000622 hops://hdsc.nm.noaa.gov/hdsctpfds/pfds_pnntpage.html?lat=31.0014&lon=-87.9958&data=depth&units=english&sedes=pds 3/4 4/13/2018 Precipitation Frequency Data Server 1001am Omi Back to Tup US D padment of Commerce National Oceanic and Atmospheric Administration National Weather Service National Water Center 1325 East West Highway Silver Spring,MD 20910 Questions?:HDSQ.Ouee60ns@n0aa.gov Dingle APC Barry_EPA_000623 hops://hdsc.nm.noaa.gov/hdsclpfds/pfds_pdntpage.html?lat=31.0014&lon=-87.9958&data=depth&units=english&sedes=pds 4/4 Plant Barry 100-year 24-hour Storm Histogram Time Incremental Intensity hours (in/hr) 0 0 1 0.15 2 0.16 3 0.18 4 0.19 5 0.21 6 0.24 7 0.27 8 0.29 9 0.38 10 0.48 11 0.76 12 5.99 13 1.53 14 0.67 15 0.47 16 0.37 17 0.3 18 0.27 19 0.23 20 0.2 21 0.18 22 0.17 23 0.16 24 0.16 *Hydrograph is forthe 300-year 24-hour storm event. **Cells highlighted yellow are the peak rainfall forthis storm event. APC Barry_EPA_000624 Geosynte& consultants CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 ATTACHMENT3 GW6489/Barry_50%Design ClosumTurt Draft APC Barry_EPA_000625 Aerodynamic Evaluations of Closure Turf Materials, GTRI Project No. 0-6244, Contract No.AGR DTD 5114110 Georgia I, Fa Tech Unod2uft Closure { Turf" PAN Pendit July 8,2010 Mr. Michael R.Ayres, P.E. Closure Turf, LCC 3005 Breckinridge Blvd. Duluth,GA 30096 Subject: Aerodynamic Evaluations of Closure Turf Ground Cover Materials References: 1:Contract#AGR DTD 5/14/10 Dear Mr.Ayres and Closure Turf LCC affiliates: The Georgia Tech Research Institute is pleased to submit the attached Report, covering the period from May 14 to July 8, 2010, in fulfillment of Reference. This document details the tasks and analysis made on contracted work performed by the GTRI Aerospace, Transportation and Advanced Systems Laboratory and its team members on Phase I of the Project entitled "Aerodynamic Evaluations of Closure Turf Ground Cover Materials". We look forward to continuation of this work for/with Closure Turf, LCC upon the adoption of Phase II activities related to aerodynamic investigation of Closure Turf Material or other desired evaluations. Sincerely, Graham M. Blaylock Principal Investigator Georgia o o Tech Doi APC Barry_EPA_000626 Aerodynamic Evaluations of Closure Turf Materials, GTRI Project No. 0-6244, Contract No.AGR DTD 5114110 Aerodynamic Evaluations of Closure Turf Ground Cover Phase IREPORT May 14—July 8, 2010 Project Expires:August 14, 2010 Contract No. AGR DTD 5/14/10 Proposal No.ATASL-AATD-30-1119 GTRI Project No. D-6244 Prepared for: Mr. Michael R. Ayres, P.E. Closure Turf, LCC 3005 Breckinridge Blvd. Duluth, GA 30096 Prepared by: Graham M. Blaylock, Research Engineer II Aerospace,Transportation and Advanced Systems Laboratory Georgia Tech Research Institute Georgia Institute of Technology Atlanta, GA 30332-0844 Pb62(a)Rtri.eatech.ed u Principal Investigator: Graham M. Blaylock, Research Engineer II Georgia Tech Research Institute Aerospace,Transportation&Advanced Systems Laboratory CCRF, Code 0844 Atlanta,GA 30332-0844 (404)407-6469, Office (404)407-8077, Fax (404)407-7586,Wind Tunnel 662Ca gtri.eatech.ed u APC Barry_EPA_000627 Aerodynamic Evaluations of Closure Turf Materials, GTRI Project No. 0-6244, Contract No.AGR DTD 5114110 Introduction GTRI has been contracted by Closure Turf, LCC to experimentally evaluate the aerodynamic properties and ballast requirements of a novel synthetic ground-cover system under a range of wind speed conditions (V,j"f). The Closure Turf Material was tested full-scale in GTRI's subsonic Model Test Facility (MTF) wind tunnel wherein the normal force loading (Ibt/ft') and the shear stress (Ibt/ft') were determined for a suitable section of the material. The turf material was tested in two configurations, one representing the perimeter of the turf installation (Fig 5) and the 2"d at a representative interior section (Fig 6). Both installations were evaluated on a flat level surface. The installation is shown in Figures la-d below. removed for perimeter test cor'fl¢. ' T Force Be b Static Pressure Tap Array - Figure la—Model Before Final Turf Layer Figure 1b—Turf Installed&Model Lowered i Traversable Pitot Static Boundary Laver Probe - - - Figure lc- Pitot Static Boundary Layer Probe Figure ld—Full Installation Looking Downstream APC Barry_EPA_000628 Aerodynamic Evaluations of Closure Turf Materials, GTRI Project No. 0-6244, Contract No.AGR DTD 5114110 Program Description Closure Turf system-The Closure Turf ground cover system consists of two independent layers.The first layer is a geomembrane to cap the upper soil layer.This is then covered with a geotextile turf layer(Fig 2a and 2b) Geomembrane Layer-The impermeable geomembrane is made from Agru 50-mil LLDPE Super Gripnet® material and is used to cap the terrain being covered. It has an array of spikes to interface to the soil below and an array of studs to interface with the turf covering above. Throughout the testing and subsequent analysis of the Closure Turf system, it was assumed that the geomembrane will be sufficiently installed to prevent movement of that layer. Geotextile Turf Layer—This component is designed to be installed on top of the geomembrane. The turf is intended to remain in place without an anchoring system linking it to the geomembrane below. It relies on the interface friction and sand ballast added on top of the turf to ensure that it remains immobile under all environmental conditions. It is constructed of two permeable sheets of woven HDPE mesh material which are linked together with synthetic blades of grass that are looped through the two HDPE substrates (Fig 2a). Integral spikes to ers high friction to sibgrade LIV resistant blades with interlocking inRR Geotextile for dimensionalstability -� Integral dads for high i rapacity drainage Figure 2a—Closure Turf Synthetic Ground Cover System APC Barry_EPA_000629 Aerodynamic Evaluations of Closure Turf Materials, GTRI Project No. 0-6244, Contract No.AGR DTD 5114110 Ge Clks MOPE Gram A9.samil LOPE Sups Gr'ipreo Benda 1.0 wirb Spite nmrm Fountlarlon Sat Geotee4lee aOAIY Membrane/ OPE of LLOPE LIna rp,� Trad itiona l Appl ication vs- C losu re TurfApplication Figure 2b—Installation of Closure Turf Purpose —The scope of this program was to conduct a full-scale wind tunnel test and experimentally isolate and measure the aerodynamic forces acting on a section of the permeable upper geotextile turf layer alone as installed above the impermeable geomembrane. The wind tunnel install configuration would simulate a wide range of wind speeds flowing over a flat and level terrain installation of the Closure Turf ground cover system (Fig la-d). The sand ballast requirements needed to counteract the resulting aerodynamic forces could then be determined. The purpose of the ballast is twofold. It serves to prevent both lift-off and tangential motion of the turf material along the geomembrane underlayment resulting from aerodynamic lift and drag acting on the turf layer. Methodoloev Model Design—The model represented a full-scale 2D section of the Closure Turf material with a 6.125" chord (stream-wise dimension) with a width of 43" that spanned the tunnel wall to wall. This area constituted the live balance section upon which the total sum of all aerodynamic forces could be measured by a 6 component force balance located under the test section. The model consisted of 4 layers listed below from the lower to uppermost turf layer 1) %" Furniture grade plywood support base — This incorporated several pressure taps on the underside in order to measure the ambient pressure(Pemb)to determine the vertical force (Fame) due to pressure acting upward on the lower surface of the model. 2) Foam Filler Layer—This represented the soil layer surrounding the lower geomembrane spikes. 3) Impermeable Goemembrane Layer — This was fixed rigidly to the base. An array of static pressure taps was installed on the upper side of this layer,shown schematically in Fig. 1a.These APC Barry_EPA_000630 Aerodynamic Evaluations of Closure Turf Materials, GTRI Project No. 0-6244, Contract No.AGR DTD 5114110 pressures were integrated numerically to determine the force (F.,o)due to pressure acting down on the membrane. 4) Geotextile Turf Layer—The turf was first mounted to a thin wire support frame to maintain the geometry and to provide a safety measure to prevent material from dislodging in the tunnel. The frame was then mounted rigidly on top of the lower construction flush with the top of the geomembrane upper surface studs. Pitot Static Boundary Layer Probe— In general, pressure variation through the height of the boundary layer is due to viscous forces which cause deficits in the total pressure as the bounding flat and level surface is approached.The static pressure remains constant. However,the unique characteristics of the flexible and permeable turf layer warranted investigating the boundary layer formation on the Closure Turf system. To accomplish this, a traverse system was built into the model to actuate a Pitot static probe vertically through the boundary layer(Fig 1c). This allows the measurement of the total and static pressure as a function of the probe height, defined as h = 0" at the upper surface of the turf HDPE woven mesh. From these measurements the flow velocity distribution was determined. This characterizes the shape of the boundary layer which is by its nature a transition from the no slip condition at the surface (V=O)to free stream conditions (V= V;"f). The characteristics of this boundary layer profile such as the BL thickness, the height required for the flow to reach free stream velocity, provide valuable insight into the observed results. Force Balance—An under floor 6 component force balance was utilized to measure the aerodynamic lift (L)and the total drag (D) of the model. These forces were transmitted to the balance through a vertical strut which mounted to the underside of the model base. It should be noted that these forces represent the total sum of all pressure distributions acting on the model resolved vertically and tangentially. As such the isolated vertical force acting on just the turf layer(L,,,,f) is found by Equation 1. Lturf = L —Lamb +Lgeo (Eq 1) Under the confines of this program, it was not feasible to separate the drag acting on just the turf from skin friction and pressure drag acting on the geomembrane. That being the case, the total drag as measured from the force balance was taken as the drag acting on the turf. This results in a conservative overestimation of the actual turf drag force present. Installation Conditions — Two installation conditions were examined separately. To more accurately simulate the actual installation conditions, both geomembrane and turf layers were installed upstream and downstream of the balance live model (Fig lb and ld). This represents an interior condition and in this case the model was located approximately 18" inboard of the perimeter. It was also suspected that the perimeter, if unaccounted for, could lead to a worse case situation. To determine the nature of this the upstream turf was removed leaving just the geomembrane as a stand in for a typical surface soil roughness that could be expected at the edge of a real world installation. This left the model mounted turf exposed at the leading edge. APC Barry_EPA_000631 Aerodynamic Evaluations of Closure Turf Materials, GTRI Project No. 0-6244, Contract No.AGR DTD 5114110 Results and Discussion These results represent the required thickness of sand for the Closure Turf system as installed on flat and level terrain.The density of the sand was provided by Closure Turf. If a different material density is to be used as ballast,the results can be recalculated via Equation 2. In all cases,the driving parameter for the depth of the sand is tangential slip due to the aerodynamic formation of shear stress. The sand ballast requirements have been illustrated in Figures 5 and 6 for several assumed representative interface coefficients of static friction (g,). The minimum required sand ballast height is found by Equation 2. hsane(in) - Psana As +P fr 12in (Eq 2) Where: lbf Plane = Weight Density of Ballast(sand) = 110 fts D Ibf r Area — Shear Stress,ft2 P = Normal Force Loading,Ibf(+tve up) Area The measured data for determining the sand depth are shown in Table I and Table II and plotted in Figures 5 and 6 for the perimeter and interior configurations respectively. The last column of each table gives the resulting sand height requirement, based on Equation 2, for µ, = 0.93. This value was determined independently from the efforts of this program by Closure Turf affiliates and supplied for use in this analysis. Perimeter Condition (PC) —The ballast requirement resulting from this configuration are substantially greater than the interior condition. For the given At.=0.93 a minimum sand height of 0.4"or 3.6lb,/ft'is needed to provide the ballast based on the resulting shear at 175 ft/s. The lifting pressure will be satisfied by this loading as shown in Figure 4. It should be noted that the required ballast height due to uplift goes from positive to negative at around 115 ft/s. There are several factors contributing to these results. PC Boundary Layer (BL) — The profile for the perimeter condition is shown in Figure 4 (Red Curve). One characteristic to note is that the boundary layer thickness reaches 99% of free stream velocity at a height of approximately 2". This subjects the turf to up to 89% of the total free stream based on a max vertical blade height of 1.25". This has several resulting effects which can be followed in Figures 3a to 3f. The cascade of effects proceeds as follows. The blades are subject to higher velocities and thus higher increasing drag as the wind speed increases. The higher drag increases the bending of the blades back onto the mesh substrate.The effect of this has 2 counteracting effects on the net lift. At lower velocities (Fig3a-b)the blades are bent slightly with the APC Barry_EPA_000632 Aerodynamic Evaluations of Closure Turf Materials, GTRI Project No. 0-6244, Contract No.AGR DTD 5114110 flow being deflected and accelerated of over the perimeter as shown by the tufts. This flow acceleration increases the local velocity and lowers the local static pressure below that of free stream static which creates the pressure differential building up in 3a and b Additionally, in this installation, the perimeter exposes the gap between the turf and the geomembrane which allows for some uplift pressure recovery beneath the turf. However, as the free stream velocity increases,the drag is increased further by virtue of greater velocity exposure in the relatively thin boundary layer, the bending angle of the turf also increases(Fig 3b-c).This bending produces an increasing down force reaction which starts to counteract the suction created by the local flow acceleration. Simultaneously, the slightly reduced turf profile geometry (caused by the increased bending) shown in Figure 3c-d begins to reduce the relative local flow acceleration and thus also reduces the suction.This continues until the net vertical force becomes zero at about 110 ft/s(Fig 3d)and continues to decrease through Figure 3f. Interior Condition (IC) — This condition owes its behavior to the formation of a drastically different boundary layer than the perimeter as shown by the blue profile in Figure 4. Compared to the Perimeter profile it is 25% thicker with no measurable velocity until the height is greater than 50% of the turf length (0.75"). The blades thusly experience a maximum velocity of 45% of free stream. This reduces the drag acting on the turf layer. Furthermore, the static pressure remains constant as a function of height through the BL which effectively prevents the formation of a pressure differential on the flat and level permeable turf membrane. The cause for the deficient boundary layer is created by longer flow paths over a given surface and all boundaries grow in thickness and increase in turbulence with increasing distance. In the case of Closure Turf, the interaction of the flow with the flexible blades causes this growth to occur quite rapidly. The distance producing the profile in Fig 4 was 18" however,the effect of the growing boundary layer can be seen even in the perimeter condition development in Figures 3a —f. The Model section (highlighted in yellow) is 6.125" wide. It is clearly seen that little to no defection occurs in the turf at a distance just over 6 inches behind the perimeter edge. Thus the boundary layer at further distances than 18" and greater from the perimeter can be expected to have minimal interaction with the turf. Figure 6 shows these results by producing measurements requiring minimal ballast. Final Comments and Executive Summary GTRI was contracted by Closure Turf to determine the effective required ballast in terms of sand thickness needed to counteract the aerodynamic forces versus wind velocity acting on a permeable geotextile synthetic turf ground covering material that is to be overlaid onto an impermeable geomembrane underlayment. It was found that in both perimeter and interior loading conditions, the shear acting on the material serves as the more demanding factor for determining the ballast. • The resulting measurements represent the forces acting on the permeable Turf layer only. The Impermeable geomembrane layer was to be assumed Immobile as a founding assumption of this program APC Barry_EPA_000633 Aerodynamic Evaluations of Closure Turf Materials, GTRI Project No. 0-6244, Contract No.AGR DTD 5114110 • If it is determined that the static interface friction coefficient(uJ between the soil and the lower side of the membrane is lower than that occurring between the turf and the membrane upper surface studs,the lowerµ:should be used in Equation 2 to recalculate the sand depth required by shear. The same shear data given in Tables I &II will apply because,as discussed within the methodology section,the measured shear could not be feasibly separated between the two layers independently and thus represents their combined effect. • The sand ballast depths represented in Figures 5&6 and Tables I &II are the Minimum depths required,the proper factor of safety has been left to be determined by Closure Turf, LCC and the authorized building permit issuing agencies. • The perimeter of the turf installation is much more demanding than interior sections. • All measurements were made on a rigidly constrained system. It was not within the scope of this investigation to determine what dynamic effects might occur,including gusts or erosion of sand ballast or any possible unstable perturbations. • All configurations consisted of flat and level terrain installation. • All calculations and measurements assume that the blade length is increased to account for any added ballast material. This is to ensure that the installation matches the conditions as tested. APC Barry_EPA_0006M Aerodynamic Evaluations of Closure Turf Materials, GTRI Project No. 0-6244, Contract No.AGR DTD 5114110 ♦N w u u s �u .am u � aas y 6 aI • 10 Y N N W W W W W 0 Y O Y N IN W W W W Yeloclty(fe/sec( Velocity(ft/sec( Figure 3a:Vinf=25 ft/sec Figure 3b:Vinf=60 ft/sec w 61vow"(R/sec) ity(k/sec)m Figure 3c:Vinf=90 ft/sec Figure 3d:Vinf=210(t/sec us � m u u •s • IOYNYWW WWW d o wmYWr».w �mw VeiecKYlfthecl velocity(k/sec) Figure 3e:Vinf=135 ft/sec Figure 3f:Vinf=170 ft/sec APC Barry_EPA_000635 Aerodynamic Evaluations of Closure Turf Materials, GTR1 Project No. 0-6244, Contract No.AGR DTD 5114110 35 --- Comparison of Boundary Layer Profile for Perimeter and Interior Installations - - - qN=25 psf,Vl,tl=155 ft/sec Ali i I I I I I I I I I I i � 45%%V,r,, 189%V,M I 23 mrerior ag — -1 , —FenmehreL j I , ---Mav Turf Blatle Heigh , ---Max%Vln!@In4tlopx ISin ' Max%Nnf Getlmehr I - I' = c , I :P�roba U—n.de.—fl.e_.c._t1 ed Turf HeFg..ht= 12+5_" __.4-1I ____.._ ____ eI,.'lIII� ..__.—.__..—__ Possible Totalrlerferemea Hi — —+-- Ti— w/gHigh LoclPlow fh sAnle _.—.__..__.. II L - 1 ' a I .L I! .......... I I I I I l I 0 0 W 20 30 40 50 60 TO 80 90 Wo V/Vi,x x 1001%) Figure 4—Non-Dimensional Boundary Layer Profiles for Perimeter and Interior Installations APC Barry_EPA_000636 Aerodynamic Evaluations of Closure Turf Materials, GTRI Project No. 0-6244, Contract No.AGR DTD 5114110 Aerodynamic Driven Requirements of Sand Ballast Thickness for 00 ---. Closure Turf Material - Conditions at Perimeter of Level Installation --- Sand Weight Density=110 lbf/ft3,NO Factor of Safety Included 0.8 ...... ....... .....� q Interface CoeRiaentofst,tickcton ash ar so-esz 0s _ Fr=Interface rrlctbn Shea Force 1 F F D.5 0J mishear stress -0 as F Normal F rce W ght fSand Wt .a = r/ N- �ShearStress 06 (N g c[s TurfM t We gh[I 0.6 —Normal Loa", y.. ----- - - - - I I I I I I I I 0n -----L.._.._.._..._J L----J.----- _.._i_.._ 1.._..._.._.._ L.._.._.. p,=0.93 E y .. _../4 1.5 f 6.z I I I I 1 I I I I I I I I I I I 0 I I i 0m 20.00 ao.0o s0.am ao.0o ma.00 tm.00 t00.00 160.00 ffia oo m0.00 Freestream WlM oebIXy,n/s Figure 5—Sand Ballast Minimum Requirement at the Perimeter of Turf Installation APC Barry_EPA_000637 Aerodynamic Evaluations of Closure Turf Materials, GTR1 Project No. 0-6244, Contract No.AGR DTD 5114110 Table I- Perimeter Installation Wind Wind Speed Turf Normal Force Loading Turf Shear Sand Height Due to Speed (ft/s) (mi/hr) (Ib ft2) Stress(Ibr/ft') Shear(in) 0.00 0.00 0 0 0 10.26 6.99 0.011689 0.023784 0.0040651 16.06 10.95 0.027798 0.053106 0.009262 20.31 13.84 0.039396 0.086922 0.0144939 25.40 17.32 0.054936 0.136103 0.0219582 30.70 20.93 0.06927 0.198423 0.0308322 35.26 24.04 0.078777 0.266915 0.0399035 40.42 27.56 0.088429 0.351918 0.0509275 44.97 30.66 0.096783 0.434606 0.0615383 49.97 34.07 0.10646 0.529776 0.0737576 54.57 37.21 0.110561 0.630469 0.0860165 59.36 40.47 0.111817 0.741903 0.099225 64.58 44.03 0,115373 0.865046 0.1140578 69.15 47.15 0.111526 0.975305 0.1265718 73.60 50.18 0,114496 1.076528 0.1387694 78.82 53.74 0.111457 1.204017 0.1533926 83.52 56.94 0.104976 1.320714 0.1663744 88.34 60.23 0.077354 1.458158 0.1794835 93.08 63.46 0.057303 1.588598 0.192597 97.86 66.72 0.058201 1.697814 0.2055063 102.89 70.15 0.024978 1.844449 0.2190825 108.12 73.72 0.007601 1.985703 0.2337562 112.58 76.76 0.002646 2.090641 0.2455251 117.87 80.37 -0.026041 2.237684 0.2596441 122.74 83.69 -0.058742 2.352732 0.2695721 127.36 86.84 -0.089852 2.479185 0.2810115 132.72 90.49 -0.122289 2.627843 0.2949108 137.29 93.61 -0.135769 2.734267 0.305924 142.65 97.26 -0.155489 2.863465 0.3189279 147.40 100.50 -0.208034 2.98848 0.3278602 153.84 104.89 -0.206002 3.134988 0.3452676 158.51 108.08 -0.21588 3.274285 0.3605298 162.63 110.88 -0.256805 3.392572 0.3699406 167.59 114.26 -0.261535 3.496667 0.3816351 173.66 118.41 -0.23928 3.626641 0.3993092 APC Barry_EPA_000638 Aerodynamic Evaluations of Closure Turf Materials, GTRI Project No. 0-6244, Contract No.AGR DTD 5114110 Aerodynamic Driven Requirements of Sand Ballast Thickness for 0.10 - Closure Turf Material - Conditions of Interior of Level Installation --- Sand Weight Density=1101bt/ft3,NO Factor of Safety Included 0.12 P• In[ertare CoefficientofStatc FrRa mm Shear S hear orm -- —t5M1 ar6tre mmu u 0 Ft Interface We g[ ral Wegh t F//FN=O.$ orm 0.08 Nor Ireu,m o93 F Normal Force W htof Sand —{ a.z N: Is I I I I I ooa _- L.._.._.._..._J _..L..._ _._.._.._.. 1 ._- I I I I E E I I I I N:=1.5 it 0 102 ...... ........ . ........... , -0A4 _. _..._..._ _ L.._ _..._.. i i_.. _ _..__ _- _. I I i am 20.00 h.D. WAO a.A. ma,00 ]20A0 t.o. 160.00 Id000 "0.00 hee5trem WIM VebdtV,h/s Figure 6-Minimum Sand Ballast Requirement in the Interior of Turf Installation APC Barry_EPA_000639 Aerodynamic Evaluations of Closure Turf Materials, GTR1 Project No. 0-6244, Contract No.AGR DTD 5114110 Table I-Interior Installation Wind Wind Speed Turf Normal Force Loading Turf Sheer Sand Height Due to Speed (ft/s) (mi/hr) (Ibr/ft') Stress(Ibr/ft') Shear(in) 0.00 0.00 -0.00419 0.000471 0 7.07 4.82 -0.00858 0.002819 -0.000605326 12.02 8.20 -0.00858 0.005658 -0.000272305 13.47 9.18 -0.009201 0.006927 -0.000191194 16.05 10.94 -0.005314 0.005174 2.72117E-05 20.91 14.26 0.003753 0.0034 0.000808245 24.64 16.80 0.006062 0.004099 0.00114213 28.56 19.47 0.009925 0.003388 0.001480147 32.94 22.46 0.011669 0.005393 0.001905592 37.27 25.41 0.011221 0.009767 0.002369798 41.09 28.01 0.013608 0.013502 0.003068321 44.90 30.61 0.015886 0.02088 0.004182285 49.08 33.47 0.011842 0.03072 0.004895374 54.21 36.96 0.006407 0.045273 0.006009561 60.31 41.12 -0.000648 0.064883 0.007540218 66.57 45.39 -0.006394 0.087581 0.009575904 73.32 49.99 -0.019878 0.112271 0.01100111 80.43 54.84 -0.037311 0.146631 0.013129826 86.42 58.92 -0.06477 0.178237 0.013841748 91.90 62.66 -0.083261 0.208285 0.01534924 96.30 65.66 -0.081403 0.236369 0.018846242 101.24 69.02 -0.097454 0.273298 0.021427071 106.76 72.79 -0.129489 0.30751 0.021945482 112.17 76.48 -0.138401 0.341067 0.024909568 117.97 80.43 -0.163997 0.378085 0.026459565 125.89 85.83 -0.193612 0.417441 0.027845377 131.07 89.36 -0.215792 0.445855 0.028758761 137.38 93.67 -0.245542 0.482763 0.029842691 141.88 96.73 -0.289393 0.520185 0.029448623 147.46 100.54 -0.317409 0.555461 0.030530279 153.47 104.64 -0.340708 0.59023 0.032067045 159.99 109.08 -0.369093 0.641021 0.034928388 165.05 112.53 -0.4029 0.677722 0.035545455 170.96 116.56 -0.437374 0.727691 0.037646121 176.00 120.00 -0.469865 0.751682 0.036915842 APC Barry_EPA_000"0 Geosynte& consultants CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 ATTACHMENT4 GW6489/Barry_50%Design ClosumTurt Draft APC Barry_EPA_000641 Comparative Climatic Data IA For the United States Through 2015 }�g 1' 11�p4tiltw`4 yr� ti J i k t� y 'a,4M ,; .� r ' S��, i 0 t+ ON National Oceanic and National Environmental Satellite, National Centers for Environmental NOAAAtmospheric Administration Data and Information Service Inform#jW,,, yjWe, NC WIND - MAXIMUM SPEED (MPH) POR JAN FEB MAR APR MAY JUN ME AUG SEP OCT NOV DEC ANN DR SP DR SP DR SP DR SP DR SP DR SP DR SP DR SP DR SP DR SP DR SP DR SP DR SP BIRMINGHAM,AL 196911-201512 225 66 240 68 270 68 270 71 270 09 340 67 260 72 360 66 70 54 280 49 225 66 190 53 270 09 HUNTSVILLE,AL 197209-201512 315 62 90 57 315 57 260 59 315 69 315 67 40 68 340 69 315 52 10 55 45 94 45 54 45 94 MOBILE,AL 196606-201512 160 52 180 61 225 61 315 61 225 62 315 67 225 64 120 83 90 97 360 59 225 57 220 63 90 97 MONTGOMERY,AL 197108-201512 270 48 225 66 270 66 315 67 260 64 360 60 360 55 90 60 315 64 80 63 225 56 250 55 315 67 ANCHORAGE,AK 195410-201512 45 72 45 74 45 74 170 51 135 48 135 46 140 41 158 54 135 53 135 60 999 90 135 62 999 90 ANNETTE,AK 195210-201512 158 98 135 74 158 74 135 78 158 72 999 70 158 59 158 69 135 03 158 03 158 90 158 92 158 98 BARROW,AK 197605-201512 80 61 225 74 90 74 250 60 220 52 250 43 270 58 270 64 225 66 90 67 70 55 225 67 225 74 BETHEL,AK 197501-201512 180 72 110 62 180 62 190 62 180 53 180 59 160 56 225 61 135 69 180 77 225 70 180 71 180 77 BETTLES,AK 199911-201512 50 40 50 44 50 44 40 30 20 37 260 45 250 43 360 36 250 33 50 40 60 44 70 40 50 48 BIG DELTA,AK 199801-201512 200 68 190 77 200 77 150 71 180 66 190 56 180 56 190 63 180 76 170 63 100 74 180 77 190 77 COLD BAY,AK 195906-201512 135 85 135 92 180 92 170 92 135 79 158 78 158 72 135 81 180 96 225 90 240 85 135 87 180 96 FAIRBANKS,AK 198412-201512 270 47 280 53 225 53 50 59 270 44 90 58 45 63 225 54 270 51 270 40 270 55 260 51 45 63 GULKANA,AK 199911-201512 360 48 160 54 360 54 150 60 170 49 180 52 160 47 160 55 160 64 160 49 10 56 160 64 360 67 HOMER,AK 199801-201511 90 56 360 63 220 63 210 74 30 75 80 44 70 44 360 44 30 49 70 58 250 54 40 69 30 75 JUNEAU,AK 195911-201512 110 66 180 69 110 69 135 61 135 54 135 46 135 47 135 48 130 71 135 71 135 92 100 68 135 92 KING SALMON,AK 194901-201512 999 84 90 94 90 94 158 71 113 77 90 69 90 75 90 66 90 74 90 75 90 83 23 84 90 94 KODIAK,AK 194901-201512 315 99 315 86 248 86 315 84 293 59 315 61 45 52 315 67 315 78 23 83 293 85 290 88 315 99 KOTZEBUE,AK 197211-201512 90 72 210 60 90 60 00 60 45 49 135 46 180 53 180 56 45 54 90 61 110 76 270 71 110 76 MCGRATH,AK 197603-201512 190 61 190 63 135 63 200 52 180 45 315 62 180 46 180 49 180 49 190 46 180 53 170 56 190 63 NOME,AK 195911-201512 90 67 45 66 90 66 315 57 45 53 90 45 135 49 135 56 225 59 180 69 180 69 180 71 180 71 ST. PAUL ISLAND,AN 197401-201512 110 75 270 91 270 91 250 68 225 74 310 53 180 48 260 61 23 64 225 71 225 84 90 79 270 91 TALKEETNA,AK 199604-201512 20 48 160 48 40 48 50 44 50 39 310 41 190 30 170 36 30 48 20 45 30 47 30 46 20 48 VALDEZ,AK 197507-201203 360 94 0 94 45 94 360 63 360 63 0 62 360 41 0 64 225 69 360 79 320 03 40 02 360 94 YAKUTAT,AX 196407-201512 135 01 130 02 135 02 135 67 135 55 135 49 140 44 135 60 135 63 135 74 120 03 135 69 120 03 FLAGSTAFF,AZ 196912-201512 230 61 220 55 200 55 220 63 180 66 230 64 90 53 220 64 230 64 50 60 225 69 30 63 225 69 PHOENIX,AZ 195311-201512 270 60 270 54 270 54 290 59 158 59 45 72 135 86 90 78 260 67 270 61 230 61 270 68 135 86 TUCSON,AZ 196912-201512 225 55 90 48 190 48 225 55 250 61 140 68 135 81 315 76 135 71 260 53 190 53 230 40 135 81 WINSLOW,AZ 197107-201512 210 61 210 68 225 68 180 72 180 74 240 71 160 58 135 66 190 60 190 75 190 62 230 69 190 75 FORT SMITH,AR 197106-201512 210 56 315 57 260 57 45 76 360 71 315 71 90 05 310 67 40 69 300 62 290 66 300 63 90 05 LITTLE ROCK,AR 197004-201512 180 62 240 67 240 67 210 66 225 57 320 07 225 56 230 77 290 51 270 63 270 59 225 60 320 07 BAKERSFIELD,CA 197101-201512 140 49 135 57 150 57 180 48 150 45 135 57 150 36 180 49 135 48 90 48 315 49 135 63 135 63 BISHOP,CA 197501-201512 999 60 230 67 999 67 999 62 999 66 999 60 999 60 999 75 10 59 350 61 999 66 999 68 999 75 BLUE CANYON,CA 197509-201512 180 72 170 67 203 67 220 60 90 49 68 38 113 44 45 40 100 44 190 53 180 66 180 72 180 72 FRESNO,CA 196911-201512 135 55 315 49 225 49 315 48 315 44 310 40 70 33 310 41 315 39 45 51 315 46 180 48 135 55 LONG BEACH,CA 197509-201512 135 49 180 49 999 49 320 48 270 43 360 40 90 32 180 29 315 51 315 49 270 78 230 48 270 78 LOS ANGELES,CA 196301-201512 210 35 60 31 10 31 350 39 360 31 140 24 300 22 220 23 260 28 20 32 330 29 10 44 10 44 REDDING,CA 198609-201512 180 70 180 64 180 64 170 48 180 54 360 60 270 52 180 46 999 44 180 66 170 63 180 85 180 05 SACRAMENTO,CA 196912-201512 140 69 150 53 150 53 340 47 360 51 160 52 320 77 180 40 320 48 320 49 180 56 140 53 320 77 SAN DIEGO,CA 196912-201512 270 64 180 52 180 52 293 43 315 40 270 37 180 30 180 33 20 45 200 39 315 48 170 58 270 64 SAN FRANCISCO,CA 194804-201512 248 78 180 71 180 71 180 61 270 62 250 66 270 52 270 49 180 56 225 64 270 68 68 92 68 92 63 APO Barty_EPA_000643 Geosynte& consultants CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 ATTACHMENT GW6489/Barry_50%Design ClosumTurt Draft APC Barry_EPA_000844 4/1 K12018 Storm Events Database-Search Results I Natural Centers for Environmental Information Storm Events Database Search Results for Baldwin and Mobile Counties,Alabama Event Types:High Wind,Hurricane(Typhoon),Marine High Wind,Marine Strong Wind,Marine Thunderstorm Wind,Strong Wind,Thunderstorm Wind, Tornado Baldwin and Mobile counties contain the following zones: 'Mobile Inland','Baldwin Inland','Mobile Central','Baldwin Central','Mobile Coastal','Baldwin Coastal' 497 events were reported between 01/01/1950 and 04/18/2018(24945 days) Summary Info: Number of County/Zone areas affected: 2 Number of Days with Event: 299 Number of Days with Event and Death: 1 Number of Days with Event and Death or Injury: 23 Number of Days with Event and Property Damage: 247 Number of Days with Event and Crop Damage: 0 Number of Event Types reported: 2 Column Definitions: 'Mag':Magnitude,'Dth':Deaths,'Inj':Injudes,'PrD':Property Damage,'CrU:Crop Damage Wind Magnitude Definitions: Measured Gust:'MG% Estimated Gust:'EG',Measured Sustained:'MS', Estimated Sustained:'ES' Click on Location below to display details. Available Event Types have changed over time.Please refer to the Database Data formore information. Select: Tomatlo F1/EF1 antl stronger • Wintl 30 kis.and stronger Sort By: OaleRme(OMesl) Location CounlvlZone aL 4affi Time Ty Tyn mag D1h IN P12 M Totals: 1 156 26.289M O.00K MOBILE CO. MOBILE CO. AL 04/18/1950 01:30 CST Tornado F3 0 15 25.00K 0.00K BALDWIN CO. BALDWIN CO. AL 04/18/1950 01:45 CST Tornado F2 0 0 2.50K O.00K MOBILE CO. MOBILE CO. AL 04/04/1952 06:20 CST Tornado F1 0 2 25.00K 0.00K MOBILE CO. MOBILE CO. AL 03/18/1953 14:22 CST Tornado F2 0 2 2.50K O.00K MOBILE CO. MOBILE CO. AL 03/31/1957 23:30 CST Tornado F1 0 4 25.00K 0.00K MOBILE CO. MOBILE CO. AL 03/31/1957 23:30 CST Tornado F1 0 0 0.03K O.00K MOBILE CO. MOBILE CO. AL 02/26/1958 21:30 CST Thunderstorm Wind 71 fete. 0 0 O.00K 0.00K MOBILE CO. MOBILE CO. AL 03/26/1959 1445 CST Tornado F1 0 0 2.50K O.00K BALDWINCO. BALDWIN CO. AL 04/20/1959 10:00 CST Thunderstorm Wind 80 Ids. 0 0 O.00K 0.00K MOBILE CO. MOBILE CO. AL 04/20/1959 10:00 CST Thunderstorm Wind 60 Ids. 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 01/29/1960 06.00 CST Tornado F1 0 0 2.50K 0.00K MOBILE CO. MOBILE CO. AL O5105/1960 07:00 CST Tornado F1 0 0 2.50K O.00K MOBILE CO. MOBILE CO. AL 05/07/1960 00.55 CST Tornado F2 0 0 25.00K 0.00K MOBILE CO. I MOBILE CO. AL 05/07/1960 01:37 CST Tornado I F2 0 0 250.00K O.00K BILE CO.MO MOBILE CO. AL 03/17/1961 07:50 CST Thunderstorm Wind 65 Ms. 0 0 O.00K 0.00K MOBILE CO. MOBILE CO. AL 04/03/1961 16:15 CST Thunderstorm Wind 58 Ids. 0 0 0.00K O.00K MOBILE CO. MOBILE CO. AL 09/10/1961 14:55 CST Tornado F1 0 0 2.50K 0.00K BALDWIN CO. BALDWIN CO. AL 03/31/1962 08:00 CST Tornado F2 0 0 250.00K O.00K MOBILE CO. MOBILE CO. IAL 05/16/1962 16:15 CST Thunderstorm Wind 87 fete. 0 0 O.00K 0.00K BALDWIN CO. BALDWIN CO. AL 07/09/1962 16.30 CST Thunderstorm Wind 70 kis. 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 05/07/1963 14:28 CST Thunderstorm Wino 62 fete. 0 0 O.00K 0.00K MOBILE CO. MOBILE CO. AL 10/04/1964 18:30 CST Thunderstorm Wind 75 Ids. 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 10/04/1964 18:30 CST Thunderstorm Wind 55 fete. 0 0 O.00K O.I BALDWIN CO. BALDWIN CO. AL 12124/1964 21:15 CST Tornado F2 0 3 25.00K O.00K APC Barry_EPA_000645 haps://w ..nodo.nma.gov/stonneventMistevents.jsp?eventType=%28Z%29+High+Wintl&eventTypem%2aZ%29+Huromne+%28Typhwn%29&eventType=%28Z%2 4/18/2018 Storm Events Database-Search Results I National Centers for Environmental Information BALDWINCO. BALDWIN CO. AL 11/10/1966 12:10 EST Tornado 'F2 0 0 25.00K O.00K MOBILE CO. MOBILE CO. AL 07/19/1967 17:00 CST Tornado Fl 0 0 0.25K O.00K BALDWINCO. BALDWIN CO. AL 10/30/1967 09:30 CST Tornado F2 0 1 25.00K O.00K MOBILE CO. MOBILE CO. AL 10/30/1967 16.00 CST Tornado F2 0 0 2.50K O.00K BALDWINCO. BALDWIN CO. AL 12/10/1967 04:10 CST Tornado F2 0 0 250.00K O.00K MOBILE CO. MOBILE CO. AL 11/03/1968 17.55 CST Tornado F3 0 14 250.00K O.00K BALDWINCO. BALDWIN CO. AL 11/03/1968 18.15 CST Tornado F3 0 4 250.00K O.00K BALDWINCO. BALDWIN CO. AL 11/03/1968 19.14 CST Tornado F3 0 0 250.00K O.00K MOBILE CO. MOBILE CO. AL 07/27/1969 15:30 CST Tornado Fl 0 0 25.00K O.00K BALDWINCO. BALDWIN CO. AL 08/22/1969 16.15 CST Tornado Fl 0 0 0.03K O.00K MOBILE CO. MOBILE CO. AL 02/01/1970 15:39 CST Thunderstorm Wind 51 kls. 0 0 O.00K O.00K BALDWINCO. BALDWIN CO. AL O6102/1970 07:30 CST Tornado F2 0 0 25.00K O.00K MOBILE CO. MOBILE CO. AL 02/12/1971 08:55 CST Tornado Fl 0 0 25.00K O.00K BALDWINCO. BALDWIN CO. AL 09/16/1971 15:25 CST Tornado Fl 0 0 250.00K O.00K BALDWINCO. BALDWIN CO. AL 09/16/1971 16:22 CST Tornado F2 0 0 250.00K O.00K MOBILE CO. MOBILE CO. AL 03/18/1972 15:00 CST Tornado Fl 0 0 25.00K O.00K MOBILE CO. MOBILE CO. AL O6/25/1972 14:22 CST Thunderstorm Wind 59 kls. 0 0 O.00K O.00K BALDWINCO. BALDWIN CO. AL 11/13/1972 14:40 CST Tornado F2 0 0 25.00K O.00K MOBILE CO. MOBILE CO. AL 01/21/1973 13:00 CST Thunderstorm Wind 51 kts. 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 12/26/1973 03:30 CST Tornado F2 0 1 25.00K O.00K BALDWIN CO. BALDWIN CO. AL 12/31/1973 10:50 CST Tornado Fl 0 0 2.50K O.00K MOBILE CO. MOBILE CO. AL 04/02/1974 03:28 CST Thunderstorm Wind 50 Ins. 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 01/10/1975 14:45 CST Tornado Fl 0 0 25.00K O.00K BALDWIN CO. BALDWIN CO. AL 01/10/1975 16:15 CST Tornado Fl 0 0 2.50K O.00K BALDWIN CO. BALDWIN CO. AL 02/16/1975 10:15 CST Tornado Fl 0 0 25.00K O.00K BALDWIN CO. BALDWIN CO. AL 02/16/1975 10:30 CST Tornado F2 0 0 250.00K O.00K BALDWIN CO. BALDWIN CO. AL 03/13/1975 17.55 CST Tornado Fl 0 0 25.00K O.00K MOBILE CO. MOBILE CO. AL 04/30/1975 12:18 CST Thunderstorm Wind 53 kts. 0 0 (LOOK O.00K MOBILE CO. MOBILE CO. AL 11/06/1975 12.30 CST Tornado Fl 0 1 25.00K O.00K MOBILE CO. MOBILE CO. AL O6116/1977 15:45 CST Tornado F2 0 0 2.50K O.00K BALDWIN CO. BALDWIN CO. AL 10/25/1977 07:00 CST Tornado Fl 0 0 25.00K O.00K MOBILE CO. MOBILE CO. AL 11/30/1977 02:40 CST Tornado Fl 0 0 250.00K O.00K MOBILE CO. MOBILE CO. AL 05/26/1978 16:30 CST Thunderstorm Wind 52 kls. 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 07/22/1978 11:28 CST Tornado Fl 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 07/24/1978 14:25 CST Thunderstorm Wind 65 kls. 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 08/19/1978 16:00 CST Thunderstorm Wind 61 Ins. 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 08/19/1978 1600 CST Thunderstorm Wind 65 kls. 0 0 O.00K 0.00K BALDWIN CO. BALDWIN CO. AL O6130/1979 1855 CST Tornado Fi 0 0 2.50K O.00K BALDWIN CO. BALDWIN CO. AL 03/20/1980 23:00 CST Thunderstorm Wind 68 k1s. 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 04/13/1980 0958 CST Tornado Fl 0 0 25.00K O.00K MOBILE CO. MOBILE CO. AL 04/13/1980 10:08 CST Tornado Fl 0 0 0.25K O.00K MOBILE CO. MOBILE CO. AL 04/13/1980 10:15 CST Tornado Fl 0 0 2.50K O.00K BALDWINCO. BALDWINCO. AL 04/13/1980 12:00 CST Tornado F2 0 0 25.00K O.00K MOBILE CO. MOBILE CO. AL 04/13/1980 12:08 CST Tornado Fl 0 0 25.00K O.00K BALDWINCO. BALDWIN CO. AL 05/17/1980 02.45 CST Tornado Fl 0 0 25.00K O.00K BALDWIN CO. BALDWIN CO. AL 05/17/1980 07:45 CST Tornado Fl 0 0 25.00K O.00K MOBILE CO. MOBILE CO. AL O5119/1980 22.10 CST Tornado F2 0 0 25.00K O.00K BALDWIN CO. BALDWIN CO. AL 02/10/1981 08:40 CST Tornado F2 0 62 2.500M O.00K BALDWIN CO. BALDWIN CO. AL 03/22/1981 17.30 CST Tornado Fl 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 08/18/1981 14:30 CST Thunderstorm Wind 60 kts. 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 04/25/1982 05:20 CST Tornado F3 0 0 250.00K O.00K MOBILE CO. MOBILE CO. AL 04/25/1982 05:25 CST Tornado Fi 0 0 2.50K O.00K BALDWINCO. BALDWIN CO. AL 04/25/1982 05:30 CST Tornado Fl 0 0 25.00K O.00K BALDWIN CO. BALDWIN CO. AL 05/07/1982 12:38 CST Tornado Fi 0 0 2.50K O.00K MOBILE CO. MOBILE CO. AL O6/24/1982 15.35 CST Thunderstorm Wind 50 kls. 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 02I01/1983 05:24 CST Thunderslonn Wind 50 kLs. 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 03/26/1983 16.50 CST Tornado F1 0 0 250.00K O.00K BALDWIN CO. BALDWIN CO. AL 04/14/1983 06:12 CST Tornado FAPC B9,ry, PA 1)M6 O.00K hops:l/ w ..nodo.nma.gov/stonnevents/listevents.jsp?eventType=%28Z%29+High+Wintl&eventTypem%2aZ/29+Hurdcane+%28Typhwn%29&eventType=%2aZ%2 4/18/2018 Storm Events Database-Search Results I National Centers for Environmental Information MOBILE CO. MOBILE CO. AL 05/03/1983 09:35 CST Thunderstorm Wind 52 kls. 0 0 O.00K O.00K BALDWINCO. BALDWIN CO. AL 07/20/1983 16.45 CST Tornado Fi 0 0 2.50K O.00K MOBILE CO. MOBILE CO. AL 08/05/1983 13:23 CST Thunderstorm Wind 50 kls. 0 0 O.00K O.00K BALDWINCO. BALDWIN CO. AL 08/06/1983 13.40 CST Thunderstorm Wind 60 Me. 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 08/29/1983 15:27 CST Thunderstorm Wind 50 kts. 0 0 O.00K O.00K BALDWINCO. BALDWIN CO. AL 11/15/1983 07.05 CST Tornado IF1 0 0 25.00K O.00K MOBILE CO. MOBILE CO. AL 11/20/1983 00:10 CST Thunderstorm Wind 50 kts. 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 12/11/1983 03.15 CST Tornado F1 0 0 25.00K O.00K BALDWIN CO. BALDWIN CO. AL 02126/1984 23:45 CST Thunderstorm Wind 152 kts. 0 0 O.00K O.00K BALDWIN CO. BALDWIN CO. AL 02/11/1985 04.50 CST Tornado Fl 0 0 25.00K O.00K MOBILE CO. MOBILE CO. AL 05/21/1985 14:53 CST Thunderstorm Wind 54 kts. 0 0 O.00K O.00K BALDWIN CO. BALDWIN CO. AL 05/21/1985 15.30 CST Thunderstorm Wind 52 kts. 0 0 O.00K O.00K BALDWIN CO. BALDWIN CO. AL 05/21/1985 15:30 CST Thunderstorm Wind 52 kts. 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 05/22/1985 10.00 CST Thunderstorm Wind 52 Ids. 0 0 O.00K O.00K BALDWINCO. BALDWIN CO. AL 06126/198518.02 CST Thunderstorm Wind 70 kts. 0 0 O.00K O.00K BALDWINCO. BALDWIN CO. AL 10/29/1985 09:50 CST Tornado Fl 0 0 25.00K O.00K IN BALDWCO. BALDWIN CO. IAL 09/08/1987 18.00 CST Thunderstorm Wind 70 k1s. 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 06/07/1989 13.00 CST Thunderstorm Wind 78 Ids. 0 0 O.00K O.00K BALDWINCO. BALDWIN CO. AL 06/08/1989 08:51 CST Tornado Fi 0 10 2.500M O.00K MOBILE CO. MOBILE CO. AL 06/08/1989 12.40 CST Thunderstorm Wind 52 Ids. 0 0 O.00K O.00K BALDWINCO. BALDWIN CO. AL 06/15/1989 03:50 CST Thunderstorm Wind 55 k1s. 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 07/02/1989 11.23 CST Tornado F2 0 0 250.00K O.00K MOBILE CO. MOBILE CO. AL 07/12/1989 14:25 CST Thunderstorm Wind 58 kls. 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 09/04/1990 16.30 CST Thunderstorm Wind 70 Ids. 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 07/02/1991 15:25 CST Thunderstorm Wind 54 kls. 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 08/09/1992 16.07 PST Thunderstorm Wind 56 Ids. 0 0 O.00K O.00K MOBILE CO. MOBILE CO. AL 11/04/1992 07:00 PST Thunderstorm Wind 51 kts. 0 0 O.00K O.00K BALDWIN CO. BALDWIN CO. AL 11/24/1992 05:00 CST Tornado Fi 0 1 25.00K O.00K EQ W. BALDWIN CO. AL O6/16/1994 15.00 CST Thunderstorm Wind 50 kts. 0 0 500.00K O.00K Stockton BALDWIN CO. AL 11/06/1994 04:15 CST Thunderstorm Wind 50 Ins. 0 0 O.00K O.00K CREOLA MOBILE CO. AL 01/26/1996 15.25 CST Thunderstorm Wind 88 kts. 0 0 5.00K O.00K LATHAM BALDWIN CO. AL 01/26/1996 16:15 CST Thunderstorm Wind 50 Ins. 0 0 2.00K O.00K GULF CREST MOBILE CO. AL 01/26/1996 17.27 CST Tornado Fl 1 3 100.00K O.00K MT VERNON MOBILE CO. AL 01/26/1996 18:00 CST Thunderstorm Wind 50 Ins. 0 0 2.00K O.00K TENS AW BALDWIN CO. AL 01/26/1996 18.10 CST Thunderstorm Wind 50 kts. 0 0 2.00K O.00K MOBILE MOBILE CO. AL 02119/1996 18:10 CST Thunderstorm Wind 60 Ids. 0 0 25.00K O.00K BAY MINETTE BALDWIN CO. AL 03/07/1996 04.15 CST Thunderstorm Wind 45 kts. 0 1 1.50K O.00K STOCKTON BALDWIN CO. AL 05/24/1996 13:29 CST Thunderstorm Wind 55 Ids. 0 0 0.50K O.00K GEORGETOWN MOBILE CO. AL 07/09/1996 16:15 CST Thunderstorm Wind 55 kts. 0 0 2.00K 0.00K LLOXLEy BALDWIN CO. AL 08/12/1996 13:00 CST Thunderstorm Wind 40 Ins. 0 0 0.50K O.00K Si MMERDAI F BALDWIN CO. AL 08/24/1996 1455 CST Thunderstorm Wind 45 kts. 0 0 90.00K O.00K BAYMINETTE BALDWIN CO. AL 08/25/1996 1350 CST Thunderstorm Wind 50 Ins. 0 0 2.50K O.00K CITRONELLE MOBILE CO. AL 09/08/1996 17:00 CST Thunderstorm Wind 50 kts. 0 0 1.50K O.00K SUMMERDALE BALDWIN CO. AL 09/21/1996 0930 CST Thunderstorm Wind 50 Ins. 0 0 2.50K O.00K MOBILE BATES FLD MOBILE CO. AL 0912111916 10:00 CST Thunderstorm Wind 50 kts. 0 0 2.50K O.00K ORANGE BEACH BALDWIN CO. AL 11/05/1996 18:00 CST Thunderstorm Wind 40 Ins. 0 0 0.50K O.00K MAGNOLIA SPGS BALDWIN CO. AL 01/15/1997 20:55 CST Thunderstorm Wind 52 kts. 0 0 0.50K O.00K CITRONELLE MOBILE CO. AL 01/24/1997 06.05 CST Thunderstorm Wind 50 Ins. 0 0 1.50K O.00K BLACKSHER BALDWIN CO. AL 01/24/1997 06.40 CST Thunderstorm Wind 50 kts. 0 0 1.50K O.00K TILLMANS CORNER MOBILE CO. AL 01/24/1997 08:40 CST Thunderstorm Wind 50 Ids. 0 0 10.001K O.00K MALBIS BALDWIN CO. AL 01/24/1997 09:00 CST Thunderstorm Wind 55 kts. 0 1 15.00K O.00K CITRONELLE MOBILE CO. AL 01/28/1997 05:00 CST Thunderstorm Wind 50 Ids. 0 0 1.50K O.00K THEODORE MOBILE CO. AL 02121/1997 11.00 CST Thunderstorm Wind 60 kts. 0 0 5.00K O.00K CITRONELLE MOBILE CO. AL 04/05/1997 13:00 CST Thunderstorm Wind 50 Ids. 0 0 1.50K O.00K BAYOU IA BATRE MOBILE CO. AL 04105/1997 13.30 CST Thunderstorm Wind 50 Ids, 0 0 2.00K O.00K FT MORGAN BALDWIN CO. AL 04/11/1997 14:50 CST Thunderstorm Wind 50 Ids. 0 0 O.00K O.00K QREOLA MOBILE CO. IAL 05/19/1997 14:10 CST Thunderstorm Wind 45 kts. 0 0 5.00K O.00K APC Barry_EPA_000647 hops:// w ..nodo.nma.gov/sW neventsllistevents.jsp?eventType=%28Z%29+High+Wintl&eventTypem%2aZ%29+Hurricane+%28Typhmn%29&eventType=%2aZ%2 4/182018 Storm Events Database-Search Results I National Centers for Environmental Information MOBILE BATES FLD MOBILE CO. AL 05/28/1997 20.40 CST Thunderstorm Wind 50 kts. 0 0 1.50K O.00K STOCKTON BALDWIN CO. AL O6120/1997 14.15 CST Thunderstorm Wind 50 Ms. 0 0 1.50K O.00K Q=NEI I E MOBILE CO. AL O6/20/1997 15:40 CST Thunderstorm Wind 50 kts. 0 0 1.00K O.00K COTTAGE HILL MOBILE CO. AL 07/05/1997 12.00 CST Thunderstorm Wind 50 Ms. 0 0 3.00K O.00K EAIRHDPE BALDWIN CO. AL 07/11/1997 17:30 CST Thunderstorm Wind 50 kts. 0 0 3.00K O.00K ALABAMA PORT MOBILE CO. AL 07/18/1997 16:10 CST Thunderstorm Wind 55 kts. 0 0 3.00K O.00K LDRI FY BALDWIN CO. AL 08/20/1997 16:45 CST Thunderstorm Wind 50 kts. 0 0 5.00K O.00K THEODORE MOBILE CO. AL 08/20/1997 19:05 CST Thunderstorm Wind 50 Ina. 0 0 5.00K O.00K GEORGETOWN MOBILE CO. AL 10/25/1997 17:20 CST Thunderstorm Wind 60 kls. 0 0 3.00K O.00K AMla MOBILE CO. AL 10/25/1997 17:50 CST Thunderstorm Wind 60 Ids. 0 0 2.50K O.00K $6B6L6UQ MOBILE CO. AL 11/21/1997 19:40 CST Tornado F3 0 0 2.000M O.00K ES MMES MOBILE CO. AL 12/24/1997 04:45 CST Thunderstorm Wind 50 Ins. 0 0 1.50K O.00K MOBILE MOBILE CO. AL 01/07/1998 05:30 CST Thunderstorm Wind 50 kls. 0 0 3.00K O.00K MOBILE BATES FLD MOBILE CO. AL 01/07/1998 06:30 CST Thunderstorm Wind 50 Ina. 0 0 3.50K O.00K WHITEHOUSEFORKS BALDWIN CO. AL 01/07/1998 07:30 CST Thunderstorm Wind 70 k1s. 0 0 25.00K O.00K GULFSHRS BALDWIN CO. AL 01/07/1998 07.30 CST Thunderstorm Wind 50 Ina. 0 0 25.00K O.00K aEMl QJ.E BALDWIN CO. AL 01/07/1998 08:20 CST Thunderstorm Wind 50 k1s. 0 0 3.00K O.00K SEMMES MOBILE CO. AL 01/22/1998 07:15 CST Thunderstorm Wind 50 Ins. 0 0 3.00K O.00K ELSANOR BALDWIN CO. AL 01/22/1998 07:57 CST Thunderstorm Wind 50 kts. 0 0 3.00K O.00K MAGNOLIA SPGS BALDWIN CO. AL 01122/199810:45 CST Thunderstorm Wind 50 Ins. 0 0 3.00K O.00K SPANISH FT BALDWIN CO. AL 02/11/1998 01:55 CST Thunderstorm Wind 55 kts. 0 0 12.00K O.00K DAUPHIN IS MOBILE CO. AL 03/07/1998 09:00 CST Thunderstorm Wind 50 Ins. 0 0 2.00K O.00K COUNTYWIDE MOBILE CO. AL O6/05/1998 22:50 CST Thunderstorm Wind 60 kts. 0 0 200.00K O.00K COUNTYWIDE BALDWIN CO. AL O6105/1998 23:25 CST Thunderstorm Wind 60 Ins. 0 0 100.00K O.00K SEMINOI E BALDWIN CO. AL 07/05/1998 16.00 CST Thunderstorm Wind 50 kts. 0 0 3.00K O.00K PERDIDO BALDWIN CO. AL 07/26/1998 19:12 CST Thunderstorm Wind 50 Ins. 0 0 5.00K O.00K ORANGE BEACH BALDWIN CO. AL 09/28/1998 09.50 CST Thunderstorm Wind 50 kts. 0 0 20.00K O.00K WILMER MOBILE CO. AL 01/02/1999 10:00 CST Thunderstorm Wind 50 Ins. 0 0 5.00K O.00K SARALAND MOBILE CO. AL 01/02/1999 10.20 CST Thunderstorm Wind 55 kts. 0 0 10.00K O.00K BAY MINETTE BALDWIN CO. AL 01102/199910:35 CST Thunderstorm Wind 55 Ins. 0 0 3.00K O.00K LILLIAN BALDWIN CO. AL 01102/199912.00 CST Thunderstorm Wind 55 k1s. 0 0 5.00K O.00K MOBILE MOBILE CO. AL 01/22/1999 11:30 CST Thunderstorm Wind 50 Ins. 0 0 10.00K O.00K SPRING HILL MOBILE CO. AL 03/03/1999 00.10 CST Thunderstorm Wind 70 kls. 0 0 50.00K O.00K FAIRHOPE BALDWIN CO. AL 03/03/1999 00:40 CST Thunderstorm Wind 58 Ins. 0 0 30.00K O.00K ELSANOR BALDWIN CO. AL 03/09/1999 05:10 CST Thunderstorm Wind 70 k1s. 0 1 70.00K O.00K GULFSHRS BALDWIN CO. IAL 03/09/1999 05:55 CST Thunderstorm Wind 60 Ins. 0 0 50.00K O.00K MOBILE MOBILE CO. AL 03/13/1999 19:05 CST Thunderstorm Wind 70 kls. 0 0 50.00K 0.00K STOCKTON BALDWIN CO. AL 03/13/1999 1920 CST Thunderstorm Wind 58 Ins. 0 0 10.00K O.00K SEMINOLE BALDWIN CO. AL 03/13/1999 21:10 CST Thunderstorm Wind 50 k1s. 0 0 3.00K O.00K BAYOU LA BATRE MOBILE CO. AL 05/28/1999 13:10 CST Thunderstorm Wind 55 Ins. 0 0 TOOK O.00K CITRONELLE MOBILE CO. AL O6104/1999 19:20 CST Thunderstorm Wind 50 Ids. 0 0 5.00K O.00K MOBILE MOBILE CO. AL O6108/1999 15:05 CST Thunderstorm Wind 50 Ins. 0 0 S.00K O.00K BEMME$ MOBILE CO. AL 07/30/1999 14:50 CST Thunderstorm Wind 50 Ids. 0 0 1.00K O.00K LITTLE RIVER BALDWIN CO. AL 07/30/1999 14:55 CST Thunderstorm Wind 50 Ins. T 0 4.00K O.00K EOLEY BALDWIN CO. AL 08/14/1999 I14:20 CST Thunderstorm Wind 50 Ids. 0 0 3.00K O.00K SEMMES MOBILE CO. AL O8119/1999 14:35 CST Thunderstorm Wind 50 Ins. 0 0 1.00K O.00K BARALMNQ MOBILE CO. AL 10/09/1999 0415 CST Tornado F1 0 0 100.00K O.00K BIG CREEK LAKE MOBILE CO. AL 10/09/1999 0445 CST Thunderstorm Wind 60 Ins. 0 0 10.00K O.00K TENSAW BALDWIN CO. AL 01/10/2000 01:00 CST Thunderstorm Wind 50 kts.E 0 0 5.00K O.00K CITRONELLE MOBILE CO. AL 03/03/2000 19:10 CST Thunderstorm Wind 50 Ins.E 0 0 S.00K O.00K MT VERNON MOBILE CO. AL 03/03/2000 19.30 CST Thunderstorm Wind 65 kts.E 0 0 15.00K O.00K TENSAW BALDWIN CO. AL 03/03/2000 19:40 CST Thunderstorm Wind 50 Ins.E 0 0 3.00K O.00K STAPLETON BALDWIN CO. AL 03/11/2000 10:40 CST Thunderstorm Wind 50 kls.E 0 0 3.00K O.00K MOBILE MOBILE CO. AL 04/24/2000 03:00 CST Tornado Fi 0 0 200.00K O.00K SEMMES MOBILE CO. AL 04/26/2000 13:40 CST Thunderstorm Wind 50 kts.E 0 0 3.00K O.00K TENSAW BALDWIN CO. AL O6/242000 14:20 CST Thunderstorm Wind 55 Ins.E 0 0 S.00K O.00K CITRONELLE MOBILE CO. AL 07/16/2000 14:50 CST Thunderstorm Wind 55 kts.E 0 0 5.00K O.00K MOBILE MOBILE CO. IAL 107/162000 15:55 CST Thunderstorm Wind 75 ins.&PC B9,ry¢PA%896 O.00K hops:l/ w ..nodo.nma.gov/stomneventMistevents.jsp?eventType=%28Z%29+High+Wintl&eventType=%28Z/29+Hurricane+%28Typhwn%29&eventType=%2aZ%2 4/18/2018 Storm Events Database-Search Results I National Centers for Environmental Information ROSINTON BALDWIN CO. AL 07/21/2000 : I CST Thuntlersorm Wind 60 kls.E 0 0 TOOK O.00K BAYMINETTE BALDWIN CO. AL 07/21/2000 13:45 CST Thunderstorm Wind 70 Ms.E 0 0 BOOK O.00K IRVINGTON MOBILE CO. AL 07/21/2000 14.00 CST Thuntlersorm Wind 70 kls.E 0 0 15.00K O.00K SILVERHILL BALDWIN CO. AL 07/21/2000 14.55 CST Thunderstorm Wind 70 Ms.E 0 0 10.00K O.00K GULF CREST MOBILE CO. AL 07/22/2000 12:42 CST Thuntlersorm Wind 55 kts.E 0 0 5.00K O.00K TILLMANS CORNER MOBILE CO. AL 07/22/2000 13.55 CST Thunderstorm Wind 55 Ms.E 0 0 6.00K O.00K THEOD -RE MOBILE CO. AL 07/22/2000 14:30 CST Thuntlersorm Wind 55 kts.E 0 0 5.00K O.00K BAYOU LA BATRE MOBILE CO. AL 07/22/2000 15.00 CST Thunderstorm Wind 55 Ms.E 0 0 5.00K O.00K MOBILE MOBILE CO. AL 08/09/2000 16:00 CST Thunderstorm Wind 55 kts.E 0 0 10.00K O.00K ELSANOR BALDWIN CO. AL 08/10/2000 14:25 CST Thunderstorm Wind 55 Ms.E 0 0 5.00K O.00K QUEQNFl i F MOBILE CO. AL 08/10/2000 14:30 CST Thuntlersorm Wind 55 kts.E 0 0 5.00K O.00K MOBILE MOBILE CO. AL 08/20/2000 14:15 CST Thunderstorm Wind 55 Ms.E 0 0 10.00K O.00K EIGHT MILE MOBILE CO. AL 08/27/2000 15:15 CST Thuntlersorm Wind 155 kts.E 0 0 15.00K O.00K STOCKTON BALDWIN CO. AL 08/27/2000 15:30 CST Thunderstorm Wind 70 kts.E 0 0 50.00K O.00K CHUNCHULA MOBILE CO. AL 09/02/2000 18:45 CST Thuntlersorm Wind 60 kts.E 0 0 5.00K O.00K DAPHNE BALDWIN CO. AL 09/02/2000 17:25 CST Thunderstorm Wind 55 kts.E 0 0 5.00K O.00K LQXLEY BALDWIN CO. AL 09/05/2000 15:05 CST Thuntlersorm Wind 50 kls.E 0 0 5.00K O.00K IRVINGTON MOBILE CO. AL 11/06/2000 21.30 CST Tornado F2 0 2 100.00K O.00K (MQS)MOBILE BATES FL MOBILE CO. AL 11/06/2000 22:10 CST Thunderstorm Wind 55 kts.E 0 0 B.00K O.00K FOLEY BALDWIN CO. AL 11/08/2000 11:05 CST Tornado Fl 0 0 150.00K O.00K FAIRHOPE BALDWIN CO. AL 11/08/2000 11.50 CST Tornado Fl 0 0 200.00K O.00K MOBILE MOBILE CO. AL 01/19/2001 07:30 CST Thunderstorm Wind 55 kts.E 0 0 2.00K O.00K (MQ@)MOBILE BATES FL MOBILE CO. AL 03/03/2001 11.30 CST Thunderstorm Wind 50 kts.E 0 0 5.00K O.00K MT VERNON MOBILE CO. AL 03/12/2001 11.25 CST Thunderstorm Wind 55 kts.E 0 0 15.00K O.00K STOCKTON BALDWIN CO. AL 03/12/2001 11.55 CST Thunderstorm Wind 65 kts.E 0 0 10.00K O.00K IRVINGTON MOBILE CO. AL 03/12/2001 12:10 CST Thunderstorm Wind 50 kts.E 0 0 5.00K O.00K MQ131LE MOBILE CO. AL 03/12/2001 12.25 CST Thunderstorm Wind 60 kts.E 0 0 3.00K O.00K GRAND BAY MOBILE CO. AL O611112001 06:20 CST Thunderstorm Wind 55 kts.E 0 0 8.00K O.00K SEMMES MOBILE CO. AL O6/1112001 06.35 CST Thunderstorm Wind 65 kts.E 0 0 100.00K O.00K GEORGETOWN MOBILE CO. AL O6/11/2001 06:45 CST Thunderstorm Wind 65 kta.E 0 0 70.00K O.00K MO STCKEON BALDIWIN CO. AL 108/19/2001 12:45 CST Thunderstorm Wind 50 kta.E 0 0 8.00K O.00K FAIRHOPE BALDWIN CO. AL 10/13/2001 06:30 CST Tornado Fl 0 0 50.00K O.00K FOLEV BALDWIN CO. AL 10/13/2001 12:25 CST Tornado F3 0 0 250.00K O.00K ROBERTSDALE BALDWIN CO. AL 10/13/2001 12:44 CST Tornado F2 0 0 200.00K O.00K WILMER MOBILE CO. AL 10/13/2001 18:15 CST Thunderstorm Wind 59 kts.M 0 0 100.00K O.00K MOBILE MOBILE CO. AL 10/13/2001 18:35 CST Thunderstorm Wind 64 kts.M 0 0 60.00K O.00K FAIRHOPE BALDWIN CO. AL 10/13/2001 19:00 CST Thunderstorm Wind 50 kts.E 0 0 1O.00K O.00K Si MMERDAI F BALDWIN CO. AL 10/13/2001 19:10 CST Thunderstorm Wind 60 kts.E 0 0 40.00K O.00K GULF SHRS BALDWIN CO. AL 10/13/2001 19:22 CST Thunderstorm Wind 60 kta.E 0 0 50.00K O.00K BUCKS MOBILE CO. AL 12/14/2001 00:45 CST Thunderstorm Wind 60 kts.E 0 0 25.00K O.00K DAWES MOBILE CO. AL 03/31/2002 1120 CST Thunderstorm Wind 55 kta.E 0 0 25.00K O.00K FAIRHOPE BALDWIN CO. AL 04/08/2002 19:25 CST Thuntlersorm Wind 55 kls.E 0 0 15.00K O.00K SUMMERDALE BALDWIN CO. AL 07/01/2002 1630 CST Thunderstorm Wind 55 kts.E 0 0 S.00K O.00K THEODORE MOBILE CO. AL 07/13/2002 16:00 1 CST Thunderstorm Wind 50 kts.E 0 0 B.00K O.00K CITRONELLE MOBILE CO. AL O8102/2002 14:00 CST Thunderstorm Wind 50 kts.E 0 0 1O.00K O.00K MOBILE MOBILE CO. AL 08/19/2002 15.15 CST Thunderstorm Wind 55 kts.E 0 0 5.00K O.00K CITRONELLE MOBILE CO. AL O8125/2002 1155 CST Thunderstorm Wind I50 kts.E 0 0 8.00K O.00K JOSEPHINE BALDWIN CO. AL 08/25/2002 14:50 CST Thunderstorm Wind 60 kts.E 0 0 35.00K O.00K THEODORE MOBILE CO. AL 10/29/2002 09:15 CST Thunderstorm Wind 50 kts.E 0 0 25.00K O.00K THEODORE MOBILE CO. AL 11/05/2002 12.55 CST Thunderstorm Wind 55 kts.E 0 0 1.00K O.00K TILLMANS CORNER MOBILE CO. AL 11/05/2002 12:55 CST Thunderstorm Wind 55 kts.E 0 0 2.00K O.00K DAEENE BALDWIN CO. AL 11/05/2002 13.30 CST Thunderstorm Wind 60 kts.E 0 0 15.00K O.00K GEORGETOWN MOBILE CO. AL 11/15/2002 16:45 CST Thunderstorm Wind 50 kts.E 0 0 S.00K O.00K STOCKTON BALDWIN CO. AL 12/19/2002 16:30 CST Thunderstorm Wind 50 kts.E 0 0 S.00K O.00K DAPHNE BALDWIN CO. AL 12/19/2002 18:00 CST Thunderstorm Wind 50 kts.E 0 0 BOOK O.00K (MQ@)MOBILE BATES FL MOBILE CO. AL 112J24/2002 03:43 CST Thunderstorm Wind 55 kts.M 0 0 O.00K O.00K APC Barry_EP _OOOfi49 hops://w ..nodo.nma.gov/sW neventsllistevents.jsp?eventType=%28Z%29+High+Wintl&eventTypem%2aZ%29+Hurricane+%28Typhmn%29&eventType=%2aZ%2 4/1812018 Storm Events Database-Search Results I National Centers for Environmental Information B_L.ELM4 MOBILE CO. AL 12124/2002 03:45 CST Thunderstorm Wind 50 kts.E 0 0 5.00K O.00K SUMMERDALE BALDWIN CO. AL 12/24/2002 04:30 CST Thunderstorm Wind 50 kts.E 0 0 10.00K O.00K (M45)MOBILE BATES FL MOBILE CO. AL 12131/2002 05:50 CST Thunderstorm Wind 52 kts.E 0 0 O.00K O.00K (MQ%MOBILE BATES FL MOBILE CO. AL 12/31/2002 06:37 CST Thunderstorm Wind 53 Ids.M 0 0 O.00K O.00K MT VERNON MOBILE CO. AL 12131/2002 07:00 CST Thunderstorm Wind 55 kts.E 0 0 20.00K O.00K GULF CREST MOBILE CO. AL 121312002 0745 CST Thunderstorm Wind 50 Ins.E 0 0 5.00K O.00K GULF SHRS BALDWIN CO. AL 12131/2002 08:40 CST Thunderstorm Wind 55 kts.E 0 0 10.00K O.00K FAIRHOPE BALDWIN CO. AL 02/212003 14:48 CST Thunderstorm Wind 53 Ina.EG 0 0 5.00K O.00K ROBERTSDALE BALDWIN CO. I AL 03/12/2003 16:00 CST Thunderstorm Wind 55 kts.EG 0 0 5.00K O.00K SUMMERDALE BALDWIN CO. AL 03/132003 02:40 CST Thunderstorm Wind 50 Ina.EG 0 0 3.00K O.00K MAGNOLIA SPGS BALDWIN CO. AL 03/13/2003 17:29 CST Thunderstorm Wind 50 kts.EG 0 0 5.00K O.00K LATHAM BALDWIN CO. AL 05/022003 16:00 CST Thunderstorm Wind 50 Ins.EG 0 0 5.00K O.00K COTTAGE HILL MOBILE CO. AL 06/03/2003 0000 CST Thunderstorm Wind 50 kts.EG 0 0 20.00K O.00K COUNTYWIDE MOBILE CO. AL O6130/2003 21:45 CST Thunderstorm Wind 50 Ina.EG 0 0 TOOK O.00K COTTAGE HILL MOBILE CO. AL O6130/2003 22:20 CST Thunderstorm Wind 50 kts.EG 0 0 5.00K O.00K STOCKTON BALDWIN CO. AL 07/012003 01:35 CST Thunderstorm Wind 50 Ina.EG 0 0 5.00K O.00K Si iMMERnAi E BALDWIN CO. AL 08/16/2003 1405 CST Thunderstorm Wind 50 kts.EG 0 0 TOOK O.00K BELFOREST BALDWIN CO. AL 11/18/2003 14:20 CST Thunderstorm Wind 50 Ins.EG 0 0 10.00K O.00K 8AV MINETTE BALDWIN CO. AL O6/02/2004 09:30 CST Thunderstorm Wind 50 kts.EG 0 0 10.00K O.00K SILVERHILL BALDWIN CO. AL 06/03/2004 06:30 CST Thunderstorm Wind 55 Ins.EG 0 0 5.00K O.00K (MDB)MOBILE BATES FL MOBILE CO. AL O6118/2004 18:10 CST Thunderstorm Wind 50 kts.EG 0 0 5.00K O.00K SARALAND MOBILE CO. AL 06/222004 09:40 CST Thunderstorm Wind 50 Ins.EG 0 0 5.00K O.00K SPRING HILL MOBILE CO. AL 07/13/2004 19.15 CST Thunderstorm Wind 50 kts.EG 0 0 15.00K O.00K SPANISH FT BALDWIN CO. AL 07/252004 13:40 CST Thunderstorm Wind 55 Ins.EG 0 0 5.00K O.00K MOBILE MOBILE CO. AL 07/25/2004 13.40 CST Thunderstorm Wind 55 kts.EG 0 0 5.00K O.00K SUMMERDALE BALDWIN CO. AL 11/27/2004 11.35 CST Tornado F2 0 4 400.00K O.00K SEMINO E BALDWIN CO. AL 11/27/2004 11.55 CST Tornado Fl 0 0 200.00K O.00K ORANGE BEACH BALDWIN CO. AL 01/292005 09:25 CST Thunderstorm Wind 50 Ins.EG 0 0 15.00K O.00K LOXLEy BALDWIN CO. AL 03/27/2005 02.35 CST Thunderstorm Wind 50 kts.EG 0 0 10.00K O.00K LOXLEy BALDWIN CO. AL 04/01/2005 05:05 CST Thunderstorm Wind 50 kts.EG 0 0 15.00K O.00K (MDB)MOBILE BATES FL MOBILE CO. AL 04/11/2005 23.49 CST Thunderstorm Wind 75 kts.MG 0 0 150.00K O.00K LOTTIE BALDWIN CO. AL 05/24/2005 20:05 CST Thunderstorm Wind 50 kts.EG 0 0 10.00K O.00K (MDB)MOBILE BATES FL MOBILE CO. AL O6/15/2005 20:15 CST Thunderstorm Wind 55 kts.EG1000 10.00K O.00K MOBILE BATES FLD MOBILE CO. AL 07/212005 16:40 CST Thunderstorm Wind 50 kts.EG12.00K O.00K ALA13AMA PORT MOBILE CO. AL 09/23/2005 14:00 CST Thunderstorm Wind 52 kts.EG4.00K O.00K ALABAMA PORT MOBILE CO. AL 09/242005 04:35 CST Thunderstorm Wind 50 Ins.EGS.00K IO.00K BAY MINETTE BALDWIN CO. AL 01/17/2006 09:20 CST Thunderstorm Wintl 50 kts.EG10.00K O.00K SEMINOLE BALDWIN CO. AL0510812006 22:05 CST Thunderstorm Wind 55 kts.EG10.00K O.00K SEMMES MOBILE CO. AL 06/23/2006 12:25 CST Thunderstorm Wind 50 kts.EG 0 0 10.00K O.00K GULF SHRS BALDWIN CO. AL O6123/2006 12:50 CST Thunderstorm Wind 50 kts.EG 0 0 10.00K O.00K ST ELMO MOBILE CO. AL 06123/2006 13:10 CST Thunderstorm Wind 50 kts.EG 0 0 15.00K O.00K GULF SHRS BALDWIN CO. AL O6123/2006 13:25 CST Thunderstorm Wind 50 kts.EG 0 0 20.00K O.00K (M-QB)MOBILE BATES FL MOBILE CO. AL 06125/2006 15.00 CST Thunderstorm Wind 50 kts.EG 0 0 10.00K O.00K FOLEY BALDWIN CO. AL 07/20/2006 13:20 CST Thunderstorm Wind 50 kts.EG 0 0 10.00K O.00K GEORGETOWN MOBILE CO. AL 08/09/2006 13:06 CST Thunderstorm Wind 50 kts.EG 0 0 30.00K O.00K GEORGETOWN MOBILE CO. AL 08/152006 19:40 CST Thunderstorm Wind 50 kts.EG 0 0 10.00K O.00K GRAND BAY MOBILE CO. AL 08/30/2006 15.30 CST Thunderstorm Wind 50 kts.EG 0 0 45.00K O.00K BAYMINETTE BALDWINCO. AL 08/302006 16:15 CST Thunderstorm Wind 50 Ins.EG 0 0 12.00K O.00K BAY MINETTE BALDWIN CO. AL 08/30/2006 16:45 CST Thunderstorm Wind 50 kts.EG 0 0 12.00K O.00K (MOB)MOBILE BATES FL MOBILE CO. AL 10/162006 17:45 CST-6 Thunderstorm Wind 50 kts.EG 0 0 6.00K O.00K (MOB)MOBILE BATES FL MOBILE CO. AL 10/16/2006 18.15 CST-6 Thunderstorm Wind 50 kts.EG 0 0 6.00K O.00K SEMMES MOBILE CO. AL 10/162006 20:45 CST-6 Thunderstorm Wind 50 kts.EG 0 0 6.00K O.00K WILMER MOBILE CO. AL 11/15/2006 05.54 CST-6 Thunderstorm Wind 50 kts.EG 0 0 10.00K O.00K BAYOU LA BATRE MOBILE CO. AL 11/15/2006 07:20 CST-6 Thunderstorm Wind 50 kts.EG 10 10 12.00K O.00K MIFLIN BALDWIN CO. AL111/1512006 10.25 CST-6 Thunderstorm Wind 50 kts.EG 0 10 10.00K O.00K BELFOREST BALDWIN CO. AL 05/132007 13:20 CST-6 Thunderstorm Wind 50 kts.EG 0 10 S.00K O.00K MOBILE MOBILE CO. AL 05/16/2007 13.15 CST-6 Thunderstorm Wind 50 kts.EG 0 0 15.00K O.00K ROBERTSDALE BALDWIN CO. AL O610M007 15:25 CST-6 Thunderstorm Wind 52 da W11C e9,ry�P % 0 O.00K hops:l/ w ..nodo.nma.gov/sW neventMistevents.jsp?eventType=%28Z%29+High+Wintl&eventType=%28Z/29+Hurricane+%28Typhmn%29&eventType=%28Z%2 4/182018 Storm Events Database-Search Results I National Centers for Environmental Information SUMMMERDAL E BALDWIN CO. AL 06/09/2007 15:40 CST-6 Thunderstorm Wind 52 kls.EG 0 0 10.00K O.00K FOWL RIVER MOBILE CO. AL 06/12/2007 12:00 CST-6 Thunderstorm Wind 52 kts.MG 0 0 20.00K O.00K W)LIAM MOBILE CO. AL 06/19/2007 15:25 CST-6 Thunderstorm Wind 50 kls.EG 0 0 15.00K O.00K MOBILE MOBILE CO. AL 07/03/2007 13.20 CST-6 Thunderstorm Wind 61 kts.EG 0 8 3.500M O.00K E61RHDPE BALDWIN CO. AL 07/11/2007 19:10 CST-6 Thunderstorm Wind 50 kls.EG 0 0 10.00K O.00K SPANISH FT BALDWIN CO. AL 07/14/2007 14.35 CST-6 Thunderstorm Wind 50 Ms.EG 0 0 10.00K O.00K BELFOREST BALDWIN CO. AL 07/14/2007 14:40 CST-6 Thunderstorm Wind 50 kts.EG 0 0 10.00K O.00K SPANISH FT BALDWIN CO. AL 08/24/2007 14.22 CST-6 Thunderstorm Wind 52 Ms.EG 0 0 10.00K O.00K GEORGETOWN MOBILE CO. AL 10/18/2007 06.00 CST-6 Thunderstorm Wind 50 kts.EG 0 0 20.00K O.00K BAYOU LA BATRE ARPT MOBILE CO. AL 10/22/2007 16:33 CST-6 Tornado EFi 0 0 750.00K O.00K DAUPHIN IS MOBILE CO. AL 02112/2008 05:03 CST-6 Thunderstorm Wind 64 kts.MG 0 0 O.00K O.00K (MQB)MOBILE BATES FL MOBILE CO. AL 02/12/2008 16.30 CST-6 Thunderstorm Wind 50 kts.EG 0 0 10.00K O.00K LDXI EY BALDWIN CO. AL 07J12/2008 17:15 CST-6 Thunderstorm Wind 50 kts.EG 0 0 55.00K O.00K GULF SHRS BALDWIN CO. AL 03/012008 0351 CST-6 Thunderstorm Wind SO kts.EG 0 0 18.00K O.00K CITRONELLE MOBILE CO. AL 05/15/2008 09:56 CST-6 Thunderstorm Wind 54 kts.EG 0 0 100.00K O.00K FAIRHOPE BALDWIN CO. I AL 05/152008 10.15 CST-6 Thunderstorm Wind 50 Ids.EG 0 0 12.00K O.00K Si MMERUAL E BALDWIN CO. AL 05/15/2008 10:25 CST-6 Thunderstorm Wind 54 kts.EG 0 0 30.00K O.00K DIXON CORNER MOBILE CO. AL 06/22/2008 15:45 CST-6 Thunderstorm Wind 50 Ids.EG 0 0 12.00K O.00K FAIRHOPE BALDWIN CO. AL 06/29/2008 07:45 CST-6 Thunderstorm Wind 55 kts.EG 0 0 25.00K O.00K (MOB)MOBILE BATES FL MOBILE CO. AL 07/122008 1778 CST-6 Thunderstorm Wind 50 kts.MG 0 0 O.00K O.00K GRAND BAY MOBILE CO. JAL 07/13/2008 14:00 CST-6 Thunderstorm Wind 50 kts.EG 0 0 O.00K IO.00K DAWES MOBILE CO. AL 03/272009 02:20 CST-6 Thunderstorm Wind 52 kts.EG 0 0 20.00K O.00K MOBILE BATES FLD MOBILE CO. AL 03/27/2009 02:20 CST-6 Thunderstorm Wind 52 kts.EG 0 0 40.00K O.00K ROBERTSDALE BALDWIN CO. AL 03/272009 03.12 CST-6 Thunderstorm Wind 75 kts.MG 0 0 O.00K O.00K ROBERTSDALE BALDWIN CO. AL 03/27/2009 03.15 CST-6 Thunderstorm Wind 104 Ids.EG 0 0 125.00K O.00K DAPHNE BALDWIN CO. AL 07/312009 03:15 CST-6 Thunderstorm Wind 52 kLs.EG 0 0 10.00K IO.00K MOBILE BATES FLD MOBILE CO. AL 07/31/2009 09.30 CST-6 Thunderstorm Wind 52 kts.EG 0 0 12.00K O.00K MOBILE BATES FLD MOBILE CO. AL 08/032009 13:59 CST-6 Thunderstorm Wind 52 kLs.EG 0 0 10.00K O.00K SEMINOi E BALDWIN CO. AL 08/04/2009 16:15 CST-6 Thunderstorm Wind 52 kts.EG 0 0 10.00K O.00K PHILLIPSVILLE BALDWIN CO. AL 08/05/2009 14:45 CST-6 Thunderstorm Wind 52 kLs.EG 0 0 10.00K O.00K PHILLIPSVILLE BALDWIN CO. AL 08/05/2009 15.05 CST-6 Thunderstorm Wind 52 kts.EG 0 0 10.00K O.00K (MOB)MOBILE BATES FL MOBILE CO. AL 12124/2009 16:40 D$T-6 Thunderstorm Wind 50 kLs.EG 0 0 O.00K O.00K PRICHARD MOBILE CO. AL 12/24/2009 17:14 CST-6 Thunderstorm Wind 50 kts.MG 0 (31 O.00K O.00K GULF SHRS BALDWIN CO. AL 12124/2009 17:38 CST-6 Thunderstorm Wind 50 kLs.EG 0 0 O.00K O.00K ELBEBTB BALDWIN CO. AL 06/16/2010 15:42 CST-6 Thunderstorm Wind 52 Me EG 0 0 12.00K O.00K ELSANOR BALDWIN CO. AL 10/24/2010 20:10 CST-6 Tornado IEF1 0 0 45.00K O.00K COTTAGE HILL MOBILE CO. AL 10/25/2010 04:17 CST-6 Tornado EFi 0 0 O.00K O.00K THEODORE MOBILE CO. AL 12111/2010 23:30 CST-6 Thunderstorm Wind 52 kLs.EG 0 0 5.00K O.00K DAPHNE BALDWIN CO. AL 12/11/2010 23:40 CST-6 Thunderstorm Wind 52 kts.EG 0 0 10.00K O.00K GULF SHRS BALDWIN CO. AL 01/18/2011 20:05 CST-6 Thunderstorm Wind 52 kLs.EG 0 0 3.00K O.00K FOLEy BALDWIN CO. AL 02101/2011 17:20 CST-6 Thunderstorm Wind 52 kts.EG 0 5 10.00K 0.00K SEMINOLE BALDWIN CO. AL 02O112011 17:51 CST-6 Thunderstorm Wind 52 kLs.EG 0 5 O.00K O.00K DELCHAMPS MOBILE CO. AL 03/05/2011 16:35 CST-6 Thunderstorm Wintl 52 kts.EG 0 0 5.00K O.00K MT VERNON MOBILE CO. AL 03/092011 08:02 CST-6 Thunderstorm Wind 61 dis EG 0 0 7.00K O.00K GRAND BAY MOBILE CO. A. 03/09/2011 08:31 CST-6 Tornado EFi 0 0 O.00K O.00K THEODORE MOBILE CO. AL 03/092011 08:37 CST-6 Tornado EF2 0 4 O.00K O.00K GRAND BAY MOBILE CO. AL 03/09/2011 08:48 CST-6 Thunderstorm Wind 70 kts.EG 0 0 20.00K O.00K SILVERHILL BALDWIN CO. AL 03/09/2011 09:17 CST-6 Tornado EF2 0 0 O.00K O.00K SPRING HILL MOBILE CO. AL 04/04/2011 19:45 CST-6 Thunderstorm Wind 50 kts.EG 0 0 O.00K O.00K NAVCO MOBILE CO. AL 04/042011 20:20 CST-6 Thunderstorm Wind 50 kLs.EG 0 0 O.00K O.00K MOBILE BATES FLD MOBILE CO. AL 06/16/2011 13:04 CST-6 Thunderstorm Wind 52 kts.EG 0 0 2.00K O.00K MOBILE BATES FLD MOBILE CO. AL 06/162011 13:04 CST-6 Thunderstorm Wind 52 kLs.EG 0 0 2.00K O.00K (M-QB)MOBILE BATES FL MOBILE CO. AL 07/02/2011 11.56 CST-6 Thunderstorm Wind 53 kts.MG 0 0 O.00K O.00K LOXLEY BALDWIN CO. AL 07/022011 13:05 CST-6 Thunderstorm Wind 61 kts.EG 0 0 10.00K O.00K (M-QB)MOBILE BATES FL MOBILE CO. AL 07/31/2011 15:55 CST-6 Thunderstorm Wind 52 Ids,EG 0 0 O.00K O.00K MOBILE BATES FLD MOBILE CO. AL 08/042011 17:34 CST-6 Thunderstorm Wind 52 kts.EG 0 0 2.00K O.00K SPRING HILL MOBILE CO. AL 08/12/2011 13:00 CST-6 Thunderstorm Wind 52 kts.EG 0 0 2.00K O.00K APC Barry_EPA_000651 hops:// w ..nodo.nma.gov/sW neventMistevents.jsp?eventType=%28Z%29+High+Wintl&eventType=%2aZ%29+Hurricane+%28Typhwn%29&eventType=%2aZ%2 4/1812018 Storm Events Database-Seaton Results I National Centers for Environmental Information GRAND BAV MOBILE CO. AL 08/24/2011 12:59 CST-6 Thunderstorm Wind 51 Ms.MG 0 0 O.00K O.00K FOLEY BALDWIN CO. AL 08/24/2011 12.59 CST-6 Thunderstorm Wind 51 Ms.MG 0 0 O.00K O.00K MOBILE BATES FLD MOBILE CO. AL 08/24/2011 12:59 CST-6 Thunderstorm Wind 53 Ms.MG 0 0 O.00K O.00K MON LOUTS MOBILE CO. AL 09/04/2011 00:02 CST-6 Tornado IEFi 0 0 45.00K O.00K LjLLAN BALDWIN CO. AL 09/04/2011 02:22 CST-6 Tornatlo EFi 0 0 200.00K O.00K MOBILE BATES FLD MOBILE CO. AL 09/05/2011 06:47 CST-6 Thunderstorm Wind 52 kts.EG 0 0 2.00K O.00K MOBILE MOBILE CO. AL 09/05/2011 07:25 CST-6 Thunderstorm Wind 56 Ms.MG 0 0 O.00K O.00K MOBILE MOBILE CO. AL 09/05/2011 07:25 CST-6 Thunderstorm Wind 56 Ins.MG 0 0 O.00K O.00K GRAND BAY MOBILE CO. AL 02/18/2012 18:10 CST-6 Thunderstorm Wind 52 kls.EG 0 0 3.00K O.00K SEMINOLE BALDWIN CO. AL 02/18/2012 17:20 CST-6 Thunderstorm Wind 61 Ins.EG 0 0 10.00K O.00K LILLIAN BALDWIN CO. AL 02/18/2012 17:40 CST-6 Thunderstorm Wind 61 kls.EG 0 0 10.00K O.00K ELSANOR BALDWIN CO. AL 05/30/2012 14:18 CST-6 Thunderstorm Wind 52 Ins.EG 0 0 B.00K O.00K BAVOU LA BATEE MOBILE CO. AL 07/02/2012 16:00 CST-6 Thunderstorm Wind 52 kls.EG 0 0 2.00K O.00K SILVERHILL BALDWIN CO. AL 07/03/2012 15:45 CST-6 Thunderstorm Wind 52 Ids.EG 0 0 TOOK O.00K allMMERUALE BALDWIN CO. AL 07/04/2012 12:20 CST-6 Thunderstorm Wind 52 kls.EG 0 0 5.00K O.00K WHITEHOUSE FORKS BALDWIN CO. AL 07/17/2012 17.45 CST-6 Thunderstorm Wind 52 Ina.EG 0 0 2.00K O.00K DAEUNE BALDWIN CO. AL 07/17/2012 18:00 CST-6 Thunderstorm Wind 52 kls.EG 0 0 2.00K O.00K FOLEY BALDWIN CO. AL 07/302012 14:20 CST-6 Thunderstorm Wind 52 Ina.EG 0 0 TOOK O.00K COTTAGE HILL MOBILE CO. AL1220/2012 04:49 CST-6 Tornado EF1 0 0 O.00K O.00K MERTZ MOBILE CO. AL 12/252012 16:54 CST-6 Tornado EF2 0 0 1.350M O.00K PIERCIE MOBILE CO. AL 12/25/2012 19:22 CST-6 Tornado IEFi 0 0 O.00K O.00K SEMMES MOBILE CO. AL 12/25/2012 19:40 CST-6 Thunderstorm Wind 61 Ins.EG 0 0 4.00K O.00K AIIRFNDINF MOBILE CO. AL 04/11/2013 16:29 CST-6 Tornado EFi 0 0 1.500M O.00K SOUTH ORCHARD MOBILE CO. AL 04/14/2013 09:06 CST-6 Thunderstorm Wind 52 Ins.EG 0 0 5.00K O.00K GULF SHRS BALDWIN CO. AL 04/14/2013 09.45 CST-6 Thunderstorm Wind 52 Ms.EG 0 0 1O.00K O.00K FAIRHOPE BALDWIN CO. AL 04/14/2013 10:00 CST-6 Thunderstorm Wind 52 Ins.EG 0 0 2.00K O.00K FAIRHOPE BALDWIN CO. AL 07/22/2013 15.45 CST-6 Thunderstorm Wind 50 Ms.EG 0 0 4.50K O.00K ROSINTON BALDWIN CO. AL 07/22/2013 15:55 CST-6 Thunderstorm Wind 50 Ins.EG 0 0 4.50K O.00K SEMINO F BALDWIN CO. AL 07/22/2013 16.15 CST-6 Thunderstorm Wind 50 Ms.EG 0 0 4.50K O.00K SEVEN HILLS MOBILE CO. AL 02/21/2014 02:00 CST-6 Thunderstorm Wind 52 Ins.EG 0 0 2.00K O.00K BAY MINETTE BALDWIN CO. AL 02/21/2014 02:30 CST-6 Thunderstorm Wind 52 kls.EG 0 0 2.00K O.00K SARALAND MOBILE CO. AL 03/16/2014 07:00 CST-6 Thunderstorm Wind 52 Ins.EG 0 0 2.00K O.00K SARALAND MOBILE CO. AL 03/16/2014 07:00 CST-6 Thunderstorm Wind 61 kls.EG 0 0 4.00K O.00K SARALAND MOBILE CO. AL 03/16/2014 07:00 CST-6 Thunderstorm Wind 61 Ins.EG 0 0 S.00K O.00K SARALAND MOBILE CO. AL 03/16/2014 07:00 CST-6 Thunderstorm Wind 52 kls.EG 0 0 2.00K O.00K ROBERTSDALE BALDWIN CO. AL 04/14/2014 06:45 CST-6 Thunderstorm Wind 52 Ins.EG 0 0 S.00K O.00K (M-QB)MOBILE BATES FL MOBILE CO. AL 04/29/2014 0105 CST-6 Thunderstorm Wind 50 kts.MG 0 0 O.00K O.00K ELSANOR BALDWIN CO. AL 05/28/2014 1740 CST-6 Thunderstorm Wind 61 kts.EG 0 0 O.00K O.00K PRICHARD MOBILE CO. AL 08/09/2014 14:30 CST-6 Thunderstorm Wind 52 kts.EG 0 0 1O.00K O.00K SARALAND MOBILE CO. AL O8/0912014 14:30 CST-6 Thunderstorm Wind 61 kts.EG 0 0 25.00K O.00K ELBEM BALDWIN CO. AL 1.23/2014 20:30 CST-6 Thunderstorm Wind 45 kts.EG 0 0 1.00K O.00K SEMMES MOBILE CO. AL 04/25/2015 13:56 CST-6 Thunderstorm Wind 52 kts.EG 0 0 2.00K O.00K TANNER WILLIAMS MOBILE CO. AL 04/25/2015 13.59 CST-6 Thunderstorm Wind 52 kts.EG 0 0 2.00K O.00K GRAND BAY MOBILE CO. AL 04/252015 14:00 CST-6 Thunderstorm Wind 52 kts.EG 0 0 1.00K O.00K ST ELMO ARPT MOBILE CO. AL 04/25/2015 14.07 CST-6 Thunderstorm Wind 52 kts.EG 0 0 1.00K O.00K ORCHARD MOBILE CO. AL 04/252015 14:07 CST-6 Thunderate"Wind 52 k, EG 0 0 LOOK O.00K SPRING HILL MOBILE CO. AL 04/25/2015 14.07 CST-6 Thunderstorm Wind 52 kts.EG 0 0 LOOK O.00K FAIRHOPE BALDWIN CO. AL 04/252015 14:20 CST-6 Thunderstorm Wind 150 Ins.MG 0 0 90.001K O.00K POINT CLEAR BALDWIN CO. AL 04/25/2015 14:24 CST-6 Thunderstorm Wind 52 kts.EG 0 0 5.001< O.00K SILVERHILL BALDWIN CO. AL 04/252015 14:29 CST-6 Thunderstorm Wind 52 kts.EG 0 0 10.00K O.00K ROBERTSDALE BALDWIN CO. AL 04/25/2015 14:30 CST-6 Thunderstorm Wind 61 kts.EG 0 0 120.00K O.00K FOLEY BALDWIN CO. AL 04/252015 14:35 CST-6 Thunderstorm Wind 52 kts.EG 0 0 10.00K O.00K ROSINTON BALDWIN CO. AL 04/25/2015 14:37 CST-6 Thunderstorm Wind 52 kts.EG 0 0 3O.00K O.00K MOBILE MOBILE CO. AL O61222015 17:15 CST-6 Thunderstorm Wind 52 kts.EG 0 0 S.00K O.00K CHICKASAW MOBILE CO. AL 06/22/2015 17:15 CST-6 Thunderstorm Wind 52 kts.EG 0 0 2.00K O.00K SEVEN HILLS MOBILE CO. AL 06/272015 14:48 CST-6 Thunderstorm Wind 52 kts.EG 0 0 2.00K O.00K (M-QB)MOBILE BATES FL MOBILE CO. AL O6127/2015 14:54 CST-6 Thunderstorm Wind 52 kts.EG 0 0 2.00K O.00K BRIDGEHEAD (BALDWIN CO. AL 07/172015 1510 CST-6 Thunderstorm Wind 61 kts.WIC 391,ry�P % 2 O.00K hops:l/ w ..nodo.nma.gov/sW nevents/listevents.jsp?eventType=%28Z%29+High+Wintl&eventType=%28Z/29+Hurricane+%28Typhmn%29&eventType=%28Z%2 4/182018 Storm Events Database-Search Results I National Centers for Environmental Information MOBILE MOBILE CO. AL 07/17/2015 15:19 1 CST-6 Thunderstorm Wind 61 kls.EG 0 0 5.00K O.00K MOBILE MOBILE CO. AL 07/17/2015 15:19 CST-! Thunderstorm Wind 61 kts.EG 0 0 5.00K O.00K MOBILE MOBILE CO. AL 07/17/2015 15:22 CST-6 Thunderstorm Wind 70 kls.EG 0 0 5.00K O.00K MOBILE MOBILE CO. AL 071 712015 1522 CST-6 Thunderstorm Wind 70 Ms.EG 0 0 5.00K O.00K MOBILE MOBILE CO. AL 07/17/2015 115,22 1 CST-6 Thunderstorm Wind 70 kls.EG 0 0 5.00K O.00K MOBILE MOBILE CO. AL 071 712015 11627 CST-6 Thunderstorm Wind 66 Ms.MG 0 0 O.00K O.00K MOBILE BATES FLD MOBILE CO. AL 07/17/2015 15:37 CST-6 Thunderstorm Wind 61 kts.EG 0 0 5.00K O.00K (MOB)MDBILE BATES FL MOBILE CO. AL 07/17/2015 15:39 CST-6 Thunderstorm Wind 61 kts.EG 0 0 5.00K O.00K THEODORE MOBILE CO. AL 07/17/2015 16:00 CST-6 Thunderstorm Wind 61 kts.EG 0 0 5.00K O.00K GULF SHRS BALDWIN CO. AL 07/19/2015 12:55 CST-6 Thunderstorm Wind 53 kts.MG 0 0 O.00K O.00K QUEDEE1 i F MOBILE CO. AL 08/08/2015 16:30 CST-6 Thunderstorm Wind 52 kts.EG 0 0 5.00K O.00K CHUNCHULA MOBILE CO. AL 08/08/2015 16.45 CST-6 Thunderstorm Wind 52 kts.EG 0 0 5.00K O.00K B6B6L6NQ MOBILE CO. AL 08/08/2015 16:50 CST-6 Thunderstorm Wind 52 kts.EG 0 0 5.00K O.00K (BFM)MOBILE BROOKLEV MOBILE CO. AL 08/08/2015 17.29 CST-6 Thunderstorm Wind 50 kts.MG 0 0 O.00K O.00K SPANISH ET BALDWIN CO. AL 08/09/2015 17:10 CST-6 Thunderstorm Wind 52 kts.EG 0 1 30.00K O.00K COTTAGE HILL MOBILE CO. AL 09/272015 17.30 CST-6 Thunderstorm Wind 52 Ids.EG 0 0 2.00K O.00K SPRING HILL MOBILE CO. AL 09/27/2015 17:45 CST-6 Thunderstorm Wind 52 kts.EG 0 0 2.00K O.00K MOBILE MOBILE CO. AL 10/312015 18:42 CST-6 Thunderstorm Wind 60 Ids.EG 0 0 3.00K O.00K GRAND BAY MOBILE CO. AL 12/23/2015 06:30 CST-6 Thunderstorm Wind 50 kts.EG 0 0 5.00K O.00K THEODORE MOBILE CO. AL 12/232015 06.48 CST-6 Thunderstorm Wind 50 kts.EG 0 0 10.00K O.00K DVAS BALDWIN CO. AL 01/21/2016 23:00 CST-6 Thunderstorm Wind 52 kts.EG 0 0 5.00K O.00K MOBILE MOBILE CO. AL 02/032016 04.19 CST-6 Thunderstorm Wind 52 kts.EG 0 0 10.00K O.00K MON LOUTS MOBILE CO. AL 02/15/2016 16:58 CST-6 Thunderstorm Wind 53 kts.EG 10 10 2.00K O.00K SEMMES MOBILE CO. AL 03/172016 13.13 CST-6 Thunderstorm Wind 52 kls EG 0 0 2.00K O.00K BBBAL.6U MOBILE CO. AL 03/17/2016 19:11 CST-6 Thunderstorm Wind 52 kts.EG 0 0 2.00K O.00K MOBILE BATES FLD MOBILE CO. AL 03/172016 19:20 CST-6 Thunderstorm Wind 52 kLs.EG 0 0 2.00K O.00K (MOB)MOBILE BATES FL MOBILE CO. AL 03/172016 19.26 CST-6 Thunderstorm Wind 54 kts.MG 0 0 2.00K O.00K TILLMANS CORNER MOBILE CO. AL 03/172016 19:35 CST-6 Thunderstorm Wind 61 kts.EG 0 0 5.00K O.00K (MDB)MOBILE BATES FL MOBILE CO. AL nV17/2016 19:36 CST-6 Thunderstorm Wind 61 kts.EG 0 0 10.00K O.00K FAIRHOPE BALDWIN CO. AL 03/172016 19:54 CST-6 Thunderstorm Wind 61 kts.EG 0 0 30.00K O.00K MALBIS BALDWIN CO. AL 03/17/2016 2002 CST-6 Thunderstorm Wind 52 kts.EG 0 0 1.00K O.00K MOBILE MOBILE CO. AL 03/24/2016 11:49 CST-6 Thunderstorm Wind 61 kts.EG 0 0 2.00K O.00K SPRING HILL MOBILE CO. AL 03/24/2016 12:00 CST-6 Thunderstorm Wind 52 kts.EG 0 0 10.00K O.00K GRAND BAY MOBILE CO. AL OS/19/2016 23:58 CST-6 Thunderstorm Wind 52 kts.EG 0 0 5.00K O.00K SEVEN HILLS S MOBILE CO. AL 05/20/2016 00:05 CST-6 Thunderstorm Wind 52 kts.EG 0 0 1.00K O.00K WILMER MOBILE CO. AL 05/202016 00:07 D$T-6 Thunderstorm Wind 52 kts.EG 0 0 5.00K O.00K KI ISHI A MOBILE CO. AL 05/20/2016 00:15 CST-6 Thunderstorm Wind 52 kts.EG 0 0 3.00K O.00K COTTAGE HILL MOBILE CO. AL 05/202016 00:16 CST-6 Thunderstorm Wind 52 kts.EG 0 0 3.00K O.00K MIER7Z MOBILE CO. AL 05/20/2016 00:20 CST-6 Thunderstorm Wind 52 kts.EG 0 0 5.00K 0.00K SOUTH ORCHARD MOBILE CO. AL 05/202016 00:20 CST-6 Thunderstorm Wind 52 kts.EG 0 0 2.00K O.00K FT MORGAN BALDWIN CO. AL 05/20/2016 00:30 CST-6 Thunderstorm Wind 60 kts.MG 0 0 O.00K 0.00K AXIS MOBILE CO. AL 05/202016 00:30 CST-6 Thunderstorm Wind 52 kts.EG 0 0 1.00K O.00K STOCKTON BALDWIN CO. AL 05/20/2016 00:44 CST-6 Thunderstorm Wind 52 kts.EG 0 0 3.00K O.00K BAYMINETTE BALDWIN CO. AL 05/202016 00:44 CST-6 Thunderstorm Wind 52 kts.EG 0 0 3.00K O.00K BUCKS MOBILE CO. AL 05/31/2016 15:42 CST-6 Thunderstorm Wind 52 kts.EG 0 0 5.00K O.00K CITRONELLE MOBILE CO. AL 06/172016 17:20 CST-6 Thunderstorm Wind 52 kts.EG 0 0 O.00K 0.00K CITRONELLE MOBILE CO. AL O6/172016 17:35 CST-6 Thunderstorm Wind 52 kts.EG 0 0 2.00K O.00K RABUN BALDWIN CO. AL 06/172016 17:40 CST-6 Thunderstorm Wind 61 kts.EG 0 0 10.00K O.00K MOBILE MOBILE CO. AL OW172016 18.40 CST-6 Thunderstorm Wind 52 kls.EG 0 0 3.00K O.00K (MOB)MOBILE BATES FL MOBILE CO. AL 07/102016 12:12 CST-6 Thunderstorm Wind 52 kts.EG 0 0 5.00K O.00K (BEM)MOBILE BROOKIL MOBILE CO. AL 07120=16 14.05 CST-6 Thunderstorm Wind 60 kts.EG 0 0 50.00K O.00K (BFM)MOBILE BROOKLEV MOBILE CO. AL 07/202016 14:35 CST-6 Thunderstorm Wind 60 kts.EG 0 0 5.00K O.00K GULF SHRS BALDWIN CO. AL 01/02/2017 14.47 CST-6 Thunderstorm Wind 70 kts.EG 0 1 950.00K O.00K (MOB)MOBILE BATES FL MOBILE CO. AL 01/022017 16:42 CST-6 Thunderstorm Wind 52 kts.EG 0 0 5.00K O.00K PIERCIE MOBILE CO. AL 01/21/2017 06:45 CST-6 Thunderstorm Wind 52 kts.EG 0 0 4.00K O.00K SEVEN HILLS MOBILE CO. AL 01/212017 07:15 CST-6 Thunderstorm Wind 52 kts.EG 0 0 10.00K O.00K COTTAGEHILL MOBILE CO. ALI01/21/2017 08:00 CST-6 Thunderstorm Wind 70 kls.EG Barry EPA 0o0653 O.00K APC hops://w ..nodo.nma.gov/stortneventMisteveMs.jsp?eventType=%28Z%29+High+Wintl&eventType=%2aZ%29+Hurricane+%28Typhwn%29&eventType=%2aZ%2 4/182018 Storm Events Database-Search Results I National Centers for Environmental Information SATSUMA I MOBILE CO. AL 02/07/2017 13:33 CST-6 Thunderstorm Wintl 61 kts.EG 0 0 2.001 O.00K BAY MINETTE BALDWIN CO. AL 02/07/2017 13.50 CST-6 Thunderstorm Wind 52 kts.EG 0 0 2.00K O.00K GULF SHRS BALDWIN CO. AL 02/07/2017 15:55 CST-6 Thunderstorm Wind 51 kts.MG 0 0 O.00K O.00K CITRONELLE MOBILE CO. AL 04/03/2017 06.25 CST-6 Thunderstorm Wind 61 kts.EG 0 0 5.00K O.00K RFMMFB MOBILE CO. AL 05/12/2017 11.54 CST-6 Thunderstorm Wind 52 kts.EG 0 0 10.00K O.00K Kul � MOBILE CO. AL 05/12/2017 12.05 CST-6 Thunderstorm Wind 52 kls.EG 0 0 4.00K O.00K BAYMINETTE BALDWIN CO. AL 05/12/2017 12:40 CST-6 Thunderstorm Wind 52 kts.EG 0 0 20.00K O.00K all LLIPSVILLE BALDWIN CO. AL 05/12/2017 12:46 CST-6 Thunderstorm Wind 61 Ids.ES 0 0 15.00K O.00K HERON BAY MOBILE CO. AL O6/21/2017 16:12 CST-6 Thunderstorm Wind 52 kls.EG 0 0 5.00K O.00K DAWES MOBILE CO. AL 06/21/2017 16:27 CST-6 Thunderstorm Wind 52 Ina.EG 0 0 5.00K O.00K MIFLIN BALDWIN CO. AL 07/28/2017 18:55 CST-6 Thunderstorm Wind 54 kls.MG 0 0 O.00K O.00K GULF SHRS BALDWIN CO. AL 07/262017 1712 CST-6 Thunderstorm Wind 52 Ins.EG 0 0 10.00K O.00K MOBILE BATES FLD MOBILE CO. AL 09/22/2017 14:58 CST-6 Thunderstorm Wintl 52 Ms.EG 0 0 5.00K O.00K Totals: 1 156 26.289M O.00K APC Barry_EPA_000654 hops:l/ w ..nodo.nma.gov/stonneventMistevents.jsp?eventType=%28Z%29+High+Wintl&eventTypem%2aZ%29+Hurricane+%28Typhmn%29&eventType=%28Z%2 Geosynte& consultants CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 ATTACHMENT GW6489/Barry_50%Design ClosumTurt Draft APC Barry_EPA_000655 4/1 812 01 8 Enhanced Fujita Tornado Damage Scale Enhanced F Scale for Tornado Damage An update to the the original F-scale by a team of meteorologists and wind engineers, to be implemented in the U.S. on 1 February 2007. FUIITA SCALE DERIVED EF OPERATIONAL SCALE EFSCALE F Fastest 1/4- 3 Second EF 3 Second EF 3 Second Number mile(mph) Guet(mph) Number Guet(mph) Number Gust (mph) 0� 40-72 45-78 0� 65-85 0� 65-85 1� 73-112 79-117 1� 86-109 1� 86-110 2� 113-157 118-161 2� 110-137 2� 111-135 3� 158-207 162-209 3� 138-167 � 136-165 4� 208-260 210-261 4� 168-199 4� 166-200 5� 261-318 262-317 5� 200-234 � Over 200 *** IMPORTANT NOTE ABOUT ENHANCED F-SCALE WINDS: The Enhanced F-scale still is a set of wind estimates (not measurements) based on damage. Its uses three-second gusts estimated at the point of damage based on a judgment of 8 levels of damage to the 28 indicators listed below. These estimates vary with height and exposure. Important: The 3 second gust is not the same wind as in standard surface observations. Standard measurements are taken by weather stations in open exposures,using a directly measured, 'one minute mile" speed. Enhanced F Scale Damage Indicators NUMBER(Details DAMAGE INDICATOR ABBREVIATION Linked) 1 Small barns, farm outbuildings SBO 2 One-or two-family residences FR12 d Single-wide mobile home (MHSW) MHSW 4 Double-wide mobile home MHDW 5 Apt, condo,townhouse(3 stories or less) ACT 6 Motel I Masonry apt. or motel MAM 1 Small retail bldg. (fast food) �SRBB AP arry_EPA_Ot3 00656 I http:/Am .spc.noaa.govftq/tornado/ef-swle.html 1/2 4/18/2018 Enhanced Fujita Tornado Damage Scale 2 Small professional(doctor office,branch bank) SPB 10 Strip mall SM 11 Large shopping mall LSM 12 Large, isolated("big box")retail bldg. LIRB 13 Automobile showroom ASR 14 Automotive service building ASB 15 School - 1-story elementary(interior or exterior halls) ES 16 School-jr. or sr. high school JIiSH 11 Low-rise(1-4 story)bldg. LRB 18 Mid-rise(5-20 story)bldg. MRB 12 High-rise(over 20 stories) HRB 20 Institutional bldg. (hospital,govt. or university) IB 21 Metal building system MBS 22 Service station canopy SSC 23 Warehouse(tilt-up walls or heavy timber) WHB 24 Transmission line tower TLT 25 Free-standing tower FST 26 Free standing pole (light,flag, luminary) FSP 21 Tree-hardwood TH 28 Tree- softwood TS A 111-page PDF file explaining the development and makeup of the Enhanced F-scale now is available,both here at SPC and from the Texas Tech server. Back to The Online Tornado FAQ Enhanced F-scale Website SPC Home Page APC Barry_EPA_000657 http:/Am .spc.noaa.govftq/tornado/ef-scale.html 2/2 Geosynte& consultants CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 ATTACHMENT GW6489/Barry_50%Design ClosumTurt Draft APC Barry_EPA_000658 YYYYWG WatershedGeo' Unearthing Solutions Summary of Benefits of ClosureTurf® Superior Performance When Compared to EPA Subtitle D Final Closure Design Watershed Geosynthetics, LLC has prepared this document to define the range of benefits of using ClosureTurf®as a final cover system in EPA Subtitle D applications. ClosureTurf offers several substantial performance benefits and environmental benefits over traditional and regulatory prescriptive designs for final closure of landfills and/or impoundments. ClosureTurf provides significant technical advantages as a final closure system in comparison with the traditional EPA Subtitle D soil and vegetative cover treatment. Those benefits have been validated through extensive documented laboratory testing conducted at leading independent and existing operating facilities. ClosureTurf is a more environmentally sound application when compared to traditional soil and vegetative covers. Some of these include improved water quality, land preservation and significant carbon footprint reduction. These environmental advantages are both quantifiable and effective. As presented below,the regulatory criteria for evaluating an alternative cover system is to control infiltration and erosion. Based on several years of real world experience on over 40 million square feet installed, and extensive university and ASTM lab evaluations,the ClosureTurf system has shown to have a leakage rate over 40 times less than subtitle D prescriptive cover and an erosion loss of over 100 times less than subtitle D prescriptive cover. ClosureTurf Benefits 1) Regulatory Compliance ClosureTurf is a three-component system comprised of a structural geomembrane, engineered synthetic turf, and a specified infill that meets and/or exceeds all of the requirements set forth by the EPA in "Subtitle D". EPA Subtitle D rules specifically state: `An alternative cover design may be used as long as it provides equivalent protection against infiltration and erosion." ClosureTurf significantly outperforms traditional Subtitle D closures based on these criteria, with the added benefit of performance well beyond the regulatory post-closure period. 2)Safety and Community Impact Reduction The system eliminates approximately 350 truck trips, per acre,from local roadways that would otherwise be used transporting soil to and from a borrow site. This reduction in size, number and duration of equipment means an overall increase in safety on both the project site and ingress and egress,while reducing dust, mud on roads and noise impacts to the surrounding community. Most traditional closures also require destruction of land in the community for project soil demands, resulting in secondary impacts and loss of future land use. APC Barry_EPA_000659 11 Page YYYYWG WatershedGeo' Unearthing Solutions 3)Sustainability ClosureTurf reduces the carbon footprint of a closure by approximately 80%when compared with traditional soil/vegetative covers. In addition,ClosureTurf provides an ideal foundation for future beneficial uses. Traditional post-closure plans identify the post-closure use simply as dead space. Note that ClosureTurf has been used for post-closure uses such photovoltaic solar panel arrays, allowing what is typically written off as "dead space"to be utilized as a renewable energy site. This feature is inherent with the ClosureTurf system and requires no immediate preparation or planning to accommodate possible future solar use. 4)Water Quality The engineered synthetic turf and specified infill effectively filters surface water, providing clean runoff with very low turbidity. In addition,the system significantly reduces sediment loading to surrounding channels and sedimentation/detention basins both on and offsite. ClosureTurf will have a positive impact on overall storm water quality for sites, allowing them to improve their effluent levels to meet or be well below the regulatory limits. 5) Geotechnical Factors of Safety ClosureTurf provides additional benefit through increased geotechnical factors of safety on the cover system. On side slopes,these factors of safety provide increased protection from sloughing and veneer failures. On flat surfaces(i.e. top decks),these increased factors of safety are realized through a significant reduction in the soil layer and subsequent loading of any underlying sludge-type waste materials that can reverse drainage and create ponding. 6) Water Conservation ClosureTurf is a very low maintenance final cover system, eliminating the need of costly re-vegetating and fertilizing of traditional soil/vegetative covers and reducing the evaporative losses and water demands to sustain the closure and its performance. In addition,the system inhibits dust-creation, eliminating the need for wasteful watering practices intended to reduce dust transmission and air particulate pollution. 7) Maintenance Cost Savings ClosureTurf effectively reduces the maintenance of a final closure system by over 90%through the elimination of maintenance activities and typical erosion repair issues associated with traditional vegetative covers. This savings continues to pay dividends year after year and protects the site from drought cycle or other severe weather damage that can have a detrimental effect on vegetative covers. 8) Land Conservation Traditional closure methods require the destruction of land to achieve the closure. ClosureTurf optimizes land conservation through the elimination of excavation borrow pits on undisturbed, native land as well as providing acreage for renewable energy sites (i.e. photovoltaic solar panel arrays)that might otherwise need to be constructed in other undeveloped areas. APC earry_EPA_000ND 21 Page YYYYWG WatershedGeo' Unearthing Solutions 9) Project Schedule/Installation Rate ClosureTurf requires fewer resources to complete a final cover closure,from pre-design through final acceptance. ClosureTurf installs significantly faster than traditional soil covers using dramatically lighter and fewer pieces of equipment. This increase in "project velocity" means that owners, operators and their design and construction team can cover more acreage far more efficiently with ClosureTurf than with traditional soil cover systems. In addition,the standardization of engineering and construction details associated with ClosureTurf reduces the burden on the regulatory review and approval process. 10) Longevity The system is designed for and proven to have a design life over 100 years of the geosynthetic protective ballast component(Engineered Turf) of ClosureTurf(with the membrane lasting many more years beyond the long life of the Engineered Turf component) ClosureTurf"^" Detail Description ClosureTurf is an environmentally friendly and aesthetically pleasing synthetic turf final cover system designed for long-term performance and a protective ballast for the structured membrane. This system eliminates the challenges of traditional vegetative cover systems such as erosion control, veneer slope stability, and post- closure maintenance. A section of ClosureTurf is shown in Figure 1. Its components include the following from bottom to top: • 50-mil Super Gripnet Structured HDPE or LLDPE Geomembrane (20%thicker than regulatory requirements); • Drainage Layer which is Integrated into the Structured Geomembrane; • Engineered Synthetic Turf(Comprised of Polyethylene Fibers Tufted through Double Layer of a Woven Polypropylene Geotextiles manufactured for high UV and heat resistance); and • Sand Infill. The ClosureTurf system is placed directly on top of the soil foundation layer above the waste. Super Grpne �GepmemEmire EnpinemOTua / nmm s.nn mni Prepared Suby,ade Figure 1—Cross Section of ClosureTurfTM System APC Barry_EPA_000N1 31 Page WGWatershedGeo' Unearthing Solutions Approvals were based on a demonstration that ClosureTurf exceeds the minimum requirements defined in applicable state or Federal EPA regulations.The minimum technical requirements for Subtitle D Final Cover Systems are contained in 40 CFR 258.60. This regulation allows for a prescriptive (minimum criteria)cover system or an alternative (performance based) cover system. The specific requirements of 40 CFR 258.60 for approval of an alternative final cover system are as follows: "i The Director of an approved State may approve an alternative final cover design that includes: (1)An infiltration layer that achieves an equivalent reduction in infiltration as the infiltration layer specified in paragraphs(a) (1)and(a) (2)of this section, and (2)An erosion layer that provides equivalent protection from wind and water erosion as the erosion layer specified in paragraph (a) (3)of this section." The analyses demonstrate that the ClosureTurf Final Cover has (1)a greater reduction in infiltration than the Prescriptive Subtitle D Cover and (2) provides greater protection from erosion, and provides several orders of magnitude of functional longevity with the structured membrane that is 20%thicker than the membrane allowed by regulations.The regulatory approvals,testing and real-world experience has been demonstrated at multiple closures having varying climate conditions as shown in Figure 2 below. Figure 2 - Completed Projects Over 40 million square feet installed in 18 states and closing... �rcury LaiMril,SK MrJtia LreeL MN �� Pert hngcles LantlM1ll.WA � C ,,f 6Mw lnntlnu, Ha ll L MA Ibl[Im�wient lfi NTw�Cranxen lvdfll,W _ M CASenea Vogel lantlfiq,P alga 5fi galwfil.CT ~ Svich®aer n4-1 Re0narL &IL NJ It w=e nL TMiberRidgelsdfil L°ulaa Ceunq lanEFtll.V� dl osaiMewn Imeriaannal Paper Conant Mo+ Lani TN 8&W Paneex LaMR1,TX' mndNI,YN �rkNey Ceunry Landfill,SC Force Base taaaga,CA LafadFGram LaaMBI,IA "Illrila Pa,ilic.GA WeaherfoM Laidnl.TX• Tamberlane Laratlal,lA� ` ilI.aMAIIR - -17F�ahea l�ndfilLW� ClesuraTurP Inatalla[iens ClosureTurf' APC Bacry_EPA_000i 41 Page WGWatershedGeo' Unearthing Solutions Infiltration Equivalency Analyses Infiltration equivalency through a cover system is typically evaluated using two methodologies. These methodologies are the Hydrologic Evaluation of Landfill Performance (HELP) Model and the Giroud Method'. Both of these methods have been used to compare the infiltration performance of the ClosureTurf'"" Final Cover System to the Prescriptive Subtitle D Cover. A summary of the results is shown in Table 1. The results show that the ClosureTurf Final Cover System provides better infiltration protection than the Prescriptive Subtitle D Standard for construction of landfill final closure systems. These results are expected since ClosureTuf" does not allow hydraulic head to build up over the geomembrane. rrfiltration Equivalency Analyses Cover System Cover System HELP Model for Site in Georgia—Average Annual 8.3 347 Infiltration (Cubic Feet/Acre/Year( Giroud Method with Silty-Sandy Soil below the 3 4.51 ClaeureTuT" (Gallons/Acre/Day) Giroud Method with Silty-Sandy Soil with Some Clay below the ClosureTurfl" (Gallons/Acre/ Day} 0'24 4.51 Table 1—Summary of Results for Infiltration Equivalency Analyses Erosion Control Rainfall Erosion Control Testing ClosureTurf was tested at TRI Environmental in accordance with ASTM 6459 -Standard Test Method for Determination of Rolled Erosion Control Product(RECP) Performance in Protecting Hillslopes from Rainfall- Induced Erosion. ClosureTurf"was tested in a rainfall simulator to an intensity of over 6.5 in/hr with less than 0.04% loss of sand infill. 'Rate Of Liquid Migration Through Defects In A Geomembrone Placed On ASemi-Permeable Medium,J.P.Giroud,T.D. King,T.R. Sanglerat,T.Hadj-Hamou and M.V.Khire,Geosynthetics International 1997,Vol.4,Nos.3-4. APC Barry_EPA_000e63 51 Pa ge YYYYWG WatershedGeo' Unearthing Solutions r r Figure 3—Rainfall Erosion Control Testing on ClosureTurf(3H:1 V Slopel The typical design criterion for sediment runoff on a traditional landfill soil cover is 3 tons/acre/year. The measured loss of sand infill (0.04%)of the ClosureTurf is approximately 0.03 tons/acre for a 6.5 in/hr rainfall intensity. Using ClosureTurf will significantly reduce sediment loads and runoff turbidity. Also,the ClosureTurf System filters the storm water and provides "clean" runoff as shown in the testing samples in Figure 4 below. Enhanced Water Quality TO 371 NTU* L1 \rTU u�ana�,..-.,- ee,y u�a, WatershedG% n rn,m;-�,:.. rlro�apahw rw.sq W7 Figure 4— Storm Water Quality Sampling before and after ClosureTurf install APC Barry_EPA_0008 61 Pa ge YYYYWG WatershedGeo' Unearthing Solutions Parameter Area with Soil Cover Area with Closure Turf^ Turbidity (N TU) 371 11 TSS (mg1L} 349 -4 pH 6.5 7.3 TOC (mglL) 174 1 TRI (mglL) 16 0 5 Table 3- Analytical Results from Storm Water Samples at Tangipahoa Landfill Large Scale Flume Testing of HydroTurf® In areas of channelized flow(bench drains, down chutes,and perimeter channels), Watershed Geosynthetics suggests that the ClosureTurf be infilled with HydroBinder® (sand cement infill) instead of just sand. We refer to the resulting product as HydroTurf. HydroTurf has been tested at Colorado State University Engineering Research Center (CSU). CSU tested HydroTurf in accordance with ASTM D 7277-Standard Test Method for Performance Testing of Articulated Concrete Block(ACB) Revetment Systems for Hydraulic Stability in Open Channel Flow. The results of the testing were analyzed in accordance with ASTM D 7276 -Standard Guide for Analysis and Interpretation of Test Data for Articulating Concrete Block (ACE) Revetment Systems in Open Channel Flow. Testing was performed to the 5-ft overtop flume capacity which resulted in over 29 fps in velocity and over 8.8 psf in shear stress. The photos in Figure 5 show this steady state testing being performed. APC Barry_EPA_000555 71 Page YYYYWG WatershedGeo' Unearthing Solutions R I i Figure 5 — Steady State Hydraulic Testing of HydroTurf"' at CSU Full-scale Wave Overtopping Testing for Side Slope Protection was also performed on the HydroTurf at CSU. CSU has the world's largest Wave Overtopping Simulator which they developed for the US Army Corp of Engineers. Testing was performed on HydroTurf for 13 hours with 9 hours at the maximum capacity of the simulator(4.0 cfs/ft which represents a generic hurricane with a 0.2 percent annual exceedance probability— 500-year event). The photos in Figure 6 show wave overtop testing on the HydroTurf. APC Barry_EPA_000666 81 Page YYYYWG WatershedGeo' Unearthing Solutions 7 P i - i Figure 6—Wave Overtop Hydraulic Tenting of Hydmiurf®at Csll Longevity and Protection Provided by ClosureTurf' ClosureTurf is not an exposed cover system, it is a hybrid system that provides full protection of the most critical element of the closure system. ClosureTurf differs from exposed geomembrane systems as follows: Access and drivability of exposed geomembrane systems are severely limited without means of protecting the geomembrane. In addition, exposed geomembranes are vulnerable to wildlife trafficking.The engineered Turf component serves as a protective ballast providing physical protection and weathering protection. APC Barry_EPA_000M7 91 Pa ge WGWatershedGeo' Unearthing Solutions Since ClosureTurf looks and feels like natural vegetation, it is significantly more aesthetically pleasing than an exposed geomembrane system with hydraulic parameters that do not create fast time of concentrations and energy dissipation issues to the degree of that of exposed membranes. ClosureTurf has a longer functional longevity than exposed geomembrane systems. For ClosureTurf,the synthetic turf layer provides protection of the structured geomembrane such that it is not exposed to the elements. If properly maintained,the Engineered Turf layer will have a 100+year functional longevity. The results for 10 years of independent weathering data for the artificial turf yarns are shown in Figure 7. When this data is extrapolated out to 100 years,the yarn has an approximate 65%retained tensile strength. In other words,the design half-life of the engineered turf layer far exceeds 176 years.This longevity has been independently evaluated by multiple organizations who are experienced in the longevity performance of geosynthetics. Halflife Projections and Field Data oa Regressionfor Field Data 90 \ Y=-10321n(x)+1050 95 L RRR w a5 N a0 w 75 70 ¢ 65 247 years 60 55 176 Years 50 \ 1 10 100 Time(Years) 216 years • New Pin,,FZVrt —U111(Laga0hM1 )and Lvrvrr(Linear)aeend5 XaMire Projections(Mchgets,M15a,201sh1 Upperand tower Bound Estimates w,m,i..d�a.aa-ce>urer�T w Ps�ssrRm Note.Geosyniec calculated on upper bound half-life of277 years G@O t�D Figure and a lower bound half-life of 214 years using the same data and method.Differeore between Geosyntec and Richgels calculations mnsulrarns 7 are amilated to rounding_ Figure 7 - Independent longevity analysis projection APC Barry_EPA_000i 101 Pa ge YYYYWG WatershedGeo' Unearthing Solutions Static and Dynamic Load Evaluations Traffic Loading Evaluation Rubber tired vehicles, and some steel-track equipment, are allowed to drive on the ClosureTurf System. Typically, on slopes we suggest vehicles with ground pressures less than 60 psi, and on flat decks(2°%or less) and designed access roads, we suggest vehicles with tire pressures less than 100 psi. Detailed calculations for puncture of the geomembrane from wheel loading have been performed as well as lateral movement on account of vehicle braking have been performed on numerous applications for final cover. Traffic Loading Evaluation Light Vehicle— Pick Up Heavy Vehicle— Fire Engine ■ TIMp WM lmvf Gnn p,o w Mtuort kvn G�n� San°Bsn1 wM 5{ww<o°r.n IJ LItl150i APC Barry_EPA_000N9 111 Pa ge WG WatershedGeo' V Unearthing Solutions Traffic Loading Evaluation Continued (Fick Up Truck) (Fire F�leinue) Applied Pressure/Load- I 4.37 2.66 Defarmation of Geotextile Backing` Tensile Strength(Lateral Movementl' 1.85 1.90' Puncture Reslstance—Geotexhle Backing Component' 299 0o Puncture Resistance on Roadways— 4 oc/sy GT 12 of/sy GT Geomerrl6rane Component ' Factor of Safety " Methodology per Koerner 12005) Reduction Factors of 1.S for Installation Damage '"•' 200 Ih geotexiile required Traffic Loading Evaluation - Breaking r J _ F6 Fa Fr ' W. L wv Vehicle SI Dpe Angie Static FS Dynamic FS Fire Engine A Degrees 4.6 1.9 Pick Up Truck 18 Degrees l3H! 2.0 2.2 Aerodynamic Evaluation ClosureTurf has features that help mitigate the forces of wind. These include a porous surface to break the vacuum, and turf blades that will increase the aerodynamic boundary conditions and react against the wind causing a resistance to the uplift component. The ClosureTurf System was evaluated in the wind tunnel at the Georgia Tech Research Institute (GTRI). It was tested up to 120 mph without uplift. Based on these results,the ClosureTurf System is projected to withstand 150+mph winds when properly designed. The photo in Figure 8 shows the test at 170 fps (120 mph). APC Barry_EPA_000670 121 Pa ge YYYYWG WatershedGeo' Unearthing Solutions 4163 a� . a a r .\4i Ili 46 4 4l5 4? AU a as a to A0 00 00 too 120 1" raa W Velocity (Pt/sec) Figure 3—Aerodynamic Eva luatian of Cla su reTurf at GTRI Carbon Footprint ClosureTurf has approximately 1/5 the carbon footprint of the Subtitle D traditional prescription cover system. The factors influencing the carbon footprint, and other environmental impacts, are related to reduction of 350 haul trucks per acre that is normally required to haul the adequate amount of cover to meet the specifications of the regulatory prescriptive cover. Other impacts include the destruction of land for borrow soil, sediment from land disturbance. The details of the carbon footprint calculations are shown in the following chart in Figure 9. APC Barry_EPA_000671 131 Pa ge YYYYWG WatershedGeo' Unearthing Solutions Pnbetlpn eon" Y�INIM TOPW SOM r 004 t�IrMlNraaN {lOtO t2Z7,0001 gB0.0001 it9Ae0! ' adl nmur ut. c.uwui. rawrd.rrm RoOm�nr rarcq nopow f 00001 `� W2u01 fae2�K0 w,nr.l ¢ynthilk AOA' M'110:n � Ruu2r�M cm Tdti CO rbdvrin# n82,200 KO Sourw: Knerner,K.,"Traditiunalvs.&posed Geomem Mane Landfill Covers- CO3(Mt Curt and Sustainabilav Perspectives',Geosynthetic Llaga_ine,Octoder 2012. Figure 9 — Carbon Footprint Evaluation of ClosureTurf vs. Traditional Cover Emission Control The ClosureTurf system prevents fugitive emissions by totally encapsulating the closed areas. When integrated with conventional gas collection systems, higher collection efficiency along with reduced oxidation potential of the waste mass can be expected. If the patented ClosureTurf Surficial Gas Collection system is utilized, high collection efficiency, no oxidation potential along with significant reduction in condensate generation can be realized.Slope stability issues associated with landfill gas buildup beneath the soil/membrane (prescriptive) caps are diminished with the ClosureTurf system as a result of no soil loading,there is nothing to fail.The ClosureTurf system also has patented designed automatic relief valves to compensate for gas buildup pressure during periods of malfunction of the primary gas collection systems. Supporting Documentation All the information presented here is available for review at www.watershedaeo.com, or can be provided as a hardcopy binder as requested for a permit application. Please contact our engineering services team at 770- 777-0386 for any questions or a request for documentation. Live Binder—ClosureTurf Technical Binder-htto://w .livebindem.coMolav/plav/1981577-Access Key for private binder: closureturf. APC Barry_EPA_000672 141 Pa ge Geosynte& consultants CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 ATTACHMENTS GW6489/Barry_50%Design ClosumTurt Draft APC Barry_EPA_000673 III) ClosureTurf° Design Guidelines Manual January 2018 .d I&�a:'� WT G Unearthing Solutions ClosureTurf®,HydroTurf®,VemaC p®and HydroBinder®products are U.S.registered trademarks that designate products by Watershed GeoWnthetics,LLC.These products are the subjects of issued U.S.and foreign patents and/or pending U.S.and foreign patent applications. APC Barry_EPA_000674 Table of Contents 1.0 Introduction......................................................................................................................................................................3 1.1 Purpose and Scope............................................................................................................................................................4 2.0 Landfill Cover Design Best Practices using ClosureTurr...................................................................................................4 2.1 Typical Landfill Cross Section............................................................................................................................................5 2.2 Diversion Berms and Benches...........................................................................................................................................6 2.2.1 Benchless Design with ClosureTurr...............................................................................................................................6 2.3 Landfill Access...................................................................................................................................................................7 2.4 Anchor Trenches...............................................................................................................................................................8 2.5 ArmorFilr..........................................................................................................................................................................8 2.6 ClosureTurr with Stone Infill for Ditches...........................................................................................................................9 2.6.1 ClosureTurrwith HydroBindei Infill for Downslope Channels......................................................................................9 2.7 Energy Dissipation...........................................................................................................................................................12 3.0 Product Data Sheets........................................................................................................................................................13 4.0:Sand Infill Stability(CT 1)...............................................................................................................................................16 4.1:Sand Infill Stability(CT 2)...............................................................................................................................................17 4.2: Interface Direct Shear Testing(CT 1).............................................................................................................................18 4.3 Interface Direct Shear Testing(CT 2)..............................................................................................................................20 4.4:Wind Uplift.....................................................................................................................................................................21 4.5 ClosureTurf°Grain Size Curve Parameters.....................................................................................................................24 5.0 Hydrology........................................................................................................................................................................24 5.1 DE-tention, Not RE-tention.............................................................................................................................................24 5.2 ClosureTurr Hydrology Parameters................................................................................................................................25 5.3 Drainage Length(CT 1)....................................................................................................................................................25 6.0 Survivability/Drivability Calculations.............................................................................................................................28 7.0 Gas Management Plan....................................................................................................................................................34 7.1 Minimum Requirements.................................................................................................................................................34 7.2 Surficial Collection Design (Where Applicable)...............................................................................................................34 7.2.1 Surficial Strips(Where Applicable) ..............................................................................................................................34 7.2.2 ClosureTurP Pressure Relief Valve..............................................................................................................................36 7.2.3 ClosureTurf- Collection Foot........................................................................................................................................37 Page 2 APC Barry_EPA_000675 8.0 References......................................................................................................................................................................38 1.0 Introduction ClosureTurf®is a patented, 3 Component System* that serves as the final cover system on landfills.Two versions of ClosureTurf' are listed below. Note that the versions lend a unique versatility to the product as the components of each may be mixed to fit performance requirements. ClosureTurf"ICTI) Component 1-An Agru Super Gripnet® LLDPE (or HDPE)geomembrane liner Component 2-An Engineered Turf Component 3-A sand infill (and/or alternatively, HydroBinder infill) ClosureTurf 9CT21 with ArmorFlfP Component 1-An Agru MicroSpike° LLDPE(or HDPE)geomembrane liner Component 2-An Engineered Turf Component 3-A sand infill with ArmorFf r polymer emulsion added to bind the sand infill 'A Watershed Geosynthetics patented (patent no. 8,585,322) gas collection system is a separate component to be utilized on sites that produce gas emissions.Pressure Relief Valves are provided at one per acre of ClosureTurfe on landfills where gas emissions are expected. In addition to the ClosureTurf* Design Guidelines document,product specific Installation Guidelines documents as well as Specifications and other technical data are also available at www.watershedgeo.com. Page 3 APC Barry_EPA_000676 1.1 Purpose and Scope This manual contains guidance to aid in the design of final landfill closures utilizing ClosureTurf 6(CTI) and (CT2)as the primary final cover system.As with any landfill liner design,it is imperative that a proper design be married to a proper installation of these products.See Figure 1 and 2 below. Minimum Minimum 1/2"Sand Layer 1/2"Sand Layer w/ArmorFiIITM Engineered Turf Engineered Turf / Woven / Woven Geotextiles IJ � Geotextiles Agru 50mil LLDPE - J Agru 40mil LLDPE or HDPE or HDPE Super Gripne& Microspike® Prepared Subgrade Prepared Subgrade Figure 1: ClosureTurf®System (CT 1) Figure 2: ClosureTurf System CT 21 This manual is meant as a guideline only.Watershed Geosynthetics LLC cannot anticipate the many ways this product may be applied either in design or installation. Varying site conditions will require close coordination between the engineer and the installer to account for any changes and adjust accordingly. When required by state and/or local regulations, a licensed professional engineer or architect will be required. 2.0 Landfill Cover Design Best Practices using ClosureTurf@ ClosureTurf 0 is a product that is used as the final surface on top of landfills and CCR (Coal Combustion Residual) covers. Since the final application of the product should be as maintenance free as possible, certain best practices for cover design should be and implemented in advance of final closure. Over the long term,a large amount of settlement both at the base of the landfill and the differential settlement of some waste profiles can cause grades to reverse and cause pockets where surface water may not drain properly. The following sections will look at specific closure cover design techniques meant to make a ClosureTurf0 cover system as maintenance free as possible.Additionally,this manual will explain specific Page 4 APC Barry_EPA_000677 unique methods to mitigate storm water issues that have not been able to be addressed before ClosureTurf•was available in the marketplace. 2.1 Typical Landfill Cross Section Typical closed landfills range in side slope from 2H:1V to 4H:1V. Overtime,these slopes settle yet usually will not reverse grade due to their initial steeper slope. However, problems may arise when the top deck of the landfill has been designed with very slight slopes (typically less than 5%). Settlement calculations must be done for both the expected base settlement of the landfill and the expected differential settlement of the waste profile within a given landfill. Obviously, a coal ash type of waste will not have nearly the differential settlement that a MSW type of waste will have. However, over time the combination of base settlement and differential settlement can be surprising. The settlement problem can become more of an issue when such items as diversion berms have been placed on the side slopes at typically less than 3%longitudinally to convey storm water.Again,settlement calculations are one key to a good, long lasting design. Figure 3 below shows typical settlement design concerns when planning for a ClosureTurf a cover system. Typical TcpCeG Differential Settlement can mare from any area he conryfrnm5%-10% and can W hadl to predict over the life of Me landfillbwarcwne SeMnrenl .11 a l Deadline3emm slnpea 5-1094 n and ca sxmo rermme sentiment.adarycadenced!flodaine va waste r/ Mate 3ettlereerd onM Sixeds ufbkle nn landfill Mae can W de iii el Mail algae 91 naa as, Base semarrant Figure 3:Typical Landfill Cross Section Page 5 APC Barry_EPA_000678 2.2 Diversion Berms and Benches Diversion berms and benches on ClosureTurf a cover systems should be designed as regulatory requirements dictate. For slopes between 3 and 5%, and where velocities are less than 4 fps, sand or gravel infill may be used. When higher flow velocities are expected velocities between 4 and 10 fps), ArmorPir infill is used. When utilizing ArmorFdr infill, the concern for typical concentrated flows as related to erosion and other failures are no longer an issue.When velocities exceed 10 fps,HydroBinder® Infill is recommended. If the velocities can be conveyed into and out of the specified infill channels safely, design concerns about flows are alleviated. A hydraulic jump calculation is suggested where downslope channels abruptly change grade from super critical to sub critical flow. Figure 4 shows a typical Diversion Berm scenario. Send,Qrevel orMmMFdm lnnll(e minsb design veWtW uireclef) ClosureTurfo P�Aaietlg'.. w Uye�is 2 Diversion Beim Fill Waste Longitudinal ditch slopes will pyicaly vary from 3%-6%. When velocities are greater tan—pa...........10 fps. Figure 4:Typical Diversion Berm 2.2.1 Benchless Design with ClosureTurf® When landfill covers are designed that utilize ArmorFilr, it may be possible leave diversion berms and down slope channels out of the design completely. Because ArmorFilr binds the sand together within the engineered turf, no drainage length limitation is necessary.This is an innovative improvement to the product that will allow storm water to stay in Sheet Flow for a longer period and therefore raise the Time of Concentration (Tc)values. Regardless of the'version'of ClosureTurf e,the designer enjoys the savings gained from not having to account for the 67 cubic yards of sediment storage,and not having to design for Water Quality Volumes (WQ).The storm water conveyed from the ClosureTurf 0 is the same quality as it fell from the sky.When ArmorFdr is added to the infill and the Tc values are increased,it will help the sizing of the storm water conveyance system just as CT 1 did,yet there can be an additional savings by not having to place diversion berms and energy dissipaters as designers were forced to do in the past. Page 6 APC Barry_EPA_000679 2.3 Landfill Access The ClosureTurf a cover system can be driven upon under certain stress conditions (See Section 6.0 Survivability/Drivability Calculations(. Extra care will need to be used according to the load placed on the system. As shown in Figure 5,areasthat receive a higheramount of lighttraffic will require 1 inch of sand and Arnint i/le to act as a cushion layer between the sand and vehicle contact. In situations where the access roads will need to be placed in areas where ClosureTurf a has been applied yet heavy traffic is still ongoing,other solutions are required to protect the liner. Figure 6 shows a typical landfill access road scenario where ClosureTurf a has been applied, and a heavy traffic haul road is designed above the closure. This is a typical detail and will need to be designed for actual loads by the professional engineer of record. ClosureTurf® Install 1'of Sand ArmorFiIITM 3 n in Main Access Road 1 2'MIN. 3 Prepared Subgrade `Waste Figure 5: Light Vehicle Access Road Section 45' ClosureTur/®w/ 30' Send Infill Aggregate Base Filter GeotexOis Engineered Turf w/ ArmorFil/ compacted protective Soil Lave Engineered Turf wl (no Super Grinner?) Agm 2-Sided GeocanpasRe-300 it ArmorFill'u 2 0- (no Super Gdpnete) dei CI w/Rip R p J Agm Super Gnpnete Geom mbmne Fusion Weld Engineered Turf ClosursTurfow/ 7 w. AnnorFifirm 3 20 2.0' 2 3.0' Road Fill Waste ClosureTur(®w/ ArmorFJl'u Transition from Said Infill to Rip Rap preparetl ubgrad. Figure 6: Landfill Access Road Section Page 7 APC Barry_EPA_000ri80 2.4 Anchor Trenches Techniques to anchor ClosursiTurf a vary, however certain precautions should be taken in the order the anchoring occurs.To get a final aesthetic look that reduces wrinkling, the product needs to be installed and allowed to relax over the course of construction while the infill is finalized. At this point, the anchor trenches may be filled and compacted. Note that all anchor trench designs will need to be reviewed and approved by the engineer.Examples shown are typical scenarios only.The project engineer is responsible for designing the proper size anchor trench for the specific site conditions.Note that the anchor trench at the top of slope is only required in the interim situation where waste placement continues to the top deck of the landfill. If the landfill is being closed over the top deck, no anchor trench at mid-slope will be necessary. Compacted soil in Anchor Trench Compacted Soil in Anchor Trench Weld C>eomembrene to Base Liner and Continue Y Engineered Turf Into ClosursT d's AnchorTrench F Il .,�d, Sat13� ✓e p �y Waste 1.6 J 1 I t I Mann Figure 7:Typical ClosureTurf®Anchor Trenches at Too and Bottom of Slope 2.5 Armoffilr Armon'Ur is a polymer emulsion that is mixed 6 parts water to 1 part concentrated ArmorFiir and then sprayed onto the previously placed sand infill. Note that ArmorRir should not be applied until the sand infill component is installed and approved.ArmorFilr may be used in addition to sand infill to protect from sand infill migration when the normal maximum drainage length is exceeded.ArmorFilr is normally utilized in any of the following conditions; • When a geomembrane with a lower drainage profile is used,such as the AGRU Microspike• geomembrane. • When concentrated flows have velocities greater than 4 fps yet less than 10 fps. • To act as a transition point between sand infill and Hydrobinder•infill. Page 8 APC Barry_EPA_ODOM 2.6 ClosureTurf®with Stone Infill for Ditches When ClosureTurf s is installed in ditches and stone infill is placed in lieu of sand infill, it creates a ditch lining armor that will allow higher flow velocities to convey without damage or maintenance to the liner system.See Figure S. S'ArmorFille ClosureTurf® Transition Zone ArmorFili® Stone Compacted Designed for Backfll ShearNelocity I 1 I t 2 Prepared Subgrede Figure 8:Typical ClosureTurf a with Stone Infilled Ditch 2.6.1 ClosureTurM with HydroBinder® Infill for Downslope Channels HydroBinder infilled ClosureTurf® downslope channels are easily constructed because only the type of infill changes.Byfollowingthe HydroBinder Installation procedures,the final placement of HydroBinder is fast and effective. Figure 9 shows typical downslope channel sections and how they may be designed according to whether waste will be removed. Figure 10 shows the typical HydroBinder infill placement area for downslope channels. Important:When HydroBinder is utilized for high velocity flows,it is important not to block the flow that occurs in the Super Gripnet®with heavy structures such as Rip Rap Check Dams. Page 9 APC Barry_EPA_000682 HydroBinder"" ClosureTurf® Prepared Subgrade W YY..Yr+� D 1?���� �Y(rcetiiSuutYiW(4uu4f( Waste Excavation Waste Note: Use this option where waste Intermediate Cover(See Note 1) excavation needs to be minimized or eliminated. Option 1 A Downslope Channel Section 1 N.T.S. HydroBinder"" �ClosureTurt® Prepared Subgrade W j � 2 ra¢�uvr........:... 1 �- WYYfYfWWfYfWWfYfWYYYfW D Waste Excavation Waste r Intermediate Cover(See Note 1) NOTE: Use this option where waste will be excavated to build downslope channel. Option 2 A Downslope Channel Section I / N.T.S. Prrepa're��d Subbgrade HydroBinder— � 1 W I 2 Trench Existing _-D1 Vegetative Layer to I Waste 3' Remain Intermediate Cover(See Note 1) NOTE: Use this option to retrofit a Existing Closure Cover Liner System HydroBinder'rY inflled downslope channel on an existing closure cover liner system. Option 3 - Retrofit A Downslope Channel Section 1 N.T.S. Figure 9:Typical Downslope Channel Sections Page 30 APC Barry_EPA_000683 \ ClowreTUR°\ CbsureTurl® /) NpvanaerTMmry21 /J J% a¢ENxm.N�W EMMx Tt J.r J] Tt rogintler 21 /z.r/ e.m I a1 3:1 Cl sunaTuri'\ o>„uw.a.mm \ ClosumTurfo Hytl Bind r' XydmaiMx^'nwv 2.1 2:1 3% mM4mtlnM�OYEglrew J:1 S1 J% 21 2.1 z:t Un— 2:1 ` nB min°A �'7 I 7 ` Clo.mTurro \ crosureTuri® A 21 WL 9:1 Figure 10:Typical HydroBindei Infill Placement in Downslope Channels / Page 11 APC Barry_EPA_000684 2.7 Energy Dissipation Energy dissipation at the base of the ClosureTu&with HydroBindei downslope channels can become significant as with any landfill closure. Internal energy dissipators, stilling basins, scour holes or a combination of these may be necessary to properly convey high surface water velocities at the toe of slope and/or around sharp angles. The velocities with most downslope channels will be high. HydroBindei infilled ClosureTurP will be able to better handle these high velocities and will not fail under very high shear stresses. Proper energy dissipation techniques can be found in FHWA Circular Number 14 (HEC 14) "Hydraulic Design of Energy Dissipators for Culverts and Channels," Sept. 1983, revised 1995.See Section 5.0 Hydrology for further hydrologic parameters. Important:When ClosureTur/°with ArnnorFilr (CT 2) is utilized,the requirement to concentrate water to get it off the cover system more readily may not be necessary. Because the ArmorFill'does not have a drainage length requirement,Diversion Berms are not required.Since there are no Diversion Berms,there will be no Downslope Channels. And without the need for downslope channels, the need for energy dissipation is greatly reduced. This technique will also keep stormwater in Sheet Flow for a maximum period before having to be channelized. Higher Time of Concentration (Tc) values help to alleviate peak storm timing. Page 12 APC Barry_EPA_000685 3.0 Product Data Sheets 16 closure Turf*wi mil SuperGillib t' ClosufeTU/f Txlakneaa(eammal),mil hum) a 1p D599a m(1.2]) M(12]) rnitknes(min a,.),mil lmm) AI D5990 all(1Rl) 4]s(121) thickness oawea lnI mu(mm) .D599a @shoe) 4n(1.08) Drainage Stutl Hei9hyton.ava),mil(mml AST.Well 130(3,30) 130(3,30) Frktbn Spoke Height(min.avg),mil lmm) ASTM D. t7hta 5) 175(1 Derecia /a ASTM D]92,Method 0.90(maa.) 0.9I(min.) Tensile promotes p,.ham directions) ASTM 06693,Type Strergb@Vle.(min.avg.),Ib/In.wath(N/mm) MIM 06693,Type IN N/A 110(193) Elongatlon@ voted pal P.an.),%(GL-1.31n.) /Sled 06693,Type N N/A 13 %vmgthYnmxk(min.an.).It wil IN/mm) MW 06693,Type of 105(18.4) no(193) Elorgallon@Break(mm,evil%(GL=1.O In.) A9M Ofifi93,TypeN ID] 2D] Tear aesiterm ma,.avg.),III IN) ASFM D1004 30(133) 381169) Puncture Examance(min.rvg)flo IN) AS TM Exped 55(MS) W(358) Urban Blah Content move%I Mme 04218 2-3 2.3 Carbon We&distance(Categary) A9M D55% Only near spherical agglomeMes 6r 10 views In Cat.1 or kneo Crack Had chence(Smgk Pdnt NCTIQ,hours MTM D5392,ApWmkx N/A VIE 6yWJ lnEUttlOn Tlme,.1.1. MW Db.,2Oul 1 Mm Or no 2140 N.eme—eve—.......Awmva..re.Eemn amrt,.rc...asrx mml+rcl+•t ou,e..Masuary...amaovm yxae m0 ENGINEERED TURF COMPONENT Cog Purcture ASTM D8241 B00 III bal method Food.(M D/XD) AST.Oum 1,00011 an .evil Rainfall Induced Emi aI 06459 0.04%111 Ims6mAr. aerodynamic Evaluation GTml Wintl Tunnel 120 mph Wth max.uplift of O12 Hoof FngineeleE Turf FibelTuh UV Stability ASTM GU] x60%retained parent,a✓omith tt IM yn, dojdered) Bactlng System DV StabiON Ind.T. A57M G1545 Modified Cyck EUVAMO 2 Ol Wft.rttalnM temlle strength at OW got Gemmlk Fulk opmtl) hrs S h auertoppiry mouMng in 29 the vNJ 5&atly State real Overtopping lClow reTUT w/ ASTM DR]]/D]2]8 and 8b psf door stresa(or Morning'sN XytlroBintlera) Value of am Full kale Weve Ovetopping Teat Cumulative Volume Co eratlo 5tste Cohmemm,Wave good tt 565,000felft (Clommmurfa with HO"Incere) Full kale Wave Overtopping Test Dluharge(Closu rein M with Colorand Onto Un'vatity Wave Sl mulatn 4.Ohsk/ft XyEraBindere) Imemal Md.of Combined Componem. ASIM D5321 35',min. ArmOlFill"'Infill ASIM maxi Enter C-33 Fine AgF(ptea w/Porma.c ranter Yam Mightimmel ProdvA Wirght) ASTM D5M1 t19 M./an.y1(a 24 M./sp.poll) mmale kreogih of Varn AS NA D225B i5 bad.min. SUPPLY INFORMATION IStanclard Roll Dlmenalonsl mil ram R m h. m W m2 Ibs kg Su per Gtlprete SD 1.25 23 ] ID] 91.4 k9W WO �CCO -13W TUrf CpnpWpm we N/A h5 4.6 3W 91A 45M 418 SQ 381 um/eN rMmtun•/oMunrlW omrvxw;Eex.1o5.8,585.aEa.At6aJR,aK9,193.i0;G.NYn Mem xa.;Ea3.aM.eM egerFmnrhMae). oaymNmto var wrpMwart avef mntnn.N N¢%Ire4 v.re%rchWk; aeiny as a—vactern vac—or �wwpupn M1amn�e w+mL non ^vpeuywmNi��feMwa Yere —c'--cfaa�ron. ru¢mem mvervlaraw yr ame riaWu¢M.ursleeNn¢afP«wlaMe munmvmaw%nem¢¢rv¢bn[kvMm wrem 01-MIS 0 Page 13 APC Barry_EPA_000686 Closure Turf-IN 40 mil MiDroSPikew ClosureTurr ThRknese(nominal),mil lmml ASTM Di 40 Um) 4o D.02) Thicknezz(min.AM.),mil(mm) ASTM D5994 3110.9]) 3810.971 Thickneselowestintliv.),migmm) ASTM D5994 so yo.se) 36(086) Asperity HaigM(min.ski pill mar) ASTM 0I466 2(10.51) 20(0.51) Density,g/cc ASTM m92,Mi8 agulhe x.) 0.94(min.) Tensile Peps ie5 is,both dometienz) ASTM 06693,Type IV Strength @Ykld(min.sug.),110,wIMM1(Wmm) ASTM D6693,Type IV N/A 89(15A) ElangatIon@neld(min.aq.),%1iiIn.) ASTM D6693,Type IV N/A 13 StrengtM1@Break(min.a,),Ib./Ia width(N/mm) ASTM D6693,Type IV 112(19.6) 88115.41 Elongation@Break(min.avg.),%(Gb2.0 in.) ASTM Looks,Type IV 400 35D Tear assistance(min.avg.k It,IN) ASTM DI004 25(111) 301133) PurcWre assistance(min.ani bs.(N) ASTM 04833 501222) 901400) Urban Black Content(range%) ASTM D4218 23 2-3 Urban Back Obcersion(Ul(Category) ASTM Di mews nvrspber"I agglomerates for l0 mews in Cat l or Smass Crack Resistarza Single Paint Ni hours ASTM D5397,Appendix N/A 500 0xidative lnduNars Times,minutes ASTM Ma95,IDYL,lalm Dc 2140 21Q At.AmeMatawmerbox re¢NXetlmwsstx,,—wenerssw.ni]Ftp]I6ISe",aM rex—i Hialle'ewho Amus a m!IWCI ENGINEERED TURF COMPONENT CBR Puncture ASTM D6241 8W It.(MARV) Tensile Product(MD/%D) ASTM M595 1,03011 min(MAW) poll Induced Choice ASTM DN59 Infill Was 6 in/Fc WD(with ArmorFilP') Aerodynamic Waluxlm GTRI Wind Tunnel 12D mph with max.uplift of 0.121b/zf Er$ineeretl Tied Fiber UV Stability ASTM GIQ >60%Asolned tensile Strength at 100 yes. (pmiected) Backing 5y4em UV Stability(Exposed!) ASTM 33545 Meddled Cide 1.WA340 110Hs./R.retained tensile strength M 6509 hrs(proh,ced) Steady State Hydraulic Overtopping(Clouseclud'w/ 5ff,overtopan8 hour,In 29 his vNaNry HydroBlndere) ASTM D]2]]/D]276 and 8.8 psi shear stress for ManninjsN Value&0.02 Full Scale Wave overtopping Test Cumulative Volume Colorado State Universe,Wave Simulator 161ft/R 1ClatureTud+with HydroBleders) Full Scale Wave Overtopping Test Discharge lCbsureTurte Colorado State University Wave Simulator 4oft fi WA HydreBdndi ale/ Internal French of ComMned Components ASTM 05321 21',min. ArmorFilP'Infill ASTM D6913 ASTM C-33 Fine Aggregates w/Pozielanic Binder Yarn Weight(Total Product Weight) ASTM D5261 219 oz./sop.yd(224 ch./sq.W.) Tenile Strength ai ASTM D2256 151M.mIn. SUPPLY INFORMATION 15tandard Roll Dimensions) .it mac ft. an k. in R° m2 Ibs IS MicmSpike° 40 1.0 23 ] 750 229 17,250 1E03 '3900 -1769 Tud Cent'rent N/A N/A 15 4.6 30D 91.44 45CV 418 Ann 381 NT/en0 XWmNTIpexi IUSIarmXa.].N3,103,a5a3.lSL 9,163.3[5.+N9,193.)d];evre4lan oaum K.Lesa,l]0;an4araer Iattmehn41vI+Mvv4emeFnareroeprepeq es eMare rree m�e 4—1,t -c mrrenbr es anree--rw 1. e eO� r+ue exa scr,a meee eysnree4erne.Ur is eX+endwmurew se, amuXsmhoMa W.n�or XewwarenM4ewvnmeW LLCauweaM'Iob�IMmmnwn[n Ferewm.nryuarememmaaewrunmrynoreeakWreNeaegereYaaiEnwnN .nMrrmiun e¢l ssic—rvwdesrsx.exwnkulaes uvlmMXunwdmmgaw¢orgarbemuudappudelmorgmmmmrreµlgvu.W ryFwpnemk u+e ree-1 mac O1d018d Page 14 APC Barry_EPA_00068] Clo3ureTurfe w/60 mil SuperGripnel ClosureTurF "add,,Data Test Method LLDPE Values HOPE Values TM1kkn.Prominal),mil lmml ASTM DSR94 0µ.52) 0(l.52) Thickness(min.a,.),millmml ASTM D5994 57 O.46) 9(1.461 TM1kkness gowest large.),mil lmml ASTM D5994 51(1.m0 51(l.30) Drainage Stud Height(min.avg.),mil(mm) ASTM DI466 130I3.301 13D(3.30) Fromm Spike Height(min.area.),mn(mm) ASTM w466 175(4.45) 17514.45) Density, /or ASTM W92,Method 8 o9at boex.) ft"been.) Temple Prcperties berg.both direttimv) ASTM 06693,Type IV Strength@Ypeld min.ass.),IMin.width(Wrom) ASTM DM93,Type IV N/A 132(23.1) Elongation@ Yield(min.avgJ,%(GL=1.3 in.) ASTM C6693,Type IV WA 13 Strenaphalmeak(min.mal Mile.wldtb(N/ram) ASTM 06593,Type IV 126(22.3) 132(23.3) Elongation@Break(min.ay.),%(Gk=2.o In.) ASTM D6693,Type IV 3DO 20D Tear Resistance(min,avg.),lbs.IN) ASTM DI004 40(1781 42(187) Puncture Resistance(min.avg.)Ibs.DID ASTM D4833 70(311) 90(40D) Carbon Mark Content Range%) ASTM 04218 2-3 2-3 Carted.Black Opspeminn(Categnry) ASTM DSS96 Only near spheral agglomerates for 10 elders in Cat.l me Starts Crack Resistance(Single Point NCTL),boom AAM D5397,4pendpx N/A 500 Oxidative lnduRbn Tlme,minutes ASTM D3895,200'C,l alm 0, 2140 11.0 apramedoaawmemaeaaaocandemwpalmanaoP adaenall,AslMm1almc).seoimm,bulsunmyvb..amn ollwµax!aa'9 ENGINEERED TURF COMPONENT Product Data Test Method Values CM Puncture ASTM D6241 BOO It.(MARV) Tensile Product(MD/XD) ASTM M595 1,000 It,/ft.man.(MARV) Rainfall Induced traded ASTM D6459 0.04%IrRill lass 6 in./hr. Aerodynamic Evaluation Ord Wind Tunnel 12D mph wllh mans.uplift of 0.121b/sf Engineered Turf Fiber Tuft UV Stability ASTM G14T MO%cted) tltensile strength at 100Yet. Backing System UV Stablllry Index Test 11D fibs./ft.relapned tensile strength a (Single GeWnpl oe Fully Exposed) ASTM G3545 Matllfletl Cycle 1.UVA340 6500M1rs Social State HydraWC Overheating(ClowreTurf w/ 5ft.overtopping resulting in 29 R/s whether HytlraBintlera) ASTM WP2/WP6 and 8.8 psf shear stress for ManninjsN Valu..W.02 Full Sale Wave Overtopping Test Cumulative Volume Colorado Sate University Wave Simulator 165,000ft/ft (ClmureTuT with HydmBinder•) Full Sale Wave Overtopping Test Discharge lClaureTuM Colorado State University Wave Simulator 4.0Its/s/ft w4lh Hytlraeldtlere) Internal Fashion of Combined Components ASTM D5321 35,min. ArmerFilP lnfill ASTM D013 ASTM C-33 Fine Aggregates w/Pozzolani[ notice Yam Weight(Toml Product Weight) ASTM D5261 z19 M./s9.0.(k a is/z9.0.) Terns Strength of Yam ASTM D2256 15Its.min. SUPPLY INFORMATION(Standard Roll Dimensions) all an. ft an ft. an W m2 lb, It) Super GdpnW fie 1.50 23 T 300 91.4 6,900 640 -30W -1360 Turf Component WA N/A 15 4.6 300 91.4 4,500 418 840 381 WwreNTland Iad0Th .1 for..Xw 1, ftx,Me"do"o"3as,aM9,1Mya;Gro9an gMm m.2Welm;aM man,Yams Porn)am,raeema,Yare NepNxMN mrsM1N4mymFmrslLC.Ni Noma4m,remmeNmb¢aMsygemwna;nrlry�nablXm�ve„vrm4gtaeueJowwNw¢a,e pax¢d upn,exnand aaw aaimedw aerektle; cmdmeagpbnenxnlwunaagnaemwenuweumiwngnamvninmm wohnsa , ,mdmnam anwar Mka��ect"uopan nxeeem wrwiemrm.nnsue�meewuxmmynaquMnwva3wimpud.umaxtywamnneememymneuaueamn�mene¢varvrn,dew M1ured watlmwawrsMnwy,Neti¢amazuwnynrilrym,mmtinn MrexnM1.a abnWerymnpkwvire wwammrmm]atlanwaFMnraanY each. or oaegYmgwtlllbu ordwmuarces M.w&uwedegglublelrvienw ryrcmmemmu6aknn XWOYUMreIn4wMewnurvW esae,ma16Ym 01-2618 0 Page 15 APC Barry_EPA_000688 Closure TWO all mil MicroDraine Liner ClosureT rfx TbiGneu(nomieal),me lmml AsiM o599e So11.2T1 5011.291 Thickness(min.av8,l,mil lmm) A51M 059M 47.5(1.21) n.511.22) Thickness(Iavest is 1,mll(min) ASTM 059% 425(1A8) 42.5(1.08) Dominate Stud Height(min.ass.),mil(mm) ASIM Di itil 30) 13D(3.30) Mior ike ASraHly height(min.avg.),poll(mm) ASTM Ola66 211 20(0.51) NosiN,R]tt ASTM W92,.... 0.94(in..) D.94(min.) Tensile Pmpertles hens,both ElrMlons) ASTM 06693,Type IV Strength ii(min.wag.),ofin.w@M1(N/mml ASTM 06693,Type IV N/A 110(19.3) Elongation@Yiid(min.ug.),%(GL=1.3in.) ASTM 06593,Type IV N/A 13 ShromphQOBreak(Yin avg.l,Ibl it.Will IN/na l ASTM 06693,Type IV 305(18.6) 130(19.3) Elorgrtion@Break(min.arg.h%(GL=2.O i..) ASTM 06693,Type IV 360 200 Tear,assume.(mi...1.), by.IN) ASfMMote 30(133) 38(169) Puncure Resismnce(min.evil lba IN) AAM O4833 55(2IS) BU1356) Carbon Ideas Content maps%) ASTM D0218 2-3 2-3 Carbon Bleak Dispersion(Calia l A.055% Only near spherical agglomerates For wrxs in Cac 1 or 2 Stress Crack Reartance(Single point Nl hours ASTM D539],Appentldx WA 500 Gutlativemtlucion Time minutes ASTM ones,M-C,1 aim Or al a140 Jamauarsalso mmem.xawmmaaempmm.Twnpennw,exw.ama maFlar4am umnm,wmauryw.asid Dr.b1g 1.1 ENGINEERED TURF COMPONENT CBR Puncture ASTM 06241 80016(MAW) Tonally Pmaint(MO/XOl AAM 04595 1,0S0Ill mdn(Mur Rainfall induced Erosion ASTM 0i 0.04%Will Was 6in./M1r. Aerodynamic Evaluation GTRI Wind Tunrrel 120 mph wllh max.rout of 0.1111 Engineered Turf Fiber Tuft UV Stability ARM G14] a60%retained tensile strength at 100 M. (emissions) Backing System UV SUddtylntlea Test ASTM G1545MotlI0etl CKIe1 WP34o 110 firi retained Works strength at 6502 (Single GeoteMlle,Fully Eapssedl hus Sleatly Side Nydraulk OvenoppinB lClosureTurt'w/ SR arxrtopong resulting In 29 Ws vedocdty Stard, ihPoincelarde .rs) ASTM DR]]/WD6 and 8.8 Psf shear stress For Manning'sN Value uo.02 .11Sod,Were,Oxrtppping Test Cumulative Volume Colorado State Univeniry Ware Simulator 165,000f/t (Charnel Will HydroBindeN) Full Scale Worse Overtopping Tort Girder,(ClosureTud'evitM1 Colorado State Univeniry Wave Simulator p.Ots/s/ft Hydroirtlers) Incemal Fission of Combined Components ASTM 05321 35,min. Armo6ill"'Infill ASTM D6913 ASTM G33 FIne AMpegaces w/Piumbric ender Yam Wall ITOUI Pmtlucl Weight) ASfM 05261 219 oz./sq.M.(a ze m./sp.yd.l Tensile Strength of Yam ARM O2256 15 to,min. SUPPLY INFORMATION(Standard Roll Dimensions) sell min t. an t, in to m2 lb, is Super Grippe 50 its 23 T 300 91A 6,900 640 -3000 -13W Turt CemForen[ N/A N/A 15 A6 300 91.4 45M 418 MR, mi wlam apmr.m/ps'—ms Tim.."tw.45a,,aiaaata.aMatae.aee;rana6an Pxameu.I..art ,nxmN,aetMOmxrym wgw ram e0eypimb virmnv nth lece.eewwde,mbNewml eretMvwmlNtltlwdldvwmnn'.W gMeNapp4dlMMl �emeporxnb4nrao..wm4 maw�waw vxnetiy^damrna.nwesssewmpoee.ivmaxtyxarersN4eam�Mbu<amce MermdsW uuw�hmhm4.maaN,to.w aaui laos;mrfspxaula- xmaxnereinmsynmmam.xmymrpietrs�aeeewi;Mwma,nn marmr�asyoen;neexnen prmlarerevpznflm,Jeemannvmeunmxeuty Hume W ypeFk HwaagavemmamryuWmn.xmM1n{Aeren um YmmeuMxpm�vnnnxaremmmeMa.mmmmryeaM M 01-201&0 Page 16 Al Barry_EPA_000NS) 4.0: Sand Infill Stability (CT 1) The bottom spiked friction surface of the Agru Super Gripnet® 4.4 mm high spikes and patterned texture provides maximum interface friction and high factor of safety against sliding at the liner/soil interface. On landfills and mine piles, sliding of the soil cover along steep side slopes is of primary concern, particularly after major storm events. On top of the Super Gripnet®liner,there are no thick, heavy cover materials to get saturated and possibly begin to creep.The sand infill is held in place by the well graded sand and the unique structure of the engineered turf that traps the sand to anchor and ballast it to the surface it covers. Additionally, the drainage studs embedded into the Super Gripnet® are designed to convey shear forces of water on the geomembrane rather than on the top of the sand. Note that: • ClosureTurP can be placed on very steep slopes • Tests indicate 39 degree peak interface friction value 4.1: Sand Infill Stability (CT 2) CT 2 will utilize ArmorFill`.This product greatly reduces the ability of the sand to migrate due to excessive shear forces by binding the sand within the Engineered Turf Component. Note that ArmorFill"may be added to the CT 1 or CT 2 profile either during construction,or when excessive sand migration is detected. Page 17 APC Barry_EPA_000690 4.2: Interface Direct Shear Testing (CT 1) Below are test results of the Interface Direct Shear Testing done on the ClosureTurPb product as it relates to the CT 1 profile. Low Normal Shear Box CLOSURETURF WNDFILLCOVERSVSIEM INTERFACE DIRECT SHEAR TESTING ASFM DSREI UppvSM�Sm:Gva'mevX n.m:xiy ea:nsXvet A�1L Ja yem IvnluN .Squbmil LLDPDP f]u S,i:er<inpei sue Knee SMe Be.:Coz rne.vW A 6p yS� bbw3p0a —va —IB —aC �Sx�E 5ab`00b R lP LD ll 1 1 O 10 I0o 00 as ID IS xo v 30 0 10 m m w W l0 WpansX141 NnvltlroW Tm Sbr om. SM n:Nie6n WSSoI sal G[1 Lms isi�a w a w w z z Iz InslaMna.r:�nil:Rlm.,X.u..::.r n..m:ur�:�:k X�e..maa�r.m..XXm.R�w.m. Ixln:e�MXml.m®m.::s++m'rwemAe'ewn:n.a e.ami.a nw.m emn�e:^W ae:weu c®mXmletre.eewu®YO�m^tla ®x.a.neorm.a. OA`FFw ST. LISrz010 FlDVRE NU Cd SG am T1CI MSil lCsf.LLC PFolEcrxo. scllaml W LMEN NO FlLENO Figure 11; Interface Direct Shear with Low Normal Stress at 10, 20 and 50(psf). Engineered Turf and Agru 50 mil LLDPE Super Gripnet®. Page 18 APC Barry_EPA_000691 High Normal Shear Box CLOSURE TURF LANDFILLCOVER SYSTEM INTERFACE DIRECT SHEAR TESTING(ASTM D SBTI Upper Shear Boa:CJna¢le send nomin lly wmWmd Eopoe dTw mi p Side(9 nynm5)epl Ag 50 mil LLDPE Super Gnpmlg—emIF—e wIh slum side upl Igwo BMer BOa:Co0.:'ele sBM w] B]II Slm Svaapl� 8 a Ra Pak 35 W 0931 � Mo LD n zs o.sw —LUwlvasl ao T. 0 0 00 oa 0,8 Iz 16 20 za ze 0 MJ 9W w w BBgaeenenl�) nwmlJrea 1p0 s� na,w see. em.N�aJ.m ca�ws.J D sJi DCL s�snmpne w Ra,si Sms flue si Time Sow Twe w 4 R w R R m % e r.1We 1 nmSli<.,Jrvfdxe)emmduAsum6ebnm JegmvelselJesefinJ pwmtloo4eEeo(JepriuA®e .�.Jiw-,nwwr"r=eafi;��m„yew.m�.,�m.e2ae:namafiw.uw.a fimm...am.mu.wnw.c.�.:m,mwam�mJ,m�.�au�ae�w w5.woaimmmw.•ro.mmn.,a,emmae:maenamemwaema.eeyme:wmia.new,e>em.m�m:a.DlJw,.Jmpn•ammlJm aJR:nemwn. �...m,a Jme..JanMwi. DATE oe TEST. Mt' 10 il00RE N0. G3 S[e_ 1<61 Rf11Na StllNCiL LLC PR03EC% SONooM COCI1MENf NO. i1LEN0 Figure 12: Interface Direct Shear Normal Stress at 200, 400 and 600 (psf). Engineered Turf and Agru 50 mil LLDPE Super Gripnet®. Page 19 APC Barry_EPA_000692 4.3 Interface Direct Shear Testing (CT 2) Below are test results of the Interface Direct Shear Testing done on the ClosureTurf* product as it relates to the CT 2 profile. Low Normal Shear Box CLOSURETURFIA.0 INTERFACE DIRECT SHEAR TESTING(ASTM D 5321) UBBer Shear Box:C33 sand lovely placed againit ClhuwreTurrwith baw geotextile down againa Allen 40-mil Microspike HDPE geomemb ene with dull side up qumt Clomm'rud I,usver Shear Box:Concrete send 35 dd Shear SlrcagW E pe 30 Peminnersl� (dcl (ne U —IA —IB —IC —IO 5a Pmk 33 0 0.998 LD 20 0 0.988 25 Cw O Pak C 0 fD 20 —unmuwkl � �Linm(LU) E5 11 w 20 0 l0 5 0 n 0.0 0.6 1.2 1.8 2.4 3.0 0 10 20 30 40 50 60 Divplaaleevr(In.] Nolmel mess(peU T., Sheer I*un. SMm 8oeka8 Crcmlidaa Www Soil Ilppc Soil OCL Shwelene he Feilurt Nn. Rua tiim S'ma� Xale Hour fine Smva Time yn pp ye py MnJu w.xlo.) ( Mom) f hma) Ilaw ( % A) R %1 % %1 Iq dean IR 12x12 10 e.M 8.5 ]5 In Iz x Iz 3a a.a Iz.4 IOA IJ 11 ¢ x n 59 D.ua 20.a 16F 0) W xs: (nsieh"(i.e..eMefuileee)rca 1n tt deturfuce bM.rau We WeeBMexWeo(ClovureTURaotl EUR ei2o(Ayu l4enepikelmPE geteffimbmce. (2)'Ihertryined until-Jm —newe,of Moline enuemtl Weldle,Wert demmninal faun a then-fil line denwn dhu hthe ell Jvlu.Cedinn Amid be eeeniaed in ueng deee alrtnyM pmxiasbreppliulm..imml,he-1 deeee aunid,Me,ado me¢rs mvnatl by 1w wneenee.Thu 1vg-0iaplexmeM(LR)iM,aRnpb w mledewe using dh Am,fwax uamne nMeeueldnlel. DATEOFTEST: 712MMI5 r FlORRE NO. 1 SLJ3 8W hs7M4Q SSURY"Mill LLC PROIECf NO. SG113014 3 DOCUMENT NO. FILE E13910.n5R.tla.Ms Figure 13: Interface Direct Shear with Low Normal Stress at 10,20 and SO(psf).Engineered Turf and Agru 40 mil LLDPE Microspiken. Page 20 APC Barry_EPA_000693 4.4: Wind Uplift Since all exposed geomembranes are susceptible to damage from hurricanes, the technology must withstand hurricane forces. A study was performed on the wind uplift reactions by the Georgia Tech Research Institute. The ClosureTurf® product indicated very small uplift (i.e. less than 0.13 psf) when exposed to 120mph winds. This is in contrast with other exposed geomembranes where extensive anchoring is required even for 50mph winds. ClosureTurf® technology provides features that help mitigate the forces of wind, such as a porous surface to break vacuum and turf blades that will increase the aerodynamic turbulent flow boundary conditions and blades bending and reacting against the wind causing a resistance to the uplift component. 0.15 0.1 0.05 N 0 -0.05 w -0.1 0. -0.1s a -0.z -0.2s -0.3 0 20 40 60 80 100 120 140 160 180 Wind Velocity (ft./sec.) Figure 14:Georgia Tech Research Institute Wind Tunnel Chart Uplift Pressure vs.Wind Velocity Page 21 APC Barry_EPA_00060 Aerodynamic Evaluations of ClosureTurf"Materials, GTRI Project No. D-62,K Contract No.AGR DTD 5114110 Aerodynamic Driven Requirements of sand Ballast Thickness for 0.0 - - Closure Turf Material-Conditions at Perimeter of Level Installation Sand Weight Density=110lbjfta,NO Factor of safety Included oe #,InterfaceCoefficientof Static Friction '.. 01 Ft=Interface Friction Shea Force �SM1ear6Vez;mu=0.93 Fx=Normal Force=Weght of Sand Lift (Neglects Turf Materfal Weight) = O6 _ _NormalLwtlin6 _ i__. _ E a e ea ... . E II 0.2 e F 0 O.W 20.00 40M 60.00 woo 100no 120.00 1"bo 160.00 180.00 200.00 free Slream WIM VelotllY.n/s Figure 15:Sand Ballast Minimum Requirement at the Perimeter of Engineered Turf Installation Page 22 APC Barry_EPA_000695 Aerodynamic Evaluations of ClasuraTun"eMaterials, GTRI Project No. D-6244, Contract No.AGR DTD 5114110 Aerodynamic Driven Requirements of sand Ballast Thickness for 0.1e Closure Turf Material-ConditionsofInteriorofLevelInstallation Sand Weight Density=110161/fta,NO Factor of Safety Included 0.12 M: Interface Cceffce t of6tatic FriGwn al Shear St :.m, os Ff Interfaae Fddion ShearFarce __ /F 0.5 sx aarStr ss,m, 0e3 Fx Normal Force Weet gantl-oft Ff x INegleaSTwf Material W¢IgX[I Shear She,an=15 9e 0.08 N r I Well, -.--.T C G0.C6 ...._... _.. a 9 o.oa _.__ __... F =0.93 - a e 0 T_y L.02 .. . . 0.00 2040 40.W 6040 MOD 100.W 120A0 140.W 16000 1e0.00 200A0 Free scream Wing velamy,Na Figure 16: Minimum Sand Ballast Requirement in the Interior of Engineered Turf Installation Page 23 APC Barry_EPA_000696 4.5 ClosureTurf® Grain Size Curve Parameters ClosureTurf® requires that specialized mixture of sand infill be placed in the engineered turf. The ClosureTurf® Grain Size Parameters are shown in Table 1 below. Optimum Infill Sand for ClosureTurf® would be a medium particle size sand meeting ASTM C-33 for fine aggregates. All infill material should meet ASTM C-33 specifications unless otherwise evaluated by Watershed Geosynthetics LLC. ASTM C-33-03 Sieve Percent Passing 9.5 mm (3/8 in.) 100 4.75 mm (No.4) 95 to300 2.36 mm (No. 8) 80 to 100 1.18 mm (No. 16) 50 to 85 600 µm (No.30) 25 to 60 300 µm (No.50) 5 to 30 150 µm (No. 100) 0 to 10 Table 1:ASTM C-33-03 Grain Size Parameters 5.0 Hydrology S1 DE-tention, Not RE-tention Any ClosureTurf•design that is chosen will be able to take advantage of the Detention of storm water rather than the erosion control method of Retaining storm water.With ClosureTurft,storm water is simply'DE'-tained long enough to mitigate downstream flooding.This allows space in the pond previously allocated for sediment storage and Water Quality Volumes to be used only for the safe conveyance of the design storm event. Page 24 APC Barry_EPA_000697 5.2 ClosureTurfs Hydrology Parameters Currently,many regulatory agencies are requiring run-off curve numbers(RCN)of 95-98 of atypical landfill closure. ClosureTur/®'s RCN should be calculated between 92 and 95. This number was derived by TRI Environmental, Inc. and Colorado State University Hydraulics Laboratory in separate tests.Table 2 below shows the typical TR-55 design parameters for Hydrology using ClosureTurf®. ClosureTurf*Hydrology TR-55 Data Curve Number Depends on Rain 92' -95 Intensity Manning's n Slopes>10% 0.12 Slopes<10% 0.22 Sheet Flow 100'-300' dependent on Manning's n until a depth Flow Length of not more than 0.1 foot is attained in the 2yr 24hr rainfall 2yr-24hr Rain SCS Land Slope design Flow Length design Shallow Concentrated Slope design Surface Flow (paved/unpaved) Unpaved X-Sect Area ft2 Wetted Perimeter Linear Feet Channel Flow Channel Slope ft/ft Manning's in 0.032 Flow Length design 1.RCN ranging from 92 in High Intensity Rainfalls to 95 in normal rainfall events. 2.Manning's n for channel flow will vary with depth of flow. Table 2:ClosureTurPn TR-55 Data The engineered turf portion of ClosureTurP will have a manning's 'n' under sheet flow that is 0.12 on slopes greater than 10%and 0.22 on slopes less than 10%. In most cases,the time of concentration for sheet flow will have the greatest impact to the overall Tc. 5.3 Drainage Length (CT 1) Critical slope length is used to define the drainage length between benches or swales where the system will discharge the flow. The graphic below shows the maximum distance allowed between benches or drainage features when using CT 1.The calculations are based on the transmissivity capacity of the Super Gripnet®to handle the flow without inundating the sand for slopes 10 percent or greater. Inundation of Page 25 APC Barry_EPA_000698 the sand in steep slopes can lead to erosion of the sand infill as shown on Figure 18. Note that inundation is allowed for slopes less than 10%as long as it does not produce shear values for cohesion exceeding 0.2 psf,or when velocities are below a maximum of 3 fps. Regulations usually require adherence a particular storm event.Since storm events such as the 100 yr 24 hr event only produce fractions of inches of total rainfall per hour, the designer will need adhere to a higher intensity,shorter time period event such as the 100 year 1 hour event to reduce the likelihood of inundating the sand on steeper slopes when this occurs. Use Figure 17 below to determine the maximum drainage lengths between drainage benches or discharge swales. Closure Turf Maximum Drainage Length IN 1 1 Watershed Geo' use chart in determine the maximum drainage lengths Design Rainfall ��.� Unearthing Solutions between drainage benches or discharge males. Wetland Intensity 90U Flow distance is calculated with a hydraulic shear of 0.1 psf _ 11 1,: in the ballast sand —2 War �11 ......3in/M1r EW _ 41n/M1r III N � ,1 11 � • .61n/M1r � .11 _ 5pp 1 `c6 son —It I Is E LW \t FIx •". ........ 200 __ _ _ _ _ . . . W _ 0 al 5% 10% 151 20% M. 30% 351 40% OS% 50% 51ope Gntlient *Based on use of specified grain size sand infill. Figure 17: ClosureTurf® CT 1 Maximum Drainage Length Page 26 APC Barry_EPA_000699 ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ •::::OXEN{■f•X:titi:•Xr•}::r.;;r.frwr}}} 'r ' ■ :}: MOORE ff ■ti• . .�■ . . ■}r■ ■ . ■ . . . ■ ■ ■ ■ ■ ON ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ LL■ ■ ■ ■ . . . . . . . . . . . . . ENO . . . r 11_ ■ L . . . . : . . r. ■ . . . Fieure 18:ClosureTurf®CT 1 Critical Leneth Section Problem 1 Example:For slopes less than 10% Determine the maximum drainage length needed for spacing of Diversion Berms. Evaluate average slope of landfill top deck: (5%) Pick Rainfall intensity from Figure 17 (2 in./hr). Read Y scale on chart to determine Maximum Drainage Length. (860 ft.) Note: Check that cohesion value does not exceed 0.2 psf. Problem 2 Example:For slopes greater than 10% Determine the maximum drainage length needed for spacing of Diversion Berms. Evaluate average slope of landfill side slopes: (4:1,25%) Pick Rainfall intensity from Figure 17 (5 in./hr). Read Y scale on chart to determine Maximum Drainage Length. (150 ft.) Page 27 APC Barry_EPA_000700 Note that shear in the sand infill is greatly reduced with lessening of the slope. Therefore slopes less than 10% may not require Diversion Berms for shear stress of the sand. However, they may still be utilized on top decks where water needs to be diverted to other areas. 6.0 Survivability/ Drivability Calculations An evaluation of drivability was completed by SGI Testing Services.Additionally, an independent Vehicle Travel Design was completed. Parameters from those reports are used in the examples below. Problem: 1. Evaluate the puncture resistance/material survivability of the ClosureTurP"system. Vehicle Details: A. Kubota Crawler Dumper Weight=6,000 lbs B. Kubota 1,300 lbs plus payload of 1,600 lbs Weight=2,900 lbs C. Pick-Up Truck, Loaded Weight=6,000 lbs D. Rubber Tire Bobcat Weight=3,000 lbs E. Tire Pressure=30-40 psi A. Evaluate the puncture resistance of ClosureTurf° geotextiles under the tire pressure of access equipment. First, using a pick-up truck with a weight of 8,000 lbs and a contact tire area of 0.53ft'or a 0.82 ft diameter circle area determine the tire contact pressure. Weight per Wheel=8,000 lbs/4 wheels=2,000 lbs/wheel Weight per Tim = 2,000lbs z Tire Contact Pressure= =3,703 Ibs/ft _-26 psi Contact Area 0.54ftz Tire Contact Pressure=26 psi = 30 psi OK Then estimate the average strength of the geotextiles. The mean strength of the ClosureTurf• engineered turf in machine direction,Tensile MD, is shown on Figure 19 and the mean strength of the ClosureTurP engineered turf in cross-machine direction,Tensile XD is on Figure 20 below. Tensile MD 2 = 2 Tensile XD 2055 1802 Tare = 1928 5lb./fl.161 lb./in. The Static Puncture(CBR)Testing(ASTM D6241)for the ClosureTurP engineered turf is shown on Figure 21. According to the CBR the Mean Puncture Strength is 1108 lbs for the ClosureTurP engineered turf. Puncture Resistance can then be calculated. Assume the entire contact area is hollow(similar to CBR testing conditions)for a more conservative approach. Pr=2 n r T,,,c Where Pr is the puncture resistance Page 28 APC Barry_EPA_000701 r is the radius=Diameter/2=9.84 inches/2=4.92 inches Taw=Tensile Strength Average= 161 lb/in Puncture Resistance=2n(4.92in)(161 Ib/in)=4974.5 Ibs Factor of Safety= Pr/Weight per Tire= 4974.5 Ibs' FS= 2.48 OK 2000 Ibs. Page 29 APC Barry_EPA_000702 SHAW INDUSTRIES WIDE-WIDTH TENSILE TESTING(ASTM D 4595) Artificial Grass Sample in MD Base Layer Consisting of Two Slit-Film Woven Geotextiles Roll#AAI7CHY SGI Sample ID No.St 7296 3000 —Tent —Ten2 —TaU 25M —Tea4 —Te L5 —Test6 2000 C in 1500 N W F 1000 500 0 0 5 10 IS 20 25 30 35 STRAIN(%) Ten Tension Tension Tension Uhimme Strein at No m2% .5% at l6% Smength Ultimate 1 172 569 II]3 12135 24A 2 146 523 II/3 1960 24.0 3 191 585 1109 1 2M2 24.0 4 138 510 1127 2155 25.9 5 139 $23 1131 1 1985 20.5 6 170 576 1191 2009 24.4 M. I59 549 1146 2055 219 STD 22 32 30 85 1.8 NOTES: Clint,: Curtis Simon'.widen(N.): 8.0 Yamcominaramn.): Not MemumC Specimen U.,h in.): 8 PnLu t11M): 17 Smin Rem(%rmu-um): 10 Spurts calculaM.d 6asc0 on a gauge 1 ngth af40 in.cuing LVDT DATE TESTED S.L FIOURENO. ] S am Ts7MM��*,u` PRO E EM SGI 011 DILENO, NO. FILE NO. S17296M,WW.ds Figure 19: Wide Tensile Strength Testing Machine Direction Page 30 APC Barry_EPA_OOO7O3 SHAW INDUSTRIES WIDE-WIDTH TENSILE TESTING(ASTM D 4595) Artificial Grass Sample in XD Base Layer Consisting of Two Slit-Film Woven Geotextiles Roll A AAI7CHY SGI Sample ID No.S17296 3000 —Test) —Tea2 —Test 3 250) —Tea4 —Test5 —Tea6 2000 C �E C 15M z F 1000 Son 0 0 3 6 9 12 15 18 21 STMIN(%) Tea Tension Tension Tension Ultimate Stminat No. a2% .5% atl0% Strength Ultimate INflOwn) INfl wn 1 433 %3 1665 1%2 13.9 2 410 958 1661 1897 13.4 3 382 918 1512 1698 13.0 4 392 916 1583 17M 11.7 5 381 902 1555 1786 12.6 6 386 904 1554 1795 13.8 Mean 397 927 is" 18W 13.1 STD 20 27 62 98 0.8 NOTES: Clamp: Curtis Spttimen avian(in0: 9.0 vnm Count(,onnot .): Not Meuured Specimen Length(in): 8 Preloe4(6e): 15 Se,un nn¢(%ter minute) 10 Saains WculaW 1—nJ on agwgc ImgN of4.0 in.using LVDT DATE TESTED: 515n013 rr PRO3ELT FIGUItENG0ND. gG13014 g S 9 SIGN TIMM"s S&RVVC LLC, FILE NO. 31]]96X WW.49 Figure 20:Wide Tensile Strength Testing Cross Machine Direction Page 31 APC Barry_EPA_0007N SHAW INDUSTRIES STATIC PUNCTURE(CBR)TESTING(ASTM D 6241) Anilcial0ums Sample Bme Layer Consistingof I Slit-Film Woven GwuAiles Roll M AA I TCHY SGI Sample ID No.SI72% 1800 —T., —Tca2 —Tn 3 —Tat4 TasO 15W —Tm6 —TW7 —Tall —Te19 —Te110 B 12M O S 900 W C 6M 30G 0 0.0 0.5 1.G 1.5 2.0 2.5 DISPLACEMENT 0..) Ten Puncm:< Oisplaccmcm al I'mim No. ..Vh Pw.clu:c Smm1h MMe br 1 1057 1.63 Puncture 2 IM9 1.79 3 1126 1.83 4 1139 1.81 5 1135 1.82 6 1102 L" t 1083 in 8 1162 1.83 9 1121 1.85 10 1110 Litt Mem 11U8 1.99 STD 36 0.06 YM55: HdEinB MeY W :µeimm5 sscuM Mrvxn rvo eorcennie alempiy nngi(plval xm6 8 bolo. DAME TED. 5/520U FIGUM NO. 4 SrS i61 TtYnNs�iAltllCiiF LLC PROIECTNG. .111014 DOCUMENTNO FRE NO S522N.CBR.KIs Figure 21:Static Puncture Testing Page 32 APC Barry_EPA_000705 Subject: Travel way breking resistance OBJECTIVE: The proposed ClosureTur(u product has been claimed to withstand vehicle traffic"without damage." This calculation determines the adequacy of the ClosureTurfim final cover system resistance to vehicle use during the postdosure period. Travel speeds while on the the proposed final cover system should be limited to 15 MPH or lower. It is dependent on the friction angles determined within the proposed artificialturf. Regular post-closure maintenance travel will consist of an ATV and pick-up trucks. Fire Protection Districts may request site aaess in event of local wildfires. Fire fighting equipment types would be wildland type tankers to incident command vehicles. GVWR for these loaded(With water)vehicles can be as high as 55,000 pounds,40,000 lbs on dual rear axles/wheels. Typical tire pressure ratings for these vehicles can be as high as 120 psi. CALCULATIONS: Bench vehicle slide potential From interface friction testing by WGS Fric.Ang. Adhesion A C Foundation sail vs.SGN(spiked)Res.friction angle ".0 118.3 Ballast sand vs.Engineered turf Res.friction angle= 36.0 1.0 "6rass"GT vs.SGN stud(from al.)Res.friaicn angle= 33.0 32.0 <=Use Fb Fa Fr Ws Wv Assume a tire contact area of$3.3 sq.infor this calculation(eq.to 120 psi) Assume a bench fill depth of 2.0 inches and material weight of 110 pd. Assume maximum bench slope at 10% Driving Forces: Ws=Weight of Roadway=83.3 sq.in/144 x 0.5/12 x 110 pd= 5His Wv=Vehicle Tire Load=10,000 His(dual wheel rear axle) Fb=static friction force on the turf product(assumed as the lowest friction angle) Assuming dead stop time is 2 sec,a=Ov/t=15 MPH/2 sec= 11 ft/see Vehicle tire load mass,m=10000/g = 311 slugs Fb=me=Vehicle Braking force = 3,416 His Resisting Forces: Fr=Frictional Force=(Wv+Ws)X coup X tano,nin Fa=Adhesion force=Bench width X Bench length X Q, (neglect c) Static Dynamic Driving Force (Ws+Wv)sinp Static+Fb 996 4,412 Fr= 6,465 6,465 FS=Resisting Forces/Driving forces = 6.5 1.5 Okay Okay CONCLUSION: The engineered turf based final cover system will resist sliding forces on benches from vehicle travel from the friction resistance alone. This calculation considered the worse case scenario of local fire district water tender vehicles traveling on the topdeck roadways. The occurence of heavy fire equipmment travel will be only in times of local fire events hence rare. Page 33 APC Barry_EPA_000706 7.0 Gas Management Plan Landfills produce emissions continually and have no "on or off"switch to prevent gas releases from occurring as a result of poorly tuned gas collection systems, system malfunction or even during construction phases of the landfill. It must be acknowledged by the engineer of record and operators who incorporate ClosureTurP that emissions are continuous in landfills and a method of managing the emissions are a responsible part of the design and operation of a landfill.A gas management plan will be developed by the design engineer.The application and design concept of the gas venting systems described in this document are covered under U.S. Patent No. 8,585,322. 7.1 Minimum Requirements The gas management plan will include at a minimum,the use of provided ClosureTu& Pressure Relief Valves, (See Figure 24)to meet the specific needs of the intended site. The minimum required gas emission venting devices will be installed at a rate of at least one vent per acre of installed ClosureTurfa (See Figure 22). Watershed Geosynthetics LLC supplies the minimum number of Pressure Relief Valves with delivery of the ClosureTurfa product. The valves must be installed on sites that produce gas to validate any warranties. Design Engineer will be responsible for designing the correct amount of Pressure Relief Valves as well as any other design elements required for the site. Pressure Relief Valves are designed to convey a maximum of 50 SCFM (Standard Cubic Feet Per Minute)under 1 inch of water column. Design Engineer will be responsible for designing the correct amount of Pressure Relief Valves required for the site. 7.2 Surficial Collection Design (Where Applicable) While it should be noted that not all projects will incorporate a Surficial collection design, the ClosureTurp System serves as an effective tool for control of fugitive emissions and can be incorporated into a conventional gas collection system or in some cases as a standalone gas collection and control system. A ClosureTurP surficial collection design will incorporate the use of surficial collection strips(See Figure 22)that provide high flow capacity (See Figure 23) and a larger radius of influence. The system design will also incorporate the surficial collection foot (See Figure 25) that serves as a wellhead base, geomembrane interface and gas conveyance path from the strips to the collection wellhead (not provided by WSG). 7.2.1 Surficial Strips (Where Applicable) Surficial strips are to be placed prior to the placement of geomembrane. Surficial Strips may consist of SuperGripnet®, single sided geocomposite or other techniques that will allow for the proper flow of gas without causing ballooning. The placement of the strips will be determined by the design engineer and included in the gas management plan. Page 34 APC Barry_EPA_000707 O Pr8ee O L ee Figure 24 Malfunction a25 Relief ValveI oot Gas Coileftion Come to GCCS 'on L O O O _ N See Fig 23 Surfici Gas Collecti trip I 2 ' Figure 22:Typical Surficial Collection Strip Placement Gap Dist. = 4.45mm or 0.0'5 ft. x 3.5'wide = 0.053 ft2 Gap 3.5' Use Super Gripnet or Single Sided Geocomposite for Strips Figure 23:Effective Cross Sectional Area:Surficial Strips Page 35 APC Barry_EPA_000708 7.2.2 ClosureTurP Pressure Relief Valve The Pressure Relief Valve is a mandatory component of the ClosureTurf-System.The primary purpose of this component is to provide for necessary release of pressure in the event the gas collection system malfunctions.The number of Pressure Relief Valves required will be determined bythe POR and installed during construction of the ClosureTurf®System K � r Vale Body Field Weld Field Weld Gas Flow--- GasFlow Figure 24:ClosureTurP PE Pressure Relief Valve(Patent Pending) Page 36 APC Barry_EPA_000709 7.2.3 ClosureTurf Collection Foot This device is designed to be the interface between the surficial collection strips,the geomembrane and a gas collection wellhead(not provided).The unit allows vacuum to flow in from beneath the geomembrane and from the surficial collection strips to create a larger radius of influence for gas collection. Placement will be determined by the gas collection system design Gas Collection Monitoring Port Piping By Others Monitoring PE Port FLEXIBLE VACUUM/ PRESSURE HOSE VC ELBOW Isolation Valve ISCO 2'Flow-Wing HDPE/PVC FLANGE ADAPTER Wellhead HDPE PIPE Monftodng Ports ///Automatic Isolation Valve Field Weld Surfcial Gas Collection Foot Field Weld '—Gas Gas Flow Flow 3.3 Wide Surficial Collection Ships(Typ.) HDPE LATERAL HDPE ELBOW Isolation Valve at all 2.0%(MIN.) GCCS connections to system TO HEADER Figure 25:ClosureTurr Surficial Collection Foot Connection to GCCS System Page 37 APC Barry_EPA_000710 valve Body Field Weld Field Weld Gas Flow Gas Flaw SurWal Stop (See Figure 23) Figure 26,ClosureTurfs Passive Gas Vent 8.0 References 1. ANSI/TIA-222-G-2005 Effective January 1,2006. 2. U.S. Army Corps of Engineers, Slope Stability, Engineering and Design Manual. EM 1110- 2-1902, October 31,2003. 3. Technical Paper No.40,SCS USDA, May 1961. 4. Georgia Tech Research Institute (GTRI), Wind Tunnel Testing of ClosureTurf®.June 2010. 5. Kashiwayanagi, M.,Sato, M., &Takimoto,J.,Six-Year Performance of Synthetic-Rubber-Sheet Facing for the Upper Pond of Seawater Pumped Storage Hydropower Plant. Proceedings of the Eighth International Conference on Geosynthetics,Yokohama,Japan,Vol.2 pp.607-601, 2006. 6. SGI Testing Services, Final Report Critical Length and Influence of Seepage Force on Slope Stability Landfill Cover System. October 2009 7. Koerner, Robert M.2005. Designing with Geosynthetics,511 Ed. New Jersey: Pearson Prentice Hall. 8. Koerner, Robert M., & Soong, T.-Y. Analysis and design of veneer cover soils. Geosynthetics International,Vol. 12, No. 1, 2005. 9. Giroud,J.P.Designing with Geotextiles. Definitions and Properties Design. 1985, pp. 266-292. Page 38 APC Barry_EPA_000711 Geosynte& consultants CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 ATTACHMENT GW6489/Barry_50%Design ClosumTurt Draft APC Barry_EPA_000712 -IIh ClosureTurf° Installation Guidelines Manual January 2018 Before utilizing this document as an installation tool, Installer should download the latest version of the Installation Guidelines Manual from the website at www.watershedgeo.com. WGWatershed Geo° Unearthing Solutions Page 1 APC Barry_EPA_000713 ClosureTurf®,HydroTurf,VersaCap®and Hydrollindero products are U.S.registered trademarks that designate products by Watershed Geosynthetics,LLC.These products are the subjects of issued U.S.and foreign patents and/or pending U.S.and foreign patent applications. Table of Contents 1.0 Introduction......................................................................................................................................................................3 1.1 Purpose and Scope............................................................................................................................................................3 2.0 Definitions.........................................................................................................................................................................4 3.0 Subgrade Preparation.......................................................................................................................................................8 4.0 Installation—Surficial Gas Management System..............................................................................................................9 4.1 Minimum Requirements...................................................................................................................................................9 4.2 Surficial Collection Design (Where Applicable).................................................................................................................9 4.2.1 Surficial Strips(Where Applicable) ................................................................................................................................9 4.2.2 ClosureTurf® Pressure Relief Valve..............................................................................................................................11 4.2.3 ClosureTurf® Collection Foot.......................................................................................................................................12 4.2.4 ClosureTurf®Passive Gas Vent.....................................................................................................................................13 5.0 Installation-Geomembrane Liner..................................................................................................................................13 5.1 Delivery—Geomembrane Liner......................................................................................................................................14 5.2 Installation- Panel Deployment and Field Seaming.......................................................................................................14 5.3 Anchor Trench Backfill ....................................................................................................................................................15 5.4 Equipment on ClosureTurf Geomembrane...................................................................................................................16 5.5 Wrinkles..........................................................................................................................................................................16 6.0 Installation—Engineered Turf.........................................................................................................................................16 6.1 Delivery—Engineered Turf..............................................................................................................................................16 6.2 Installation—Engineered Turf-Surface Preparation......................................................................................................17 6.2.1 Installation—Engineered Turf—Deployment& Field Seaming...................................................................................17 6.2.1.1 Installation—Engineered Turf—Fusion Seaming Method........................................................................................17 6.2.1.2 Installation—Engineered Turf—Fusion Seaming Method Trial Seam Requirements..............................................18 6.2.1.3 Installation—Engineered Turf—Sewn Seam Method ..............................................................................................19 6.2.2 Installation—Engineered Turf Repairs and Tie-In Procedures....................................................................................19 6.2.3 Installation—Equipment on Engineered Turf..............................................................................................................19 7.0 Installation—Sand Infill...................................................................................................................................................19 7.1 Submittals and Testing—Sand Infill................................................................................................................................20 7.2 Installation—Sand Infill Deployment..............................................................................................................................20 Page 2 APC Barry_EPA_000714 7.30osureTurr with Rock Rip Rap Infill for Ditches.............................................................................................................20 7.3.1 Installation—Alternate Infill-HydroBinder'for Downslope Channels........................................................................21 7.3.2 Installation—Brushing in the HydroBinder`Infill.........................................................................................................22 7.3.3 Installation—Hydration of the HydroBinder`Infill.......................................................................................................22 7.3.4 Installation—Cold Weather Placement and Curing of the HydroBinder....................................................................23 7.3.5 Installation—Alternate Infill-ArmorFill.......................................................................................................................... 7.4 Installation—Coverage-ArmorFill'................................................................................................................................25 7.4.1 Installation—Coverage-HydroBinder........................................................................................................................25 7.5 Post Installation-Maintenance and Monitoring............................................................................................................25 7.5.1 Exposed Geotextiles.....................................................................................................................................................25 7.5.2 Damage to the Geomembrane or Engineered Turf Components ...............................................................................25 1.0 Introduction ClosureTurf' is a patented, 3 Component System' that serves as the final cover system on landfills. The 3 components ofthis unique system are: Component 1-An Agru Super Gripnet® LLDPE(or HDPE)geomembrane liner, or other liner approved for use by WatershedGeo. Component 2-An Engineered Turf Component 3-A sand infill (and/or alternatively, Hydrobindera,or AmorFill'-E infill) 'A Watershed Geosynthetics® patented(patent no.8,585,322)gas collection system is a separate component to be utilized on sites that produce gas emissions. Pressure Relief Valves are provided at one per acre of ClosureTurf® on landfills where gas emissions are expected. 1.1 Purpose and Scope The ClosureTurf® Installation Guidelines document has been prepared to provide the Engineer / Contractor / Installer general guidance to the proper installation of the ClosureTurf°System.This document should be used in conjunction with the ClosureTurf®CSI (Construction Standards Institute)Specifications for the proper installation of the product. This manual is meant as a guideline only. Watershed Geosynthetics LLC cannot anticipate the many ways this product may be applied either in design or installation. Varying site conditions will require close coordination between the engineer and the installer to account for site conditions and adjust accordingly. When required by state and/or local regulations,a licensed professional engineer or architect will be required. Page 3 APC Barry_EPA_000715 2.0 Definitions Whenever the terms listed below are used,the intent and meaning will be interpreted as indicated. Acclimation Physiological/thermal adjustment. Required in the geomembrane deployment process. ArmorFill® Armor-Fill` Liquid Emulsion is a proprietary Polymer Emulsion product used to bind the ASTM-C33 sand infill component of the ClosureTurf'System. ASTM ASTM International, known until 2001 as the American Society for Testing and Materials, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services. ClosureTurfa A patented 4 component system consisting of a Watershed Geosynthefics specific Gas Management System(if applicable), a Structured Geomembrane(LLDPE or HDPE), an Engineered Turf, and a specific grade of sand infill(or alternatively a HydroBinder® and/or ArmorFill® infill). Construction Quality Assurance(CQA) Construction Quality Assurance includes but is not limited to observations and documentation of materials and workmanship necessary to show that a particular project is being constructed according to site-specific specifications and within regulatory guidelines. Construction Quality Assurance(CQA)Personnel Construction Quality Assurance(CQA)personnel are representatives of the Professional of Record(POR)who work under direct supervision of the POR. The CQA personnel are responsible for quality assurance monitoring, applicable conformance sampling and performing onsite tests and observations. Construction Quality Assurance Professional of Record (POR) The POR is an authorized representative of the Owner and has overall responsibility for CQA efforts and to confirm the project was constructed in general accordance with site-specific specifications approved by the regulatory authority and contract documents. The POR must be licensed as a Professional Engineer in the State the project is located and experienced in geosymbetics. Page 4 APC Barry_EPA_000716 Construction Quality Control(CQC)Personnel CQC Personnel me representatives of the Geosynthetics Installer who work under direct supervision of the Geosymbetics Installer. The Geosynthetics Installers' CQC Personnel are responsible for construction quality control, applicable conformance sampling and performing onsite tests and observations. Contract Documents Written,printed,or electronic matter that provides information or evidence that serves as an official record and are issued by the owner or operator. The documents include bidding requirements that include but are not limited to, contract forms, contract conditions, contract specifications, CQA plan, contract drawings, addenda, and contract modifications. Contract Specifications The requirements which are to be followed in the construction of the ClosureTurf' System. The standard specifications, supplemental specifications, special provisions, and all written or printed agreements and instructions that pertain to the method and manner of perforating the work. Contractor One that agrees to furnish materials or perform services at a specified price, especially for construction work. Design Engineer An individual licensed to practice as a Professional Engineer or a Professional Service Finn that is responsible for the preparation of the project construction drawings and specifications. Earthwork A general engineering term relating to the relocation and utilization of soil during the process of construction. Engineered Turf A component of the ClosureTurfo System. A synthetic structured material consisting of one or more geotextiles tufted with polyethylene yarns that resemble grass blades. Final Cover System Evaluation Report(FCSER) Upon substantial completion of closure activities, the POR is responsible for the documentation of construction activities relating to the project, and any other inspections or verifications required by the regulatory authority. The FCSER will be signed and stamped by the POR and include documentation necessary for certification closure. Fish Mouth A semi-conical opening of the seam that is formed by an edge wrinkle in one sheet of the geomembrane component. Page 5 APC Barry_EPA_000717 Geomembrane A synthetic lining material that is a component of the ClosureTurfo System. Used as the primary barrier to infiltration and exfiltration of covered materials. GSI Geosynthetic Institute 475 Kedron Avenue Folsom,PA 19033-1208 USA TEL(610) 522-8440 FAX (610) 522-8441 HydroTurf' A patented 3 component system consisting of a Structured Geomembrane Liner, a specialized Engineered Turf, and HydroBinder®infill material. HydroBinder® A proprietary pozzolanic infill utilized where higher surface water velocities may occur as well as in anchor trenches where specified. Geosynthetics Contractor/Installer The entity responsible for geosynthetic installation. Independent Testing Laboratory An organization,person, or company that tests products and materials, etc. according to agreed requirements. The entity shall be independent of ownership or control by the Owner or any party to the construction of the final cover or the manufacturer of the final cover products used. The entity shall also have proper legal authority where required to issue opinions and document the results of tests requested by the Owner. Installation Supervisor The person on-site who works for the Geosynthetics Installer and is in charge of the Geosynthetics Personnel and following the site specifications for the installation of the geosynthetics. Manufacturing Quality Control(MQC) A planned system of inspection and verification to ensure the quality of the final product. Page 6 APC Barry_EPA_000718 Nonconformance A deficiency in characteristics, documentation, or procedures that render the quality of an item or activity unacceptable or indeterminate. Examples of non-conformances include,but are not limited to, physical defects, test failures, and inadequate documentation. Operator The entity in control and responsible for the facility. Owner The entity that owns facility and land. Owner's or Operators Representative An official representative of the Owner or Operator responsible for planning, organizing, and controlling construction activities. Panel A general reference to a unit area of either the Structured Geomembrane(LLDPE or HDPE), or the Engineered Turf component of the ClosureTurf® System. Quality Assurance A planned and systematic pattern of procedures and documentation to ensure that items of work or services meet the requirements of the contract documents. Quality Control These actions provide a means to measure and regulate the characteristics of an item or service to comply with the requirements of the contract documents. Relief Valve A mechanical device used specifically to relieve gas buildup pressure underneath the ClosureTurfo system. Representative Sample (With respect to geomembrane destructive testing) -A random specimen of either the Structured Geomembrane (LLDPE or HDPE) or the Engineered Turf component consisting of 1 or more cut pieces(commonly referred to as coupons) from the same rectangular portion of material, oriented along a seam that is removed for field or laboratory testing purposes. Ripple Smaller in nature than a wrinkle. A result of thermal/or manufacturing that cannot be folded over. Page 7 APC Barry_EPA_000719 Snapping A manual method to an open-ended seam to remove tenting as a result of the welding of the geomembrane seams. Spike A systematic design for interface friction located on the bottom of the Super Gripnet®. Specimen (With respect to geomembrane destructive testing) -A specimen is the individual test strip (sometimes called coupon) from a sample location. A sample location can consist of many specimens. Studs A systematic design for drainage located on the top side of the Super Gripnet®. Surficial Collection Foot A manufactured device utilized specifically for collection of gas beneath the Super Cmpnet®. Surficial Strip A strip of Super Gripnet®used for gas conveyance below the ClosureTurf system. Tenting A vertical ridge that is caused by wedge welding geomembrane. Wrinkle A portion of the geomembrane that does not lay relatively flat and is not a result of subgrade irregularity and which can be folded over. 3.0 Subgrade Preparation Prior to ClosureTurf system installation,the subgrade(e.g., protective cover soil)will be inspected. Observe the following: • The protective cover soil is substantially free of surface irregularities and protrusions. • The protective cover soil surface does not contain stones or other objects that could damage any of the ClosureTurf•components. • The surface will be substantially smooth and free of foreign and organic material,sharp objects, particles or other deleterious material. • Maximum particle size (e.g. rocks)will be specified by the by the design and contract specifications. • The anchor trench dimensions have been checked, and the trenches are free of sharp objects and other deleterious material. • Construction stakes and hubs have been removed and the resultant holes have been backfilled. Page 8 APC Barry_EPA_000720 • The geosynthetics contractor, FOR or his representative, and the permittee or his representatives have certified in writing that the surface on which the ClosureTurf°System will be installed is acceptable. • Final grades on the slopes as well as benches dimensions and grades conform to the design grades. • Survey shots and as-built drawings will be carefully reviewed and evaluated to insure the surface grades will drain as intended in the design drawings. 4.0 Installation - Surficial Gas Management System 4.1 Minimum Requirements The gas management plan will include at a minimum,the use of provided ClosureTurf® Pressure Relief Valves, (See Figure 3) to meet the specific needs of the intended site. The minimum required gas emission venting devices will be installed at a rate of at least one vent per acre of installed ClosureTurf• (See Figure 1). Watershed Geosynthetics LLC supplies the minimum number of Pressure Relief Valves with delivery of the ClosureTurf®product. The valves must be installed on sites that produce gas to validate any warranties. Design Engineer will be responsible for designing the correct amount of Pressure Relief Valves as well as any other design elements required for the site. Pressure Relief Valves are designed to convey a maximum of 50 SUM (Standard Cubic Feet Per Minute)under 1 inch of water column. Design Engineer will be responsible for designing the correct amount of Pressure Relief Valves required for the site. 4.2 Surficial Collection Design (Where Applicable) While it should be noted that not all projects will incorporate a surficial collection design, the ClosureTurf° system serves as an effective tool for control of fugitive emissions and can be incorporated into a conventional gas collection system or in some cases as a standalone gas collection and control system. A ClosureTurf® surficial collection design will incorporate the use of Surficial collection strips (See Figure 1)that provide high flow capacity (See Figure 2) and a larger radius of influence. The system design will also incorporate the surficial collection foot (See Figure 4) that serves as a wellhead base, geomembrane interface and gas conveyance path from the strips to the collection wellhead (not provided). 4.2.1 Surficial Strips (Where Applicable) Surficial strips are to be placed prior to the placement of geomembrane. Surficial Strips may consist of SuperGripnet®, single sided geocomposite or other techniques that will allow for the proper flow of gas without causing ballooning. The placement of the strips will be determined by the design engineer and included in the gas management plan. Page 9 APC Barry_EPA_000721 O L POSSUM Relief Valve Surfici Foot See Figure 3 Gas Co on Conn d to GCCS 'on See re4 N Figure 1:Typical Surficial Collection Strip Placement Gap Dist.=4.45mm or 0.015 R.x 3.5'wide =0.053 f Gap 1111 1111 11 3.5' f Use Super Gdpnet or Single Sided Geocomposite for Strips Figure 2: Effective Cross Sectional Area:Surficial Strips Page 10 APC Barry_EPA_000722 4.2.2 ClosureTurP Pressure Relief Valve The Pressure Relief Valve is a mandatory component of the ClosureTurfe System.The primary purpose of this component is to provide for necessary release of pressure in the event the gas collection system malfunctions.The number of Pressure Relief Valves required will be determined by the POR and installed during construction of the ClosureTurP System. 2 [; r •, � 5 Valve Body Field Weld Field Weld Gas Flow�� i. ii✓•!��/��V���V� ��������VA���/�A�/.�,C✓G� -GasFlcw Figure 3:ClosureTurf® Pressure Relief Valve(Patent Pending) Page 11 APC Barry_EPA_000723 4.2.3 ClosureTurf® Collection Foot This device is designed to be the interface between the surflcial collection strips,the geomembrane and a gas collection wellhead(not provided).The unit allows vacuum to flow in from beneath the geomembrane and from the surficial collection strips to create a larger radius of influence for gas collection. Placement will be determined by the gas collection system design. Gas Collection Mon ng Purl Pip,0,01lrers Monibnnq RE PM FLE%ISLL VFCUUMI PRESSURE HOSE C ELBOW Iwlatlon Valve ISCO!'FlowWing HDPE/PVC FLANGE ADAPTER WellOeetl HOPE PIPE Monilon, Pone ///Aulcma& / Iedelkn Veke Fi:O WNd Su�fival Gas FiMtl W.M C011aolion Fast Flow 3.aI yype Surgyy l Flow Collection SMpa(Typ.) HOPE LATERAL ROPF FLRO'N HOMIion VaNealall '10°/.((MIN) GCCS xnneclane to ss to TO HEAD Figure 4,ClosureTurf®Surficial Collection Foot Connection to GCCS System Page 12 APC Barry_EPA_000724 4.2.4 ClosureTurf® Passive Gas Vent Valve Body i Field Weld Field Weld X o Gas Flow X Gas Flow Surficial Strip Figure 5: Passive Gas Vent When a GCCS system is not required, Passive Gas Vents may be utilized in lieu of the Pressure Relief Valves.The number of Passive Gas Vents required will be determined by the POR and installed during construction of the ClosureTurf System. 5.0 Installation - Geomembrane Liner Installation of the Geomembrane Liner must be completed by a geosynthetics contractor approved by Watershed Geosynthetics. Qualification requirements for geosynthetics personnel are shown in WatershedGeo Installation Specification 0173 19. Each component of the ClosureTurf® system will require specific testing and submittals before, during and after installation of the component. For information concerning submittals, see contract specifications. It is the responsibility of the contractor to ensure that each prior component installation has been approved by the POR before continuing with installation of the next ClosureTurf°component. Page 13 APC Barry_EPA_000725 5.1 Delivery - Geomembrane Liner Upon delivery of the geomembrane,observe that: • The geomembrane is delivered in rolls and not folded.Any evidence of folding or other shipping damage is cause for rejection of the material. • Equipment used to unload and store the rolls or pallets does not damage the geomembrane component. • The geomembrane is stored in an acceptable location in accordance with the specifications and stacked no more than five rolls high. • The geomembrane component is protected from puncture, dirt, grease, water, moisture, mud, mechanical abrasions,excessive heat, or other damage. • Manufacturing documentation required by the specifications has been received and reviewed for compliance with the technical specifications.This documentation will be included in the FCSER. • The geosynthetics receipt log form has been completed for materials received. • Geomembrane component that is damaged or has been rejected due to improper manufacturer documentation will be removed from the site or stored at a location separate from the accepted geomembrane component. S.2 Installation - Panel Deployment and Field Seaming ClosureTurf° installation requires some additional care and techniques beyond those of the typical geomembrane installation. General panel deployment techniques as well as special techniques are listed below. General • Observe that the geomembrane component is placed in direct and uniform contact with underlying protective cover soil or subgrade soil. • Observe the sheet surface as it is deployed and record panel defects and repair of the defects (e.g. panel rejected, patch installed, etc.) on the repair sheet. Repairs must be made in accordance with the contract specifications and located on a repair drawing. • Observe that support equipment is not allowed on the geomembrane component during handling (See Section 6.4). • Observe that the subgrade beneath the geomembrane component has not deteriorated since previous acceptance. • Observe that there are no stones, construction debris, soil clogs or other deleterious items on the subgrade that could cause damage to the geomembrane component. • The geomembrane component will not be deployed during inclement weather conditions as defined in the site specific specifications. • Observe that people working on the geomembrane component do not smoke,wear boots/shoes that could damage the Closure7urf• system components, or engage in activities that could damage the ClosureTurf®system components. • Observe that the method used to deploy the sheet reduces wrinkles but does not cause bridging and that the sheets are anchored to prevent lifting or movement by the wind (geosynthetics contractor is responsible for any damage to or from windblown geomembrane). Page 14 APC Barry_EPA_000726 • Observe that horizontal or cross seams on the side slopes are staggered so that long horizontal seams across the slope are not produced. • The POR shall be responsible for approving the integrity of horizontal seams. Acclimation and Adjustments • The geomembrane component requires acclimation to ambient temperature after being deployed and before seaming operations begin. • Acclimation time is dependent on the current weather conditions. • By allowing the panels to acclimate,excessive wrinkling can be avoided. • Final panel adjustments can be completed after the panel has properly acclimated to ambient temperature. • After the panel has acclimated and before seaming operations begin,wrinkles will be worked toward the toe of slope. Either manpower or equipment may be utilized for working out excess material. • Once the above items are addressed,a final adjustment is required to pull the liner at the bottom of the slope. Wedge Welding • After proper acclimation and final adjustments/wrinkle removal,wedge welding may proceed. • Wedge welding machines are a low-profile machine with a vertical height(wedge height) not to exceed 3 inches, measured from flat surface to top of heating wedge. • Wedge welding will be completed in accordance with the contract specifications. • Sand bags will be applied as the wedge welding progresses to reduce tenting. Snapping • As a result of wedge welding, "ridges" or "tenting" of the seams may occur. A process called "snapping" must be employed to remove the excess slack caused by the welding process. • Normally, this technique requires several people lined up along the open seam at the edge of the geomembrane and applying clamps to the edge.The panel is then "snapped" into position and when applied properly,the excess slack is removed. • The snapping technique will be applied while the welding seam is still warm. • Previously applied sand bags along the wedge welded seam will reduce rebound tenting. 5.3 Anchor Trench Backfill ClosureTurf• only relies on the anchor trenches to serve as a termination point. Top anchor trenches should be backfilled as quickly as practical after Engineered Turf Component is installed(prior to sand infill placement). Vertical anchor trenches as well as anchor trenches along the toe will not be backfilled until sand infill of the engineered turf is in place,unless previously approved by the FOR. Anchor trench dimensions will be shown in the drawings. Backflilling or sand bag loading the bottom and side anchor trenches should be considered and applied when cool temperatures are anticipated to assist with creep reduction. Page 15 APC Barry_EPA_000727 When HOPE material is utilized, additional anchoring methods may be required to reduce wrinkling due to the overnight contraction of the material. Contraction of the HOPE material may be site specific/seasonal and should be discussed onsite to develop an effective method to alleviate potential issues. 5.4 Equipment on ClosureTurf® Geomembrane Construction equipment on the ClosureTurf® geomembrane component will be limited to reduce the potential for geosynthetics damage. Observe/provide the following: • Use power source generators capable of providing constant voltage to all required equipment under combined-line load. • Secondary containment to catch spilled fuel under equipment where applicable. • No equipment with tire or track pressures exceeding 5 psi will be allowed on the partially constructed ClosureTurf°system until after the completed installation of the sand infill component. • No equipment will be left running and unattended over the constructed geomembrane component. • Equipment operators shall check for sharp edges, embedded rocks, or other foreign materials stuck into or protruding from tires prior to operating equipment on the geomembrane component. • Path driven on geomembrane component will be as straight as possible with no sharp turns,sudden stops or quick starts. 5.5 Wrinkles Wrinkles occur during the geomembrane installation due to changes in geomembrane temperatures and deployment methods.The wrinkles may interfere with the installation of the engineered turf layer as well as the final appearance of the ClosureTurf®system.Observe that: • Snapping procedures are followed. • Wrinkles are repaired if they can be folded over as defined the morning after the seam is developed and the liner is in a cool state. 6.0 Installation - Engineered Turf Qualification requirements for the personnel who install the Engineered Turf component are shown in WatershedGeo Installation Specification 017319. 6.1 Delivery- Engineered Turf Box trucks will deliver 27 rolls per truck. Rolls will be strapped in groups of 9 allowing equipment(i.e. pick-up truck, skid steer)to pull the grouped rolls to the front of the truck. Rolls can be pulled directly to the ground or carpet stingers can move the rolls to a designated area. Observe the following: Observe the following: • The engineered turf is wrapped in rolls with protective covering. • The rolls are not stacked more than 3 high. Page 16 APC Barry_EPA_000728 • The rolls are not damaged during unloading. • Protect the engineered turf from mud,soil,dirt,dust, debris,cutting,or impact forces. • Each roll must be marked or tagged with proper identification. • Rolls that have been rejected due to damage are be removed from the site or stored at a location separate from accepted rolls,designated by the Owner/Operator. • Rolls that do not have proper manufacturer's documentation will be stored at a separate location until documentation has been received and approved. 6.2 Installation - Engineered Turf- Surface Preparation Prior to installation of Engineered Turf,observe the following: • ClosureTurf'geomembrane has been installed in accordance with the contract specifications. • The geomembrane installation documentation has been completed and approved by the FOR for areas were the Engineered Turf is to be installed. • The supporting surface (i.e.,the geomembrane)does not contain stones, debris, membrane grindings or large scraps left over from the installation process that could damage or impede surface water flow through the Engineered Turf. 6.2.1 Installation - Engineered Turf- Deployment & Field Seaming During deployment of Engineered Turf, observe the following: • Observe the turf as it is deployed. • Verify that equipment used does not damage the turf or underlying geomembrane by handling, trafficking,leakage of hydrocarbons, or by other means. • Verify that during deployment,the Engineered Turf filaments point upslope. • Verify that the turf is anchored to prevent movement by the wind (the contractor is responsible for any damage resulting to or from windblown Engineered Turf). • Verify that the turf remains free of contaminants such as soil,grease,fuel, etc. • Observe that the turf is laid substantially smooth and substantially free of tension, stress, folds, wrinkles,or creases. • Observe the deployment of the panels to insure proper flipping to expose the turf surface up after seaming operations. After the first panel of the project is deployed,deployment will be done on the adjacent turf panel to avoid damage. • Horizontal cross seam/panel extension on slopes will not be more than one aligned side by side (i.e., no adjacent cross seams on slopes). • At least one complete panel shall separate any horizontal cross seam/panel extension. • Horizontal cross seams performed with either wedge welding or sewing will be performed prior to the vertical production seaming. • Once the horizontal cross seam/panel extension is completed,the excess seam overlap on the bottom of the weld or seam shall be cut off. 6.2.1.1 Installation - Engineered Turf- Fusion Seaming Method • Engineered Turf fusion seaming device will be a DemTech VM20/4/A fusion welder only. • Fusion seams require a minimum of 5 inches of overlap. • Frayed or loose geotextile strands will be cut off or removed. Page 17 APC Barry_EPA_000729 • Prior to starting the production fusion seaming,trial seams must be performed as outlined in Section 7.2.1.3 below. • Demonstrate the preparation methods and equipment utilized for removal of the salvage from the outside edge of the rolls of turf(i.e.trimming&cutting devices). • Electrical trimming and cutting devices will be utilized for salvage trimming. • Box blades and knives will not be utilized for salvage trimming. • Demonstrate and control the fraying of geotextile strands when performing the removal of salvage. • Any damage that occurs due to production seaming will be repaired as outlined in WG Installation Guidance Documents. • Any defects will be repaired as outlined in 7.2.2. 6.2.1.2 Installation - Engineered Turf- Fusion Seaming Method Trial Seam Requirements 1. Prior to turf component welding, CQA personnel shall observe and document the following: a. Turf welding apparatus are tested; b. at daily start-up;and c. immediately after any break;or d. anytime the machine is turned off for more than 30 minutes. 2. Procedures: a. The turf trial weld will be completed under conditions like the panels that will be welded. b. If at any time,the CCA Personnel believe that an operator or fusion welding apparatus is not functioning properly,a Field Trial Seam Test must be performed. c. Any dispute concerning proper installation techniques or the proper function of fusion welding equipment will be resolved by the OWNER'S REPRESENTATIVE. d.The trial weld must be allowed to cool to ambient temperature before seam snapping or panel adjustments are applied. 3. Trial Sample Test Results: a. Trial weld samples must comply with "VISUAL PASSING CRITERIA"Visual passing criteria is verified when a manual peel/pull test is performed and the top turf panel tufts transfer to the bottom turf panel.The transfer of approx.75%of the tufts constitutes a passing trial weld. 4. Field Seam Test Failure: a. Less than approx.75%of the top turf panel tufts do not transfer to the bottom turf panel. 5. Additional Trial Sample Testing Requirements: a.Two consecutive trial welds meet the visual passing criteria. 6. The trial weld sample must be a minimum of 3 feet long and 12 inches wide,with the seam centered lengthwise. 7. If a welding apparatus exceeds 5 hours in the second half of the day,another trial seam must be performed. 8.COLA documentation of trial seam procedures will include the following: a. The names of the seaming personnel; b. The name of the fusion seaming technician; c. the welding apparatus number,time, date; Page 18 APC Barry_EPA_000730 d. ambient air temperature; and e. welding apparatus temperature&speed setting. 6.2.1.3 Installation - Engineered Turf- Sewn Seam Method • A single stitch prayer type seam is constructed using an American Newlong sewing machine or equivalent. The thread will be Polyester or equivalent. • Sewing will occur between the V and 2nd row of tufts from the edge. 6.2.2 Installation - Engineered Turf Repairs and Tie-In Procedures When Repairs and Tie-Ins to Engineered Turf occur,observe the following: • Tie-in's to Engineered Turf will be completed by using a fusion seam. • Seaming equipment for Engineered Turf will be a DemTech VIA 20/4/A welder and/or Varimat V2. • A hand-held heat gun should be used in smaller/concentrated areas. 6.2.3 Installation - Equipment on Engineered Turf No equipment will be allowed on slopes exceeding 15% until Sand Infill is in place. On slopes less than 15%, such as top decks, ATV type vehicles will be allowed prior to infill placement if the rubber tire or track pressure is less than 5 psi. Post construction (full specified sand infill thickness) drivability tire pressures on slopes greater than 10% should be limited on the ClosureTurf• system to less than 35 psi. Allowable rubber tire or track pressures on top decks may increase to as much as 120 psi if sustained traffic load is not expected. In all phases of construction, equipment used on the ClosureTurf® product will not be allowed to change speed or direction in a manner that could displace or damage the ClosureTurf®system. High traffic areas will require sand to be placed at the full height of the turf.ArmorFill®may also be utilized in high traffic areas to reduce sand migration due to the increased sand thickness. 7.0 Installation - Sand Infill This component of the ClosureTurf'system is a specialized mixture of sand infill that is placed between the tufts of the Engineered Turf component. Observe that the following general requirements regarding Sand Infill are met: • Sand Infill will meet ASTM C-33 specifications. • Areas that are to receive sand infill must be inspected and accepted by the POR or CQA Personnel before placement of sand infill takes place. Page 19 APC Barry_EPA_000731 7.1 Submittals and Testing- Sand Infill See contract specifications for Sand Inf II MQC Submittals and submittal/testing requirements regarding the Sand Infill. 7.2 Installation - Sand Infill Deployment Observe that the following installation guidelines regarding the Sand Infill: • Sand infill thickness will be verified at a frequency of 20 measurements per acre of final cover installed. • The sand infill layer will be placed to a%inch minimum thickness not to exceed''% inch thick. • The sand infill will be worked into Engineered Turf as infill between the synthetic yarn blades. • No equipment will be allowed on slopes exceeding 15%until the sand infill is in place. • Conveyor systems and/or Express Blowers are the preferred method to spread and place the sand infill. • Contractor shall explain in detail in the pre-construction meeting the method of sand infill deployment to be used. • The sand infill deployment method will be approved prior to installation of the sand infill. • For slopes 3H: 1V or steeper the sand infill will be placed using high speed conveyor belts or using air express blower methods that demonstrate achievable results. • The sand infill placement will be done in front of the deployment equipment to improve the bearing capacity of the previously installed ClosureTurf°components. • Sand infill placement cannot occur with snow or ice on the Engineered Turf component. • Verify that underlying geosynthetics installations are not damaged during placement operations. Mark damaged geosynthetics and verify that damage is repaired. • Verify no geotextiles are exposed once the sand infill is complete. The method for measuring the Sand Infill thickness will be performed utilizing a digital caliper with depth rod capabilities,or a FOR approved alternate measuring device. 7.3 ClosureTurf®with Rock Rip Rap Infill for Ditches When ClosureTurf• is installed in ditches and rock rip rap infill is placed in lieu of sand infill, it creates a ditch lining armor that will allow high flow velocities to convey without damage or maintenance to the liner system.See Figure S. Page 20 APC Barry_EPA_000732 5'ArmorFi#a ClosureTurt® Transition Zone AnnorFO Compacted Backfill Rip Rap J t 1 2 f Prepared Subgmde Figure 5:Typical ClosureTurf®with Rip Section Typical ClosureTurf®with RioRap Ditch Section 7.3.1 Installation -Alternate Infill - HydroBinder®for Downslope Channels HydroBinder'is typically delivered to the jobsite on pallets in either 3O00#bulk bags(1 per pallet)or 80ft bags(42 per pallet). It is delivered on a flatbed with 16 pallets(typical) per truckload. Verify the following regarding installation of HydroBinder' Infill: • The HydroBinder` infill layer may be placed using any appropriate equipment capable of completing the work while meeting loading requirements specified herein. • Manual hand spreading is acceptable when equipment isn't practical. • Contractor / Installer will explain in detail in the pre-construction meeting the method of HydroBinder°infill deployment. • Installation of HydroBinder infill will only be performed by a Watershed Geosynthetics'licensed and approved infill installer. • The HydroBinder will be installed into the turf while it is in a dry state. • Prior to placing the HydroBinder',the engineered turf will be dry. • If the turf is wet from rain or dew,the installer shall wait until it is dry. • The installer may attempt to speed up the drying process by using a blower(i.e.,leaf blower,industrial blower,etc.). • The HydroBinder will be worked into the tufts so the tufts are in an upright position. • The HydroBinder infill layer will be placed to a%inch minimum thickness not to exceed 1 inch thick. • Reduce trapped tufts as much as practical. • Do not backfill anchor trenches until turf has been installed with HydroBinder' infill unless approved by the POR. • The hydration process must occur the day of the HydroBinder'infill placement. • The desired HydroBinder infill thickness will be achieved prior to the hydration process. • The cemented infill is hydrated thoroughly however care must be taken to avoid displacement of the non-hydrated infill. Page 21 APC Barry_EPA_000733 • The objective is to soak the area to start the hydration process but not to inundate with water beyond saturation. • Once hydration is completed as described, backfill and compaction of the vertical anchor trenches should take place. • The infill is to be placed / spread using a manual drop spreader, top-dresser and/or drop spreader attached to low ground pressure equipment with adequate dust control. • If weep holes are required for draining the internal drainage layer through the engineered turf, remove the HydroBinder in the areas of the weep holes prior to hydration or block the weep hole locations prior to infilling. Blocks may consist of pipe, dowels, etc. Weep holes are typically%to in diameter and are located at the toe of slope on 2-ft centers. 7.3.2 Installation - Brushing in the HydroBinder®Infill The HydroBinder`infill will need to be worked into the tufted fibers of the engineered turf such that the turf fibers are in an upright position.This can be achieved as follows: • The infill will be worked into the tuft fibers so the tuft fibers are in an upright position with the infill at a measurable%inch minimum depth.This is achieved with common mechanical turf broom,power broom,shop broom,yard rakes,or greens groomer rakes. • Brushing should be performed in all four directions starting with the direction against the lay of the fibers. Multiple passes may be required. • The HydroBinder° may need to be placed in 2 to 3 lifts with brushing in between lifts to effectively work the material into the tufts and achieve fibers that are upright. • The engineered turf will be visually inspected to confirm that the turf fibers are upright and that there are no trapped fibers. • Thickness measurements of the HydroBinder`infill will be taken using a caliper or equivalent device. • Measurements will be taken at a minimum frequency of 10 measurements per 1,000 sf(for smaller projects)or 20 per acre(for larger projects)of installed area. • The desired HydroBinder°infill thickness will be achieved prior to the hydration process. ClosureTurf with HydroBinder contains a unique drainage system where some water will drain on the Super Gripnet° liner. This water may build up and cause the Engineered Turf and HydroBinder® infill to lift.This is not normally an issue to the overall performance of the product. However,the Super Gripnet® must be allowed to drain at all times. If surface water flows are pinched off by various construction techniques such as placing rip rap check dams in channels,the Turf and HydroBinder®will lift as needed until the pressure can be alleviated. 7.3.3 Installation - Hydration of the HydroBinder®Infill The HydroBinder`infill will be hydrated in place as follows: • The hydration process will occur on the same day as the HydroBinder'infill placement. • Hydrate the infill thoroughly without causing displacement of the product.This may require another pass after waiting momentarily to allow the initial water application to soak in. • Estimated application rate is between 0.20 gallons per square foot of area. • The installer shall not overhydrate the infill so that water begins to runoff and cause loss of cement infill during the process. Page 22 APC Barry_EPA_0007M • Visual verification can be performed that the HydroBinder°inf II has been fully hydrated,and not over hydrated. • Visually observe that the top of the HydroBinder® has a wet sheen (denoting saturation) but that water is not ponding on top. • Excavate(with finger or small tool)into the HydroBinder°at a rate of 1 probe per 100 sq.ft.on smaller jobs and 20 per acre on large jobs to confirm full hydration of the section has been achieved. • An additional method to check saturation is to tap the surface a few minutes after saturation. Water should be brought up and pool at the surface. • To improve curing,the hydrated area may be covered with plastic sheeting. • If freezing temperatures are expected, the hydrated area should be covered with burlap and / or plastic sheeting. • The HydroBinder infill will harden within 24 hours following hydration. • The 28-day compressive strength is tested by the HydroBinder manufacturer before shipping. • If the HydroBinder®should harden to the touch within 24 hours. • Personnel access on the HydroBinder® infilled surface will be prohibited for 24-hr following the hydration of the HydroBinder'. • Once hydration is completed and the HydroBinder°has set up, backfill and compaction of the anchor trenches may be performed. 7.3.4 Installation - Cold Weather Placement and Curing of the HydroBinder® Cold weather placement and curing techniques for HydroBinder`shall be consistent with industry standard techniques used for concrete and cement products. The following guidelines are suggested: • Follow the procedures in American Concrete Institute(ACI)306-Guide to Cold Weather Concreting. • ACI 306 defines cold weather as three consecutive days of the following: - Average daily temperature falls below 40 dg F;or - The air temperature does not rise above 50 deg F for more than half of a day in one 24-hour period. • At the time of HydroBinder placement,the subgrade and surface of the engineered turf will be at a temperature of at least 36 deg F and rising. • Ensure that frost or frozen surfaces are thawed with no standing water. • If the temperature can fall below 32'F within 24 hours of application, heated tarps and/or insulated blankets are required to maintain the temperature above 50 deg F. • Heated tarps and/or insulated blankets are required to maintain the temperature above 50 deg F for a period of at least 7 days. • If heated tarps begin to dry out the HydroBinder ,water may need to be added to keep it moist. The project design engineer and/or resident engineer shall provide technical specifications and guidance for cold weather concreting based upon project specific details(i.e.,geographical location,weather, and time of year),and the engineer shall review and approve all proposed installation methods. 7.3.5 Installation - Alternate Infill - ArmorFillg Verify the following regarding installation of ArmorFIII*Infill: • Installation of ArmorFill' will be completed by or managed by an infill installer certified by Watershed Geosynthetics. Page 23 APC Barry_EPA_000735 • Apply ArmorFill'under dry weather conditions and when precipitation is not expected for at least 24 hours after installation. • Apply Armorl'ill'on a previously installed ClosureTurf•system that is free of leaves and other material that may inhibit the penetration of the Armorl'ill'into the sand component. • Apply ArmorFill'only after approval of the finished ClosureTurf®product installation. • Verify ArmorFill'and water mix ratio by logging volume mixed of each component. • Verify that ArmorFill'has saturated the sand by inserting a probe and displacing a 1-inch area of sand. • Check saturation randomly at a rate of 20 probes per acre. • Verify proper application rate by marking a known area and applying the proper volume to that area. • Adjust delivery rate to match the delivery volume per area. • Mix in a hydraulic conveyance system such as a water truck or portable tank. • Utilize a small agitation pump to mix and recirculate the ArmorFill'within the tank to impede separation. • ArmorFill'application equipment will have a 2-inch diameter hose with a spray adjus•ent nozzle and cut off function in the nozzle head. • Reduce the number of equipment set-ups required and take care with the application hose so as previously applied ArmorFill' is not displaced by dragging of the hose. • Spray product evenly. • Apply ArmorFill'at a ratio of 6 parts water to one-part ArmorFill'on slopes. • A 6:1 ratio is approximately 3400 gallons of the mixed product per acre(Approx.90 ounces per square yard) • Apply ArmorFill'at a ratio of 3 parts water to one-part ArmorFill'in ditches and areas where concentrated flows are expected. • Do not apply ArmorFill' in inclement weather or in freezing temperatures. • At the completion of ArmorFill`placement activities,clean the equipment thoroughly and purge the tank and hoses of the product. • All waste product will be disposed of in accordance to site regulations • Avoid unnecessary foot traffic on the applied product for 24 hours. No vehicle traffic is allowed on the applied product for 7 calendar days. Page 24 APC Barry_EPA_000736 7.4 Installation - Coverage -ArmorFill® For most applications, use a 6:1 mix ratio unless otherwise stated by the Engineer. 7.4.1 Installation - Coverage - HydroBinder® Table t Approximate Coverage Area for HydroBinder"'Infll Coverage in Sq. Amount of Water(gal) Amount of Water Yield(Cubic Coverage in Sq. Amount of Water Product Bag Size F[.for3/4 in. to Apply Sq.F[.(3/4 (g Apply per Sq. Feet) Thick' Ft.for 1 in.Thick' to Mix per Bag(gal) in..Thick)' Thickl' R F[.(1 in.Thick)' 40lbs. 0.3 4.8 3.6 0.6 0.12 0.16 W lbs. 0.45 7.2 5.4 0.9 0.12 0.16 HydroBinder so lbs. 0.6 9.6 7.2 1.2 0.12 0.16 Infill 1 Cubic Yard (Super Sack) 27 432 324 55 0.13 0.17 '-Values are approximate 7.5 Post Installation - Maintenance and Monitoring The ClosureTurf° System is designed to be a very low maintenance final cover. If maintenance issues or damage occurs to the ClosureTurf®System,please refer to the following guidelines. 7.5.1 Exposed Geotextiles If the engineered turf backing becomes exposed,then the ASTM C-33 graded infill is to be placed and brushed into the exposed turf backing areas. WG suggested guidance is to evaluate the closure system at a frequency of no less than once every 5 years. Additionally, UV resistant coating can be applied to the exposed area and sand immediately applied onto the coating material, this provides a flexible UV barrier for the underlying geotextiles. The UV coating product is manufactured by Quikrete, product number 8640 and Sakrete, product number 60205006, concrete sealants and can be purchased at most Lowes & Home Depot Home Improvement stores. Sand with ArmorFill' can also be utilized for this purpose. 7.5.2 Damage to the Geomembrane or Engineered Turf Components If damage occurs to the geomembrane or geotextile Components,call an approved ClosureTurf° installer for repairs.Contact WatershedGeota at 770 777 0386 for a list of qualified installers. Page 25 APC Barry_EPA_000737 Geosynte& consultants CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 ATTACHMENT10 GW6489/Barry_50%Design ClosumTurt Draft APC Barry_EPA_000738 TRI/ENVIRONMENTAL, INC. A Texas Research Inramallonal Conpany GEOMEMBRANE TEST RESULTS AIA Manufacturing, Inc. TRI Log Number. E3000-54-05 Product: 40 mil smooth HDPE Attn: Mr. Allen Short Report Date: 02-18-94 218 Bolivar Street Reissued: 03-01-94 Canton, MA 02021 Coefficient of Linear Thermal Expansion ASTM D696 (cm/cm C x 10 E4) 12 I 12 AI0/i Quality Review The testing herein is based upon accepted industry practice as well as the test method listed. TRI neither accepts responsibility for nor makes claim as to the final use and purpose of the material. 9063 Bee Caves Road•Auslin,TX 78733.6201 •(512)263-2101 • FAX(612)263.2558 APC Barry_EPA_000739 Geosynte& consultants CP: MFL Date: 0824/18 APC: MGB Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 ATTACHMENT 11 GW6489/Barry_50%Design ClosumTurt Draft APC Barry_EPA_000740 Geosyntec consultants CALCULATION PACKAGE COVER SHEET Client: Alabama Power Company & Project: Plant Barry Ash Pond Closure Project#: GW6489 Southern Company Services Project TITLE OF PACKAGE: DRAFT CALCULATION OF PULL-OUT RESISTANCE FOR CLOSURETURF® COVER SYSTEM F CALCULATION PREPARED BY: Signature 24 August 2018 (Calculation Preparer,CP) a Name Marta F.Limas Date d ASSUMPTIONS&PROCEDURES Signature 24 August 2018 CHECKED BY: (Assumptions&Procedures Checker,APC) Nre Sid Nadukuru Date 3 Signature 24 August 2018 COMPUTATIONS CHECKED BY: � (Computation Checker,CC) Name Tamer Y.Elkady Date BACK-CHECKED BY: Signature 24 August 2018 (Calculation Preparer,CP) rYj Name Maria F.Limas Date a m APPROVED BY: Signature 24 August 2018 z (Calculation Approver,CA) iName Glenn J.Rix,P.E. Date REVISION HISTORY: NO. DESCRIPTION DATE CP APC CC CA A Draft Closure Design Calculation Package 8/27/2018 MFL MGB MGB GJR APC Barry_EPA_000741 Geosynte& consultants Page 1 or 9 CP: MFL Date: 0824/18 APC: SN Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Projea No: GW6489 CALCULATION OF PULL-OUT RESISTANCE FOR CLOSURETURF®COVER SYSTEM PURPOSE The pull-out resistance of the geomembrane of the ClosureTurf system (i.e., 50-mil HDPE MicroDrain® herein referred to as MicroDmin") is evaluated for two cases of anchorage: (i) MicroDrain9 runout beneath a riprap channel and(ii) anchor trench. For this purpose, the tensile force induced by thermal contraction of the MicroDmina is calculated to estimate: (i)the minimum length of MicroDrain0 runout required beneath riprap channels; and(it)the minimum dimensions of the anchor trench. The tensile force induced by thermal contraction is expected to be smaller for LLDPE MicroDrain®due to the lower coefficient of expansion and elasticity modulus of LLDPE compared to HDPE. Therefore, the factors of safety against pull-out are expected to be larger for LLDPE MicroDrain0. METHODOLOGY The factors of safety against pull-out of the MicroDraint runout and anchor trenches were evaluated based on a force equilibrium analysis as the ratio of the sum of the resisting forces, Freseb , to the sum of the driving forces,Faruu,, as follows: 1'.Frests[tng FSpuuout = EFactetng (1) Driving Force The driving force consists of the tensile force caused by thermal contraction of the MicroDram" after installation,calculated as follows: Tt =J • a * AT (2) where: Tr = tensile force due to thermal contraction of MicroDrain® [pounds per foot (lb/ft)]; J = elastic modulus of MicroDraine(lb/ft); a = coefficient of thermal expansion for MicroDrain®[inverse degrees Celsius (1/°C)]; and GW6489/13arry_50%Desip_ClosureTurF_Attachment 11-Pull-Out Resistaacc_Drul APC Barry_EPA_000742 Geosynte& consultants Page 2 of 9 CP: MFL Date: 0824/18 APC: SN Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Projea No: GW6489 AT = temperature change of MicroDrain® component after installation [degrees Celsius(°C)]. The elastic modulus (J) for the MicroDrain® is not provided in the manufacturer product data sheets(Attachment 8);therefore,the elastic modulus was calculated from the tensile yield strength (o,) and corresponding yield strain(e)reported in the product data sheets as follows: I = er (3) where: J = elastic modulus for 50-mil MicroDrain®(lb/ft); ay = tensile strength at yield for 50-mil MicroDmin® (i.e., 110 lb/in = 1,320 lb/ft); and E = tensile strain at yield for MicroDmin®(i.e., 13%). The elastic modulus for the MicroDmin® was calculated to be approximately 10,000 Ib/ft using Equation 3. The coefficient of thermal expansion(a)for HDPE MicroDrain®was estimated to be 1.2x10'/°C based on ASTM D696 testing on a 40-mil HDPE geomembrane(Attachment 10). The temperature change (AT) was estimated as the difference of the temperature during installation and the minimum or maximum temperatures (i.e., ranging from-20eC to 50°C)MicroDrain®is expected to experience after installation. For this calculation, OT was conservatively selected as 70°C. Resisting Force Alone Runout For the case of a MicroDraine runout beneath a riprap channel,the resisting force against pull-out was calculated as the frictional force between the MicroDrain® component and the underlying material(FL), as shown in Figure A.10-1. The resisting frictional force was calculated as follows: FL = LRO • dA • YA • (tan 6L) (4) where: FL = resisting frictional force between MicroDrain®and the subsurface (lb/ft); Lxo = length of MicroDrain®Dracut beneath riprap channel (ft); GW6489/13arry_50%Desip_ClosureTurf_Attachment 11-Pull-Out Resistancc_craft APC Barry_EPA_000743 GeosyntecO' consultants Page 3 or 9 CP: MFL Date: 0824/18 APC: SN Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 dR = thickness of riprap above MicroDram"(ft); yR = unit weight of riprap [pounds per cubic foot(pcf)]; and Sc = interface friction angle between MicroDrain®and underlying material. No frictional forces between the ClosureTurf® system and the riprap (Fu) were included as a resisting force as shown in Figure A.10-1, because the riprap and the ClosureTurf system are expected to move as one system(i.e., no movement of riprap relative to the ClosureTurf®system). Also,the pull-out force induced by thermal contraction was conservatively estimated to act parallel to the resisting friction force, as shown in Figure A.10-1. Using Equations 1 thorough 4, the minimum length of MicroDrain®runout required to resist the pull-out force for a given factor of safety can be calculated as follows: Tt*FSP-11_out LRO — dR*YR*(taa 6p) (�) Resistive Force Alona Anchor Trench For the MicroDram" anchor trench, the analysis of resisting forces was performed based on a frictionless pulley system(Qian et al., 2002),which allows the MicroDrain®to be considered as a continuous member along its entire length. The resisting forces against pull-out were calculated as the frictional forces between both sides of the ClosureTurf® system and the adjacent materials along the anchor trench, as shown in Figure A.10-1. The frictional forces that act along flat planes of the ClosureTurf® system were calculated as the product ofthe normal force acting on the plane and the tangent of the interface friction angle between the ClosureTurf® system component and the adjacent material. For forces Fl and F2, the normal force was taken as the weight of the overlying soil. For forces F3 and F4, the normal force was estimated as the at-rest lateral earth pressure at mid-depth within the anchor trench. The frictional forces Fi through F4 were calculated according to the Equations 6 through 9 below and act in the direction shown in Figure A.10-1. F1 = YAT * dAT * WAT * tan(6u) (6) FZ = YAT * dAT * WAT * tan(6c) (7) F3 = 0.5 * YAT * dAT2 * Ko * tan(6u) (8) GW6489/13arry_50%Desip_ClosurerurF_Attachment I I-Pull-Out Resistancc_craft APC Barry_EPA_000]44 Geosynte& consultants Page 4 at 9 CP: MFL Date: 0824/18 APC: SN Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 F4 = 0.5 *YAT * dAT2 * K0 * tan((5L) (9) where: YAT = unit weight of anchor trench backfill material (pcf); dAT = depth of anchor trench(ft); WAT = width of anchor trench(1t); Su = interface friction angle between turf and overlying anchor trench backfill material (degrees); SL = interface friction angle between MicroDrain® and underlying material (degrees); Ko = coefficient of at-rest earth pressure [i.e., 1-sin(+)]; and = friction angle of anchor trench backfill material(degrees). Site specific data is not available to estimate the interface friction angle between the MicroDramla and the underlying material(SL). However,direct shear testing tests(i.e.,ASTM S 5321)performed by SGI Testing Services on a ClosureTurf® system sample with SuperGripnet® (Attachment 8) resulted in sliding at the interface between the engineered turf and the upper side of the SuperGripnet®, which is equal to the upper side of MicroDrain®. This suggests that the interface friction angle between the SuperGripnet®and the underlying material used for the test(i.e.,concrete sand)is greater than the interface friction angle between the engineered turf and the SuperGripnet®. The interface friction angle between the engineered turf and the MicroDrain® is provided in the manufacturer product data sheets(Attachment 8)w 35 degrees;therefore,the interface friction angle between the MicroDrain®and the underlying material(SL)was conservatively taken as 35 degrees for this analysis. The interface friction angle between the turf and the overlying backfill material (Su)was estimated to be lower than SL, because the grass blades are expected to provide a lower frictional resistance on the upper side of the engineered turf. For this calculation, Su was estimated as two thirds of SL (i.e.,23.3 degrees). CALCULATIONS The tensile force due to thermal contraction of the MicroDraino was calculated using Equation 2: Tt = 10,000 [lb/ft] * 1.2x10-4 [1/°C] * 70 [°C] = 84 [Ib/ft] GW6489/13arry_50%Desip_ClosureTurf_Attachment 11-Pull-Out Resistaacc_craft APC Barry_EPA_000745 Geosynte& consultants Page 5 at 9 CP: MFL Date: 0824/18 APC: SN Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 The values for elasticity modulus O and coefficient of thermal expansion (a) used above correspond to HDPE MicroDrain®. These values are expected to be lower for LLDPE MicroDrain®, which would result in a smaller tensile force(T,). The length of Microl3rain® runout required to resist the tensile force caused by the thermal contraction was calculated using Equation 5 for a selected unit weight of 140 pcf for the riprap and varying riprap thicknesses and factors of safety. Figure A.10-2 shows calculated mnout lengths for varying riprap thicknesses and factors of safety of 1.5 and 2.0. Fora riprap thickness of 1.0 ft (lowest thickness of riprap obtained from the final cover system design) and for a factor of safety of 1.5,the minimum length of MicroDrain®mnout required to resist pull-out is the following: RO — 84[m/ft1.1.5 = 1.3 [ft] 1.0-140[Pcf]-(tnn35) The resisting frictional forces acting along the anchor trench were calculated using Equations 6 through 9 for a proposed 2-ft deep and 2-ft wide anchor trench (i.e., dat = war= 2 ft), as shown below. A typical value of unit weight of backfill(ynt) of 125 pcf was used for this calculation. Ko = 1 — sin(rp) = 0.47 F3 = 125 [pcf] + 2 [ft] * 2 [ft] + tan(23.3) = 215 [Ib/ft] F2 = 125 [pcf] • 2 [ft] * 2 [ft] + tan(35) = 350 [Ib/ft] F3 = 0.5 * 125 [pcf] * (2 [ft])2 * 0.47 * tan(23.3) = 50.7 [Ib/ft] F4 = 0.5 * 125 [pcf] * (2 [ft])2 * 0.47 * tan(35) = 82.3 [Ib/ft] The sum of resisting forces acting along the anchor trench was calculated,as follows: E Fresisaiug = 215 + 350 + 50.7 + 82.3 = 699 [lb/ft] The sum of resisting forces was compared to the tensile yield strength of the MicroDrain®: 699 [Ib/ft] < 1320 [Ib/ft] O.K. The factor of safety against pull-out was calculated using Equation 1, as follows: 699 [Ib/ft] FS PULL our 8.2 85.3 [lb/ft] — GW6489/13any_50%Desip_ClosureTurF_Attachment 11-Pull-Out Resistance_Dray APC Barry_EPA_000746 Geosyntec"' consultants Page 6 of 9 CP: MFL Date: 0824/18 APC: SN Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 SUMMARY AND CONCLUSIONS To resist tensile forces induced by thermal contraction of the MicroDrain®, two cases of anchorages were evaluated: (i) MicroDrain®rimout beneath a riprap channel; and (ii) anchor trench. These evaluations are summarized below. Minimum Runout Length Beneath A Riprap Channel Figure A.10-2 shows the calculated minimum length of MicroDmin® runout for different values of riprap thickness and factor of safety against pull-out. Fora factor of safety of 1.5 and a riprap thickness of 1.0 ft,the minimum ranout length is calculated as 1.3 ft. For riprap thicknesses greater than 1.0 ft or runout lengths greater than 1.3 ft,the calculated factor of safety will be greater than 1.5. Anchor Trench The factor of safety against pull-out of the MicroDrain®in an anchor trench was calculated for a 2- ft deep and 2-ft wide anchor trench proposed by the final cover system design. The factor of safety against pull-out is calculated as 8.2,and therefore,the MicroDrain®is not expected to pull out of the anchor trench due to forces induced by thermal contraction. REFERENCES Qian, X; Koemer, R.M.; and Gray, D.H. (2002). "Geotechnical Aspects of Landfill Design and Construction".Prentice-Hall Inc. GW6489/13arry_50%Desip_ClosurcTurf_Attachment 11-Pull-Out Resistancc_craft APC Barry_EPA_000747 Geosynte& consultants Page ] at 9 CP: MFL Date: 0824/18 APC: SN Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 FIGURES GW6489/13arry_50%Desip_ClosurcTurF_Attachment I I-Pull-Out Resistaacc_craft APC Barry_EPA_000748 Geosyntec"' consultants Page 8 or 9 CP: MFL Date: 0824/18 APC: SN Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 Riprap Channel Closure Turf Riprap(YR) T FR =0 dR T FL= LROYR dR tan(60 LRO Anchor Trench Closure Turf T Backfill(TAT) PP— ATAT 0.5Y d P 2K PA—0.5YATAT d A 2K dAT 1 F FL= LRGYAT dAT tan(6J E LRO Figure A.10-1.MicroDrain®Anchorage with Riprap Channel and Anchor Trench GW6489/13arry_50%Desip_ClosurcTurF_Attachment I I-Pull-Out Resistaacc_craft APC Barry_EPA_000749 Geosynte& consultants Page 9 or 9 CP: MFL Date: 0824/18 APC: SN Date: 08/24/18 CA: GJR Date: 08/24/18 Client: APC/SCS Project: Plant Barry Ash Pond Closure Project Project No: GW6489 3.0 Y N N w_ It FS-1.5 C 2.5 — Fs=zo 0 0 `u 2.0 uA C 19 1.5 N LZ � 1.0 a tY w O w ✓+ 0.5 N C Y u L ~ 0.0 0 1 2 3 4 5 6 7 8 9 10 Calculated Length of Micro Drain® Runout (feet) Notes: 1. Based on ClosureTurf® system with 50-mil Micro Drain® 2.Calculated for an estimated unit weight of riprap of 140 pcf Figure A.10-2.MicroDrain®Runout Length Required to Resist Pull-Out Forces Induced by Thermal Contraction GW6489/13arry_50%Desip_ClosurerurF_Attachment I I-Pull-Out Resistaacc_Draft APC Barry_EPA_000750 Geosynte& Consultants CALCULATION PACKAGE COVER SHEET Client: Alabama Power Company & Project: Plant Barry Closure Design- Project M: GW7193 Southern Company Services North Final Grades Settlement TITLE OF PACKAGE: NORTH FINAL GRADES SETTLEMENT ANALYSIS 3� CALCULATION PREPARED BY: Signature 12/9/2021 a (Calculation Preparer,CP) Name Livingstone Dnumen�u Ph.D. Date ASSUMPTIONS&PROCEDURES Signature /I/ 12/9/2021 CHECKED BY: // V (Assumptions&Procedures Checker,Al Name Juan M.Pestana,Sc.D. Date 3 m S COMPUTATIONS CHECKED BY: Signature a,� ��,Q�� a�/ 3/11/2021 (Computation Checker,CC) Name Qiwei Man Date sm Signature 12/9/2021 BACK-CHECKED BY: 4 (Calculation Prepacer,CP) e' Name Livingstone Dumenu Ph.D. Date APPROVED BY: Signature 4" �..-�/y— 12/9/2021 ® (Calculation Approver,CA) Name William Tanner,P.E. Date REVISION HISTORY: NO. DESCRIPTION DATE CP APC CC CA 0 Draft 4/16/2021 LD JMP QM WT 1 IFC Final 12/9/2021 LD JMP WT WT �i Cl;any_�ooa75t Geosynte& consultants Page 1 of M CP: LD Date: 2/8121 APC: 3MP Date: 3/9121 CA: WT Date: 0/16rn Client: SCS Project PlantBarry—North Final Grades Settlement Project No: GW7193 NORTH FINAL GRADES SETTLEMENT ANALYSIS PURPOSE AND ORGANIZATION This North Final Grades Settlement calculation package (Package)was prepared in support of the design to close the existing coal combustion residuals (CCR) ash pond at Alabama Power Company's (APC's) Plant Barry (Site), located in Bucks, Alabama. The ash pond will be closed using a "consolidate and cap-jn-place" method whereby CCR will be consolidated into an approximately 300-acre area that will be constructed in the central portion of the existing ash pond using soil containment berms and a final cover system. The soil containment berms will be constructed immediately over a locally variable, low strength- high compressibility organic clay subgrade, referred to here as Clay 1. Preloading the areas that will be impacted by the CCR excavation to construct the final soil containment berm (SCB) has been identified as a cost-effective technology to reduce the compressibility and increase the strength of Clay 1 and thus increase the long term stability of the final soil containment berms and short term stability of temporary CCR cut slopes during construction. The purpose of this Package is to present engineering calculations to estimate the settlement as a result of the placement of dredged CCR and construction of a final cover system in the consolidated footprint. Specifically, this Package presents settlement calculations of the final cover system along sections typical for the side slopes and drainage channels and compares the post-settlement grades of those features to minimum grade criteria.Design drawings for this package are provided in Attachment 1. This Package is organized into the following sections: (i) design criteria (it) site background and subsurface stratigraphy; (iii) a description of material and design properties; (iv) a description of the settlement modeling performed; (v) a discussion of the results; (vi) conclusions and recommendations for construction. GW7193North FinalGndes settlement Narrative IFC APC Barry_EPA_000752 Geosynte& Consultants Page 2 of M CP: LD Dale: 2/8121 APC: 3MP Date: 3/9121 CA: WT Date: 0Uyn Client: SCS Project PlantBarry—North Final Grades Settlement Project No: GW7193 DESIGN CRITERIA The design of the proposed consolidated footprint will be performed in accordance with the provisions of the United States Environmental Protection Agency's(USEPA's)federal CCR Rule contained in 40 CFR §257 [1]. The following design criteria were selected from the regulation mentioned above and recommendations defined in the Design Basis package [2] are considered for the settlement calculations presented in this Package: • The final cover system will be designed such that differential settlement of the cover system resulting from compression of CCR,liner,and foundation soils will not cause grade reversal of the cover system. • Post-settlement final cover slopes will not be less than 3 percent nor greater than 25 percent. • Post-settlement longitudinal (i.e., along the channel axis) drainage channel slopes within CCR limits will not be less than 0.5 percent nor greater than 33 percent. Longitudinal channel slopes outside of CCR limits may be less than 0.5 percent due to topographic constraints. • Post-settlement drainage channel side slopes will not be greater than 33 percent(25 percent if the slope is resting against the cover system). • Post-settlement cross slopes of the benches will not be less than 0.5 percent nor greater than 25 percent. • Differential settlements of the final cover system as a result of settlement of foundation soils and CCR will not cause tensile strains in the final cover system to exceed an allowable tensile strain of 5 percent for the geomembrane layer system [3]. SITE BACKGROUND AND SUBSURFACE STRATIGRAPIIY The Site is located on the western edge of the Mobile River delta, approximately 22 miles north of the delta front transition to Mobile Bay. The geology at the Site is defined by an aggmding fluvial- deltaic system comprised of backwater lagoons, cutoff meanders, broad natural sand levees or splays, distributary channels, and actively meandering rivers. Given the Site's current location within the inside bend of a broad meander,the Site has likely been subjected to both fluvial erosional and depositional process associated with the Mobile River [4]. Across the site, native soils are divided into four stratigraphic units beneath the existing CCR and perimeter soil containment berms GWW9193Nonh Fing0odes Settlement Narretive IFC APC Barry_EPA_000753 Geosyntec° consultants Page 3 of M CP: LD Date: 2/8121 APC: 3MP Date: 3/9121 CA: WT Date: 0/16rn Client: SCS Project PlantBarry—North Final Grades Settlement Project No: GW7193 that include, from top to bottom, Clay 1, Sand 1, Clay 2, and Sand 2. These stratigraphic units are divided spatially at the site into varying "Design Reaches", which are defined in the Materials Package [5], due to the spatial variability in stress history and undrained shear strength parameters for subsurface units;especially for Clay 1 and Clay 2.Under post-closure configuration,the existing CCR in the consolidated footprint will be overlain by compacted CCR that will be excavated from the southern portion of the Site (Excavation Area) placed on top of the existing CCR. Figure 1, Attachment 1 presents the plan view of the design final grades for the northern half of the consolidated footprint and shows the Sections considered for this package. There are two distinct groundwater conditions characterizing the site which are controlled by the water elevation within the existing CCR in the pond area and the pool level in the adjacent Mobile River referred to as upper and lower groundwater table (GWT), respectively. For the purpose of the analysis presented here,the upper groundwater table is assumed to apply to the existing CCR and Clay 1 and was defined based on piezometric head elevations encountered in the various field investigations and visual observations at the site. The lower GWT is the piezometric head applied to the Sand 1, Clay 2 and Sand 2 layers and appears to be controlled by the water elevation of the Mobile River. MATERIAL AND DESIGN PARAMETERS Subsurface stratigraphy,material parameters, and engineering design parameters were previously developed for the Site [5] (Materials Package).Herein, information obtained from a series of cone penetration test (CPTs) (PDCPT-02, PDCPT-33, PDCPT-34, PDCPT-37, PDCPT-42 and CPT- A5) located close to Sections A-A and B-B as well as information from reach zones (1, 3A, 5A and 5B)were used to modify engineering design parameters for soil units to be more representative of the conditions for the two cross sections analyzed. Table 1 lists the CPTs considered for developing the subsurface stratigraphy,the corresponding locations and ground surface elevations. Figure 2, Attachment 1 shows the reach location plan with regards to the Sections selected for the package. o For Section A-A,PDCPT-02 and PDCPT-42 were used to create the design profile and stratigraphy to the west with PDCPT-02 beneath the preloaded area to the west. PDCPT-37 was used to create the design profile and stratigraphy beneath the center of the pond. CPT-A5, PDCPT-33, and PDCPT-34 were used to create the design profile and stratigraphy to the east with PDCPT-33, and PDCPT-34 beneath the preloaded area to the east. Figure 3, Attachment 1 details the design profile and stratigraphy developed for Section A-A. GW7193N.n FinalOodes settlement Narretive IFC APC Barry_EPA_000754 Geosyntec° consultants Page 4 of M CP: LD Dale: 2/8121 APC: 3MP Date: 3/9121 CA: WT Date: 4/16Y21 Client: SCS Project Plant Barry—North Final Grades Settlement Project No: GW7193 o For Section B-B,PDCPT-37 was used to create the design profile and stratigraphy beneath the center of the pond as shown in Figure 4,Attachment 1. For CPTs PDCPT-02 and PDCPT-33,Clay 1 was subdivided into three layers,from top to bottom, including: Clay 1 C,representing an overconsolidated crust present within the top 1.0 to 5.8 ft of Clay 1. Clay 1 M,representing a slightly over-consolidated middle layer ranging from 2.5 to 10.7 ft in thickness. Clay l L,representing a slightly over-consolidated lower layer ranging from 1.3 to 1.8 ft in thickness. The subsurface soil layer thicknesses generated are based on discrete points from local CPTs and are not necessarily representative of the entire Northern half of the consolidated footprint. The static groundwater table (GWT) within Clay 1 M was assumed to be equal to the upper GWT while the lower GWT(used in Sand 1, Clay 2, and Sand 2)was used for Clay 1 L, as the piezometric head at the bottom of Clay 1 will be closer to the lower GWT. This assumption was made to simplify the calculations and it is believed to provide a conservative estimate of settlements.Actual groundwater conditions in Clay 1 will be complex and varying over the site with piezometric levels transitioning from the upper GWT to the lower GWT with a general downward hydraulic gradient.The sand units(e.g.,Sand 1 and Sand 2)below Clay 1 have variable fine content and may also contribute to the transition between piezometric levels corresponding to the upper and lower GWT. The design compressibility parameters previously developed by Geosyntec [5, 6] and representative unit weights are presented in Table 2. The unit weights of the Clay 1 sub-layers were selected from GPSPs presented in Attachment 2 with compressibility parameters assumed to be the same for all Clay 1 layers. The contribution to the settlements due to the compression of the Sand 2 layer is relatively small compared to those arising from the compression of Clay 1,Clay 2 and Sand 1 layers. The analyses included the soil profile to an elevation of-40ft. Additional settlements arising from the compression of deeper layer (i.e., elevations lower than -40 ft) are expected to be small and relatively uniform and thus will not contribute significantly to the differential settlement across the site. The final cover system proposed for the closure of the Site is a ClosureTurfO cover system as presented in the northern half design drawings [7]. The final cover system detail consists of,from bottom to top: (i) a geocomposite drainage layer, (ii) a 0.5-ft prepared subgrade soil; (iii) a structured geomembrane (50-mil); and (iv) 0.75-in thick sand fill and engineered turf. For the purpose of this analysis,the final cover system was modeled to be 0.5-ft thick with a typical total unit weight of 120 pcf as defined in Table 2. GW7193Motth FinalGredes settlement Narrative IFC APC Barry_EPA_000755 Geosyntec° consultants Page 5 of M CP: LD Dale: 2/8121 APC: 3MP Date: 3/9M CA: WT Date: 0/16Y21 Client: SCS Project PlantBarry—North Final Grades Settlement Project No: GW7193 SETTLEMENT ANALYSIS Cross Sections Analyzed The locations of the two cross sections selected for analysis in this Package are shown on Figure 1, Attachment 1. The two-dimensional analysis cross sections selected were chosen due to the following factors: (i) low preconsolidation pressures in Clay l relative to other areas of the Northern half of the consolidated pond,(ii) the final grades reach maximum height via the steepest slopes along portions of the sections (for section A-A only), and(iii) the highest elevation of the drainage benches which will experience the largest settlements. Cross section A-A runs approximately from west to east passing through the peak of the proposed consolidated footprint limited by the preloaded areas to the west and the east. Cross Section B-B lies near the center of the northern part of the consolidated footprint and runs along the drainage benches closest to the peak of the northern half of the consolidated pond to evaluate the change in grades of the drainage benches. The profiles for Sections A-A and B-B are shown in Figure 3 and 4,Attachment 1,respectively. Settlement was calculated assuming one-dimensional (1D) consolidation at 61 and 24 discrete points along cross section A-A and B-B, respectively. These calculation points were defined wherever the slope of the final grade system changed significantly (i.e. drainage bench crests, inverts). Compiled results from the series of calculation points were used to evaluate total settlements, grade changes along the final cover system, and tensile strains in the geomembrane liner of the final cover system. Locations of the calculation points are provided on Figure 3 and 4,Attachment 1,respectively. Total Settlement The total settlements for the calculations points along the sections were computed using Settle3D, a 3-dimensional (3D) program for the analysis of vertical settlement and consolidation under surface loads by Rocscience [8]. An example Settle3D output can be found in Attachment 3. Details of the settings used in the Settle3D analysis are listed below. • Settle 3D Details o Version: 2018 4.015 o Method: Boussinesq o Time Stages: 7 GW7193Monh Fing0oul a Settlement Narretive IFC APC Barry_EPA_000756 Geosyntec° consultants Page 6 of M CP: LD Dale: 2/8121 APC: 3MP Date: 3/9121 CA: WT Date: 0Uyn Client: SCS Project. PlantBarry—North Final Grades Settlement Project No: GW7193 Model Geometry A three-dimensional subsurface model was created in SettIe3D for each calculation point using material interfaces(i.e. subsurface stratigraphy)described above.The stratigraphic interfaces were tabulated for each calculation point and for each point entered into SettIe3D as a borehole to create a uniform thickness 3D subsurface model. Initial groundwater conditions prior to loading were assigned using the upper groundwater table (GWT) within existing CCR, Clay 1 (1 C and 1 M) and the lower GWT within Clay 1L, Sand 1, Clay 2 and Sand 2.The lower GWT was assumed to be equal to an average Mobile River elevation (EL.3 ft)as described in previous section.The Upper GWT was assumed to be equal to the existing CCR surface. The fill loads including CCR fill, Soil Containment Berm(SCB)and Fill, and Closure Turf Cover system fill, as shown in Figure 3, were modeled as rectangular fill loads applied to the ground surface at various time stages(time stages are discussed in more detail below).For preloaded areas at the east and west edges of Section A-A, as presented in Figure 3, Attachment 1, an excavation stage was considered prior to loading with SCB and Fill and closure turf. Construction and Time Stages The duration considered in the settlement analysis in this Package is 45 years (analysis period), which includes approximately 10 years for closure construction of the northern half of the closure pond. Staging of construction was evaluated for distinct areas within the north half of the pond and it is summarized in Table 3. The fill loads were applied in time stages to represent the planned fill construction sequence for CCR Fill, SCB and Fill, and Closure Turf fill loads based on construction schedules provided to Geosyntec by the contractor and to estimate settlements occurring after the fill loads are constructed. For preloaded areas, an excavation time stage was introduced prior to SCB and Fill placement in which the exisfing CCR was excavated to the expected design elevation of-0.7 It and 1.8 fit at the west and east ends,respectively of Section A- A and fill loads were applied to the bottom of the excavation. For simplicity, each fill load was assumed to be instantaneously placed in the Settle3D model at the time of fill construction. To calculate post construction settlement, additional time stages were added between Closure Turf and Post-settlement(45 years)time stages. Under the post-closure conditions,the groundwater conditions within the consolidated footprint is expected to drop due to the encapsulation of the consolidated footprint with final cover system and the operation of an internal drainage system to lower groundwater level within the consolidation GWW9193Monh FinalOodes Settlement Nafretive IFC APC Barry_EPA_000757 Geosyntec° consultants Page 7 of M CP: LD Dale: 2/8121 APC: 3MP Date: 3/9121 CA: WT Date: 0Uyn Client: SCS Project PlantBarry—North Final Grades Settlement Project No: GW7193 footprint. The reduction in groundwater levels will induce an additional increase in vertical effective stresses within the existing CCR and subsurface soils, which will result in additional settlements. The groundwater level within the consolidation footprint was lowered from the top of the existing CCR to a long-term elevation of approximately 3 ft. This was modeled as an instantaneous change at the end of Closure Turf construction. Grade Chanties Using post-settlement grades, the slope changes (i.e. the change in elevations between calculation points within the final grade system)were evaluated using Equation 1 below: S _ Elx+a—Elx ( ) STAx+t—STAx 1 where: S = Slope between adjacent calculation points; El = elevation at calculation points x and x+1 (ft); and STA = stations of calculation points x and x+1 (ft). The post-settlement slopes were compared to the pre-settlement slopes. Changes in slope sign indicated a grade reversal. Strain Calculations Using post-settlement grades, the tensile strains (i.e. the change in length relative to the initial length between calculation points) within the geomembrane component of the final cover system were assessed using Equation 2 below: Lf—Lo e = (2)Lo where: E = strain in the geomembrane component (+ indicates tension; - indicates compression); GW 193Monh FinalGredes settlement Narrative IFC APC Barry_EPA_000758 Geosyntec° consultants Page 8 of M CP: LD Dale: 2/8121 APC: 3MP Date: 3/9121 CA: WT Date: 0/16rn Client: SCS Project PlantBarry—North Final Grades Settlement Project No: GW7193 Lf = final length between adjacent calculation points based on post-settlement elevations; and Lo = initial length between adjacent calculation points based on pre-settlement elevations. The initial and final lengths between adjacent calculation points were calculated using Equation 3. L = (EI:+1 — Elx)2 + (STA:+1 —STA:)2 (3) where: L = length between adjacent calculation points; El = elevation at calculation points x and x+l (ft); and STA = stations of calculation points x and x+l (ft). RESULTS Settlements induced by construction of the consolidated pond and closure system were calculated at 61 and 24 discrete points for section A-A and Section B-B, respectively, assuming 1D consolidation,using Settle3D. Post settlement profiles along the design Sections A-A and Section B-B of the final grades and cover system at the end of the 45 years analysis period are presented in Figure 1 and 2, respectively. Total Settlement The calculated total settlements for calculation points along cross sections A-A and B-B at the end of analysis period(45 years design life)are presented in Tables 4 and Table 5, respectively. The calculated total settlements ranges from 0.36 ft to 7.35 It for Section A-A, and from 5.86 ft to 6.51 ft for Section B-B. The larger settlements occurred at calculation points with thicker CCR Fill and subsurface clay layers. Smaller settlements were observed to occur at calculation points within the preloaded areas due to the subsurface soil layers having undergone preloading consolidation prior to construction of the final grades and due to relatively low net loads (i.e. excavation unloads the soil before new loads are added,thereby resulting in low incremental loads relative to the initial condition). GW 193Morth FinalGredee settlement Narrative IFC APC Barry_EPA_000759 Geosyntec° consultants Page 9 of M CP: LD Dale: 2/8121 APC: 3MP Date: 3/9121 CA: WT Date: 0/16rn Client: SCS Project. PlantBarry—North Final Grades Settlement Project No: GW7193 Post-construction settlement was evaluated using settlement at the end of Closure Turf construction and the settlement at the end of the 45-year design life. The calculated post- construction settlement ranges from 0.24 ft to 2.11 ft for Section A-A and 1.44 ft to 1.88 ft for Section B-B. Grade Chanee The calculated grades for cross sections A-A and B-B of the final cover at the end of analysis period are presented in Tables 4 and Table 5, respectively. The calculated minimum post- settlement grade of the final grade along the side slopes of Section A-A are 2.67, 3.15, and 2.86 percent at station 726.79 (point 213), 1356.05 (point 218), and 4275.15 (point 237), respectively. The post-settlement grades at stations 726.79 and 4275.15 do not satisfy the design criteria of minimum of 3.0 percent post-settlement grades as detailed in the design criteria [2]. For these locations,a 1.5 ft overbuild will be required as indicated in Figure 1 and discussed in the following section. Slopes between station 1609.92(point 219)and station 4275.15 (point 237)correspond to the intersection of two slopes and therefore not a representative of the maximum grades of the immediate slopes. The calculated minimum post-settlement grade along the drainage channel of Section B-B is 0.92 percent at station 1455.86 (point 114) of Section B-B which satisfies the minimum design criteria of 0.5 percent. No grade reversal was observed in the cover system following the post-settlement of the cover system resulting from the compression of the existing CCR and subsurface soil layers. Geomembrane Tensile Strain The maximum post-settlement tensile strain within the gomembrane of the final cover system is calculated to be 0.34 percent for Section A-A (at station 3561.55, point 231) and 0 percent for Section B-B (at multiple stations). These calculated maximum tensile strains are below the allowable tensile strain of 5 percent. Also, small compression strains were observed for both Sections A-A and B-B. GW 193Monh FinalGndes settlement Narrative IFC APC Barry_EPA_000760 Geosynte& consultants Page 10 of M CP: LD Dale: 2/8121 APC: 3MP Date: 3/9121 CA: WT Date: 0Uyn Client: SCS Project: Plant Barry—North Final Grades Settlement Project No: GW7193 SUMMARY CONCLUSIONS AND RECOMMENDATIONS Settlement of existing CCR and native soils due to the placement of additional CCR,SCB and Fill, and a final cover system were estimated and presented in this calculation package. The post- settlement elevations of the final grade show that the final grades met the design criteria. The computed settlement induced tensile strains in the geosynthetic components of the final cover system were found to be lower than the design criteria of 5%. Based on the settlement calculations presented in this Package the following observations are made: • the calculated minimum post-settlement grade of the final cover system for points 213 and 237 on the side slopes did not satisfy the design criteria minimum of 3 percent; • the calculated minimum post-settlement grade along the selected drainage bench within the CCR limit exceeds the minimum of 0.5 percent and meets the design criteria ; • the calculated maximum tensile strain within the geomembrane of the final cover system is 0.37 percent, which meets the design criteria allowable tensile strain of 5 percent. • No grade reversal was observed in the cover system of the Sections considered for this analysis. For side slopes that failed the design criteria minimum of 3 percent,Geosyntec recommends a 1.5 ft CCR Fill overbuild of the final cover elevation at points 214 and 237 of Section A-A with the overbuild thickness approaching 0 ft at the slope toe(i.e. points 213 and 238)as shown in Figure 1, Attachment 4. The approximate area for the CCR fill overbuild is presented in Figure 2, Attachment 4. GW 193Monh FinalGredes settlement Narrative IFC APC Barry_EPA_000761 Geosynte& consultants Page 1 of M CP: LD Date: 2/8121 APC: 3MP Date: 3/9121 CA: WT Date: 0/16rn Client: scs Project PlantBarry—North Final Grades Settlement Project No: GW7193 REFERENCES [1] United States Environmental Protection Agency, "Code of Federal Regulations (CFR) Title 40, Parts 257 and 261, Hazardous and Solid Waste Management System: Disposal of Coal Combustion Residuals from Electric Utilities;Extension of Compliance Deadliens for Certain Inactive Surface Impoundments; Respons," 2016. [2] Geosyntec Consultants, 'Design Basis for the Plant Barry Ash Pond CLosure at Plant Barry of Alabama Power Company. Revision A," Kennesaw, 2018. [3] R. B. Ryan R. Berg, "Long-Term Allowable Tensile Stresses for Polythene Geomembranes," Geotextiles and Geomemhranes, vol. 12,pp. 287-306, 1993. [4] A. B. Rodriguez, D. L. J. Green, J. B. Anderson and A. R. Simms, 'Response of Mobile Bay and eastern Mississippi Sound, Alabama, to changes in sediment accommodation and accumulation," Response of Upper Gulf Coast Estuaries to Holocene Climate Change and Sea-Level Rise: Geological Society afAmerica Special Paper 443, pp. 13-29,2008. [5] Geosyntec Consultants, "Draft Material Properties and Major Design Parameters," St. Louis, 2018. [6] Geosyntec Consultants, "Draft Preloading Pilot Study Summary Report,"Kennesaw,2020. [7] Geosyntec Consultants, 'Northern Half Design Drawings, Drawing 016 of 037, Plant Barry CCR Pond Closure,Northern Half Design, Mobile County,Alabama," Kennesaw, 2020. [8] Rocscience Inc., "Settle3," Rocscience, Toronto, Ontario,2018. [9] Rocscience Inc., "Slide2 Modeler,"Rocscience, Toronto, Ontario, 2020. (3 '193Morth Final(lndes settlement Narrative IFC APC Barry_EPA_000762 Geosyntec c consultants Page 2 of 50 CP: LD Date: 2/0/21 APC: JMP Date: 3/9/21 CA: WT Date: 4/1621 Client: SCS Project: Plant Barry—North Final Grades Settlement Project No: GW7193 TABLES Table 1—CPT Location Information and Summary Table 2—Material and Design Compressibility Parameters Table 3—Time Stages Table 4—Results: Total Settlements and Grades of the Surface for Cross Section A-A Table 5—Results: Total Settlements and Grades of the Surface for Cross Section B-B FIGURES Figure 1 —Post Settlement prone for Section A-A Figure 2—Post Settlement profile for Section B-B Figure 3—Typical Fill Loads ATTACHMENTS 1. Drawings 2. Geotechnical Parameter Summary Plots 3. Settle3 Model Example Details 4. CCR Fill Overbuild GW7193NoM FinalCm 3enlement Nnrmtive IPC APC Barry_EPA_000763 Geosyntec c consultants Page 3 of 50 CP: LD Date: 2/8/21 APC: JMP Date: 3/9/21 CA: WT Date: 4/1621 Client: SCS Project: Plant Barry—North Final Grades Settlement Project No: GW7193 TABLES Table 1 -CPT Location Information and Summary Investigation t u) Elevation 1) Ground Surface Program Year Section CPT ID Northing (ft) Easting (a) t21(111PDCPT-02 2018 364460.6 1810606.8 21.4 PDCPT-42 2018 365082.7 1810823.3 33.9 A A PDICPT-37 2018 365216.2 1812861.3 30.6 CPT-A5 2020 365592.0 1812881.6 28.7 PDCPT-33 2018 366736.6 1813222.8 22.6 PDCPT-34 2018 366859.1 1812914.8 23.2 B-B PDCPT-37 2018 365216.2 1812861.3 30.6 Notes: IHorlmnial coordinntes are in the North American Datmnof 1983(NAD83),Alabstm West Zone. Vertical coordinates are in the North American Vertical Datum of 1988 AVD88 OW/193North Final('mdes Settlement Narmtive IPC APC Barry_EPA_0007f Geosyntec c consultants Page 4 of 50 CP: LD Date: 2/0/21 APC: JMP Date: 3NM CA: WT Date: 4/1621 Client: SCS Project: Plant Barry—North Final Grades Settlement Project No: GW7193 Table 2—Material and Design Compressibility Parameters Pre Over Burden Secondary Coefficient of Total Unit mm Elastic Modulus, Recompression Compression Material Reach Pressure POP Compression Consolidation,cv Weight(per) (Psi) E(psi) Ratio,CR Ratio,Ca(Psi) a Ratio,Car (Bt/min New CCR 97 0 SCB and Fill All 115 0 - - - - - ClosumTrrf 120 0 Existing CCR 92 0 0.010 0.100 0.0015 0.02 1 94 600 0.O19 0.263 0.035 0.00083 Clay I !A 105 1,200 5B 105 750 1 I10 Sand 1 3A 115 SA I10 OCR 2500000 1.0 x 100 0.1 - 0.008 5B 115 1 101 0 - 0.014 0.14 0.03 0.0008 Clay 3A 102 5A 5B Not Present Sand AD 120 3000000 Notes Pro-overburden presswes refs w de difiueme between the rscr past prcros (Pp)aal in sim vertical e&cfiw stress 2Prelpaded areas aesuaed Clay IC IK IL and final le ern,.od POP equalw overwmolldau. 'n OC of ISM sf GW7193MortA_FinalGmdea 6enlement Nnrrative_IPC APC Barry_EPA_000765 Geosyntec c consultants Page 5 of 50 CP: LD Date: 2/0/21 APC: JMP Date: 3/9/21 CA: WT Date: 4/Ml Client: SCS Project: Plant Barry—North Final Grades Settlement Project No: GW7193 Table 3—Time Stages Summary Stage No. Trove(days) 1 0 Existing 2 183-475/11 CCR FiIVSCB and Fill"i 3 548- 1095111 Closure Turf 4 1825 5 Years 5 3650 10 yews 6 10950 30 years 7 16425 45 years Notes: 'Time dependent on the construction activities(C2,C3,C5,Fl,F3,F4,F5,F6,and F7)as presented in the construction schedule provided by the Contractor that corresponds to the respective calculation points. 2Excavation stage is introduced prior to the placemem of SCB end Fill construction sequence within unclouded areas. OW7193Morth FinalC des Sealement Narretive IFC APC Barry_EPA_000766 Geosyntec e consultants Page 6 of 50 CP: LD Date: 2/8/21 APC: JMP Date: 3/9/21 CA: WT Date: 4/1641 Client: SCs Project Mant Barry-North PSnal Grades Settlement Project No: GW7193 Table 4-Results: Total Settlements and Grades of the Surface for Cross Section A-A Calculation Total SekFi..IMA, mementat root Condrnrdon Dai�Final Finil Slopes a[ curer Swain Pointm 6tafion(R) atanaiff L"s(at Settlement(0) Grader(%) Year d5(%.) (%) C000s 02W 298.78 0. L19 1.08 32.82 30. 0 -0.80 201 317.30 0. 0.67 0.67 1.01 1.01 0.00 202 539.16 0. M7 0.60 25.00 25.03 0.01 203 545.16 0. 0.67 OA7 0.00 0.27 0.00 2" 555.16 0. 0.M 0.64 25.00 24.32 -0.16 205 561.16 0. 0.69 0.68 1.15 1.13 ON 206 581.25 0. 0.69 0.69 33.32 29.82 -1.M 207 601.79 0. 1.41 1.37 1.00 0.89 0.00 208 626.79 0. 1.38 1.35 8.23 7.01 -0.09 209 1 676.78 0.00 0.77 0.77 0.99 2.24 0.02 210 688.34 0.00 0.63 0.63 7.57 7.52 0.00 211 701.55 0.00 0.63 0.63 3.96 2.74 AN 212 724.40 O.W 0.91 0.91 24.93 24.75 AN 213 726.79 0.00 0.92 0.92 3.50 2.76 -0.M 210' 1274.88 3.15 4.99 1.83 2231 19.10 -0.63 215 1288.34 2.56 4.55 2.00 0.29 -3.90 Us 216 12W.07 3.16 5.00 1.85 4.43 5.11 0.03 217 1353.63 2.52 4.63 2.11 2A.17 M.44 -0.38 218 1356.05 2.56 4.67 2.11 3.50 3.15 -0.01 219 1609.92 3.63 5.56 1.93 L91 Lr 0.00 220 2233.30 439 6.48 2.09 19.30 20.50 023 221 2249.05 4.M 6.67 2.03 0.59 0.53 0.00 222 2261.31 4.63 6.66 2.03 297 2.77 -0.01 223 2315.65 4.79 6.77 1.99 1.30 1.24 0.00 224 2324.68 1 4.80 6.78 1.98 21.65 19.99 -0.33 225 2327.79 4.86 6.83 1.97 216 2.08 000 226 2991.92 5.90 7.35 1.45 0.02 0.11 0.00 227 3021.13 5.88 7.33 1.45 3.01 2.77 -0.01 228 3494.84 4.83 6.18 1.35 24.02 M.44 -0.35 229 3497.22 4.79 6.14 1.35 3.95 3.40 -0.02 230 3550.98 4.59 5.84 1.26 0.16 0.38 0.00 231 3561.55 459 5.82 1.23 23.00 24.51 034 232 3574.81 4.75 5.62 0.87 3.02 2.76 -0.01 23310 4197.08 326 4.02 0.76 da Na -0." 2M 4197.54 322 4.01 Q]9 3.93 3]8 -0.01 235 4251.73 3.08 3.93 0.85 0.15 -0.02 0.00 236 4262.11 3.10 3.95 0.85 1 22.85 1 21.37 -0.31 237m 4275.15 3A7 4A4 0.67 3.49 2.86 -0.02 238 4860.53 0.00 OA7 0.47 1.71 1.89 0.00 239 4915.83 0.00 0.57 0.57 12.19 9.68 -0.36 N. Tdv niaWo.d-N. dow¢WaNd-MreprexM@e node alo%He dye bneh eOvnduldrturtd m-s ne-dniw Mom criaria. GW7193MoM FinalCm Se0lement Nermtive 1PC APC Barry_EPA_000767 Geosyntec c consultants Page 7 of 50 CP: LD Date: 2/8/21 APC: JMP Date: 3/9/21 CA: WT Date: 4/Ml Client: SCS Project: mant Barry-North Final Grades Settlement Project No: GW7193 Table 4-Continued. Calculation Total Settlement Total Settlementat Post Con Palo Final Find Slopes a[ Cover Strain ID Station(it) at end of Final Deign Life(at Settlement(0) Grader(%) Year d5(%.) M) Coortrp00 0 d5 can 0 241 4997.69 0.00 036 0.36 3.00 0.4 0.00 242 5018.21 0.W OA5 0.45 0.00 -0.40 0.00 242 5018.21 0.00 0.45 0.45 0.03 -0.09 0.00 243 5074.67 0.00 0.38 0.38 1&85 16.72 -0.02 2" 5075.98 0.00 0.38 0.38 10.09 10.06 0.00 245 5078.31 OAO 0.38 0.38 17.18 15.63 -0.25 246 5093.09 0.00 0.61 0.60 2.71 2.71 0.00 247 5110.28 0.01 0.61 0.60 25.24 25.08 -0.M 248 5112.38 0.01 0.61 0.60 6.89 9.74 0.14 2Wt 5112.56 0.01 0.61 0.60 rda Na 0.10 250 5113.43 0.09 0.61 0.51 23.81 22.86 -0.21 251 5114.48 0.01 0.62 0.60 0.71 0.71 0.00 252 5149.47 0.02 0.62 0.60 23.65 23.48 -0.04 253 5165.17 0.00 0.59 0.59 OA3 0.13 0.00 254 5297.95 0.00 0.59 0.59 31.28 30.66 -0.17 255 5325.57 0.00 OA2 0.42 0.00 -0.26 0.00 256 5384.81 0.01 0.57 0.56 33.33 33.21 -0.03 2571'1 5407.10 0.01 0.60 0.59 Na Na -0.15 258 5408.02 0.02 0.60 0.59 1.00 0.95 0.00 259 5533.45 0.10 0.66 0.56 23.65 23.56 -0.02 260 5559.82 0.13 0.68 0.56 OA5 0.44 0.00 Note Attie ulculatipa olo-W witlua oo-asE-.I d-ml wR ro a,a alo tle yai be¢h GW7193MoM FinalGm Se0lement Nermtive 1PC APC Barry_EPA_000768 Geosyntec c consultants Page S of 50 CP: LD Date: 2/8/21 APC: JMP Date: 3/9/21 CA: WT Date: 4/1Uu Client: SCS Project Plant Barry-North Final Grades Settlement Project No: GW7193 Table 5-Results: Total Settlements and Grades of the Surface for Cross Section B-B C.ktda6on Total Settlement Total Settlementat NO Uesign Dnu1 Final SN,esat Cover Strvin Pow Sta6on(n) at end of Finall)om lifeoo Conetrvetian Grades(%) year45(•/.) (%) Construetbn a 45 eary R Settlemem (t 100 110.73 4.82 633 1.51 24.03 22,45 -0.35 101 13145 4.37 6.00 1.63 0.00 0.05 OM 102 142.26 4.35 6.00 L64 24.01 22AO -0.35 103 163 4.82 633 1.51 1.00 0.94 0.00 IN 450.49 4.93 6.51 1.59 1.01 0.94 0.00 105 731.76 4.86 6.31 146 19.23 18.10 -0.20 106 757.98 4.52 6.02 1,50 0.10 0.09 0.00 107 770.26 4.52 6.02 1.50 2L42 20.18 -0.25 108 79619 4.90 6.34 LM 2.62 2A7 0.00 109 869.74 5.01 6A6 LM 1.00 0.95 0.00 Ito 112U6 4.72 633 L61 24.01 2231 -0.37 ip11 1141 4.29 5.98 1.69 0.00 0.05 0.00 Ill 1151.83 427 5.97 1.70 23.96 22.27 -0.37 113 1172.61 4.69 6.32 I.M 1.00 0.93 0.00 114 1455A6 4.91 6.51 1.60 1.00 0.92 0.00 115 1733.09 452 628 1.76 21.02 1928 -0.34 11610 1757.21 4.00 5A6 1.87 0.03 0.03 0.00 117 1770A4 4.00 5.86 1.87 19.52 IT91 -0.29 Its 1799.72 4.58 6.M 1.75 2.97 2.75 -0.01 119 1867.65 4.]] 648 +VJ1J2 1.00 0.95 0.00 120 21M.9 4.16 6.33 24.01 22AO -0.35 121 2165.67 4.366000.00 0.000.00in 2V6.49 4.36 6AO 24.01 nA3 -035 123 2197.26 4.44 6.331." 2.61 2.32 -0.01 Nate 'MN cIl Watiou oond is 1a9ed wiWiu at..,da-.c ®i Mes w[re a .do&m 1e Wo [he @ei berch. OW7193MoM FinalCm Se0lement Nermtive TFC APC Barry_EPA_000769 Geosyntec c consultants Page 9 of 50 CP: LD Date: 2/0/21 APQ JMP Date: 3/921 CA: WT Date: 4/1621 Client: SCS Project: Plant Barry—North Final Grades Settlement Project No: GW7193 80 —Top of Cover,PreSettlement —Top of Cover,Post-Settlement 70 60 50 Grade=3.50% C 0 40 / Grade Grade=3.5)% / Grade=3.50% W 30 Grade=2.86% Grade=3.12%with 1.5 ft Overbuild 20 Grade=2.76% Grade=3.00%with 1.5 ft Overbuild ]0 0 0 1000 2000 3000 4000 5000 6000 Distance,It Figure 1. Post Settlement profile for Section A-A 6W7193Monh FuedGredes Settl.ent Narretive IFC APC Barry_EPA_000770 Geosyntec c consultants Page 10 of 50 CP: LD Date: 2/0/21 APC: JMP Date: 3/921 CA: WT Date: 4/1621 Client: SCS Project: Plant Barry—North Final Grades Settlement Project No: GW7193 70 —Top of Cover,Pre-Settlement Grade=1.0% —Top of Cover,Post-Settlement 60 50 / Grade=0.92% 40 c 0 W 30 20 l0 0 0 500 1000 1500 2000 2500 Distance, ft Figure 2. Post Settlement profile for Section B-B. GW7193Morth FinalGmdm Settlement Nazmtive IFC APC Barry_EPA_000771 Geosyntec c consultants Page 11 of 50 CP: LD Date: 2/0/21 APC: JMP Date: 3MM CA: WT Date: 4/Ml Client: SCS Project: Plant Barry—North Nord Grades Settiment Project No: GWII93 7 FN Cv.�IGoeuerureow Sym.l Ctli Fi $oieaeivmi S—ae Fi FiW CwxtCbiniulCwx 9/aemt Fy�p�y 9bulvu Sae Figure 3. Typical Fill Loads. GW7193Morth FinalGmdm Settlement Nazmtive IFC APC Barry_EPA_000772 Geosyntec c consultants Page 12 of 50 CP: LD Date: 2/0/21 APC: JMP Date: 3/9/21 CA: WT Date: 4/Ml Client: SCS Project: Plant Barry—North PSnal Grades Settlement Project No: GW7193 ATTACHMENT 1 DRAWINGS OW7193NoM FiaalCm Senlement Nnrmtive IPC APC Barry_EPA_000773 Geosyntec c consultants Page 13 of 50 CP: LD Date: 2/0/21 APC: JMP Date: 3/9/21 CA: WT Date: 4/Ml Client: SCS Project: Plant Barry—North PSnal Grades Settlement Project No: GW7193 ATTACHMENT 2 GEOTECHNICAL PARAMETER SUMMARY PLOTS OW7193NoM FiaalCm Senlement Narmtive IPC APC Barry_EPA_000774 Geosyntec c consultants Page 14 at 90 CP: LD Date: M/21 APC: JMP Date: 3/9/21 CA: WT Date: 4/Ml Client: SCS Project: Plant Barry—North PSnal Grades Settlement Project No: GW7193 ATTACHMENT SETTLE3 MODEL DETAILS OW7193NoM FiaalCm Senlement Narmtive IPC APC Barry_EPA_000775 Geosyntec c consultants Page 15 of 50 CP: LD Date: 2/0/21 APC: JMP Date: 3/9/21 CA: WT Date: 4/Ml Client: SCS Project: Plant Barry—North PSnal Grades Settlement Project No: GW7193 ATTACHMENT 4 CCR FILL OVERBUILD OW7193NoM FiaalCm Senlement Narmtive IPC APC Barry_EPA_000776 Geosynte& consultants CALCULATION PACKAGE COVER SHEET Client: Alabama Power Company & Project: Plant Barry Closure Design- Project#: GW7193 Southern Company Services North Final Grades Stability TITLE OF PACKAGE: NORTH FINAL GRADES STABILITY ANALYSIS CALCULATION PREPARED BY: Signature 12/7/2021 (Calculation Preparer,CP) Name Zachary Fallen, P.E. Daze a ASSUMPTIONS&PROCEDURES Signature --71e 12/' 10?1 CHECKED BY: (Assumptions&Procedures Checker,APC) Name Juan M.Pestana,Sc.D. ttmc 3 COMPUTATIONS CHECKED BY: Signature 12/7/2021 (Computation Checker,CC) Name Livingstone D,umenu/ Date BACK-CHECKED BY: Signature /�//�/ 12/7/2021 �7 (Calculation P cparer,CP) Name Zachary Fallen,P.E. Date APPROVED BY: Sigaemre 12/7/2021 m° (Calculation Approver,CA) Name William Tanner,P.E. Daze REVISION HISTORY: NO. DESCRIPTION DATE CP APC CC CA 0 Draft 2/23/2021 ZJF IMP LD WT 1 IFC Final 12/7/2021 ZJF JMP LD WT APC Barry_EPA_000777 Geosynte& consultants Page 1 of 185 CP: ZJF Date: 2123M APC: JMP Date: 2n2121 CA WT Date: 3Wn Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 NORTH FINAL GRADES STABILITY ANALYSIS PURPOSE AND ORGANIZATION This North Final Grades Stability calculation package (Package) was prepared in support of the design to close the existing coal combustion residuals (CCR) ash pond at Alabama Power Company's (AFC's) Plant Barry(Site), located in Bucks, Alabama. The ash pond will be closed using a "consolidate and cap-in-place" method whereby CCR will be consolidated into an approximately 300-acre area that will be constructed in the central portion of the ash pond using soil containment berms with a final cover system. The soil containment berms will be constructed immediately over a locally variable, low strength- high compressibility organic clay subgrade, referred to here as Clay 1. Preloading the areas that will be impacted by the CCR excavation to construct the final soil containment berm has been identified as a cost-effective technology to reduce the compressibility and increase the strength of Clay 1 and thus increase the long term stability of the final soil containment berms and short term stability of temporary CCR cut slopes during construction. A slope stability analysis was performed to evaluate the stability of the final grades (i.e. final constructed condition) of the northern half of the consolidated ash pond. These analyses included predicted soil improvements due to preloading. Additional loading of the eastern dike raise as shown in the Draft Design Drawings [I]in Attachment 1 was also included. Possible strength increases due to the eastern dike raise were conservatively excluded from this analysis because the timing of the dike raise construction is uncertain. Detailed slope stability analyses were performed for (i) short term conditions including construction loads, (ii) short term conditions without construction loads, (in) long term conditions, and (iv) pseudo-static seismic conditions. The various preload areas,as well as the location of all field cone penetration tests(CPTs)are presented in Figure 1,Attachment 1.This Package describes these analyses for two cross sections: The East (E) section and the West (W) section. For reference, the East section is immediately next to the Mobile River. A third cross section, the Center section (C), was used for final grades within the pond and is discussed in more detail in the Model Geometry section later in this Package.The two- dimensional cross sections used for verification were selected based on the following: GW7193NoM_FirelGoul. Stability_Nartazivcd.c APC Barry_EPA_000778 Geosynte& consultants Page 2 of 185 CP: ZJF Date: 2123M APC: JMP Date: 2n2121 CA WT Date: 3Wn Client: SCS Project: PlantBarry—North Final Grades Stability Project No: GW7193 • CPTs which show a weaker and relatively thick Clay 1. o Across the Site, the undrained shear strength, S„ of Clay 1 ranges from 200 psf to 1100 psf. The S. of Clay 1 within the analyzed cross-sections ranges from 200 psf to 1000 psf. o Across the Site, Clay 1 ranges from approximately 6.7 to 20.0 It thick. Within the analyzed cross-sections, Clay 1 ranges from 10.0 to 18.0 ft thick. • Low outboard dike toe elevation. o The East and West sections were chosen where relatively low toe elevations coincided with the weakest strengths in Clay 1. • Maximum Final Grades. o The final crest of the consolidated pond reaches El. 74 ft. Both the East and West sections utilize the Center section(see Model Geometry section for details), which cuts perpendicular to the pond grades (i.e. steepest slope) and reaches the crest elevation. This Package is organized into the following sections: (i) site background and subsurface stratigraphy; (ii) a description of material properties; (iii) a description of the stability modeling performed;and(iv)a discussion ofthe results,conclusions,and recommendations for construction. SITE BACKGROUND AND SUBSURFACE STRATIGRAPHY The Site is located on the western edge of the Mobile River delta, approximately 22 miles north of the delta front transition to Mobile Bay. The geology at the Site is defined by an aggrading fluvial- deltaic system comprised of backwater lagoons, cutoff meanders, broad natural sand levees or splays, distributary channels, and actively meandering rivers. Given the Site's current location within the inside bend of a broad meander,the Site has likely been subjected to both fluvial erosional and depositional process associated with the Mobile River [2]. Across the East and West cross sections chosen for analysis, native soils are divided into four stratigraphic units beneath the CCR and perimeter dikes that include, from top to bottom, Clay 1 (approximately 10.0 ft to 18.0 ft thick), Sand 1 (approximately 1.4 to 7.5 ft thick), Clay 2(approximately 3.0 to 8.6 ft thick), and Sand 2 (at least 20 If thick) — these thicknesses are based on discrete points from local CPTs and are not necessarily representative of the entire Northern half of the Consolidated Pond area. These stratigraphic units are divided spatially at the site into varying"Design Reaches"which are defined in the Materials Package [3]. The groundwater regime at the site is defined by using two characteristic piezometric levels, referred to as upper and lower groundwater table (i.e., upper GWT and lower GWT). The upper groundwater table applies to the perimeter dike material, CCR and Clay 1 and was defined based GW7193MoM_Fi.[Goxi. Stability_Nana ivcd.c APC Barry_EPA_000779 Geosyntec° consultants Page 3 of 185 CP: ZJF Date: 2123M APC: JMP Date: 2n2121 CA WT Date: 3Wn Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 on piezometric head elevations encountered in the various field investigations and visual observations within the pond footprint (i.e. ponded water in low spots). The lower GWT is the piezometric head applied to the Sand 1, Clay 2 and Sand 2 layers and is largely controlled by the water elevation of the Mobile River. It must be noted that the upper GWT conditions vary little, while the lower GWT varies significantly as a function of the water level stages in the Mobile River(approximately El. 0 ft to 16 ft). Material Parameters Subsurface stratigraphy, material parameters, and engineering design parameters were previously developed for the Site [31 (Materials Package). Herein, information obtained from a series of five CPTs was used to modify engineering design parameters for soil units across the East and West sections. Two CPTs (CPT-E3 and CPT-W l) within the dikes at the East and West sections were advanced through the perimeter dike crest between April 8-20, 2020. These CPTs were advanced by Thompson Engineering of Mobile, Alabama, overseen by a Geosyntec representative, and each CPT location was hydro-excavated (i.e. water jetted) to a depth of approximately 4 to 5 It below grade, in order to avoid impacting buried utilities. The hydro-excavation process resulted in the softening and removal of soil within the top 4 to 5 feet of the CPT sounding;CPT data from hydro- excavated portions of the CPTs were considered non-representative of soil conditions and was not used for developing material parameters. The other three CPTs used, denoted as pre-design (PD) CPTs, were previously presented in the Material Package but were re-evaluated as part of this analysis (PDCPT-02, PDCPT-36, PDCPT- 37). CPT locations we provided in Table 1 and shown in plan in Attachment 1. Each CPT was characterized using a Geotechnical Parameter Summary Plot(GPSP),similar to those provided for other CPTs at the Site within the Materials Package [3]. GPSPs for each CPT are provided in Attachment 2. Features involved in evaluating information from all five CPTs specific to this analysis included: a The normalized soil behavior type (SBTn) was calculated for each data point within each CPT, following the Robertson (2016) approach [4]. This approach classification of each soil type as clay-like, sand-like, or transitional, in addition to estimating if the soil behaved in a contractive manner(looser than critical state)or a dilative manner(denser than critical state) during shear. A SBTa plot for each CPT is provided with the CPT GPSPs in Attachment 2. GW7193MoM_FirelGredea_Sta nht,_Nartazivcd.c APC Barry_EPA_000780 Geosynte& consultants Page a of 185 CP: ZJF Date: 2123M APC: JMP Date: 2n2121 CA WT Date: 3Wu Client: SCS Project: PlantBarry—North Final Grades Stability Project No: GW7193 • The perimeter dike was subdivided into two-layers: U Dike,representing the top 7.5 to 9.4 It of the dike, and L Dike, representing the lower 6.5 to 8.3 ft of the dike. The two layers were selected based on the observed differences in soil strength, unit weight, and/or being separated by CCR (i.e., resulting from the two previous raises of the dike). The U Dike material is equally dense to slightly denser than L Dike and it is less clayey.Both materials, U Dike and L Dike, were primarily clay at both the East and West sections. The U Dike has an interpreted S. of 1600 to 2000 psf and the L dike has an interpreted S. of 750 to 2000 psf. • Shear strengths for Clay 1, whether improved by preloading or not, were estimated using the Stress History and Normalized Soil Engineering Properties (SHANSEP) model [5] presented in the Materials Package [3] . The m parameter within the SHANSEP model was updated to 0.98, relative to the 0.83 presented in the Materials Package [3], based on Constant-Rate of Strain(CRS)tests performed as part of the preloading pilot study. These calculations have been provided in previous calculation packages, including the P16-P20 Preloading Stability Analysis Package [6] and they are not discussed here. • Clay 1 was subdivided into multiple layers in three of the five CPTs(note that the strengths discussed here exclude improvements due to preloading): o In one of the five CPTs(CPT-E3), Clay 1 was subdivided into two layers, from top to bottom, including: Clay 1 M, representing a slightly over-consolidated middle layer 13.0 ft in thickness. Clay 1 L,representing a slightly over-consolidated lower layer ranging 5.0 ft in thickness. These layers were based on the CPT-correlated Pp, SHANSEP-correlated Sa, and NKT-based S„ within Clay 1. The static groundwater table (GWT) within Clay 1 M was assumed to be equal to the upper GWT while the lower GWT(used in Sand 1, Clay 2,and Sand 2)was used for Clay 1 L, as the piezometric head at the bottom of Clay 1 will be closer to the lower GWT. o In two of the five CPTs (PDCPT-02 and CPT-WI), a third layer within Clay 1 was added: Clay 1 C, representing an overconsolidated crust present within the top 1.7 to 2.1 ft of Clay 1. This layer was based on the CPT-correlated,NKT-based Sa within Clay 1. For Clay 1 C, the static piezometric head was assumed to be the upper GWT. o In two of the five CPTs (PDCPT-36 and PDCPT-37)Clay 1 remained a single unit representing a normally to slightly over-consolidated middle layer ranging from 10.0 to 11.5 ft in thickness. These layers were based on the CPT-correlated P P, SHANSEP-correlated S„ and NKT-based Sr within Clay 1. The static groundwater table (GWT)within Clay 1 M was assumed to be equal to the upper GWT. G W 7193MoM_FinalGredea_Stability_Nartazive.dacx APC Barry_EPA_000781 Geosynte& consultants Page 5 of 185 CP: ZJF Date: 2123M APC: JMP Date: 2n2121 CA WT Date: 3Wn Client: SCS Project: PlantBarry—North Final Grades Stability Project No: GW7193 a Sand 1 behaves sand-like, based on the SBT of the Sand 1 material(generally sand-like or transitional) in four(CPT-E3,PDCPT-37,PDCPT-02, and CPT-WI) of the five CPTs and clay-like or transitional in the remaining one CPT (PDCPT-36). Where Sand 1 behaves sand-like, the interpreted 1p ranged from of 30 to 32 deg and where Sand 1 behaves clay- like, the interpreted S.was 1300 ps£ a Design shear strengths (except for those improved by preloading) and representative unit weights are shown on the GPSPs in Attachment 2. These design values were assigned to represent approximate mean values for unit weight and lower-third values for shear strength, based on the characterized data from CPTs nearest to the section. o For the East Section CPT-E3 was used to create the design profile and stratigraphy beneath and downstream of the dike, PDCPT-36 was used to create the design profile and stratigraphy beneath the preloaded area (except for Clay 1 strength as noted below)and PDCPT-37 was used to create the design profile and stratigraphy beneath the center of the pond. The section location was chosen based on these three CPTs which show a thicker and overall lower strength Clay 1 layer. o Forthe West Section CPT-Wl was usedto create the designprofile and stratigraphy beneath and downstream of the dike, PDCPT-02 was used to create the design profile and stratigraphy beneath the preloaded area (except for Clay 1 strength as noted below) and, as with the East section PDCPT-37 was used to create the design profile and stratigraphy beneath the center of the pond. The section location was chosen based on these three CPTs which show a thicker and overall lower strength Clay 1 layer. o Undrained shear strength parameters used in the stability analysis are summarized in Tables 2 and 3, for the East and West sections, respectively. o Drained shear strength parameters for L Dike, Clay 1 C, Clay 1 M, Clay 1 L, Clay 2, Sand 2 and CCR materials were based on site-specific laboratory testing, as characterized in the Materials Package [3]. Drained shear strength parameters for all materials are provided in Table 4. G W 7193MoM_FirelGra to_Stat ility_NartaziveAr cx APC Barry_EPA_000782 Geosynte& consultants Page 6 of 185 CP: ZJF Date: 2123M APC: JMP Date: 2n2121 CA WT Date: 3Wn Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 For the stability analysis material parameters for Clay 1 C, Clay 1 M, Clay 1 L, Sand 1, and Clay 2 were divided into six spatial variants which represent different stress conditions that the subsurface soils have experienced, from downstream to upstream: • Downstream of Dike: These material parameters were selected from CPT-E3 and CPT-WI for the East and West section, respectively;the exception being Clay 1 M as noted below. • Beneath Dike: These material parameters were based on CPT-E3 and CPT-W 1 that were pushed through the dike at the East and West section, respectively. They represent soils that were not preloaded but have experience higher stresses, relative to areas within the pond, due to the presence of the existing dike. • Upstream of Dike: These material parameters were based on PDCPT-36 and PDCPT-02 for the East and West section, respectively;the exception being Clay 1 M as noted below. • Preloaded Area: These material parameters were based on PDCPT-36 and PDCPT-02 for the East and West section, respectively;the exception being Clay 1 as noted below. • Beneath CCR dEe of Pond): These material parameters were based on PDCPT-36 and PDCPT-02 for the East and West section, respectively. • Beneath CCR(Center of Pond): These material parameters were based PDCPT-37 for both the East and West Sections due to the central location of PDCPT-37. The boundaries between these spatial variants were chosen as follows: • Downstream of Dike Beneath Dike: This boundary was placed at the dike toe. • Beneath Dike(Upstream of Dike: This boundary was placed at the dike heel. • Upstream of Dike/Preloaded Area: This boundary was placed at the downstream toe of the PI and POI preload platforms for the East and West sections,respectively. • Preloaded Area/Beneath CCR(Edge of Pond): This boundary was placed at the upstream toe of the PI and POI preload platforms for the East and West sections,respectively. • Beneath CCR (Edge of Pon"eneath CCR (Center of Pond): This boundary was placed midway between PDCPT-37 (Center of Pond) and PDCPT-36 and PDCPT-02 (Edges of Pond), for the East and West sections, respectively. While Sand 2 has also been subjected to these same stresses, it is not as spatially variable and, based on site experience, does not play a significant role in stability modeling; therefore, one conservative set of parameters was selected to represent Sand 2 across the entire analyzed area. A summary of which CPTs were used for analyzed material properties is provided in Tables 5 and 6 for the East and West Sections,respectively. GW7193NoM_FirelGoul a Stability_Nartazive.da x APC Barry_EPA_000783 Geosyntec° consultants Page 7 of 185 CP: ZJF Date: 2123M APC: JMP Date: 2n2121 CA WT Date: 3Wn Client: sCs Project: PlantBarry—North Final Grades Stability Project No: GW7193 Note that some entries in Tables 5 and 6 are"Discrete Function" for some Clay 1 sublayers. This indicates that the design undrained shear strength for those select regions are defined by stress history, which in some cases includes preloading as described below. Further explanation of how the shear strength of Clay 1 was defined for each spatial variant is provided below. Undrained Shear Strength Definition of Clay 1M The tr drained shear strength of normally consolidated Clay 1 M was assessed to be dependent on in situ stresses,following SHANSEP, and therefore varying across the slope stability analysis cross- section based on variations in stress. Strength assignments were divided spatially based on stress history into the six spatial variants described above. Methods used to define tr drained shear strengths in each zone are provided below. Undrained Shear Strength Beneath Existing Perimeter Dike Shear strengths within Clay 1 M beneath the existing dike were calculated using a stress-history based approach and the SHANSEP model following the procedure presented in the Materials Package [3]. Within the SHANSEP model, the stress history of Clay 1 M was developed beneath the existing dike considering vertical effective stresses present at three separate times: • Time 1: Prior to construction of the existing dike; • Time 2: After construction of the original existing dike (dike crest at El. 18 ft), but prior to filling of the ash pond with water and CCR; and • Time 3: Under current conditions with the two upstream raises to El. 24 ft. [7], and sluiced CCR present upstream of the dike. Vertical effective stresses for each of these times were estimated. The highest of these vertical effective stresses was assumed to be the maximum past pressure (P p) for Clay 1M, and the over- consolidation ratio was calculated by comparing P v to in situ vertical effective stresses at Time 3. Undrained shear strengths under current conditions were then estimated using the SHANSEP parameters(S=0.258,m=0.98) developed for Clay 1 M. Undrained shear strengths were calculated on a grid of discrete points within Clay 1 M, using a spreadsheet. These points were calculated at vertical profiles spaced 5-10 ft apart horizontally with vertical point spacing at approximately 1 ft. This approach was used so that the laterally- and vertically-variable undrained shear strengths could be imported into slope stability analysis software. This calculation was performed in spreadsheets that is provided in Attachment 3. G W 7193MoM_FinslGredea_StabiBty_Narrauvcd.c APC Barry_EPA_0007M Geosynte& consultants Page 8 of 185 CP: ZJF Date: 2123M APC: JMP Date: 2n2121 CA WT Date: 3Wn Client: SCS Project: PlantBarry—North Final Grades Stability Project No: GW7193 Undrained Shear Strength of Preloaded Area The improved undrained strength of Clay 1 (Clay 1 C, Clay 1 M, and Clay 1 L were combined in this zone) beneath the preloads was also defined using a discrete function similar to that used to define the undrained shear strength beneath the existing dike. To obtain the stresses within Clay 1 for use in the SHANSEP calculation, the following procedure was followed: 1. A settlement model was created using Settle3 (v. 5.005) [8]. Details of these models are provided in Attachment 4. a. A pseudo-3D model created for both the East and West sections by extruding the respective models into the third dimension. b. A generalized embankment was constructed over a one-month time frame and consolidation was allowed to occur for the predicted times provided in Geosyntec's Preloading Pilot Study Summary Report [9], which were two and four months for the East and West sections,respectively. c. Initial effective stress, effective stress at the chosen time, vertical loading stress, and excess pore water pressure at the chosen time were then extracted from the model and used, along with the excavation geometry, to calculate the undrained shear strength using SHANSEP. These calculations and the resulting discrete functions are provided in Attachment 3. Undrained Shear Stretu th Beneath CCR Undrained strengths of Clay 1 M beneath the CCR were defined using strength profiles like those defined in the Material Package [3]. The cohesion elevation datum and rate of change were selected based on PDCPT-37 beneath the center of the pond and CPT-E3 and CPT-WI beneath the edges of the pond for the East and West sections,respectively. Undrained Shear Strength Upstream and Downstream of Perimeter Dike Undrained strengths of Clay 1 M downstream of the existing dike were defined using a similar model as for clays beneath CCR. Site investigation data is not available near these locations, however preliminary evaluations of the pump pad indicated an operative undrained shear strength of approximately 150 psf for this location. This minimum undrained shear strength of 150 psf is consistent with the lower overburden stress beyond the downstream toe of the perimeter dike(where CCR and dike overburden materials we not present). The minimum undrained shear strength used (i.e., 150 psf) and its rate of change with depth and elevation datum were selected to match the downstream edge undrained shear strength profile of the discrete function beneath the existing dike. GW7193NoM_FirelGoul a Stability_Nartazivcda x APC Barry_EPA_000785 Geosyntec° consultants Page 9 of 185 CP: ZJF Date: 2123M APC: JMP Date: 2n2121 CA WT Date: 38 1 Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 Similarly, the undrained strength of Clay 1 M upstream of the existing dike was defined using the same model but the rate of change with depth, minimum undrained shear strength, and elevation datum were selected to match the upstream edge undrained shear strength profile of the discrete function sheet beneath the existing dike. Undrained Shear Strength Definition for Clay 1 C, Clay 1 L, and Clay 2 Material properties for Clay 1 C, Clay 1 L, and Clay 2 were developed using the CPT-based NKr S.profiles. A uniform strength was chosen for design based on the respective CPT for each section and spatial variant, as listed in Tables 5 and 6 for the East and West sections,respectively. SLOPE STABILITY ANALYSIS Minimum acceptable slope stability factor of safety(FS), as prescribed in the USEPA CCR Rule [10], must be 1.30 for interim construction conditions. This corresponds to "end of construction" (EoC) conditions within the CCR Rule, which is a temporary condition prior to the completion of closure construction. Therefore, 1.30 was selected as the minimum FS for EoC and EoC with surcharges. For long term conditions and seismic conditions, the CCR Rule prescribes 1.50 and 1.00,respectively, which were used for this analysis. The two-dimensional analysis cross sections selected were chosen due to the fallowing factors: (i) a lower toe elevation than surrounding areas, (ii)has the thickest and weakest areas of Clay 1, (iii) includes fill for the dike modifications(East section only),and(iv)the final grades reach maximum height via the steepest slopes. Slip surfaces were evaluated using SLIDE, a 2-dimensional(2D) limit-equilibrium slope stability software developed by Rocscience [11]. All Slide outputs can be found in Attachment 5. Details of the settings used in the SLIDE analysis are listed below. 0 SLIDE Details o Version: 2018 8.032 o Method: Spencer [12] with vertical slices o Optimization: Yes Maximum Iterations: 5000 o Non-Circular Surfaces o Search method(s): Auto Refine(Limits) and Block o Minimum Slip Surface Depth: 10 ft GW7193MoM_FinalGredea_Stability_Nartazive.da x APC Barry_EPA_000786 Geosynte& consultants Page 10 of 185 CP: ZJF Date: 2123121 APC: JMP Date: 2122121 CA: WT Date: 31821 Client: SCs Project: Plant Bury—North Final Grades Stability Project No: GW7193 In order to account for stability gains caused by the relatively small width of construction equipment, a 3-dimensional (3D) correction factor was applied to results found in SLIDE for the EoC surcharged scenarios. This 3D correction uses Equation 1 to account for the stabilizing end effects caused by additional shear resistance provided at either end of the slip surface that are left unaccounted for in a 2D stability analysis [13] [14]. A 3D correction factor was used to estimate the maximum allowable width of loading that achieved the target factor of safety for conditions where the SLIDE 2D factor of safety was below the target of 1.30. These calculations can be found in Attachment 6. PP—, _ [1 + 0.7(LR)] (Equation 1) where: F=3Dfactor of safety F° 2D factor of safety DR=R,aarR.jn R,aa=maximum radius of the shear surface (See Equation I Figure, below) Rain minimum radius of the shear surface(See Equation I Figure, below) 2L= total length offailure surface (i.e., 3'd dimension) R mo� Rmin or DR a Rmaa— Rmin Equation I Figure. Definition ofRmax and Rmin Model Geometry The steepest grades and maximum elevation of the final grading did not coincide with Sections E and W; therefore, Section C was also selected, and composite sections were used in this analysis. For the East section, Section E was used for final grades from the existing dike to the soil containment berm (SCB) crest and Section C grades were used from the SCB dike crest to the pond center. The same method was used for the West section using Section W and Section C. Drawings depicting the sections E, W,and C profiles are provided in Attachment 1. Subsurface stratigraphy was previously developed as part ofthe Materials Package[3] and updated using the five CPTs evaluated as part of this analysis; stratigraphy was created by linearly connecting the stratigraphy of each CPT in that section. For instance, for the East section, layer GW7193Monh_rnalGnul a Stability_Nanative.da APC Barry_EPA_000787 Geosynte& consultants Page 11 of 185 CP: ZJF Date: 2123M APC: JMP Date: 2n2121 CA WT Date: 3Wn Client: SCS Project: PlantBarry—North Final Grades Stability Project No: GW7193 elevations were connected between CPT-E3, PDCPT-36, and PDCPT-37; beyond CPT-E3 (downstream) and PDCPT-37, layer elevations were extended horizontally to the edges of the model. Existing dike geometry was developed using aerial survey data along with the historic design drawings as found in the History of Construction report for Plant Barry [7]; this included considering two upstream dike raises constructed separately in 1992 and 1998 over sluiced CCR. These raises consisted of a 3 ft raise from the original dike elevation of 18.0 ft to 21.0 ft, and another to the existing crest elevation of approximately 24 ft. Based on anecdotal evidence of dike improvements provided during conversations with plant personnel, it was also assumed that the original dike was constructed at a 2H:1 V slope on both the downstream and upstream face; the dike toe was slightly flattened at some time after the dike raises were completed. The preload platform final grades were exported directly from the CAD design drawings; these drawings we provided in Attachment 1. The upper groundwater table (GWT)within the perimeter dike, CCR,Clay 1 U, and Clay 1 M was defined based on OW elevations encountered in the CPTs and visual observations (i.e. ponded water in low spots) at the site. The GWT within the CCR was assumed to be equal to the ground surface and drop to El. 16 ft and El. 14 ft, as found in CPT-E3 and CPT-Wl for the East and West sections, respectively. The upper GWT at the toe of the dike and downstream was assumed to be equal to the ground surface elevation, as this area is often flooded by the Mobile River. The lower GWT (i.e., piezometric head corresponding to the Clay 1L, Sand 1, Clay 2 and Sand 2 layers)was defined based on the toe elevation of the perimeter dike(El. 7.0 and 6.3 ft for the East and West sections, respectively). The encountered elevations within the dike CPTs ranged from El. 0 to 3 ft. Therefore, the modeled elevations were conservative but considered reasonable due to seasonal variations in the Mobile River elevation that may increase the lower GWT elevation beyond the elevations observed at the time the CPTs were conducted. Analyzed Loadin¢ Conditions Each scenario described below was evaluated using limits(circular slip surface) and block(wedge slip surface) search methods. End of construction (EoQ analyses evaluate stability immediately following construction of Final grades; undrained soil strengths are used in materials expected to behave in an undrained manner during construction loading, while drained soil strengths are used in materials expected to behave in a drained manner during construction loading. Long term GW7193MoM_FirelGoul a Stability_Nartazivcda x APC Barry_EPA_000788 Geosynte& consultants Page 12 of 185 CP: ZJF Date: 2123M APC: JMP Date: 2n2121 CA WT Date: 3Wn Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 analyses evaluate stability after pore pressures induced by construction loading have dissipated; drained soil strengths are used for all soils. Each scenario described below was also evaluated for the existing dike only, and for the final grades within the pond. This was done to more accurately evaluate the stability of the final consolidated pond, as well as analyze the effects on stability of the existing dike of the fill placed between the new SCB and existing dike. Construction surcharges were applied in short term scenarios (i.e., described earlier) to model construction equipment on top of slopes. In some cases, the critical slip surface began downslope of the applied surcharge. For those cases, the construction surcharge was moved to sit on the critical surface. On the existing dike, these surcharges were assumed to be 700 psf loads applied over a 13 ft width(corresponding to the typical wheel-based width of construction equipment), as these loading magnitudes are representative of typical construction equipment expected to be used for construction. On the final grades within the pond (on the CCR stack) this surcharge was doubled in width to 26 If wide because on the pond surface there will be more space for equipment to maneuver and it will be possible for multiple pieces of equipment to be working in close proximity. EoC scenarios were analyzed with (w/) and without (w/o) construction surcharges. Long term scenarios did not include construction surcharges because the construction surcharge is a short- duration, transient loading event and is not expected to be of enough duration to allow for excess pore pressures to dissipate and for drained conditions to develop. The purpose of analyzing the construction surcharges was to calculate the maximum permissible width (i.e., length perpendicular to the cross-section) of the construction surcharge, so that construction surcharging width restrictions, if needed,can be developed for the site. The following scenarios were analyzed, and all results are provided in Tables 7 and 8 for the East and West sections,respectively: • End of Construction(EoQ: This loading condition corresponds to conditions immediately after the preload fill and dike modification have been constructed. The loading condition analyzes an outboard slip surface comprised ofboth the preload platform and existing dike, as well as an inboard failure of the preload platform into the ash pond. It assumes a fully constructed final condition of the consolidated CCR pond with no consolidation and strength gains in the underlying cohesive soils. Undrained soil parameters were used as indicated in Tables 2 and 3 for the East and West sections,respectively. G W 7193Monh_hnalGredes_SWnht,_Narrauvcd.c APC Barry_EPA_000789 Geosynte& consultants Page 13 of M CP: ZJF Date: 2123M APC: JMP Date: 2n2121 CA WT Date: 3Wn Client: SCS Project: PlantBarry—North Final Grades Stability Project No: GW7193 • End of Construction - Surchareed (EoC-Surcharged): This loading condition is the same as EoC except the surcharges, as previously discussed, were applied. In each case of a surcharge on the existing dike, a 3D factor was applied to the results to obtain surcharge load width restrictions; these calculations are provided in Attachment 6. Undrained soil parameters were used as indicated in Tables 2 and 3 for the East and West sections, respectively. • Pseudo-static (Seismic): This loading condition corresponds to conditions that may occur during a seismic event. A horizontal pseudostatic coefficient of 0.02 was applied to each scenario as prescribed by the Geosyntec's Draft Closure Stability Analysis— Seismic [15]. Undmined soil parameters were used as indicated in Tables 2 and 3 for the East and West sections,respectively. • Long Term: This loading condition corresponds to conditions long after construction when all excess pore water pressures induced by construction of the consolidated pond have dissipated. Drained strengths were used for all materials, as indicated in Table 4. G W 7193MoM_FirelGoxio_Sta t ility_NartaziveAr cx APC Barry_EPA_000790 Geosynte& consultants Page 14 of 185 CP: ZJF Date: 212321 APC: JMP Date: 2n2121 CA WT Date: 3Wn Client: SCS Project: PlantBarry—North Final Grades Stability Project No: GW7193 SUMMARY AND CONCLUSIONS From the analyses summarized here, calculated factors of safety that are equal to or above the USEPA CCR Rule criteria for Norther final grades during end-of-construction, seismic, and long- term conditions. In selected cases, additional restrictions on the lateral extent of surface loads during construction and other recommendations are listed below: Northern Final Grades Construction Restrictions o Geosyntec reserves the right to halt construction of final grades based on their interpretation of the geotechnical instrumentation data. o Construction surcharges (i.e. equipment loads, material stockpiles, etc.) on the existing dike should be limited to dimensions of no more than 13 It in width and 350 ft in length parallel to the dike crest and should not exceed an indicative value of 700 psf; this construction load is based on the expected maximum equipment load provided to Geosyntec by the contractor as of the date of this calculation package. • The Contractor should provide Geosyntec with proposed construction surcharges, including equipment dimensions and weights, and the location of any proposed material or dead load stockpiles. Geosyntec will then review the surcharge magnitudes relative to these calculations and will inform the contractor if the surcharges are acceptable or not. • Geosyntec's review may include performing additional slope stability analyses, if surcharge loading proposed by the Contractor is significantly different than analyzed by Geosyntec within this calculation package. Geotechnical Monitoring Considerations o Stability of the existing dike, excess pore pressures in Clay 1 and Clay 2, beneath the existing dike, and hydraulic head in Sand 1 should be monitored throughout construction. This will require the design of the appropriate geotechnical instrumentation program to measure relevant construction performance. GW7193NoM_FirelGoul s Stability_Nartazive.da x APC Barry_EPA_000791 Geosynte& consultants Page 15 of 185 CP: ZJF Date: 2123f21 APC: JMP Date: 2n2121 CA WT Date: 3Wn Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 REFERENCES [1] Geosyntec Consultants, 'Plant Barry East Dike Modifications Draft 100 Percent Design Drawings," Mobile County, Alabama, April 2020. [2] A. B. Rodriguez,D. L. J. Green,J. B.Anderson and A. R. Simms, 'Response of Mobile Bay and eastern Mississippi Sound, Alabama, to changes in sediment accommodation and accumulation," Response of Upper Gulf Coast Estuaries to Holocene Climate Change and Sea-Level Rise: Geological Society ofAmerica Special Paper 443, pp. 13-29,2008. [3] Geosyntec Consultants, "Draft Material Properties and Major Design Parameters," St.Louis, 2018. [4] P. Robertson, "Cone penetration test (CPT)-based soil behaviour type (SBT) classification system- an update," Canadian Geotechnical Journal, vol. 53,pp. 1910-1927, 2016. [5] C. C. Ladd and R. Foott, 'New Design Procedure for Stability of Soft Clays,"Journal of the Geotechnical Engineering Division, pp. 763-78, 1974. [6] Geosyntec Consultants, "Plb Through P20 Preloading Stability Analysis," St. Louis, MO, 2020. [7] Alabama Power Company, "History of Construction for Existing CCR Surface Impoundment- Plant Barry Ash Pond,"Birmingham, Alabama, 2016. [8] Rocscience Inc., "Settle3," Rocscience, Toronto,Ontario, 2020. [9] Geosyntec Consultants, "Draft Preloading Pilot Study Summary Report," Kennesaw, 2020. [10] United States Environmental Protection Agency, "Code of Federal Regulations (CFR) Title 40, Parts 257 and 261, Hazardous and Solid Waste Management System: Disposal of Coal Combustion Residuals from Electric Utilities; Extension of Compliance Deadliens for Certain Inactive Surface Impoundments;Respons," 2016. [11] Rocscience Inc., "Slide2 Modeler," Rocscience, Toronto, Ontario, 2020. [12] E. Spencer,"A Method of Analysis of the Stability ofEmbankments Assuming Parallel Inter- Slice Forces," Geotechnique, vol. 17, no. 1, pp. 11-26, 1967. [13] A. S. Azzouz, "Three-Dimensional Analysis of Slopes - Doctoral Dissertation," Massachusetts Institute of Technology, Cambridge, 1978. [14] A. S. Azzouz, M. M. Baligh and C. C. Ladd, "Corrected Field Vane Strength for Embankment Design," Journal of Geotechnical Engineering, vol. 109, no. 5, pp. 730-734, 1983. [15] Geosyntec Consultants, 'Draft Closure Stability Analysis-Seismic," Kennesaw, 2018. GW7193MoM_FinalGredea_Stability_Nartazivcda x APC Barry_EPA_000792 Geosyntec consultants Page 16 of iss CP: ZJF Date: =3121 APC: JW Date: =2nl CA: WT Date: 3IN21 Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 TABLES Table 1 —CPT Location Information and Summary Table 2 —Design Undrained Condition Soil Parameters for East Section Table 3 —Design Undrained Condition Soil Parameters for West Section Table 4—Design Drained Shear Strength Parameters Table 5—Design Strength Parameters and Stratigraphy Sources for East Section Table 6—Design Strength Parameters and Stratigraphy Sources for West Section Table 7—Results: 2D and 3D Stability Factors of Safety for East Section Table 8—Results: 2D and 3D Stability Factors of Safety for West Section ATTACHMENTS 1. Drawings 2. Geotechnical Parameter Summary and CPT SBTn Plots 3. Discrete Function Spreadsheets 4. Settle3 Model Details 5. SLIDE Outputs 6. Three-Dimensional Correction Calculations GW7193NoM_FinalGredes_Stability_Nanaai d.cx APC Barry_EPA_000793 Geosyntec consultants Page 17 of ]Ss CP: ZJF Date: =3121 APC: JW Date: UUM CA: WT Date: 3IN21 Client: SCS Project: Plant Harry—North Final Grades Stability Project No: GW7193 TABLES Table 1 —CPT Location Information and Summary Section CPT ID Investigation Northing(ft)1 Easting (ft)1 Ground Surface Pro ram Year Elevation ft East CPT-E3 2020 367190.5 1812585.9 23.0 PDCPT-36 2018 366522.2 1812342.6 32.1 East and West PDCPT-37 2018 365216.2 1812861.3 30.6 West PDCPT-02 2018 363427.2 1810606.9 21.4 CPT-WI 2020 364601.7 1810103.2 20.3 No(.: 'Horizontal wordinates are in the North American Datum of 1983(NAD83),Alabama Want Zone. 'Vertical wordinates are in the North American Vertical Datum of 1988(NAVD88) GW]193NoM_Fi.[Chades_Stabihty_Nanaai ,dacx APC Barry_EPA_000794 Geosyntec"' consultants Page Is of Ills CP: ZJF Date: =3121 APQ JMP Date: 2I22nI CA: WT Date: 3mi Cheat: SCS Project: Plant Barry-North Final Grades Stability Project No: GW7193 Table 2 —Design Undrained Condition Soil Parameters for East Section Unit and Properties Middle Pond East Side Preloaded Area Upstream Beneath Dike Downstream Non-Preloaded GWr U rEL it Ori ' IGS I Or ma1GS GS I GS 15.0 GS Lower EL ft 7.0(T.Ebvadon) U Dike Y'(Rf) 120 S•(Pat) 2000 L Dike 7' 120 S•( f) 2000 SCB and Fill 7'(PC f) 115 S•( f) 600 Compacted 7,(PCf) 97 CCR da 36 CCR 7' f) 92 de 36 yt 100 98 102 92 105 92 Clay 1 M Mar S.( sf) 150 300 SHANSEP: 150 SHANSEP: 150 Cohesim Cban f/ft 10.00 9.00 Min S•=300 psf 10.99 Min S.=150 psf 11.14 Dam El. ft 10.00 3.00 '••"^°••rc n^a•""' 19.59 POP=300 psf 18.56 Clay 1 L Y'(R]) Not Present Not Present Not Present 104 104 104 S•(Pat) 830 830 830 Band 1 Y'(I-f) 107 S.(pat) Drained Only 1200 1200 1200 1200 1 1200 Clay 2 S.( t) 100 00 Not Present Sand 2 7'( f) 120 �' de 38 Notes: GS- Bound Surface POP=Pre-0verbuwosP ssure S•=Undrained Shear Strength GW7193Morth FhulGrades_Stability_Narradve.don APC Barry_EPA_000795 Geosyntec"' consultants Page 19 of 185 CP: UP Date: =3121 APQ JMP Date: 2I2221 CA: WT Date: 3mi Client: SCS Project: Plant Barry-North Final Grades Stability Projeet No: GW7193 Table 3 —Design Undrained Condition Soil Parameters for West Section Unit and Properties Middle Pond West Side PreWaded Area Upstream Beneath Dike Downstream Non-Preloaded GWT UpW EL(to Original GS OrginalGS I GS I GS 15.0 GS Lower EL(to 7.0(T.Elevadun) U Dike f) 114 &(Pat) 1600 L Dike 109 S.(Pat) 750 SCB and F711 7'(Pct) 115 Sy(Pat) 600 Compacted y, f) 97 CCR de 36 CCR 7'(Pcf) 92 de 36 Clay 1C ri(Pcf) Not Present 100 100 106 &(Pat) 400 yt(pcf):96 WIT 400 600 7,(p-f) 100 96 96 101 92 Clay 1 M Mal Ss(peg 150 150 150 SHANSEP: 150 Cohesion Chan sUft 10.00 9.00 SHANSEP: 9.96 Mm S.=150 paf 9.96 DotsonEL ft 10.00 5.00 Min Su-3W psf 8.90 POP=300 pf -8.38 Clay L S�Pef) Not Present 600 p--v. a.as� 6 0 1� Sand 1 ri(pcf) 110 de 32 Clay ' 100 102 &(Pat) 600 550 Sand 2 7'(Pct) 120 de 38 Notes: (H-Qound Surface POP-Pre-Overburden Pressure S.=Undranred Shear Strenglb GW7193North FhialGrades_ tability_Narradve.don APC Bany_EPA_000796 Geosyntec° consultants Page 20 of iss CP: ZJF Dale: 2nni APC: JMP Date: =2121 CA: WT Date: 3Ml Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 Table 4-Design Drained Shear Strength Parameters Drained Shear Stren th Soil Unit Cohesion, Friction Angle, c'(PsA tV'(deg) Dilre U 260 29 Dice L 260 29 SCB and Fill 50 27 Compacted CCR 0 36 CCR 0 36 Clay 1C,M,&L 75 31 Sand 1 East Section 0 30 Sand 1 (West Section 0 32 Cla 2 75 31 Sand 2 0 38 Table 5—Design Strength Parameters and Stratigraphy Sources for East Section Beneath CCR Beneath CCR Upstream of Downstream of Son Unit (CenterofPond) (Edge of Pond) Preloaded Area Dike Beneath Dike Dike Dice Not Present Not Present Not Present Not Present CPT-E3 Not Present Clay 1 C Not Present Not Present Not Present Nor Present Not Present Not Present Clay 1 M PDCPT-37 PDCPT-36 Discrete Function Discrete Function Discrete Fraction Discrete Function Clay 1 L Not Present Not Present Not Present Discrete Function CPT-E3 CPT-E3 Sand 1 PDCPT-37 PDCPT-36 PDCPT-36 PDCPT-36 CPT-E3 CPT-E3 Clay 2 PDCPT-37 Not Present Not Present Nor Present NotPresent Not Present Sand2 PDCPT-37 "Discrete Function"indicates that the strengths were derived Gomthe discrete function spreadsheets provided in Attachment 3. Table 6—Design Strength Parameters and Stratigraphy Sources for West Section Son Unit Beneath CCR Beneath CCR Preloatletl Area Upstream of Beneath Dike Dowvstreamof (CenterofPond) (Edge ofPood) Dike Dike Dice Not Present NorPresent Not Present Net Present CPT-WI Not Present Clay IC Not Present PDCPT-02 Discrete Function PDCPT-02 CPT-WI CPT-WI Clay 1 M PDCPT-37 PDCPT-02 Discrete Function Discrete Function Discrete Function Discrete Function Clay IL Not Present PDCPT-02 Discrete FunctFm Discrete Function CPT-WI CPT-WI Sandi PDCPT-37 PDCPT-02 PDCPT-02 PDCPT-02 CPT-WI CPT-WI Clay 2 PDCPT-37 PDCPT-02 PDCPT-02 PDCPT-02 PDCPT-02* PDCPT-02- Sand 2 PDCPT-37 "Discrete Function"indicates that the strengths were derived fionthe discrete function spreadsheets provided in Attachment 3. *=-W I refused befog penetrating Clay 2;however,say 2 shatigrephy was chosen based on she eVenence in the area ofthe West section and shear strength parameter OonP -02 wan conservatively stifled. GW7193Mor0n_FimlGredes_Stability Narrance.dore APC Barry_EPA_000797 Geosyntec° consultants Page 21 of 185 CP: MIT Dale: 2123/21 APC: JMP Date: =2121 CA: WT Date: 3Ml Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 Table 7—Results: 2D and 3D Stability Factors of Safety for East Section Slip Surface 2D Factor 3D Factor Allowable Scenario Sob-Scenario Search of Safety of Safety Width in 3rd Method Dimension ft End of Existing Dike Units 1.36 NA NA Construction Only Block 1.35 NA NA (Min FS= 1.30) All Final Units 5.22 NA NA Grades Block 3.09 NA NA End of Existing Dike Units 1.29 1.30 2950 Construction- Only Block 1.28 1.30 1450 Surcharged All Final Lrtnits 3.64 NA NA Min FS= 1.30 Grades Block 2.88 NA NA Existing Dike Lrtnits 1.23 NA NA Pseudo-static Only Block 1.23 NA NA (Min FS= 1.00) All Final Units 3.04 NA NA Grades Block 1.78 NA NA Existing Dike Units 2.69 NA NA Long Term Only Block 2.57 NA NA (Min FS= 1.50) All Final Units 5.23 NA NA Grades Block 5.20 NA NA GW7193Nonh_FinelGnmi a Stability_N&na ive.docx APC Barry_EPA_000798 Geosyntec° consultants Page 22 of 183 CP: ZJF Dale: 2123/21 APC: JMP Date: =2121 CA: WT Date: 3W21 Client: SCS Project: Plant Barry-North Final Grades Stability Project No: GW7193 Table S-Results: 2D and 3D Stability Factors of Safety for West Section Slip Surface 2D Factor 3D Factor Allowable Scenario Sub-Scenario Search of Safety of Safety Width in 3rd Method Dimension ft End of Existing Dike Limits 1.35 NA NA Constmction Only Block 1.47 NA NA (Min FS= 1.30) All Final Litnits 4.82 NA NA Grades Block 2.66 NA NA End of Existing Dike Lintits 1.22 1.30 350 Construction- Only Block 1.22 1.30 350 Surcharged A0 Final Limits 3.36 NA NA Min FS= 1.30 Grades Block 2.48 NA NA Existing Dike Limits 1.19 NA NA Pseudo-static Only Block 1.22 NA NA (Min FS= 1.00) A0 Final Limits 2.41 NA NA Grades Block 1.53 NA NA Existing Dike Litnits 2.34 NA NA Long Term Only Block 2.32 NA NA (Min FS= 1.50) A0 Final Lmlits 6.80 NA NA Grades Block 7.01 NA NA GW7193Nonh_FinelGnmi a Stability_N&na ive.docx APC Barry_EPA_000799 Geosyntec° consultants Page 23 of iss CP: ZJF Dale: 2123/21 APC: JMP Date: =2121 CA: WT Date: 3M1 Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 ATTACHMENT DRAWINGS GW7193Nonh_FimlGredea_Stability_Nana ive.da x APC Barry_EPA_000800 LEGEND 10 EXISTING GROUND ELEVATION(FEET) CPT E3 -.(CPT E4 $ i3 —\ PROPOSED CONTOUR ELEVATION(FEET) CPT-E1 MIO� C/PT-E2� . CPT�ES � 'o CPT-El— r ` PDCPT 4�POCPT-33 CPT(GEOSYNTEC)AND ^� \ PDCPT41 PDCPT 35 \\ CPT/OPT COLLOCATED ' P21-CPT 22 0 /w{/ Q P21-CPT P 'LPDCPT 36 PDCPT 32 PDCPT-31\\ PDCPT 30, PDCPT-29� NORTH PDCPT-38 NORTHWH ill / CLOSURE o� G LAYDOWN ARCAREA F PARATE IFC SE PDCPT3] 'b PDCPT<P D , PDCPT-01 A0' CPT-w1 eo � £ PDCPT 02 CPT-W2� PT-W3 o \ PDCPT03 SOUTH - - \PDCPT-04 CLOSURE AREA o CPT-W4l li\ / i ' 0 800 � PDCPT 06 - GPT-W5 � SCALE IN FEET ♦ BARRY CLOSURE COVER PLAN AND i CPT LOCATIONS g PLANT BARRY s 7" a- i MOBILE COUNTY, ALABAMA � c " .. � ,. Geosyntec° FIGURE $ COnsull8nts PROJECT NO: GW7193 FEBRUARY 2021 ' APC Barry_EPA_000801 w o �s = �7 0 o > W: _ 25 � � 5 10 _N_ P-18 zzS 'so i Q 1 0 h a }. M1S OO 1S ]5 P-17 o 0 c x s � o �o t Jd ?i EAST SECTION CLOSUE OVER PLAN PLANT R LEGEND MOBILE COUNTY, ALABAMA 10 EXISTING GROUND ELEVATION(FEET) 10 PROPOSED CONTOUR ELEVATION(FEET) J`• S � COnsultants0 Geos\/�tech FIGURE APPROXIMATE PRELOAD COVER LOCATION 2 § SCALE IN FEET PROJECT NO: GW7193 FEBRUARV 2021 APO Barry_EPA_000802 60 60 50 2019 LIDAR TOPO 50 a W 40 NORTH CLOSURE TOP OF LINER(2020) 40 F- LL 30 — — — _ 30 U_ G Z 20 — — — — \ 20 Z a O O 10 10 F > 0 0 W -10 EXCAVATION (2020) -10 W 20 20 SOIL CONTAINMENT BERM (2020) $ 30+00 1+00 2+00 3+00 4+00 5+00 6+00 7+00 8+00 9+000 DISTANCE (FEET) $ E HORIZONTAL: 1" =200' VERTICAL: 1" =40' a $ o zoo P18, P19, AND P20 PRELOAD SECTION PLANT BARRY HORIZONTAL MOBILE COUNTY,ALABAMA SCALE IN FEET 6w-simmij GeOSyn[eCD FIGURE s VERTICAL Consultants s8 SCALE IN FEET 3 § PROJECT NO: GW7193 DECEMBER 2020 APC Barry_EPA_000803 MOBILE RIVER \ S _,J� NORTH h CLOSURE �� P AREA NORTHWEST LAYDOWN AREA SEPARATE IF06ET Y w � souTH _ 1 \%ry b o �� LOSURE AREA o III EXISTING ' � 11i'� ryPtCP 9 PERIMETER DIKE rp0 �0 COOLING WATER \\ �o YDISCHARGE CANAL ^6 SCALE IN FEET BARRY CLOSURE COVER SECTION PLANT BARRY MOBILE COUNTY,ALABAMA IIIIIP FACILITYBOUNDARY \ Geosyntec° FIGURE 9b Tpn consultants 9 DISPOSAL AREA BOUNDARY PROJECTNO: GW7193 I JANUARY2021 4 APC 3arry_EPA_0008N 160 — 160 _ 120 120 ~ BARRY CLOSURE COVER SYSTEM H W U3 LL 80 80 LU s O 40 40 O 0 J J W -40 EXISTING GROUND (2019 LIDAR) -40 W s -80 -80 a 0+00 4+00 8+00 12+00 16+00 20+00 24+00 28+00 32+00 36+00 40+00 44+00 48+00 52+00 56+00 60+00 64+00 68+00 DISTANCE (FEET) C HORIZONTAL: 1" =800' VERTICAL: 1" =100' Y 0 50o BARRY CLOSURE COVER SECTION PLANT BARRY HORIZONTAL MOBILE COUNTY,ALABAMA SCALE IN FEET 0 100 li-.� Geosyntec° FIGURE VERTICAL Consultants SCALE IN FEET 5 § PROJECTNO: GW7193 JANUARY2021 APC Barry_EPA_000805 5? 22 N N C 22 2� N vY tiry ` V- C` L 2S s � 1p 3s e \ \ ° led s a O ° po P-02 Z° '0 9x v ds ryx� o WEST SECTION CLOSURE COVER PLAN s\ PLANT BARRY LEGEND MOBILE COUNTY, ALABAMA 10 EXISTING GROUND ELEVATION(FEET) 15 PROPOSED CONTOUR ELEVATION(FEET) Geosyntec° FIGURE s �° consWtants 6 g APPROXIMATE PRELOAD COVER LOCATION SCALE IN FEET PROJECT NO: GW7193 FFEBRUARY 2021 APO Barry_EPA_000806 50 50 40 NORTH CLOSURE TOP OF LINER(2020) 40 s W 30 2019 LIDAR TOPO 30 W e _ — Z 20 _ - - _ — — — 20 Z 10 SOIL CONTAINMENT BERM (2020) 10 O 10 § W 0 0 W a 0J III-10 - EXCAVATION (2020) -10 2 0 0+00 1+00 2+00 3+00 4+00 5+00 6+00 7+00 8+00 9+00 10+00 DISTANCE (FEET) W HORIZONTAL: 1" =150' z VERTICAL: 1" =30' ° 0 1so P01 PRELOAD SECTION PLANT BARRY �{ HORIZONTAL MOBILE COUNTY,ALABAMA 5 SCALE IN FEET 0 30 li—.� GeosynteC FIGURE $ VERTICAL Consultants y SCALE IN FEET 7 y PROJECT NO: GW7193 I DECEMBER 2020 APC Barry_EPA_000807 emnrenex � _ o..m ^W `.max.tit a ,> � G �•5'eY w wVIOINITY MAP Wu �, PUW eW vewwew m\e ' � `p2J DIKE MODIFICATION PIAN$TA O+]B T018+W � r� r. x x x x .,a®:.m. 3t a S a y4 • eve °� Y eo �✓� � PLAN , � I h. ® g G2 DIKE MOOIFILATION PIpN$TA 16+GG T03$+W q Y➢ i � a�yrv✓^ \ Im ` t rwnemm e_ � A � �Y It � t w e F a q 4 A l d d g g -._ i • IEGENO '� Y � rmnxouwewnrwp�n uae wruwr:,vemwmm p a ns i�. Zarwwmuowr r:..rw♦ �. .:..r..r A ! I�F/A d ewtvrmrw�raQrraeuwe rrte� +' \ p y � ffi • , .�ruxr 3 PLAN 0 ..,�.ue«�w�xr 'x Tl °� l �� O � � \/ \�` `01J DIKE MOOIFIG4TION PLAN STA 35+W T05]+GG o m m e e ww -_ ;�, uaorunoxmmuw a - m £ d vaaraniwvoxeran • R PLAN x 'err o'ru°w"'aa•..`:": " _ _ A 000808 _ Gs DIKE MODIFlCAnon PLAN siNs]+aGio]G+pt ISSUED FOR CONSTRUCTION .��. um OMWING 0 OF W s UMMC ME- 2m , k 5 " ". - e .,NIIDI LEGEND gz g a + mm � " , m . Colo _" A 000809 ISSUED FOR CONSTRUCTION DAnwwc w ov a Geosyntec° consultants Page 33 of 183 CP: ZJF Dale: 2123/21 APC: JMP Date: =2121 CA: WT Date: 3M1 Client: sCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 ATTACHMENT GEOTECIMCAL PARAMETER SUMMARY AND CPT SBTa PLOTS GW7193Nonh_FimlGredea_Stability_Nana ive.da x APC Barry_EPA_000810 2/4/2021 7:32 PM CPT Corrected Tip CPT Side Friction Pore Pressure Clay Undrained Shear Clay Preconsolidation� Sand Effective Friction Resistance (f„ISO (u, psf) Total Unit Weight(pcf) Strength (psf) and Vertical Effective Angle(Deg) 4, tsf) Stress (psf) 0 25 50 75 0.0 0.5 1.0 0 2000 4000 6000 8000 70 80 90 100 110 120 130 0 1000 2000 3000 0 3000 6000 9000 25 30 35 40 45 50 30 �� 1 �� �� f — T� EI. 23.0 ft Hydroexcavated 20 El. 19.0 It U Dike — U p rGWTEI.= 16ft UDike 15.5 = 120 S„=2000 psf CCR El. 1:3It Z CCR 10 7t=92 pcf L Dike L Dike Yt= 120 act S„=2000psf EI. 4.0 ft r g kGlay 1 M Clay i M r Clay 1 M= TOP)= 174�sf r.)d 1 M r SHANSEP y n=105Pcf S�(TOP)= 450psfBOT100 pa92asf OT)= 590psf33 El. -9.0 ft 0 m10 C)a�r .) L Clay 1 L Cley 1 L= SHANSEP 'm w E. -14.011 Y�=104Pcf T P = psf Sand 1 Clay 1 L Profile S„(BOT)= 830 psf o0 o Sand 1 and 1 n=113Pcf Sp=830 psf 880 �o o V= 30 deg -20 LowerGWTEI.= 3ft CIay1L P'p(TOP) 3206psf P'p(BOTI 3411psf Sand 2 Sand2 POP= 0 psf o 7,=120pcf -30 Sand 2 0 0'= 38 deg EI. 37.2 fl OltOm 0 oun trig —CPT-Correlated P'p 40 — —CPT-Correlated P'p-Organic Soils —CPT U2 Reading CPT-Correlated Su —Design Profile o CPT-Correlated Phi' —Design Profile Design Profile —Design Profile Corrected CPT Tip —CPT Side Ftictlon —CPT Corrosion!Unit Weight ____.SHANSEP —Insitu Vertical Effectve Stress R _Design Profile -50 esistance o CPT PPD Test —Discrete Function Profile Notes: Dike/Preload 1.All elevations are In the NAVD88 datum.All figures were clipped to El.♦30 ft and El.-50 ft. CCR 2.GWT-groundwater table;PPD=pore pressure dissipation test.Upper GWT is applicable to CCR and Clay 1;Lower GWT is applicable to Sand 1,Clay 2,and Sand 2 Clay 1 3.Yt-total unit weight;Solectetl Yt values for stress calculations were presented on the figure 4.Sp=untamed shear strength(values were clipped to 3000 pap Geotechnical Parameter Summary Plot 5.P'p=poecre3didaticn stress(values were clipped to 9000 paQ;POP=preOpwourden pressure CPT-E3 6.Value of k=0.33(recommended by Robertson and Cabal,2015)was used to calculate P'p(Kulhawy and Mayne,1990) Plant Barry Ash Pond Closure 7.t'=effect.fti angle Southern Company Services 8.CPT-based unit weight correlations were performed in accordance with Robertson and Cabal,2015 9.CPT-based machined shear strength correlations were pefformed in accordance with Robertson and Cabal,2015,and utilized Na=17 Geosyntl Figure 10.CPT-based effective friction angle correlations were performed in accordance with Kulhawy and Mayne,1990 consuhants 1711. SHANSEP-beset orphaned!shear strength correlations(Ladd and Food,1974)utilized S=0.258 and in=0.98 GW7193 I April 2020 \\Ara-Ol\prjl$\Alabama Power\Plant Barry\18_Engineering_Support\02_IFC\04_Final_Grade\Northern\Geotech\FinalGrades5tability\EastSide\CPTs\CPT-E3_GPSP&SBTn_CPTanly_20200422_revl_P36-20.xlsx APC Barry_EPA_000811 2/4/20217:32 PM 1,000 - - = Normalized Soil Behavior Type (SBTn) $D B ?Z---- CCS: Clay-like- Contractive -Sensitive --- --- CC: Clay-like -Contractive --- TD --- CD: Clay-like - Dilative CD TC: Transitional- Contractive _-- _-- TD: Transitional- Dilative • • • 00� SC: Sand-like - Contractive 0 SD: Sand-like - Dilative _ o 100 CD= (Q,- 11)(1 + 0.06Fr)17 0 Is = 100(Qm + 10)/(70 + QmFr) •~• x x • e 0 0 0 e -- • —° x SC T=: • • x �xxx oU Dike • • >Ixx --- _ • — 9;F�xx x x •CCR ° • x x x x Xcx 0 ° • • • x 1%0 x L Dike 10 • je �Otx •� oClay 1 M -- ~ f•� f •• �0 $ *Clay 1 L -- ar �� *Sand 1 --- ' •�•� --- 0 •Sand2 CCS 1 CC 0.1 1.0 10.0 Reference: Fr (ON Robertson, P.K. (2016). Cone penetration test(CPT)-based soil behaviour type (SBT) Count of Classification Data Points classification system-an update. Canadian Hydroexca U CCR L Dike Clay 1 M Clay 1 L Sand 1 Sand 2 Geotechnical Journal, 53: 1910-1927. vated CCS N/A 0% 0% 0% 0% 29% 3% 0% N/A Normalized CPT Soil Behavior Type Chart(SBTn) CC N/A 0% 16% 2% 99% 67% 32% 0% N/A CPT-E3 CD N/A 61% 84% 80% 0% 0% 0% 0% N/A Plant Barry Ash Pond Closure TC N/A 0% 0% 0% 1% 3% 17% 0% N/A Southern Company Services TD N/A 35% 0% 13% 0% 0% 7% 0% N/A SC N/A 0% 0% 0% 0% 1% 20% 1% N/A GeOSynteCc' Figure SD N/A 4% 0% 5% 001 0% 20% 99% N/A consultants Total 0 54 49 126 198 76 69 285 0 Gw71e3 Apd12020 2 APC Barry_EPA_000812 \\Aro-Ol\prjl$\Alabama Power\Plant Barry\18_Engineering_Support\02_IFC\04_Final_Grade\Northern\Geotech\FinalGradesStability\EastSide\CPTs\CPT-E3_GPSP&SBTn_CPT-only_20200422_revl_P36-20.xlsx 2/4/2021 7:32 PM CPT Contacted Tip CPT Side Friction Pore Pressure Atlerte rg Limit,Moisture, ClayP.sp aidal SPT(NU. Sand EffacWe Friction nce Resista and Organic Content(%) Total Unit Weight(pi Glay Undrained Shear and Vertical Effective ( �° An le(Deg) (gn tsfl (f,.had) (u,pi Strength gal Stress(ash (blowsHoW) 9 0 25 0 ]5 0.0 0.5 lU 0 ZOO 4000 WOO 8000 0 SO 100 150 200 WO WO 350 70 SO N 100 110 120 130 0 1000 WOO 3000 0 3000 6000 9000 0 5 10 15 20 25 30 35 40 25 30 35 40 45 W El. 32.1 fl W OC= S % 20 O• CCR ♦ CCR fl= 92 pcf 10 Clay Prate rUpperGWTEI. • Min S„= 300 psf OC-72 % AS,/a2=9 Peal O e Datum El.=3 fi 0 El. 0.0 fl O �y{ PI= 56 % Cla 1 17 CIay1 = Idyl OC= 6.2 % Y SHANBEP Pp(TOPj=161psf Clay i 98 S (TOP1= 32ops Pp(BOT)= 16 4P COG 4.5 % S BOT =420 pay OP= 0 psf O I�10 El. -115fl Sand 1 Bdntl, _ = 1 W pct 9.0 Sand 1 -20 $„= 1300 psf P'n=5000 psf wyis - Sand 2 5and2 BoIIY• Lower GWT EI. 10ft H= 120 Pcf � � 0 0antl2 �2ff9 38 tleg -30 Bo11om of OPT BOdng 3lF El. -29 fi ft —CPT-0onelathetl tar,enlc9ol15 ate, —CPTCen¢IekN On —CPT C¢nelared P'a Jg - - -----SHANSEP-Conelaletl 8u _pesign Pmtile Phi —Design Profile CPT-Oooeld M re Design Profile Kulbawy and Mayne o organic Content —Cesign ProOla 4 Me9su""Suhom Cllu % —CPT In-sW VeryC¢I EX¢dlve —ne—hLLN CPTTIp —CPT U2 Realin 54ess �Dasign Pro01e Resistance —OPT Side Fricfion 9 • all Content —CPT-Oooela.d Unil Weiple a MeesurN Su tram UU T% • MeesureO Vp fmm Inc.Conml •SPT iNt 6p 50 o CPTPPDTeM �p0eperg Limi6 • Measured Total Unit Weigh Meni Peak Su from Vat ♦ Masi up from CRS Cannot • SPT-Conelaletl PPhi'— Notes: DIkaeProloatl 1.Nl elevatiorar are In gs NAVD08datti-Al figures were dipped W EI.150 fl and El.-50fl. CCR 2.GWT=gmundwakrWele:WD=porepmsuredlsslpetlontet Upp"WTlsappllcebleWCCRmdCleyl;l rGNTisepplimble WSendl,Gey2,end Se 2 Clay 1 3.ILL=liquid limit MC-moisture¢ntenti PL=gestic limit PI=11-PL-density IMec OC=organic wndrd. $antl 1 4.Yt-1pal unit weight,Ylxted a aaluesror stress<almlmlons were presentM on tneflgure 5.8„=urba fined sM1eerstrengN Wall were cupped le 0033 psn 8.P'p=precmwlitlation stress(values were dipped Will 5.Value W k�0.33 anebmmentlei by ReberKm aM cabal,Wilg was used ro¢alaMle F'p(KUIM1soyaM Mayne,1990) Geotechnlcal Parameter Summary Plot TV¢lueot k=0.33p¢cOmmend¢d by Radertson and Cartel,2015)was used locMwlete P'v(Knioned aN Mayne,mat PDCPT46 and co-lopated PDS-12 a.OPT(i,T)m Wloes were dipped W 40 Plant Barry Ash Pond Closure 9.p'-eaecfive Mufionergle Southern Company Services 10.LPT-boa ed unit weight wnelafions were Performed In axcrdanre with Robertson and Label,W15 p 11.CPT-based untanned spearstrengN«nMatom were paddennad inacwreaneewim Robarden and Cabal,2p15,and uguue Nm=17 Geosyntee Figure mn W an 12.LPT-baaetl eflecfiro fricfim angle ccrteladorar were pedarmetl in acwrtlarce x11M1 KUIM1arIyand Mayne,1990 1 13.SHPNSEP-basetl unbranded days strength wneMfions(Lead and Fcde,19]4)unit 5-0.258 and m-cast GW7193 I Apol No0 \\Aro-01\prj1$\Alabama Power\Plant Barry\38_Engineering_Support\02_IFC\04_Final_Grade\Northern\Geotech\FinalGradesStability\EastSide\CPTs\PDCPT-36_GPSP&SBTn_CPT-wcc-located-5PT_20200427_revl.xlsz APC Barry_EPA_000813 2/4/20217:33 PM 1,000 _-- ___ — _= Normalized Soil Behavior Type (SBTn) SD --- I B ---- CCS: Clay-like- Contractive -Sensitive • --- --- CC: Clay-like -Contractive --- TD --- CD: Clay-like - Dilative TC: Transitional- Contractive --- • —CD TD: Transitional- Dilative • SC: Sand-like - Contractive • • SD: Sand-like - Dilative 100 Ma—�_ --_—_—CD 70 • --- is = 100(Q0, + 10)/(70 + QraFr) e • ° 0 0 ° ° 00 0 00 °o° 0 ° - •CCR •Clay 1 ° 0 o M o TCOoy�° 0o 0 0 ° o 10 0 0 ° °p o° — 0 o ° ° e °� ° —0-�� •O°o 00 ---- •Sandi •Sand2 • • • 0%4f 0 00 c. ---- 0 0 1 t• . CCS • CC 1 0.1 1.0 10.0 Reference: Fr (ON Robertson, P.K. (2016). Cone penetration test(CPT)-based soil behaviour type (SBT) Count of Classification Data Points classification system-an update. Canadian CCR Clay 1 Sand 1 Sand 2 Geotechnical Journal, 53: 1910-1927. CCS 2% 91% 57% 11% N/A N/A N/A N/A N/A Normalized CPT Soil Behavior Type Chart(SBTn) CC 6% 6% 15% 0% N/A N/A N/A N/A N/A PDCPT-36 CD A 0% 0% 0% 0% N/A N/A N/A N/A N/A Plant Barry Ash Pond Closure TC 17% 1% 20% 7% N/A N/A N/A N/A N/A Southern Company Services TD 2% 1% 2% 7% N/A N/A N/A N/A N/A p SC 47% 0% 4% 9% N/A N/A N/A N/A N/A Geosyntec Figure SD 26% Oa/o 2a/o 65% N/A N/A N/A N/A N/A consultants Total 193 70 46 55 0 0 0 0 0 Apd12020 2 APC Barry_EPA_000814 \\Aro-O3\prj1$\Alabama Power\Plant Barry\18_Engineering_Support\02_IFC\04_Final_Grade\Northern\Geotech\FinalGradesStability\EastSide\CPTs\PDCPT-36_GPSP&SBTn_CPT-w-co-located-SPT_20200427_revl.xlsx 2/4/2021 7:58 PM CPT Garecled Tip CPT Side Friction Pore Pressure Atlerberg Limit,Moisture, Clay Preconsdidatim SPT Nt Sand EffecWe Friction Clay Undraimed Shear ( )sn Resistance and Organic Cmtent(%) Total Unit Weight(pcf) and Vertical Effecllve blawsHoW Angle(Deg) its,had) (u.Pat) Strength(Pat) ( ) 0 251Qe left 75 0.0 0.5 1.0 0 20 0 4000 WOO 8000 0 W 100 1W 200 70 W 90 100 110 120 130 0 1000 moo 3000 0 30010�s(000 9000 0 5 10 15 20 25 30 35 40 25 30 35 40 45 W E15.a30.6 fl 30 pperGWT EI.30.01 20 CCR ccR r,= ao pN ill 10 Clay 1 Prafle Min S,= 150 pef aS,/A2= 10 p ift Ole1 X 0 ELOfl OC=22 Yo Datum El.= Pat q OC=10% Clay 1 Q SHANay1 SHANSEP Po(SOT)-1371 pill @c y 01 100 S„(TOP)= 260psf (GOT)= Pat Psf y-10 EL-10X O 9% S„(BOT)= 350psf POP=150 psf ♦ ♦ �Santl32tleg w a IP=23% an 110 y EL-1fi tt • Cla 2 0C=1.4h 100 Si psf -20 V.WT El. 11R ♦ Send2 0® Bantl 2 0'= 38 deg ®]9 pPt�4aa O 30 Bl..I 9.7ft T BO ntlin0 O El.-29.]fl - � —CPT Cortelaletl P' p Sails •p- ryenlc BOttem of SPT Haring, —Cp nOomelalect an —cpi correlated I 40 EL-36.8ft ___ �i --$XANSERComeleleO Su _(resign Pmtile _ —Oeaign Prolile Design Prolile CPT Co andM Mayne O pryenic Content —pesgn Pm4le su —cPT ln-sW Ver6cel EXedlve KUlhawyantl Mayne —CPT U2 ReeElrg • Meawretl SU M1om LIU TX 54ess —Design Prolile • MO¢Wre Content —CPT-CObi Total Unit • Measured Vp fmm Inc.Conml —LPT Side Faction WQg�Mre • menaabac USuhom UU TX ♦$PT N1 o cPT PPpTssI �pry¢rrner9 Llmlts • M d Total Unit ( tall • SPT-Coneleted PM' -50 —Co..CPT Ti, )yepht M¢esUred P¢ek$U fmm V$T ♦ MeesUred Vp fmm CR$Cni6ol Resislanm Notes: DlkelPrelOatl 1.Al elevaliores are In led NAVD08dalum.All figures were dipped o El.IN fl and El.-50fl. CCR 2.GWT=9mundwekrlebl¢;PPp=pore pressure dlsslpe11on 1esal.Upp"WTlsappllcebleWCCRmdCleyl;t rGNTisepplimble W$endl,O"Zend Se 2 Clay 3.LL=liquid limit MC-moisture¢nlenli PL=plastic limit PI=t1-PL-plasficiryIMec Oc=organic cones. Land 1 4.Tt-usual use weight,salean do wluesror stresstalmlmlons were presented on tnellgure 5.6,=unstained!theerslre"gN nuance were cupped ba 3033 Ped 8.P'p=precrosolitlalion stress(values were dipped b 90[5.Valueal k�.33(rxpnmentletl by ReberKm aM Label,2015)was umi rocalalale F'p(NUIM1soyaM Mayne,1990) G•otechnlcal Parameter Summary Plot T Value W k=0.33(recommended by Robertson and Carnal,2015)was used tocelwlale Pv IKUIM1abi Mayne,19%) PDCPT-37 and co4ocated GSBi a.SPT INd.Values were dipped W40 Plant Barry Ash Pmtl Closure 9.p—eaective Mctionergle Southern Company Services 10.CPT-based unit weight coneletions were perlamM In accordance with Rcberlson and Cabal,W15 p 11.CPr-based unnreroed abearstmarb crerebuom were pe,fomred W acaamancewdh Robertson and Cabal,mini and uguu m e Nm=17 GeowUll Figure n Ww 12.CPT-based eflecfiro fricfim argue ccrtelauorar were Informed in accortlarce x11M1 KUIM1arIyaM Mayne,1990 13.SHPNSEP-basetl untrained shear beendh correlations(Laid and Focus,1974)ufilizetl 5-0.2W and m-0W GW7193 I Arm 2 M \\Aro4)1\prj1$\Alabama Power\Plant Barry\38_Engineering_Support\O2_IFC\04_Final_Grade\Northern\Geotech\FinalGradesStability\WestSide\CPTs\PDCPT-37_GPSP&SBTn_CPT-w-co-located-SPT_20200504_rev0.xlsx APC Barry_EPA_000815 2/4/20217:33 PM 1,000 _— _ Normalized Soil Behavior Type (SBTn) ��- — B2— -- CCS: Clay-like- Contractive -Sensitive - — --� --- CC: Clay-like -Contractive • TD --- CD: Clay-like - Dilative % • TC: Transitional- Contractive / ;*;O ,0 o m °o o —CD TD: Transitional- Dilative •' SC: Sand-like - Contractive ' S_• •_ ' '0 0 SD: Sand-like - Dilative 10 • e o 100 _ — 0+ o°g° o o — --- CD= (Qm- 11)(1 + O.O6F,p' •• • 0 ' — is = 100(Q0, + 10)/(70 + QraFr) • ' • ° V000 °° 0 C cr o 000 0 0 8 SC ° ° o g o° • - o • ° � -- •CCR *Clay �0 C 0 10 TC °° ° __= b o o •_— •Sand1 •CIay2 --- • ' — o owe � • am --- i`: • e •Sand 2 CCS °CC 1 0.1 1.0 10.0 Reference: Fr (ON Robertson, P.K. (2016). Cone penetration test(CPT)-based soil behaviour type (SBT) Count of Classification Data Points classification system-an update. Canadian CCR Clay 1 Sand 1 Clay 2 Sand 2 Geotechnical Journal, 53: 1910-1927. CCS 8% 100% 35% 71% 6% N/A N/A N/A N/A Normalized CPT Soil Behavior Type Chart(SBTn) CC 0% 0% 0% 18% 0% N/A N/A N/A N/A PDCPT-37 CD 0% 0% 0% 0% 0% N/A N/A N/A N/A Plant Barry Ash Pond Closure TC 13% 0% 0% 6% 0% N/A N/A N/A N/A Southern Company Services TD 13% 0% 0% 0% 2% N/A N/A N/A N/A p SC 26% 0% 6% 0% 1% N/A N/A N/A N/A Geosyntec Figure SD 42% 00/0 590/n 60/6 90% N/A N/A N/A N/A consultants Total 183 61 17 17 81 0 0 0 0 Apd12020 2 APC Barry_EPA_000816 \\Aro-O3\prj1$\Alabama Power\Plant Barry\18_Engineering_Support\02_IFC\04_Final_Grade\Northern\Geotech\FinalGrades5tability\EastSide\CPTs\PDCPT-37_GPSP&SBTn_CPT-w-co-located-SPT_20200504_revO.xlsx 2/4/2021 7:33 PM CPT Corrected Tip CPT Side Friction Pore Pressure Clay Undrained Shear Clay Preconsolidation� Sand Effective Friction Resistance (f„tsf) (u, PsiTotal Unit Weight(Pe) Strength (pall and Vertical Effective Angle(Deg) (q„ tsf) Stress (psi0 25 50 75 0.0 0.5 1.0 0 2000 4000 6000 8000 70 80 90 100 110 120 130 0 1000 2000 3000 0 3000 6000 9000 25 30 35 40 45 50 30 F---F� I I I 1 7-- — TF— EI.214ft 20 UpperGWTEI.= 24ft CCR 10 CCR Min 92 act Clay 1 Profile Min S.= 150 par Asrw= 9 psf/ft Datum El.= 5 ft 0 Ell O ft Clay i C Clay 1 C Clav 1 C 71- of S = 400 par P' = 1300 psi El,-1.7 ft Clay 1 Clay 1 M=SHANSEP Clay M P' (TOP)= 836 psf y S�(TOP)= psf PP BOT - 119 Ci'd 1 M Y�=96 PC S�(BOT)= 310 sf v( )- P 4Psf sf 0 --10 El,-12 4 ft Clay i L a 1 L w - =99 cf a - far n Santl 1 = 600 _ .y2 de,_ EL-15.2 ft yt=110 pd Clay 2-20 US 2 Clay2 Sn 550 ay = 2454 S„= Psf P'p(TOP) psf y�=102 per 'p(BOT)= 2786psf EI.-2 .8 ft -30 Sand 2 Sand 7,=120Pcf Sand 2 0 0 p'= 38 deg i Bottom of CPT Sound no. Lower GWT EL= 1ft-40 El.-37 ft —CPT-Correlated P'p — _ —CPT-Correlated Fla-Organic Soils —CPT U2 Reading —CPT-Correlated Su —Design Profile —Design Profile a CPT-Correlated Phi' Corrected CPT Tip —CPTSide Poctlon —Design Profile —Design Profile —train Vertical Effective Stress 50 Resistance o CPTPPDTest —CPT Correlated Unit Weight ____-SHANSEP —Design Profile — Notes: Dike/Preload 1.All elevations are In the NAVD88 datum.All figures were clipped to El.♦50 ft and El.-50 ft. CCR 2.GWT-groundwater table;PPD=pore pressure dissipation test.Upper GWT is applicable to CCR and Clay 1;Lower GWT is applicable to Sand 1,Clay 2,and Sand 2 Clay 1 3.Yt-total unit weight;Selected Yt values for stress calculations were presented on the figure Sand 1 4.Sp=undamed shear strength(values were clipped to 3000 pap Geotechnical Parameter Summary Plot 5.P'n=preconsolidaticn stress(values were clipped to 9000 psf);POP=preOverburden pressure PDCPT-02 6.Value of k=0.33(recommended by Robertson and Cabal,2015)was used to calculate P'p(Kulhawy and Mayne,1990) Plant Barry Ash Pond Closure 7.�'=effective Motion angle Southern Campany Services 8.CPT-based unit weight correlations were performed in accordance with Robertson and Cabal,2015 9.CPT-based curtained shear strength correlations were Performed in accordance with Roberson and Cabal,2015.and utilized Nu Geosyntec° Figure 10.CPT-based effective friction angle correlations were perfom,ed in accordance with Kulhawy and Mayne,1990 consultants 11.SHANSEP-based untanned shear strength correlations(Ladd and Foott,1974)utilized S=0.258 and m=0.98 GW7193 December 2020 \\Ara-Ol\prjl$\Alabama Power\Plant Barry\18_Engineering_Support\02_IFC\04_Final_Grade\Northern\Geotech\FinalGrades5tability\WestSide\CPTs\PDCPT-02_GPSP&SBTn_CPT-only_20201228_rev0.xlsx APC Barry_EPA_000817 2/4/20217:34 PM 1,000 - - = Normalized Soil Behavior Type (SBTn) SD --- B ?2---- CCS: Clay-like- Contractive -Sensitive --- --- CC: Clay-like -Contractive --- TD --- CD: Clay-like - Dilative CD TC: Transitional- Contractive --- TD: Transitional- Dilative • Ay • SC: Sand-like - Contractive •••1� •y • • SD: Sand-like - Dilative --- CD= (Qb,- 11)(1 + 0.06Fr)17 —� IB = 100(Q°, + 10)/(70 + Q,nFr) o J • po ��� p O • • _ •CCR V SC D O O 00� 0 0C 0• • 00. 0 _ •Clay 1C o ee• o Clay 1 M O • TC O 0 9 0 • e • •Clay 1L 10 G 0 9 O = •Sand l CP U U •Cla 2 -- 36 Y • •Sand2 lb _--- p 0 0 - — CCS CC 1 0.1 1.0 10.0 Reference: Fr `ON Robertson, P.K. (2016). Cone penetration test(CPT)-based soil behaviour type (SBT) Count of Classification Data Points classification system-an update. Canadian Clay 1 M Clay 1 L Sand 1 Clay 2 Sand 2 Geotechnical Journal, 53: 1910-1927. CCS 0% 0% 3% 63% 11% 6% 0% N/A N/A Normalized CPT Soil Behavior Type Chart(SBT°) CC 15% 40% 77% 38% 11% 94% 0% N/A N/A PDCPT-02 CD 16% 60% 5% 0% 0% 0% 0% N/A N/A Plant Barry Ash Pond Closure TC 4% 0% 5% 0% 22% 0% 1% N/A N/A Southern Company Services TD 22% 0% 2% 0% 0% 0% 1% N/A N/A D SC 16% 0% 8% 0% 22% 0% 1% N/A N/A Geosyntec Figure SD 26% 0% 2% 0% 33% 0% 96% N/A N/A consultants Total 97 10 66 8 9 52 79 0 0 GW7193 December 2020 2 APC Barry_EPA_000818 \\Aro-Ol\prjl$\Alabama Power\Plant Barry\38_Engineering_Support\02_IFC\04_Final_Grade\Northern\Geotech\FinalGradesStability\WestSide\CPTs\PDCPT-02_GPSP&SBTn_CPT-only_20201228_rev0.xlsx 2/4/2021 7:34 PM CPT Corrected Tip CPT Side Friction Pore Pressure Clay Undrained Shear Clay Preconsolidation� Sand Effective Friction Resistance (f„tsf) (u, PsiTotal Unit Weight(Pe) Strength (pat) and Vertical Effective Angle(Deg) (qr, tsf) Stress (psi0 25 50 75 0.0 0.5 1.0 0 2000 4000 6000 8000 70 80 90 100 110 120 130 0 1000 2000 3000 0 3000 6000 9000 25 30 35 40 45 50 30 F I I I I I I I I I I 1 1 7-- ---F---F- 20 Hydroexcavated El. 15.5 ft U Dike U Dike 10 Dilill yam= 114pcf S,,=1600 psf UpperGWTEI.= 14R — EI.6.1 ft Dike L LDike Dike 109 0 EL-0.4ft fl-- Pcf S = 750 psf ;(BOT) Sly Clay 1 C S = 600 psf Psf Yt= i 0fipd Clay 1 P)SHANSEP F. psf c M Clay101 Pof Cl (TOP)= psf psf490 10 EI.-12.3 ft Clay 1 L W Y =103pcf a 1 L f EI.-14.0 ft Sand 1 ° s Sand 1 - owe,GWT El.= Oft 7t=110 per 6 0 00� .20 ottom of CPT Sounding, Sand 1 -19.5 ft m'= 32 deg -30 — —CPT-Correlated P'p -40 4 — —CPT-Correlated P'p-Organic —CPT U2 Read ing —CPT-Correlated Su Soils 9 —Design Profile 0 CPT-Correlated Phi' —Design Profile —Design Profile —Corrected CPT Tip —Design Profile -----SHANSEP —CPT Side Fdctlon —Insitu Vertical Effective Stress Resistance o CPT PPD Test —CPT Correlatetl Unit Weight _Discrete Function Profile —Design Profile 50 Notes: Dike/Preload 1.All elevations are In the NAVD88 datum.All figures were clipped to El.♦50 ft and El.-50 ft. CCR 2.GWT-groundwater table;PPD=pore pressure dissipation test.Upper GWT is applicable to CCR and Clay 1;Lower GWT is applicable to Sand 1,Clay 2,and Sand 2 Clay 1 3.Yr-total unit weight;Selected Yt values for stress calculations were presented on the figure Sand 1 4.Sp=endremed shear strength(values were clipped to 3000 pap Geotechnical Parameter Summary Plot 5.P'n=preconsolitlation stress(values were clipped to 9000 psf);POP=preopWiturden pressure CPT-W1 6.Value of k=0.33(recommended by Robertson and Cabal,2015)was used to calculate P'p(Kulhawy and Mayne,1990) Plant Barry Ash Pond Closure 7.t'=eased.Micron angle Southern Campany Services 8.CPT-based unit weight correlations were performed in accordance with Robertson and Cabal,2015 9.CPT-based undreined shear strength correlations were performed in accordance with Robertson and Cabal,2015.and utilized Nu Geosyntec° Figure 10.CPT-based effective friction angle correlations were performed in accordance with Kulhawy and Mayne,1990 consultants 1 11.SHANSEP-based undrainetl shear strength correlations(Ladd and Fori 1974)utilized S=0.258 and m=0.98 GW]193 December 2020 \\Ara-Ol\prjl$\Alabama Power\Plant Barry\18_Engineering_Support\02_IFC\04_Final_Grade\Northern\Geotech\FinalGrades5tability\WestSide\CPTs\W1_GPSP&SBTn_CPT-only_20201228_revO.xlsx APC Barry_EPA_000819 2/4/20217:34 PM 1,000 - - = Normalized Soil Behavior Type (SBTn) SD B ?Z---- CCS: Clay-like- Contractive -Sensitive --- --- CC: Clay-like -Contractive --- TD --- CD: Clay-like - Dilative ° o CD TC: Transitional- Contractive TD: Transitional- Dilative ¢0 ° ° o o SC: Sand-like - Contractive 0 � o o ° QD ° 0 0 ° 0 o o SD: Sand-like - Dilative 0 09° _ 100 —0�00 ���— CD= (Qb,- 11)(1 + 0.06Fr)" o- o moo- °ate la = 100(Q°, + 10)/(70 + Qjr) o • o 1010 -o e o 0 0 x x x ° O x x x x_xx O Dike U SC 0 o l� 000 x x x x O �D x Dike L x_ % xO � 0 • 0 x ' 0 00 •Clay1C TC ° # • ° O� x • OCIay1M 10 ° ° — --- •Clay 1 L —_ 0 -- --- ° o Sand 1 --_ • e 0i OQ� --- a 0 CC/�S O ° O -- _O_ CC 1 0.1 1.0 10.0 Reference: Fr M Robertson, P.K. (2016). Cone penetration test(CPT)-based soil behaviour type (SBT) Count of Classification Data Points classification system-an update. Canadian Hydroexca Dike U Dike L Clay 1 C Clay 1 M Clay 1 L Sand Geotechnical Journal, 53: 1910-1927. vated CCS N/A 0% 1% 0% 3% 54% 0% N/A N/A Normalized CPT Soil Behavior Type Chart(SBTn) CC N/A 2% 27% 97% 93% 38% 12% N/A N/A CPT-WI CD N/A 61% 40% 3% 0% 0% 1% N/A N/A Plant Barry Ash Pond Closure TC N/A 4% 1% 0% 2% 0% 7% N/A N/A Southern Company Services TD N/A 23% 32% 0% 0% 4% 1% N/A N/A D SC N/A 1% 0% 0% 2% 0% 5% N/A N/A Geosyntec Figure SD N/AL-t 9% 0% 0% 1% 4% 73% N/A N/A consultants Total 0 142 98 32 149 26 83 0 0 cw7tsa December 2020 2 APC Barry_EPA_000820 \\Aro-Ol\prjl$\Alabama Power\Plant Barry\38_Engineering_Support\02_IFC\04_Final_Grade\Northern\Geotech\FinalGradesStability\WestSide\CPTs\W3_GPSP&SBTn_CPT-only_20201228_rev0.xlsx Geosyntec° consultants Page dA of iss CP: ZJF Dale: 2123/21 APC: JMP Date: =2121 CA: WT Date: 3M1 Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 ATTACHMENT DISCRETE FUNCTION SPREADSHEETS GW7193Nonh_FimlGredea_Stability_Nana ive.da x APC Barry_EPA_000821 Geosynte& consultants Page 45 of 185 CP: ZJF Dale: 2123/21 APC: JNP Date: =2121 CA: WT Date: 3M1 Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 East Section—Beneath Dike GW7193Nonh_FimlGredea_Stability_Nana ive.da x APC Barry_EPA_000822 APC Barry_EPA_000823 APC Barry_EPA_000824 APC Barry_EPA_000825 APC Barry_EPA_000826 Geosyntec° consultants Page 50 of MIS CP: ZJF Dale: 2123/21 APC: JNP Date: 2/22/21 CA: WT Date: 3Ml Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 East Section—Preloaded Area GW7193Nonh_FimlGredea_Stability_Nana ive.da x APC Barry_EPA_000827 APC Barry_EPA_000828 APC Barry_EPA_000829 APC Barry_EPA_000830 APC Barry_EPA_000831 APC Barry_EPA_000832 Geosynte& consultants Page 56 of 185 CP: ZJF Dale: 2123/21 APC: JNP Date: =2121 CA: WT Date: 3M1 Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 West Section—Beneath Dike GW7193Nonh_FimlGredea_Stability_Nana ive.da x APC Barry_EPA_000833 ®�®a----------------mmmm-- �����®-mmm----------mmmm-- --��------------mmmm-- amm�®�—�®------------mmmm-- m•m�a o,�—®�------------mmmm-- —��mvn�o,�—®®------------mmmm-- — �0000ao—oa00o©0000000©00©0 m �e��0®0�omm�m®mmmmmmm®m�m�000 — m��o.®m,®mmmmmoomommmmomoommmm � moo.®m,®mmm—mmmmmmmmmoomm®mmm m��ev� o.0otmommmmmmmmmm®moomm—mmm �®— ��o.mm®mmmmmmmmmmomommm0mm0m �®o �®moo,®mmmmmmmmmmmmmmmmmommm �®o �®®®m.mmmmmmmmmmmmmmmmmmmmm �®o ��®®®otmmmmmmmmmmmmmmmmmmmmm gym® ��m.®®®o®m®®oommmmmmmmmmmmmm �®® moo.®®o.o®m®000m0000mmmmmmmmo �®® �m.�o,moommom®m®om®mmmmm®mmm �®® �mmmommmmmmmmmmmmmmmmmmmmm �®® ��— ®®mmmmmmmmmmm® �®® ®®®m,mmommmmmmmmmmmmmmmmmm �®® ®®®o,mmmmmmmmmmmommmmmmmm® �®® ®®®m,mmmmmmmmmmmmmommmmmmm �®® o.®®o,mmmmmmmmmmmmmmmmmmmmm �®® ®®®o,mmmmmmmmmmmmmmmmmmmmm �®® o.®®o,mmmmmmmmm®mmmmm®mmmmm �®® ®®®o,mmmmmmmmmmmmmmmmmmmmm �®® ®®®m,moo®o®®mm®mmmmmmmmmmm �®® ®®®o,mmmmmmmmmo®®mmmmmmmmm �®® 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mmmmmmmmmmmmm®®®—®®®®mmmm Imo mmmmmmmmmmmmm®®--®®®®mmmm ��— ©a®®®®®®©®®©©©©©©©©©©©©©© mmm ®�mt®®mmmmmm®®mmmmmmm000®® ��o o.�mtmt®mmmm®o®oommmmmm000®® ��o m.�mt®®mmmomo®mmmmmm00000®® ��o o.�mt®mmmoomommomo®mmm000®® ��— ®o_ot®om000mo®mmm—om00000®® ��— ®�mt®mmm00000®mmm®mmm000®® ��— ®moo,®000®mmm®®mmmoo®memo®® ��— ©a©©m®®®©®®©©©©©©©©©©©©©© mmm APC Barry_EPA_000835 APC Barry_EPA_000836 APC Barry_EPA_000837 Geosynte& consultants Page 61 of 183 CP: ZJF Dale: 2123/21 APC: JNP Date: =2121 CA: WT Date: 3M1 Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 West Section—Preloaded Area GW7193Nonh_FimlGredea_Stability_Nana ive.da x APC Barry_EPA_000838 APC Barry_EPA_000839 APC Barry_EPA_OOOMO APC Barry_EPA_OOOM1 APC Barry_EPA_OOOM2 APC Barry_EPA_ODOM APC Barry_EPA_0008 APC Barry_EPA_ODOW Geosyntec° consultants Page 69 of iss CP: ZJF Dale: 2123/21 APC: JMP Date: =2121 CA: WT Date: 3M1 Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 ATTACHMENT SETTLE3 MODEL DETAILS GW7193Nonh_FimlGredea_Stability_Nana ive.da x APC Barry_EPA_WOW Geosynte& consultants Page 70 of MIS CP: ZJF Dale: 2123/21 APC: JNP Date: 2/22/21 CA: WT Date: 3Ml Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 East Section GW7193Nonh_FimlGredea_Stability_Nana ive.da x APC Barry_EPA_o0OW Total Settlement (in) 0.0 4.2 8.4 12.6 16.8 21.0 25.2 ® 29.4 orel de] 1315pBbW69 BoreB hde 11 Boreh As 1 33.6 37.8 42.0 x (stage) : 35.45 i Ix (all) : 41.07 i s s aehde Embankment Load 1 BpeB'al®Mole 5 Embank 0 200 400 600 80 vio/t Plant Barry Interim Stability P01 Preloaded Discrete Function Il cienc BY Z. Fallen ° �r Geosyntec 12/22/2020 Preload_P19-18_Z3F_20210204_rev0.s3z APC Barry_EPA_000848 [.1S Plant Barry Interim Stability: Page 1 of 37 : ience Settle3 Analysis Information Plant Barry Interim Stability Project Settings Document Name Preload_P19-18 ZJF_20210204_mv0.s3z Project Title Plant Barry Interim Stability Analysis P01 Preloaded Discrete Function Author Z. Fallert Company Geosyntec Date Created 12/22/2020 Stress Computation Method Boussinesq Time-dependent Consolidation Analysis Time Units days Permeability Units feeUminute Minimum settlement ratio for subgrade modulus 0.9 Use average properties to calculate layered stresses Improve consolidation accuracy Ignore negative effective stresses in settlement calculations Preload_P19-18_DF_20210204revO.s3z APC Barry 84k/22/2020 [e1S —ience-e Rant Barry Interim Stability: Page 2 of 37 : Stage Settings Stage# Name Time [days] 1 Existing 0 2 EoL-Bridge 6 3 EoL-1 8 4 EoL-2 10 5 EoL-3 12 6 Eol-4 14 7 EoL5 16 8 EoLS 18 9 EoL-7 20 10 EoL-8 22 11 EoL-9 24 12 EoL-10 26 13 EoL-11 28 14 EoL-12 30 15 2 Months 61 16 3 Months 91 17 4 Months 122 18 5 Months 152 19 6 Months 183 20 7 Months 213 21 8 Months 243 22 9 Months 274 23 10 Months 304 24 11 Months 335 25 12 Months 365 Results Time taken to compute: 0 seconds Stage: Existing zz 0 d Preload_P19-1B_ZIF_20210204reW.s3z APC Barry 85j11/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 3 of 37 : i Data Type Minimum Maximum Total Settlement[in] 0 0 Total Consolidation Settlement[in] 0 0 Virgin Consolidation Settlement[in] 0 0 Recompression Consolidation Settlement[in] 0 0 Immediate Settlement[in] 0 0 Secondary Settlement[in] 0 0 Loading Stress ZZ[ksf] 0 0 Loading Stress XX[ksf] 0 0 Loading Stress YY[ksf] 0 0 Effective Stress ZZ[ksf] 0 5.56817 Effective Stress XX[ksf] 0 5.56817 Effective Stress YY[ksf] 0 5.56817 Total Stress ZZ [ksf] 0 9.74897 Total Stress XX[ksf] 0 9.74897 Total Stress YY[ksf] 0 9.74897 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0 0 Pore Water Pressure[ksf] 0 4.1808 Excess Pore Water Pressure [ksf] 0 0 Degree of Consolidation [%] 0 0 Pre-consolidation Stress [ksf] 0.0002484 5.56569 Over-consolidation Ratio 1 2.48423 Void Ratio 0 1.1 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0 Stage: Eo L-Bridge = 6 d Preload P19-18_ZIF_20210204_reW.s3z APC Barry 85112/22/2020 [-1,%ei -ence-e Plant Barry Interim Stability: Page 4 of 37 Data Type Minimum Maximum Total Settlement[in] 0 1.74154 Total Consolidation Settlement[in] 0 1.66485 Virgin Consolidation Settlement[in] 0 1.66485 Recompression Consolidation Settlement[in] 0 0 Immediate Settlement[in] 0 0.0791752 Secondary Settlement[in] 0 0 Loading Stress ZZ[ksf] 0 0.423898 Loading Stress XX[ksf] -0.0629279 0.386756 Loading Stress YY[ksf] -0.197077 0.624447 Effective Stress ZZ[ksf] 0 5.56817 Effective Stress XX[ksf] 0 5.87445 Effective Stress YY[ksf] -0.140854 6.1909 Total Stress ZZ [ksf] 0 10.0905 Total Stress XX[ksf] 0 10.3968 Total Stress YY[ksf] -0.140854 10.7132 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0 0.0617018 Pore Water Pressure[ksf] 0 4.55318 Excess Pore Water Pressure [ksf] 0 0.423898 Degree of Consolidation [%] 0 25.6886 Pre-consolidation Stress [ksf] 0.000266633 5.56569 Over-consolidation Ratio 1 2.48423 Void Ratio 0 1.1 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength -1.11022e-16 0.0126494 Stage: EOL-1 =8 d Preload P19-18_ZIF_20210204_reW.s3z APC Barry 85pt/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 5 of 37 : i Data Type Minimum Maximum Total Settlement[in] 0 4.63062 Total Consolidation Settlement[in] -0.000584012 4.51723 Virgin Consolidation Settlement[in] 0 4.50988 Recompression Consolidation Settlement[in] -0.000584012 0.0207082 Immediate Settlement[in] 0 0.114935 Secondary Settlement[in] 0 0 Loading Stress ZZ[ksf] 1.20925e-05 0.604962 Loading Stress XX[ksf] -0.113413 0.551228 Loading Stress YY[ksf] -0.287889 0.866594 Effective Stress ZZ[ksf] 1.20925e-05 5.90969 Effective Stress XX[ksf] 0.0401692 6.25805 Effective Stress YY[ksf] -0.140303 6.60654 Total Stress ZZ [ksf] 1.20925e-05 10.1466 Total Stress XX[ksf] 0.0401692 10.4949 Total Stress YY[ksf] -0.140303 10.8434 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain -1.42081 a-05 0.143924 Pore Water Pressure[ksf] 0 4.35277 Excess Pore Water Pressure [ksf] 0 0.565957 Degree of Consolidation [%] 0 68.8088 Pre-consolidation Stress [ksf] 0.00502072 5.90724 Over-consolidation Ratio 1 2.11924 Void Ratio 0 1.10003 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength -2.90469e-05 0.0204119 Stage: EOL-2 zz 10 d Preload P19-18_ZIF_20210204_reW.s3z APC Barry 8U2/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 6 of 37 : i Data Type Minimum Maximum Total Settlement[in] 0 6.72939 Total Consolidation Settlement[in] -0.000857334 6.55528 Virgin Consolidation Settlement[in] 0 6.54534 Recompression Consolidation Settlement[in] -0.000857334 0.0386231 Immediate Settlement[in] 0 0.151293 Secondary Settlement[in] 0 0.0621165 Loading Stress ZZ[ksf] 6.07316e-05 0.79033 Loading Stress XX[ksf] -0.164309 0.724926 Loading Stress YY[ksf] -0.376758 1.13092 Effective Stress ZZ[ksf] 6.07316e-05 5.96576 Effective Stress XX[ksf] 0.0441449 6.35584 Effective Stress YY[ksf] -0.158259 6.73981 Total Stress ZZ [ksf] 6.07316e-05 10.2024 Total Stress XX[ksf] 0.0441449 10.5925 Total Stress YY[ksf] -0.155291 11.057 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain -2.4082e-05 0.159412 Pore Water Pressure[ksf] 0 4.3514 Excess Pore Water Pressure [ksf] 0 0.747347 Degree of Consolidation [%] 0 77.8668 Pre-consolidation Stress [ksf] 0.00545084 5.96332 Over-consolidation Ratio 1 2.06637 Void Ratio 0 1.10005 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength -2.19859e-05 0.0332161 Stage: EOL3 zz 12 d Preload P19-18_ZIF_20210204_reW.s3z APC Barry 86¢2/22/2020 [-1,%ei -ence-e Plant Barry Interim Stability: Page 7 of 37 Data Type Minimum Maximum Total Settlement[in] 0 8.91928 Total Consolidation Settlement[in] -0.00103395 8.69903 Virgin Consolidation Settlement[in] 0 8.6871 Recompression Consolidation Settlement[in] -0.00103395 0.04523 Immediate Settlement[in] 0 0.187754 Secondary Settlement[in] 0 0.0817927 Loading Stress ZZ[ksf] 0.00118503 0.970167 Loading Stress XX[ksf] -0.213685 0.875471 Loading Stress YY[ksf] -0.465429 1.39632 Effective Stress ZZ[ksf] 0.00118503 6.02159 Effective Stress XX[ksf] 0.0406435 6.45301 Effective Stress YY[ksf] -0.238128 7.10371 Total Stress ZZ [ksf] 0.00118503 10.258 Total Stress XX[ksf] 0.0406435 10.7158 Total Stress YY[ksf] -0.238128 11.4409 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain -3.34938e-05 0.168475 Pore Water Pressure[ksf] 0 4.3499 Excess Pore Water Pressure [ksf] 0 0.928242 Degree of Consolidation [%] 0 82.9241 Pre-consolidation Stress [ksf] 0.00602202 6.01915 Over-consolidation Ratio 1 2.03727 Void Ratio 0 1.10007 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength -5.13666e-05 0.0428998 Stage: EOL-4= 14 d Preload P19-18_ZIF_20210204_reW.s3z APC Barry a5jq/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page B of 37 : i Data Type Minimum Maximum Total Settlement[in] 0 11.3731 Total Consolidation Settlement[in] -0.00108165 11.1131 Virgin Consolidation Settlement[in] 0 11.099 Recompression Consolidation Settlement[in] -0.00108165 0.0498338 Immediate Settlement[in] 0 0.22415 Secondary Settlement[in] 0 0.103358 Loading Stress ZZ[ksf] 0.00184406 1.14738 Loading Stress XX[ksf] -0.261451 1.04704 Loading Stress YY[ksf] -0.550381 1.66242 Effective Stress ZZ[ksf] 0.00184406 6.07717 Effective Stress XX[ksf] 0.0389045 6.62361 Effective Stress YY[ksf] -0.31627 7.49095 Total Stress ZZ [ksf] 0.00184406 10.3335 Total Stress XX[ksf] 0.0389045 10.9597 Total Stress YY[ksf] -0.31627 11.8307 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain -4.10775e-05 0.174906 Pore Water Pressure[ksf] 0 4.34834 Excess Pore Water Pressure [ksf] 0 1.10652 Degree of Consolidation [%] 0 86.1277 Pre-consolidation Stress [ksf] 0.00669634 6.07474 Over-consolidation Ratio 1 2.02436 Void Ratio 0 1.10009 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength -0.000123858 0.0520513 Stage: EOLS zz 16 d Preload P19-18_ZIF_20210204_reW.s3z APC Barry 85k/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 9 of 37 : i Data Type Minimum Maximum Total Settlement[in] 0 13.7062 Total Consolidation Settlement[in] -0.000792313 13.4134 Virgin Consolidation Settlement[in] 0 13.3993 Recompression Consolidation Settlement[in] -0.000792313 0.0521335 Immediate Settlement[in] 0 0.25447 Secondary Settlement[in] 0 0.12008 Loading Stress ZZ[ksf] 0.00248022 1.29303 Loading Stress XX[ksf] -0.29803 1.15667 Loading Stress YY[ksf] -0.619428 1.88648 Effective Stress ZZ[ksf] 0.00248022 6.15267 Effective Stress XX[ksf] 0.0386196 6.8563 Effective Stress YY[ksf] -0.380008 7.85353 Total Stress ZZ [ksf] 0.00248022 10.4643 Total Stress XX[ksf] 0.0386196 11.1679 Total Stress YY[ksf] -0.380008 12.1683 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 4.4139e-05 0.179159 Pore Water Pressure[ksf] 0 4.31998 Excess Pore Water Pressure [ksf] 0 1.25556 Degree of Consolidation [%] 0 89.3394 Pre-consolidation Stress [ksf] 0.00734439 6.15032 Over-consolidation Ratio 1 2.0173 Void Ratio 0 1.10009 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength -0.000176768 0.0607284 Stage: EOL$zz 18 d Preload P19-18_ZIF_20210204_reW.s3z APC Barry 851Y2/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 10 of 37 : i Data Type Minimum Maximum Total Settlement[in] 0 15.8349 Total Consolidation Settlement[in] -0.000547847 15.51 Virgin Consolidation Settlement[in] 0 15.4958 Recompression Consolidation Settlement[in] -0.000547847 0.05303 Immediate Settlement[in] 0 0.284646 Secondary Settlement[in] 0 0.133733 Loading Stress ZZ[ksf] 0.00315873 1.43882 Loading Stress XX[ksf] -0.333382 1.29936 Loading Stress YY[ksf] -0.688805 2.1105 Effective Stress ZZ[ksf] 0.00315873 6.28347 Effective Stress XX[ksf] 0.0384898 7.06673 Effective Stress YY[ksf] -0.441914 8.19331 Total Stress ZZ [ksf] 0.00315873 10.5943 Total Stress XX[ksf] 0.0384898 11.3806 Total Stress YY[ksf] -0.441914 12.5072 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain -4.19043e-05 0.18273 Pore Water Pressure[ksf] 0 4.31882 Excess Pore Water Pressure [ksf] 0 1.40278 Degree of Consolidation [%] 0 90.547 Pre-consolidation Stress [ksf] 0.00803381 6.28114 Over-consolidation Ratio 1 2.01417 Void Ratio 0 1.10009 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength -0.000204225 0.0676375 Stage: EOL-7 zz 20 d Preload P19-18_ZIF_20210204_reW.s3z APC Barry 85k/22/2020 [-1,%ei -ence-e Plant Barry Interim Stability: Page 11 of 37 Data Type Minimum Maximum Total Settlement[in] 0 17.8493 Total Consolidation Settlement[in] -0.000396738 17.4926 Virgin Consolidation Settlement[in] 0 17.4785 Recompression Consolidation Settlement[in] -0.000396738 0.0534764 Immediate Settlement[in] 0 0.314671 Secondary Settlement[in] 0 0.145259 Loading Stress ZZ[ksf] 0.0038717 1.59366 Loading Stress XX[ksf] -0.367465 1.44206 Loading Stress YY[ksf] -0.756538 2.33422 Effective Stress ZZ[ksf] 0.0038717 6.41348 Effective Stress XX[ksf] 0.0383492 7.27955 Effective Stress YY[ksf] -0.502288 8.53448 Total Stress ZZ [ksf] 0.0038717 10.7235 Total Stress XX[ksf] 0.0383492 11.5926 Total Stress YY[ksf] -0.502288 12.8475 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain -3.29019e-05 0.185808 Pore Water Pressure[ksf] 0 4.31758 Excess Pore Water Pressure [ksf] 0 1.5475 Degree of Consolidation [%] 0 90.755 Pre-consolidation Stress [ksf] 0.00875684 6.41117 Over-consolidation Ratio 1 2.01033 Void Ratio 0 1.10007 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength -0.000109783 0.0742738 Stage: EOL-8 zz 22 d Preload P19-18_ZIF_20210204_reW.s3z APC Barry 85132/22/3030 [-1,%ei -ence-e Plant Barry Interim Stability: Page 12 of 37 Data Type Minimum Maximum Total Settlement[in] 0 19.767 Total Consolidation Settlement[in] -0.000133892 19.379 Virgin Consolidation Settlement[in] 0 19.3648 Recompression Consolidation Settlement[in] -0.000133892 0.0539209 Immediate Settlement[in] 0 0.344533 Secondary Settlement[in] 0 0.155226 Loading Stress ZZ[ksf] 0.00461302 1.74979 Loading Stress XX[ksf] -0.400239 1.5372 Loading Stress YY[ksf] -0.822627 2.55881 Effective Stress ZZ[ksf] 0.00461302 6.54269 Effective Stress XX[ksf] 0.0381092 7.49158 Effective Stress YY[ksf] -0.561339 8.87695 Total Stress ZZ [ksf] 0.00461302 10.8519 Total Stress XX[ksf] 0.0381092 11.8037 Total Stress YY[ksf] -0.561339 13.189 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain -1.65678e-05 0.188513 Pore Water Pressure[ksf] 0 4.31629 Excess Pore Water Pressure [ksf] 0 1.68917 Degree of Consolidation [%] 0 91.2442 Pre-consolidation Stress [ksf] 0.00950747 6.54039 Over-consolidation Ratio 1 2.00574 Void Ratio 0 1.10003 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 4.45835e-05 0.0806578 Stage: EOL.9 zz 24 d Preload P19-1B_ZIF_20210204_reW.s3z APC Barry 86k/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 13 of 37 : i Data Type Minimum Maximum Total Settlement[in] 0 21.5962 Total Consolidation Settlement[in] 0 21.1774 Virgin Consolidation Settlement[in] 0 21.1632 Recompression Consolidation Settlement[in] 0 0.0543508 Immediate Settlement[in] 0 0.374108 Secondary Settlement[in] 0 0.163999 Loading Stress ZZ[ksf] 0.00537773 1.90588 Loading Stress XX[ksf] -0.419717 1.69144 Loading Stress YY[ksf] -0.870052 2.88292 Effective Stress ZZ[ksf] 0.00537773 6.67105 Effective Stress XX[ksf] 0.0397341 7.77398 Effective Stress YY[ksf] -0.609181 9.33962 Total Stress ZZ [ksf] 0.00537773 10.978 Total Stress XX[ksf] 0.0397341 12.084 Total Stress YY[ksf] -0.609181 13.6497 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000100296 0.190924 Pore Water Pressure[ksf] 0 4.31442 Excess Pore Water Pressure [ksf] 0 1.82641 Degree of Consolidation [%] 0 92.6609 Pre-consolidation Stress [ksf] 0.0102808 6.66877 Over-consolidation Ratio 1 2.00046 Void Ratio 0 1.09979 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0868071 Stage: EoL-10 =26 d Preload P19-18_ZIF_20210204_reW.s3z APC Barry 86112/22/2020 [-1,%ei -ence-e Plant Barry Interim Stability: Page 14 of 37 Data Type Minimum Maximum Total Settlement[in] 0 23.3422 Total Consolidation Settlement[in] 0 22.893 Virgin Consolidation Settlement[in] 0 22.8789 Recompression Consolidation Settlement[in] 0 0.0557141 Immediate Settlement[in] 0 0.403275 Secondary Settlement[in] 0 0.171827 Loading Stress ZZ[ksf] 0.00616166 2.06189 Loading Stress XX[ksf] -0.438065 1.84611 Loading Stress YY[ksf] -0.914948 3.20955 Effective Stress ZZ[ksf] 0.00616166 6.79724 Effective Stress XX[ksf] 0.0411576 8.05588 Effective Stress YY[ksf] -0.654746 9.79962 Total Stress ZZ [ksf] 0.00616166 11.1007 Total Stress XX[ksf] 0.0411576 12.3626 Total Stress YY[ksf] -0.654746 14.1064 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000116573 0.1931 Pore Water Pressure[ksf] 0 4.3118 Excess Pore Water Pressure [ksf] 0 1.95757 Degree of Consolidation [%] 0 93.3952 Pre-consolidation Stress [ksf] 0.0110729 6.79498 Over-consolidation Ratio 1 1.99529 Void Ratio 0 1.09972 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0927313 Stage: EoL-11 =28 d Preload P19-18_ZIF_20210204_reW.s3z APC Barry 86h/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 15 of 37 : i Data Type Minimum Maximum Total Settlement[in] 0 25.0083 Total Consolidation Settlement[in] 0 24.5299 Virgin Consolidation Settlement[in] 0 24.5158 Recompression Consolidation Settlement[in] 0 0.0562959 Immediate Settlement[in] 0 0.431283 Secondary Settlement[in] 0 0.178888 Loading Stress ZZ[ksf] 0.00695983 2.21776 Loading Stress XX[ksf] -0.466997 1.93489 Loading Stress YY[ksf] -0.954762 3.52422 Effective Stress ZZ[ksf] 0.00695983 6.91991 Effective Stress XX[ksf] 0.0359276 8.31483 Effective Stress YY[ksf] -0.694205 10.2284 Total Stress ZZ [ksf] 0.00695983 11.2117 Total Stress XX[ksf] 0.0359276 12.6067 Total Stress YY[ksf] -0.694205 14.5203 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.00011658 0.195081 Pore Water Pressure[ksf] 0 4.30383 Excess Pore Water Pressure [ksf] 0 2.07662 Degree of Consolidation [%] 0 94.6693 Pre-consolidation Stress [ksf] 0.0118786 6.91766 Over-consolidation Ratio 1 1.98979 Void Ratio 0 1.09972 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0984367 Stage: EoL-12 as 30 d Preload P19-18_ZIF_20210204_reW.s3z APC Barry 86h/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 16 of 37 : i Data Type Minimum Maximum Total Settlement[in] 0 26.5977 Total Consolidation Settlement[in] 0 26.0907 Virgin Consolidation Settlement[in] 0 26.0766 Recompression Consolidation Settlement[in] 0 0.0566238 Immediate Settlement[in] 0 0.458796 Secondary Settlement[in] 0 0.18488 Loading Stress ZZ[ksf] 0.00777045 2.37347 Loading Stress XX[ksf] -0.494762 2.07795 Loading Stress YY[ksf] -0.992292 3.83835 Effective Stress ZZ[ksf] 0.00777045 7.03095 Effective Stress XX[ksf] 0.0304654 8.56049 Effective Stress YY[ksf] -0.731589 10.6409 Total Stress ZZ [ksf] 0.00777045 11.3191 Total Stress XX[ksf] 0.0304654 12.8486 Total Stress YY[ksf] -0.731589 14.929 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000116587 0.196899 Pore Water Pressure[ksf] 0 4.30082 Excess Pore Water Pressure [ksf] 0 2.18857 Degree of Consolidation [%] 0 95.9816 Pre-consolidation Stress [ksf] 0.0126963 7.02873 Over-consolidation Ratio 1 1.9854 Void Ratio 0 1.09972 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.103893 Stage: 2 Months=61 d Preload P19-18_ZIF_20210204_reW.s3z APC Barry 86¢2/22/2020 [-1,%ei -ence-e Plant Barry Interim Stability: Page 17 of 37 Data Type Minimum Maximum Total Settlement[in] 0 35.4538 Total Consolidation Settlement[in] 0 34.9301 Virgin Consolidation Settlement[in] 0 34.916 Recompression Consolidation Settlement[in] 0 0.0585902 Immediate Settlement[in] 0 0.458796 Secondary Settlement[in] 0 0.244521 Loading Stress ZZ[ksf] 0.00777045 2.37347 Loading Stress XX[ksf] -0.494762 2.07795 Loading Stress YY[ksf] -0.992292 3.83835 Effective Stress ZZ[ksf] 0.00777045 7.13829 Effective Stress XX[ksf] 0.0304654 8.66783 Effective Stress YY[ksf] -0.731589 10.7482 Total Stress ZZ [ksf] 0.00777045 11.3191 Total Stress XX[ksf] 0.0304654 12.8486 Total Stress YY[ksf] -0.731589 14.929 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000116587 0.197439 Pore Water Pressure[ksf] 0 4.1808 Excess Pore Water Pressure [ksf] -0.014897 1.59226 Degree of Consolidation [%] 0 100 Pre-consolidation Stress [ksf] 0.0126963 7.13609 Over-consolidation Ratio 1 1.91558 Void Ratio 0 1.09972 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.109149 Stage: 3 Months=91 d Preload P19-18_ZIF_20210204_reW.s3z APC Barry 86f2/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 18 of 37 : i Data Type Minimum Maximum Total Settlement[in] 0 37.0111 Total Consolidation Settlement[in] 0 36.4421 Virgin Consolidation Settlement[in] 0 36.428 Recompression Consolidation Settlement[in] 0 0.0605127 Immediate Settlement[in] 0 0.458796 Secondary Settlement[in] 0 0.277052 Loading Stress ZZ[ksf] 0.00777045 2.37347 Loading Stress XX[ksf] -0.494762 2.07795 Loading Stress YY[ksf] -0.992292 3.83835 Effective Stress ZZ[ksf] 0.00777045 7.13829 Effective Stress XX[ksf] 0.0304654 8.66783 Effective Stress YY[ksf] -0.731589 10.7482 Total Stress ZZ [ksf] 0.00777045 11.3191 Total Stress XX[ksf] 0.0304654 12.8486 Total Stress YY[ksf] -0.731589 14.929 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000116587 0.197723 Pore Water Pressure[ksf] 0 4.1808 Excess Pore Water Pressure [ksf] -0.0329167 1.03381 Degree of Consolidation [%] 0 100 Pre-consolidation Stress [ksf] 0.0126963 7.13609 Over-consolidation Ratio 1 1.87012 Void Ratio 0 1.09972 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.109149 Stage: 4 Months zz 122 d Preload P19-18_ZIF_20210204_reW.s3z APC BarryAFJ%(WQ86g1/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 19 of 37 : i Data Type Minimum Maximum Total Settlement[in] 0 38.0365 Total Consolidation Settlement[in] 0 36.8097 Virgin Consolidation Settlement[in] 0 36.7956 Recompression Consolidation Settlement[in] 0 0.0605159 Immediate Settlement[in] 0 0.458796 Secondary Settlement[in] 0 0.887752 Loading Stress ZZ[ksf] 0.00777045 2.37347 Loading Stress XX[ksf] -0.494762 2.07795 Loading Stress YY[ksf] -0.992292 3.83835 Effective Stress ZZ[ksf] 0.00777045 7.13829 Effective Stress XX[ksf] 0.0304654 8.66783 Effective Stress YY[ksf] -0.731589 10.7482 Total Stress ZZ [ksf] 0.00777045 11.3191 Total Stress XX[ksf] 0.0304654 12.8486 Total Stress YY[ksf] -0.731589 14.929 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000116587 0.197925 Pore Water Pressure[ksf] 0 4.1808 Excess Pore Water Pressure [ksf] -0.0449022 0.655762 Degree of Consolidation [%] 0 100 Pre-consolidation Stress [ksf] 0.0126963 7.13609 Over-consolidation Ratio 1 1.85384 Void Ratio 0 1.09972 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.109149 Stage: 5 Months zz 152 d Preload P19-18_ZIF_20210204_reW.s3z APC Barry 861h/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 20 of 37 : i Data Type Minimum Maximum Total Settlement[in] 0 38.7166 Total Consolidation Settlement[in] 0 36.8959 Virgin Consolidation Settlement[in] 0 36.8818 Recompression Consolidation Settlement[in] 0 0.0605159 Immediate Settlement[in] 0 0.458796 Secondary Settlement[in] 0 1.45561 Loading Stress ZZ[ksf] 0.00777045 2.37347 Loading Stress XX[ksf] -0.494762 2.07795 Loading Stress YY[ksf] -0.992292 3.83835 Effective Stress ZZ[ksf] 0.00777045 7.13829 Effective Stress XX[ksf] 0.0304654 8.66783 Effective Stress YY[ksf] -0.731589 10.7482 Total Stress ZZ [ksf] 0.00777045 11.3191 Total Stress XX[ksf] 0.0304654 12.8486 Total Stress YY[ksf] -0.731589 14.929 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000116587 0.198075 Pore Water Pressure[ksf] 0 4.1808 Excess Pore Water Pressure [ksf] -0.0232209 0.421897 Degree of Consolidation [%] 0 100 Pre-consolidation Stress [ksf] 0.0126963 7.13609 Over-consolidation Ratio 1 1.85384 Void Ratio 0 1.09972 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.109149 Stage: 6 Months zz 183 d Preload P19-1B_ZIF_20210204_reW.s3z APC Barry 86&/22/2020 [-1,%ei -ence-e Plant Barry Interim Stability: Page 21 of 37 Data Type Minimum Maximum Total Settlement[in] 0 39.2357 Total Consolidation Settlement[in] 0 36.9179 Virgin Consolidation Settlement[in] 0 36.9038 Recompression Consolidation Settlement[in] 0 0.0605159 Immediate Settlement[in] 0 0.458796 Secondary Settlement[in] 0 1.93095 Loading Stress ZZ[ksf] 0.00777045 2.37347 Loading Stress XX[ksf] -0.494762 2.07795 Loading Stress YY[ksf] -0.992292 3.83835 Effective Stress ZZ[ksf] 0.00777045 7.13829 Effective Stress XX[ksf] 0.0304654 8.66783 Effective Stress YY[ksf] -0.731589 10.7482 Total Stress ZZ [ksf] 0.00777045 11.3191 Total Stress XX[ksf] 0.0304654 12.8486 Total Stress YY[ksf] -0.731589 14.929 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000116587 0.198201 Pore Water Pressure[ksf] 0 4.1808 Excess Pore Water Pressure [ksf] -0.0197155 0.267466 Degree of Consolidation [%] 0 100 Pre-consolidation Stress [ksf] 0.0126963 7.13609 Over-consolidation Ratio 1 1.85384 Void Ratio 0 1.09972 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.109149 Stage: 7 Months zz 213 d Preload P19-1B_ZIF_20210204_reW.s3z APC Barry 86k/22/2020 [-1,%ei -ence-e Plant Barry Interim Stability: Page 22 of 37 Data Type Minimum Maximum Total Settlement[in] 0 39.6452 Total Consolidation Settlement[in] 0 36.9231 Virgin Consolidation Settlement[in] 0 36.909 Recompression Consolidation Settlement[in] 0 0.0605159 Immediate Settlement[in] 0 0.458796 Secondary Settlement[in] 0 2.31749 Loading Stress ZZ[ksf] 0.00777045 2.37347 Loading Stress XX[ksf] -0.494762 2.07795 Loading Stress YY[ksf] -0.992292 3.83835 Effective Stress ZZ[ksf] 0.00777045 7.13829 Effective Stress XX[ksf] 0.0304654 8.66783 Effective Stress YY[ksf] -0.731589 10.7482 Total Stress ZZ [ksf] 0.00777045 11.3191 Total Stress XX[ksf] 0.0304654 12.8486 Total Stress YY[ksf] -0.731589 14.929 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000116587 0.20013 Pore Water Pressure[ksf] 0 4.1808 Excess Pore Water Pressure [ksf] -0.0200779 0.172074 Degree of Consolidation [%] 0 100 Pre-consolidation Stress [ksf] 0.0126963 7.13609 Over-consolidation Ratio 1 1.85384 Void Ratio 0 1.09972 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.109149 Stage: 8 Months zz 243 d Preload P19-1B_ZIF_20210204_reW.s3z APC Barry 8792/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 23 of 37 : i Data Type Minimum Maximum Total Settlement[in] 0 39.996 Total Consolidation Settlement[in] 0 36.9244 Virgin Consolidation Settlement[in] 0 36.9103 Recompression Consolidation Settlement[in] 0 0.0605159 Immediate Settlement[in] 0 0.458796 Secondary Settlement[in] 0 2.65161 Loading Stress ZZ[ksf] 0.00777045 2.37347 Loading Stress XX[ksf] -0.494762 2.07795 Loading Stress YY[ksf] -0.992292 3.83835 Effective Stress ZZ[ksf] 0.00777045 7.13829 Effective Stress XX[ksf] 0.0304654 8.66783 Effective Stress YY[ksf] -0.731589 10.7482 Total Stress ZZ [ksf] 0.00777045 11.3191 Total Stress XX[ksf] 0.0304654 12.8486 Total Stress YY[ksf] -0.731589 14.929 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000116587 0.202192 Pore Water Pressure[ksf] 0 4.1808 Excess Pore Water Pressure [ksf] -0.0113475 0.110703 Degree of Consolidation [%] 0 100 Pre-consolidation Stress [ksf] 0.0126963 7.13609 Over-consolidation Ratio 1 1.85384 Void Ratio 0 1.09972 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.109149 Stage: 9 Months=274 d Preload P19-1B_ZIF_20210204_reW.s3z APC Barry 87p2/22/2020 [-1,%ei -ence-e Plant Barry Interim Stability: Page 24 of 37 Data Type Minimum Maximum Total Settlement[in] 0 40.3137 Total Consolidation Settlement[in] 0 36.9248 Virgin Consolidation Settlement[in] 0 36.9106 Recompression Consolidation Settlement[in] 0 0.0605159 Immediate Settlement[in] 0 0.458796 Secondary Settlement[in] 0 2.9617 Loading Stress ZZ[ksf] 0.00777045 2.37347 Loading Stress XX[ksf] -0.494762 2.07795 Loading Stress YY[ksf] -0.992292 3.83835 Effective Stress ZZ[ksf] 0.00777045 7.13829 Effective Stress XX[ksf] 0.0304654 8.66783 Effective Stress YY[ksf] -0.731589 10.7482 Total Stress ZZ [ksf] 0.00777045 11.3191 Total Stress XX[ksf] 0.0304654 12.8486 Total Stress YY[ksf] -0.731589 14.929 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000116587 0.204062 Pore Water Pressure[ksf] 0 4.1808 Excess Pore Water Pressure [ksf] -0.0147066 0.0701811 Degree of Consolidation [%] 0 100 Pre-consolidation Stress [ksf] 0.0126963 7.13609 Over-consolidation Ratio 1 1.85384 Void Ratio 0 1.09972 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.109149 Stage: 10 Months=304 d Preload P19-1B_ZIF_20210204_reW.s3z APC Barry 87F2/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 25 of 37 : i Data Type Minimum Maximum Total Settlement[in] 0 40.5878 Total Consolidation Settlement[in] 0 36.9249 Virgin Consolidation Settlement[in] 0 36.9107 Recompression Consolidation Settlement[in] 0 0.0605159 Immediate Settlement[in] 0 0.458796 Secondary Settlement[in] 0 3.26237 Loading Stress ZZ[ksf] 0.00777045 2.37347 Loading Stress XX[ksf] -0.494762 2.07795 Loading Stress YY[ksf] -0.992292 3.83835 Effective Stress ZZ[ksf] 0.00777045 7.13829 Effective Stress XX[ksf] 0.0304654 8.66783 Effective Stress YY[ksf] -0.731589 10.7482 Total Stress ZZ [ksf] 0.00777045 11.3191 Total Stress XX[ksf] 0.0304654 12.8486 Total Stress YY[ksf] -0.731589 14.929 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000116587 0.205675 Pore Water Pressure[ksf] 0 4.1808 Excess Pore Water Pressure [ksf] -0.0124689 0.0451506 Degree of Consolidation [%] 0 100 Pre-consolidation Stress [ksf] 0.0126963 7.13609 Over-consolidation Ratio 1 1.85384 Void Ratio 0 1.09972 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.109149 Stage: 77 Months=335 d Preload P19-1B_ZIF_20210204_reW.s3z APC Barry 871k/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 26 of 37 : i Data Type Minimum Maximum Total Settlement[in] 0 40.8433 Total Consolidation Settlement[in] 0 36.9249 Virgin Consolidation Settlement[in] 0 36.9107 Recompression Consolidation Settlement[in] 0 0.0605159 Immediate Settlement[in] 0 0.458796 Secondary Settlement[in] 0 3.5617 Loading Stress ZZ[ksf] 0.00777045 2.37347 Loading Stress XX[ksf] -0.494762 2.07795 Loading Stress YY[ksf] -0.992292 3.83835 Effective Stress ZZ[ksf] 0.00777045 7.13829 Effective Stress XX[ksf] 0.0304654 8.66783 Effective Stress YY[ksf] -0.731589 10.7482 Total Stress ZZ [ksf] 0.00777045 11.3191 Total Stress XX[ksf] 0.0304654 12.8486 Total Stress YY[ksf] -0.731589 14.929 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000116587 0.207179 Pore Water Pressure[ksf] 0 4.1808 Excess Pore Water Pressure [ksf] -0.01056 0.0286234 Degree of Consolidation [%] 0 100 Pre-consolidation Stress [ksf] 0.0126963 7.13609 Over-consolidation Ratio 1 1.85384 Void Ratio 0 1.09972 Permeability [ft/min] 0 0.109221 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.109149 Preload P19-1B_ZIF_20210204_reW.s3z APC Barry 87¢2/22/2020 [e1S -ence-e Plant Barry Interim Stability: Page 27 of 37 : i Stage: 12 Months=365 d Data Type Minimum Maximum Total Settlement[in] 0 41.0687 Total Consolidation Settlement[in] 0 36.9249 Virgin Consolidation Settlement[in] 0 36.9107 Recompression Consolidation Settlement[in] 0 0.0605159 Immediate Settlement[in] 0 0.458796 Secondary Settlement[in] 0 3.82565 Loading Stress ZZ[ksf] 0.00777045 2.37347 Loading Stress XX[ksf] -0.494762 2.07795 Loading Stress YY[ksf] -0.992292 3.83835 Effective Stress ZZ[ksf] 0.00777045 7.13829 Effective Stress XX[ksf] 0.0304654 8.66783 Effective Stress YY[ksf] -0.731589 10.7482 Total Stress ZZ [ksf] 0.00777045 11.3191 Total Stress XX[ksf] 0.0304654 12.8486 Total Stress YY[ksf] -0.731589 14.929 Modulus of Subgrade Reaction (Total)[ksf/ft] 0 0 Modulus of Subgrade Reaction (Immediate)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ft] 0 0 Total Strain 0.000116587 0.208506 Pore Water Pressure[ksf] 0 4.1808 Excess Pore Water Pressure [ksf] -0.00440202 0.0184146 Degree of Consolidation [%] 0 100 Pre-consolidation Stress [ksf] 0.0126963 7.13609 Over-consolidation Ratio 1 1.85384 Void Ratio 0 1.09972 Permeability [tt/min] 0 0.109221 Coefficient of Consolidation[ft"2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.109149 Embankments 1. Embankment: "Embankment Load 1" Label Embankment Load 1 Center Line (297.15, 0)to (297.15, 500) Near End Angle 18.4 degrees Far End Angle 18.4 degrees Number of Layers 13 Base Width 459.11 Preload P19-la_ZIF_20210204_reW.s3z APC Barry 87fI2/22/2020 [e1S -ience Plant Barry Interim Stability: Page 28 of 37 : Layer Stage Lek Bench Left Angle Height Unit Weight Right Angle Right Bench Width (ft) (deg) (fl) (kips/ft ) (deg) Width (ft) EoL-Bridge 1 = 6d 0 18.4 3 0.125 90 0 2 EoL-1 = 8 d 0 18.4 0.5 0.125 90 0 3 EoL-2= 10 d 0 18.4 0.5 0.125 90 0 4 EoL-3= 12 d 0 18.4 0.5 0.125 90 0 5 EoL-4= 14 d 0 18.4 0.5 0.125 90 0 6 EoL5= 16 d 0 18.4 0.5 0.125 90 0 7 EoLB= 18 d 0 18.4 0.5 0.125 90 0 8 EoL-7= 20 d 0 18.4 0.5 0.125 90 0 9 EoL-8=22 d 0 18.4 0.5 0.125 90 0 10 EoL-9=24 d 0 18.4 0.5 0.125 90 0 11 EoL-100 d 0 18.4 0.5 0.125 90 0 12 EoL-218 d 0 18.4 0 0.125 90 0 13 EoL-30 d 0 18.4 0 0.125 90 0 2. Embankment: "Embankment Load 2" Label Embankment Load 2 Center Line (649.08, 0)to (649.08, 500) Near End Angle 18.4 degrees Far End Angle 18.4 degrees Number of Layers 13 Base Width 244.76 Layer Stage Left Bench Left Angle Height Unit Weight Right Angle Right Bench Width (fl) (deg) (fl) (kips/ft ) (deg) Width (fl) EoL-Bridge 1 = 6 d 0 90 3 0.125 18.4 0 2 EoL-1 = 8 d 0 90 1.5 0.125 18.4 0 3 EoL-2= 10 d 0 90 1.5 0.125 18.4 0 4 EoL-3= 12 d 0 90 1.5 0.125 18.4 0 5 EOL-4= 14 d 0 90 1.5 0.125 18.4 0 6 EoL5= 16 d 0 90 1.25 0.125 18.4 0 7 EoLB= 18 d 0 90 1.25 0.125 18.4 0 8 EoL-7=20 d 0 90 1.25 0.125 18.4 0 9 EoL-8= 22 d 0 90 1.25 0.125 18.4 0 10 EoL-9=24 d 0 18.4 1.25 0.125 18.4 0 11 EoL-26 d 0 18.4 1.25 0.125 18.4 0 12 EoL-218 d 0 18.4 1.25 0.125 18.4 0 13 EoL-30 d 0 18.4 1.25 0.125 18.4 0 Soil Layers Ground Surface Drained: Yes Borehole 1: (67.59,0) Preload_P19-18_ZIF_20210204reW.s3z APC Barry 87k/22/2020 [.1S Plant Barry Interim Stability: Page 29 of 37 : ience Layer# Type Thickness [ft] Depth [ft] Drained at Bottom 1 CCR 25.42 -27.06 No 2 Clay 1 C 0 -1.64 No 3 Clay 1 M 11.64 -1.64 No 4 Clay 1 L 0 10 Yes 5 Sand 1 6.82 10 No 6 Clay 2 0 16.82 Yes 7 Sand 2 43.18 16.82 Yes ® ar 1.64 10 16.82 60 ft Borehole 2: (153.74,0) Layer# Type Thickness [tt] Depth[ft] Drained at Bottom 1 CCR 25.34 -27.11 No 2 Clay 1 C 0 -1.77 No 3 Clay 1 M 11.77 -1.77 No 4 Clay 1 L 0 10 Yes 5 Sand 1 6.88 10 No 6 Clay 2 0 16.88 Yes 7 Sand 2 43.12 16.88 Yes ® 31 1.77 10 -16.8e Go ft Borehole 3: (162.71,0) Preload_P19-1B_ZIF_20210204reW.s3z APC Barry 871'2/22/2020 [e1S —ience Plant Barry Interim Stability: Page 30 of 37 : Layer# Type Thickness [ft] Depth [ft] Drained at Bottom 1 CCR 29.22 -31 No 2 Clay 1 C 0 -1.78 No 3 Clay 1 M 11.78 -1.78 No 4 Clay 1 L 0 10 Yes 5 Sand 1 6.89 10 No 6 Clay 2 0 16.89 Yes 7 Sand 2 43.11 16.89 Yes ar 1.78 to 16.a9 6o ft Borehole 4: (580.75,0) Layer# Type Thickness [tt] Depth[ft] Drained at Bottom 1 CCR 23.35 -26.35 No 2 Clay 1 C 0 -3 No 3 Clay 1 M 12.5 -3 No 4 Clay 1 L 0 9.5 Yes 5 Sand 1 8.25 9.5 No 6 Clay 2 0 17.75 Yes 7 Sand 2 42.25 17.75 Yes ® 31 3 as -17.75 Go ft Borehole 5: (614.6, 0) Preload_P19-1B_ZIF_20210204reW.s3z APC Barry 8M/22/2020 [e1S —ience Plant Barry Interim Stability: Page 31 of 37 : Layer# Type Thickness [ft] Depth [ft] Drained at Bottom 1 CCR 18.88 -22 No 2 Clay 1 C 0 -3.12 No 3 Clay 1 M 12.56 -3.12 No 4 Clay 1 L 0.62 9.44 Yes 5 Sand 1 7.78 10.06 No 6 Clay 2 0 17.84 Yes 7 Sand 2 42.16 17.84 Yes 1 z 12 9,44 17.04 Borehole 6: (771.46,0) Layer# Type Thickness [tt] Depth [ft] Drained at Bottom 1 CCR 19.34 -23.04 No 2 Clay 1 C 0 -3.7 No 3 Clay 1 M 12.85 -3.7 No 4 Clay 1 L 3.51 9.15 Yes 5 Sand 1 5.62 12.66 No 6 Clay 2 0 18.28 Yes 7 Sand 2 41.72 18.28 Yes 31 23,04 3.7 0 -9,15 P77777—E 18,28 60 ft Borehole 7: (67.59, 500) Preload_P19-1B_ZIF_20210204reW.s3z APC Barry 87$1/22/2020 [e1S -.eience Plant Barry Interim Stability: Page 32 of 37 : Layer# Type Thickness [ft] Depth [ft] Drained at Bottom 1 CCR 25.42 -27.06 No 2 Clay 1 C 0 -1.64 No 3 Clay 1 M 11.64 -1.64 No 4 Clay 1 L 0 10 Yes 5 Sand 1 6.82 10 No 6 Clay 2 0 16.82 Yes 7 Sand 2 43.18 16.82 Yes ® ar 1,64 10 16.82 60 ft Borehole 8: (153.74,500) Layer# Type Thickness [tt] Depth[ft] Drained at Bottom 1 CCR 25.34 -27.11 No 2 Clay 1 C 0 -1.77 No 3 Clay 1 M 11.77 -1.77 No 4 Clay 1 L 0 10 Yes 5 Sand 1 6.88 10 No 6 Clay 2 0 16.88 Yes 7 Sand 2 43.12 16.88 Yes ® 31 1,77 10 -16.8e Go ft Borehole 9: (162.71, 500) Preload_P19-1B_ZIF_20210204reW.s3z APC Barry 88111/22/2020 [.1S -.eience Plant Barry Interim Stability: Page 33 of 37 : Layer# Type Thickness [ft] Depth [ft] Drained at Bottom 1 CCR 29.22 -31 No 2 Clay 1 C 0 -1.78 No 3 Clay 1 M 11.78 -1.78 No 4 Clay 1 L 0 10 Yes 5 Sand 1 6.89 10 No 6 Clay 2 0 16.89 Yes 7 Sand 2 43.11 16.89 Yes ar 1.78 ao 0.09 Go ft Borehole 10: (580.75, 500) Layer# Type Thickness [tt] Depth[ft] Drained at Bottom 1 CCR 23.35 -26.35 No 2 Clay 1 C 0 -3 No 3 Clay 1 M 12.5 -3 No 4 Clay 1 L 0 9.5 Yes 5 Sand 1 8.25 9.5 No 6 Clay 2 0 17.75 Yes 7 Sand 2 42.25 17.75 Yes ® 31 3 as -17.75 Go ft Borehole 11: (614.6, 500) Preload_P19-1B_ZIF_20210204reW.s3z APC BarryffiRJ%d(WQa8112/22/2020 [e1S -.eience Plant Barry Interim Stability: Page 34 of 37 : Layer# Type Thickness [ft] Depth [ft] Drained at Bottom 1 CCR 18.88 -22 No 2 Clay 1 C 0 -3.12 No 3 Clay 1 M 12.56 -3.12 No 4 Clay 1 L 0.62 9.44 Yes 5 Sand 1 7.78 10.06 No 6 Clay 2 0 17.84 Yes 7 Sand 2 42.16 17.84 Yes 1 z 12 9,44 17.04 Borehole 12: (771.46, 500) Layer# Type Thickness [tt] Depth [ft] Drained at Bottom 1 CCR 19.34 -23.04 No 2 Clay 1 C 0 -3.7 No 3 Clay 1 M 12.85 -3.7 No 4 Clay 1 L 3.51 9.15 Yes 5 Sand 1 5.62 12.66 No 6 Clay 2 0 18.28 Yes 7 Sand 2 41.72 18.28 Yes 31 23,04 3.7 0 -9,15 P77777—E 18.28 60 ft Soil Properties Preload_P19-1B_ZIF_20210204reW.s3z APC Barry 88pt/22/2020 t.',%ei —ence-e Plant Barry Interim Stability: Page 35 of 37 Property CCR Clay 1 M Sand 1 Clay 2 Color 0 0 0 0 Unit Weight [kipsfft3] 0.092 0.098 0.107 0.1 Saturated Unit Weight[kips/ft3] 0.092 0.098 0.107 0.1 KO 1 1 1 1 Immediate Settlement Disabled Disabled Enabled Disabled Es[ksf] - - 2500 Esur[ksf] - - 2500 Primary Consolidation Enabled Enabled Enabled Enabled Material Type Non-Linear Non-Linear Non-Linear Non-Linear Coe 0.05 0.263 0.1 0.14 Cris 0.01 0.019 le-11 0.014 e0 1.1 1.1 1.1 1.1 Pc[ksf] - - 5 3 OCR 1 - OCM [ksf] - 0 - - Cv[ft2/min] 0.02 0.00083 0.008 0.0008 Cvr[ft2/min] 0.02 0.00083 0.008 0.0008 B-bar 1 1 1 1 Secondary Consolidation Standard Standard Disabled Standard Cae 0.0015 0.035 - 0.03 Care 0.0015 0.035 - 0.03 Undrained Su A[kips/ft2] 0 0 0 0 Undrained Su S 0.2 0.2 0.2 0.2 Undrained Su m 0.8 0.8 0.8 0.8 Piezo Line ID 2 2 1 1 Preload_P19-18_ZIF_20210204revO.s3z APC Barry M/22/2020 [e12' eience-e Rant Barry Interim Stability: Page 36 of 37 : Property Sand 2 Clay 1 C Clay 7 L Color 0 0 0 Unit Weight [kipslft3] 0.12 0.1 0.104 Saturated Unit Weight[kipa/ft3] 0.12 0.1 0.104 KO 1 1 1 Immediate Settlement Enabled Disabled Disabled Es[ksf] 3000 - Esur[ksf] 3000 - Primary Consolidation Disabled Enabled Enabled Material Type Non-Linear Non-Linear Coe - 0.263 0.263 Cris - 0.019 0.019 e0 - 1.1 1.1 OCR - 1 - OCM [ksfJ - - 0.4 CV[ft2/min] - 0.00083 0.00083 Cvr[ft2/min] - 0.00083 0.00083 Bbar - 1 1 Secondary Consolidation Disabled Standard Standard Cae - 0.035 0.035 Care - 0.035 0.035 Undrained Su A[kips/ft2] 0 0 0 Undained Su S 0.2 0.2 0.2 Undrained Su m 0.8 0.8 0.8 Piezo Line ID 1 2 1 Groundwater Groundwater method Piezometric Lines Water Unit Weight 0.0624 kips/ft3 Piezometric Line Entities ID Depth(ft) 7 it 2 22 ft Query Lines Line# Query Line Name Start Location End Location Horizontal Divisions Vertical Divisions 1 Query Line 1 67.595, 250 771.46, 250 71 Auto: 57 Preload_P19-18_ZIF_20210204rev0.s3z APC BarryffFJ%dWQ8Bk/22/2020 [.1S -ience-e Plant Barry Interim Stability: Page 37 of 37 : Preload_P19-1B_ZIF_20210204reW.s3z APC Barry 88k/22/2020 Geosyntec° consultants Page 109 of 183 CP: ZJF Dale: 2123/21 APC: JNP Date: 2/22/21 CA: WT Date: 3Ml Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 West Section GW7193Nonh_FimlGredea_Stability_Nana ive.da x APC Barry_EPA_000886 Total Settlement (in) 0.0 3.5 7.0 10.5 14.0 orel ale 4 Barehnle 5 Bar ale 6 17.5 21.0 24.5 28.0 31.5 35.0 max (stage) : 28.47 it max (a11) : 34.32 i, 4 d 0 orshoin'l Emban di ehnle3 200 300 400 500 600 700 vio/t Plant Barry Interim Stability P01 Preloaded Discrete Function Ilcience—BY Z. Fallen ° �r Geosyntec �vre 12/22/2020 fAe1b'"` Preload Section I_DF_20210205_rev1.s3z APC Barry_EPA_000887 [.1S Plant Barry Interim Stability: Page 1 of 34 : ience Settle3 Analysis Information Plant Barry Interim Stability Project Settings Document Name Preload_Section I_ZJF_20210205_revl.s3z Project Title Plant Barry Interim Stability Analysis P01 Preloaded Discrete Function Author Z. Fallert Company Geosyntec Date Created 12/22/2020 Stress Computation Method Boussinesq Time-dependent Consolidation Analysis Time Units days Permeability Units feeUminute Minimum settlement ratio for subgrade modulus 0.9 Use average properties to calculate layered stresses Improve consolidation accuracy Ignore negative effective stresses in settlement calculations Preload_Section I_ZJF_20210205_revl.s3z APC Barry M/22/2030 [e1S —ience-e Rant Barry Interim Stability: Page 2 of 34 : Stage Settings Stage# Name Time [days] 1 Existing 0 2 EoL-Bridge 6 3 EoL-1 8 4 EoL-2 10 5 EoL-3 12 6 Eol-4 14 7 EoL5 16 8 EoLS 18 9 EoL-7 20 10 EoL-8 22 11 EoL-9 24 12 EoL-10 26 13 EoL-11 28 14 EoL-12 30 15 2 Months 61 16 3 Months 91 17 4 Months 122 18 5 Months 152 19 6 Months 183 20 7 Months 213 21 8 Months 243 22 9 Months 274 23 10 Months 304 24 11 Months 335 25 12 Months 365 Results Time taken to compute: 0 seconds Stage: Existing=0 d Preload Section]_Z1F_20210205_re,1.s3z APC Barry 8M/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 3 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 0 Total Consolidation Settlement[in] 0 0 Virgin Consolidation Settlement[in] 0 0 Recompression Consolidation Settlement[in] 0 0 Immediate Settlement[in] 0 0 Secondary Settlement[in] 0 0 Loading Stress ZZ[ksf] 0 0 Loading Stress XX[ksf] 0 0 Loading Stress YY[ksf] 0 0 Effective Stress ZZ[ksf] 0 4.93729 Effective Stress XX[ksf] 0 4.93729 Effective Stress YY[ksf] 0 4.93729 Total Stress ZZ [ksf] 0 9.07441 Total Stress XX[ksf] 0 9.07441 Total Stress YY[ksf] 0 9.07441 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0 0 Pore Water Pressure[ksf] 0 4.13712 Excess Pore Water Pressure [ksf] 0 0 Degree of Consolidation [%] 0 0 Pre-consolidation Stress [ksf] 7.36e-05 4.93522 Over-consolidation Ratio 1 2.06559 Void Ratio 0 1.1 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0 Stage: Eo L-Bridge = 6 d Preload_Section I_2JF_20210205_revl.s3z APC Barry89111/22/2030 [-1S -ence-e Plant Barry Interim Stability: Page 4 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 0.523722 Total Consolidation Settlement[in] 0 0.448406 Virgin Consolidation Settlement[in] 0 0.448406 Recompression Consolidation Settlement[in] 0 0 Immediate Settlement[in] 0 0.0753493 Secondary Settlement[in] 0 0 Loading Stress ZZ[ksf] 0 0.385241 Loading Stress XX[ksf] -0.074743 0.374773 Loading Stress YY[ksf] -0.189033 0.628875 Effective Stress ZZ[ksf] 0 4.93729 Effective Stress XX[ksf] 0 5.29879 Effective Stress YY[ksf] -0.139387 5.50596 Total Stress ZZ [ksf] 0 9.35509 Total Stress XX[ksf] 0 9.67237 Total Stress YY[ksf] -0.0798987 9.98216 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0 0.185362 Pore Water Pressure[ksf] 0 4.50521 Excess Pore Water Pressure [ksf] 0 0.382422 Degree of Consolidation [%] 0 6.92541 Pre-consolidation Stress [ksf] 0.0031556 4.93522 Over-consolidation Ratio 1 2.06559 Void Ratio 0 1.1 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength -1.11022e-16 0.00954915 Stage: EOL-1 =8 d Preload_Section I_Z1F_20210205_revl.s3z APC Barry89112/22/3030 [-1S -ence-e Plant Barry Interim Stability: Page 5 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 5.35953 Total Consolidation Settlement[in] 0 5.2611 Virgin Consolidation Settlement[in] 0 5.21322 Recompression Consolidation Settlement[in] 0 0.0480941 Immediate Settlement[in] 0 0.100423 Secondary Settlement[in] 0 0 Loading Stress ZZ[ksf] 2.17816e-05 0.5 Loading Stress XX[ksf] -0.0995697 0.488297 Loading Stress YY[ksf] -0.255716 0.819922 Effective Stress ZZ[ksf] 2.17816e-05 5.21797 Effective Stress XX[ksf] 0.0288282 5.58638 Effective Stress YY[ksf] -0.180301 5.97148 Total Stress ZZ [ksf] 2.17816e-05 9.46769 Total Stress XX[ksf] 0.0288282 9.82506 Total Stress YY[ksf] -0.134437 10.2259 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain -2.19915e-05 0.191608 Pore Water Pressure[ksf] 0 4.25941 Excess Pore Water Pressure [ksf] 0 0.496033 Degree of Consolidation [%] 0 74.1155 Pre-consolidation Stress [ksf] 0.0113925 5.21595 Over-consolidation Ratio 1 1.98034 Void Ratio 0 1.10005 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0155953 Stage: EOL-2 ac 10 d Preload_Section I_Z1F_20210205_revl.s3z APC Barry89pt/22/3030 [-1S -ence-e Plant Barry Interim Stability: Page 6 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 7.25633 Total Consolidation Settlement[in] 0 7.12533 Virgin Consolidation Settlement[in] 0 7.00826 Recompression Consolidation Settlement[in] 0 0.117442 Immediate Settlement[in] 0 0.125477 Secondary Settlement[in] 0 0.0620982 Loading Stress ZZ[ksf] 9.54775e-05 0.625 Loading Stress XX[ksf] -0.123821 0.611437 Loading Stress YY[ksf] -0.321692 1.01221 Effective Stress ZZ[ksf] 9.54775e-05 5.33057 Effective Stress XX[ksf] 0.0480039 5.74097 Effective Stress YY[ksf] -0.233056 6.22775 Total Stress ZZ [ksf] 9.54775e-05 9.58218 Total Stress XX[ksf] 0.0583045 9.98597 Total Stress YY[ksf] -0.187376 10.4849 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 5.67311 e-05 0.196904 Pore Water Pressure[ksf] 0 4.25923 Excess Pore Water Pressure [ksf] 0 0.58468 Degree of Consolidation [%] 0 80.3839 Pre-consolidation Stress [ksf] 0.0114803 5.32855 Over-consolidation Ratio 1 1.80997 Void Ratio 0 1.09988 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0216999 Stage: EOL3 ac 12 d Preload_Section I_DF_20210205_revl.s3z APC Barry 89h/22/2030 [-1S -ence-e Plant Barry Interim Stability: Page 7 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 8.82535 Total Consolidation Settlement[in] 0 8.64529 Virgin Consolidation Settlement[in] 0 8.44448 Recompression Consolidation Settlement[in] 0 0.204672 Immediate Settlement[in] 0 0.150512 Secondary Settlement[in] 0 0.0766781 Loading Stress ZZ[ksf] 0.000229208 0.749999 Loading Stress XX[ksf] -0.147479 0.734231 Loading Stress YY[ksf] -0.385328 1.20541 Effective Stress ZZ[ksf] 0.000229208 5.44509 Effective Stress XX[ksf] 0.0555663 5.90347 Effective Stress YY[ksf] -0.284574 6.50218 Total Stress ZZ [ksf] 0.000229208 9.69763 Total Stress XX[ksf] 0.088056 10.1527 Total Stress YY[ksf] -0.239003 10.7609 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 9.49806e-05 0.201127 Pore Water Pressure[ksf] 0 4.25905 Excess Pore Water Pressure [ksf] 0 0.65572 Degree of Consolidation [%] 0 84.4666 Pre-consolidation Stress [ksf] 0.0116306 5.44308 Over-consolidation Ratio 1 1.71955 Void Ratio 0 1.09961 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0273831 Stage: EOL-4 ac 14 d Preload_Section I_2JF_20210205_revl.s3z APC Barry 8902/22/2030 [-1S -ence-e Plant Barry Interim Stability: Page B of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 10.2762 Total Consolidation Settlement[in] 0 10.0621 Virgin Consolidation Settlement[in] 0 9.77928 Recompression Consolidation Settlement[in] 0 0.286773 Immediate Settlement[in] 0 0.175525 Secondary Settlement[in] 0 0.0857511 Loading Stress ZZ[ksf] 0.000420759 0.874998 Loading Stress XX[ksf] -0.170528 0.838301 Loading Stress YY[ksf] -0.446794 1.3995 Effective Stress ZZ[ksf] 0.000420759 5.56051 Effective Stress XX[ksf] 0.0629768 6.07173 Effective Stress YY[ksf] -0.334995 6.80034 Total Stress ZZ [ksf] 0.000420759 9.81368 Total Stress XX[ksf] 0.108478 10.324 Total Stress YY[ksf] -0.289494 11.0586 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000106159 0.204661 Pore Water Pressure[ksf] 0 4.25885 Excess Pore Water Pressure [ksf] 0 0.704477 Degree of Consolidation [%] 0 87.3619 Pre-consolidation Stress [ksf] 0.0118398 5.55851 Over-consolidation Ratio 1 1.65376 Void Ratio 0 1.09937 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0321806 Stage: EOLS ac 16 d Preload_Section I_DF_20210205_revl.s3z APC Barry 89k/22/2030 [-1S -ence-e Plant Barry Interim Stability: Page 9 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 11.6459 Total Consolidation Settlement[in] 0 11.4047 Virgin Consolidation Settlement[in] 0 11.0759 Recompression Consolidation Settlement[in] 0 0.359139 Immediate Settlement[in] 0 0.200516 Secondary Settlement[in] 0 0.0899761 Loading Stress ZZ[ksf] 0.000664654 0.999996 Loading Stress XX[ksf] -0.192946 0.960202 Loading Stress YY[ksf] -0.506301 1.59473 Effective Stress ZZ[ksf] 0.000664654 5.67656 Effective Stress XX[ksf] 0.0702042 6.24441 Effective Stress YY[ksf] -0.384421 7.10953 Total Stress ZZ [ksf] 0.000664654 9.9302 Total Stress XX[ksf] 0.115655 10.4989 Total Stress YY[ksf] -0.33897 11.3669 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000116408 0.207706 Pore Water Pressure[ksf] 0 4.25864 Excess Pore Water Pressure [ksf] 0 0.735517 Degree of Consolidation [%] 0 89.5054 Pre-consolidation Stress [ksf] 0.0121014 5.67457 Over-consolidation Ratio 1 1.60002 Void Ratio 0 1.09918 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0360913 Stage: EOL$ac 18 d Preload_Section I_2JF_20210205_revl.s3z APC Barry 89k/22/2030 [-1S -ence-e Plant Barry Interim Stability: Page 10 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 13.0096 Total Consolidation Settlement[in] 0 12.742 Virgin Consolidation Settlement[in] 0 12.3956 Recompression Consolidation Settlement[in] 0 0.397271 Immediate Settlement[in] 0 0.225483 Secondary Settlement[in] 0 0.0954943 Loading Stress ZZ[ksf] 0.000954872 1.12499 Loading Stress XX[ksf] -0.214716 1.08197 Loading Stress YY[ksf] -0.564052 1.79082 Effective Stress ZZ[ksf] 0.000954872 5.7931 Effective Stress XX[ksf] 0.077232 6.43725 Effective Stress YY[ksf] -0.43293 7.42055 Total Stress ZZ [ksf] 0.000954872 10.0471 Total Stress XX[ksf] 0.122645 10.6825 Total Stress YY[ksf] -0.387517 11.6775 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000125822 0.210382 Pore Water Pressure[ksf] 0 4.25842 Excess Pore Water Pressure [ksf] 0 0.804288 Degree of Consolidation [%] 0 91.1429 Pre-consolidation Stress [ksf] 0.0124091 5.79111 Over-consolidation Ratio 1 1.55531 Void Ratio 0 1.09897 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0404853 Stage: EOL-7=20 d Preload_Section I_Z1F_20210205_revl.s3z APC Barrya9f2/22/1010 [-1S -ence-e Plant Barry Interim Stability: Page 11 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 14.4144 Total Consolidation Settlement[in] 0 14.1206 Virgin Consolidation Settlement[in] 0 13.7674 Recompression Consolidation Settlement[in] 0 0.421824 Immediate Settlement[in] 0 0.250425 Secondary Settlement[in] 0 0.101354 Loading Stress ZZ[ksf] 0.00128579 1.24999 Loading Stress XX[ksf] -0.235821 1.18009 Loading Stress YY[ksf] -0.620443 1.98767 Effective Stress ZZ[ksf] 0.00128579 5.91003 Effective Stress XX[ksf] 0.084054 6.6444 Effective Stress YY[ksf] -0.480584 7.73364 Total Stress ZZ [ksf] 0.00128579 10.1643 Total Stress XX[ksf] 0.129438 10.8882 Total Stress YY[ksf] -0.4352 11.9897 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000134487 0.21277 Pore Water Pressure[ksf] 0 4.25818 Excess Pore Water Pressure [ksf] 0 0.889043 Degree of Consolidation [%] 0 92.4247 Pre-consolidation Stress [ksf] 0.012757 5.90805 Over-consolidation Ratio 1 1.5179 Void Ratio 0 1.09876 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0447423 Stage: EOL-8 ac 22 d Preload_Section I_2JF_20210205_revl.s3z APC Barry 89&/22/2030 [-1S -ence-e Plant Barry Interim Stability: Page 12 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 15.9029 Total Consolidation Settlement[in] 0 15.5833 Virgin Consolidation Settlement[in] 0 15.228 Recompression Consolidation Settlement[in] 0 0.430033 Immediate Settlement[in] 0 0.275341 Secondary Settlement[in] 0 0.107454 Loading Stress ZZ[ksf] 0.00165243 1.37498 Loading Stress XX[ksf] -0.256244 1.29543 Loading Stress YY[ksf] -0.677112 2.18516 Effective Stress ZZ[ksf] 0.00165243 6.02714 Effective Stress XX[ksf] 0.0906705 6.85068 Effective Stress YY[ksf] -0.527436 8.04837 Total Stress ZZ [ksf] 0.00165243 10.2813 Total Stress XX[ksf] 0.136031 11.0932 Total Stress YY[ksf] -0.482075 12.3035 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000142479 0.214926 Pore Water Pressure[ksf] 0 4.25793 Excess Pore Water Pressure [ksf] 0 0.951832 Degree of Consolidation [%] 0 93.4477 Pre-consolidation Stress [ksf] 0.01314 6.02517 Over-consolidation Ratio 1 1.48807 Void Ratio 0 1.09853 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0488708 Stage: EOL.9=24 d Preload_Section I_Z]F_20210205_revl.s3z APC Barry 8M/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 13 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 17.419 Total Consolidation Settlement[in] 0 17.0738 Virgin Consolidation Settlement[in] 0 16.717 Recompression Consolidation Settlement[in] 0 0.433378 Immediate Settlement[in] 0 0.300226 Secondary Settlement[in] 0 0.112827 Loading Stress ZZ[ksf] 0.0020505 1.49997 Loading Stress XX[ksf] -0.275971 1.41622 Loading Stress YY[ksf] -0.732408 2.38319 Effective Stress ZZ[ksf] 0.0020505 6.14421 Effective Stress XX[ksf] 0.0970864 7.05602 Effective Stress YY[ksf] -0.57384 8.36401 Total Stress ZZ [ksf] 0.0020505 10.3985 Total Stress XX[ksf] 0.142428 11.2974 Total Stress YY[ksf] -0.528186 12.6185 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000149867 0.216892 Pore Water Pressure[ksf] 0 4.25767 Excess Pore Water Pressure [ksf] 0 1.01634 Degree of Consolidation [%] 0 94.2774 Pre-consolidation Stress [ksf] 0.0135538 6.14224 Over-consolidation Ratio 1 1.46362 Void Ratio 0 1.09829 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0534654 Stage: EoL-10 =26 d Preload_Section I_2JF_20210205_revl.s3z APC Barry90p1/22/2030 [-1S -ence-e Plant Barry Interim Stability: Page 14 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 18.8791 Total Consolidation Settlement[in] 0 18.5085 Virgin Consolidation Settlement[in] 0 18.1511 Recompression Consolidation Settlement[in] 0 0.432506 Immediate Settlement[in] 0 0.325081 Secondary Settlement[in] 0 0.117665 Loading Stress ZZ[ksf] 0.00247631 1.62496 Loading Stress XX[ksf] -0.294989 1.54032 Loading Stress YY[ksf] -0.786436 2.58283 Effective Stress ZZ[ksf] 0.00247631 6.26143 Effective Stress XX[ksf] 0.10331 7.26035 Effective Stress YY[ksf] -0.619537 8.68049 Total Stress ZZ [ksf] 0.00247631 10.5159 Total Stress XX[ksf] 0.148636 11.5006 Total Stress YY[ksf] -0.573574 12.9344 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000156714 0.218699 Pore Water Pressure[ksf] 0 4.25739 Excess Pore Water Pressure [ksf] 0 1.068 Degree of Consolidation [%] 0 94.9595 Pre-consolidation Stress [ksf] 0.0139947 6.25946 Over-consolidation Ratio 1 1.44248 Void Ratio 0 1.09805 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0568036 Stage: EoL-11 =28 d Preload_Section I_Z1F_20210205_revl.s3z APC Barry 90112/22/3030 [-1S -ence-e Plant Barry Interim Stability: Page 15 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 20.3083 Total Consolidation Settlement[in] 0 19.9125 Virgin Consolidation Settlement[in] 0 19.5546 Recompression Consolidation Settlement[in] 0 0.436065 Immediate Settlement[in] 0 0.349901 Secondary Settlement[in] 0 0.12209 Loading Stress ZZ[ksf] 0.00292667 1.74995 Loading Stress XX[ksf] -0.313287 1.61675 Loading Stress YY[ksf] -0.839289 2.78305 Effective Stress ZZ[ksf] 0.00292667 6.37877 Effective Stress XX[ksf] 0.109351 7.46357 Effective Stress YY[ksf] -0.664522 8.99772 Total Stress ZZ [ksf] 0.00292667 10.6329 Total Stress XX[ksf] 0.154663 11.7029 Total Stress YY[ksf] -0.618273 13.2511 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000163072 0.22037 Pore Water Pressure[ksf] 0 4.25709 Excess Pore Water Pressure [ksf] 0 1.10794 Degree of Consolidation [%] 0 95.5368 Pre-consolidation Stress [ksf] 0.0144596 6.37681 Over-consolidation Ratio 1 1.42396 Void Ratio 0 1.09784 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0610069 Stage: EoL-12 =30 d Preload_Section I_2JF_20210205_revl.s3z APC Barry/22/2030 [-1S -ence-e Plant Barry Interim Stability: Page 16 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 21.6322 Total Consolidation Settlement[in] 0 21.2447 Virgin Consolidation Settlement[in] 0 20.8557 Recompression Consolidation Settlement[in] 0 0.43918 Immediate Settlement[in] 0 0.374686 Secondary Settlement[in] 0 0.126183 Loading Stress ZZ[ksf] 0.00339885 1.87493 Loading Stress XX[ksf] -0.330855 1.73635 Loading Stress YY[ksf] -0.89105 2.98375 Effective Stress ZZ[ksf] 0.00339885 6.49578 Effective Stress XX[ksf] 0.115068 7.66561 Effective Stress YY[ksf] -0.70883 9.3156 Total Stress ZZ [ksf] 0.00339885 10.7501 Total Stress XX[ksf] 0.160522 11.904 Total Stress YY[ksf] -0.662316 13.5683 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000168991 0.221924 Pore Water Pressure[ksf] 0 4.25677 Excess Pore Water Pressure [ksf] 0 1.14534 Degree of Consolidation [%] 0 96.0334 Pre-consolidation Stress [ksf] 0.0149456 6.49382 Over-consolidation Ratio 1 1.40756 Void Ratio 0 1.09766 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0651528 Stage: 2 Months=61 d Preload_Section I_2JF_20210205_revl.s3z APC Barry/22/2030 [-1S -ence-e Plant Barry Interim Stability: Page 17 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 28.467 Total Consolidation Settlement[in] 0 27.7632 Virgin Consolidation Settlement[in] 0 27.3726 Recompression Consolidation Settlement[in] 0 0.445876 Immediate Settlement[in] 0 0.374686 Secondary Settlement[in] 0 0.690043 Loading Stress ZZ[ksf] 0.00339885 1.87493 Loading Stress XX[ksf] -0.330855 1.73635 Loading Stress YY[ksf] -0.89105 2.98375 Effective Stress ZZ[ksf] 0.00339885 6.61297 Effective Stress XX[ksf] 0.116123 7.76694 Effective Stress YY[ksf] -0.707775 9.43122 Total Stress ZZ [ksf] 0.00339885 10.7501 Total Stress XX[ksf] 0.160522 11.904 Total Stress YY[ksf] -0.662316 13.5683 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000168991 0.222464 Pore Water Pressure[ksf] 0 4.13712 Excess Pore Water Pressure [ksf] -0.0529454 0.36998 Degree of Consolidation [%] 0 99.9983 Pre-consolidation Stress [ksf] 0.0149456 6.61102 Over-consolidation Ratio 1 1.37177 Void Ratio 0 1.09766 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0793465 Stage: 3 Months=91 d Preload_Section I_2JF_20210205_revl.s3z APC BarryAFJ%dWQ9M/22/2030 [-1S -ence-e Plant Barry Interim Stability: Page 18 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 29.8623 Total Consolidation Settlement[in] 0 28.4837 Virgin Consolidation Settlement[in] 0 28.0931 Recompression Consolidation Settlement[in] 0 0.44671 Immediate Settlement[in] 0 0.374686 Secondary Settlement[in] 0 1.30445 Loading Stress ZZ[ksf] 0.00339885 1.87493 Loading Stress XX[ksf] -0.330855 1.73635 Loading Stress YY[ksf] -0.89105 2.98375 Effective Stress ZZ[ksf] 0.00339885 6.61297 Effective Stress XX[ksf] 0.116123 7.76694 Effective Stress YY[ksf] -0.707775 9.43122 Total Stress ZZ [ksf] 0.00339885 10.7501 Total Stress XX[ksf] 0.160522 11.904 Total Stress YY[ksf] -0.662316 13.5683 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000168991 0.222748 Pore Water Pressure[ksf] 0 4.13712 Excess Pore Water Pressure [ksf] -0.0431643 0.0778812 Degree of Consolidation [%] 0 100 Pre-consolidation Stress [ksf] 0.0149456 6.61102 Over-consolidation Ratio 1 1.37015 Void Ratio 0 1.09766 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0795932 Stage: 4 Months=122 d Preload_Section I_2JF_20210205_revl.s3z APC Barry/22/2030 [-1S -ence-e Plant Barry Interim Stability: Page 19 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 30.9153 Total Consolidation Settlement[in] 0 28.7061 Virgin Consolidation Settlement[in] 0 28.311 Recompression Consolidation Settlement[in] 0 0.446816 Immediate Settlement[in] 0 0.374686 Secondary Settlement[in] 0 2.17696 Loading Stress ZZ[ksf] 0.00339885 1.87493 Loading Stress XX[ksf] -0.330855 1.73635 Loading Stress YY[ksf] -0.89105 2.98375 Effective Stress ZZ[ksf] 0.00339885 6.61297 Effective Stress XX[ksf] 0.116124 7.76694 Effective Stress YY[ksf] -0.707775 9.43122 Total Stress ZZ [ksf] 0.00339885 10.7501 Total Stress XX[ksf] 0.160522 11.904 Total Stress YY[ksf] -0.662316 13.5683 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000168991 0.22295 Pore Water Pressure[ksf] 0 4.13712 Excess Pore Water Pressure [ksf] -0.0124326 0.0462529 Degree of Consolidation [%] 0 100 Pre-consolidation Stress [ksf] 0.0149456 6.61102 Over-consolidation Ratio 1 1.36683 Void Ratio 0 1.09766 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0797008 Stage: 5 Months=152 d Preload_Section I_2JF_20210205_revl.s3z APC Barry/22/2030 [-1S -ence-e Plant Barry Interim Stability: Page 20 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 31.6238 Total Consolidation Settlement[in] 0 28.7487 Virgin Consolidation Settlement[in] 0 28.3535 Recompression Consolidation Settlement[in] 0 0.446846 Immediate Settlement[in] 0 0.374686 Secondary Settlement[in] 0 2.97202 Loading Stress ZZ[ksf] 0.00339885 1.87493 Loading Stress XX[ksf] -0.330855 1.73635 Loading Stress YY[ksf] -0.89105 2.98375 Effective Stress ZZ[ksf] 0.00339885 6.61297 Effective Stress XX[ksf] 0.116124 7.76694 Effective Stress YY[ksf] -0.707775 9.43122 Total Stress ZZ [ksf] 0.00339885 10.7501 Total Stress XX[ksf] 0.160522 11.904 Total Stress YY[ksf] -0.662316 13.5683 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000168991 0.2231 Pore Water Pressure[ksf] 0 4.13712 Excess Pore Water Pressure [ksf] -0.0247563 0.0601437 Degree of Consolidation [%] 0 100 Pre-consolidation Stress [ksf] 0.0149456 6.61102 Over-consolidation Ratio 1 1.36449 Void Ratio 0 1.09766 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0798428 Stage: 6 Months=183 d Preload_Section I_Z]F_20210205_revl.s3z APC Barry901'2/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 21 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 32.204 Total Consolidation Settlement[in] 0 28.7557 Virgin Consolidation Settlement[in] 0 28.3606 Recompression Consolidation Settlement[in] 0 0.446855 Immediate Settlement[in] 0 0.374686 Secondary Settlement[in] 0 3.63755 Loading Stress ZZ[ksf] 0.00339885 1.87493 Loading Stress XX[ksf] -0.330855 1.73635 Loading Stress YY[ksf] -0.89105 2.98375 Effective Stress ZZ[ksf] 0.00339885 6.61297 Effective Stress XX[ksf] 0.116124 7.76694 Effective Stress YY[ksf] -0.707775 9.43122 Total Stress ZZ [ksf] 0.00339885 10.7501 Total Stress XX[ksf] 0.160522 11.904 Total Stress YY[ksf] -0.662316 13.5683 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000168991 0.223226 Pore Water Pressure[ksf] 0 4.13712 Excess Pore Water Pressure [ksf] -0.015718 0.0271305 Degree of Consolidation [%] 0 100 Pre-consolidation Stress [ksf] 0.0149456 6.61102 Over-consolidation Ratio 1 1.36264 Void Ratio 0 1.09766 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0798428 Stage: 7 Months ac 213 d Preload_Section I_Z]F_20210205_revl.s3z APC BarryAFJ%dWQ9M/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 22 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 32.6737 Total Consolidation Settlement[in] 0 28.7567 Virgin Consolidation Settlement[in] 0 28.3616 Recompression Consolidation Settlement[in] 0 0.446857 Immediate Settlement[in] 0 0.374686 Secondary Settlement[in] 0 4.17874 Loading Stress ZZ[ksf] 0.00339885 1.87493 Loading Stress XX[ksf] -0.330855 1.73635 Loading Stress YY[ksf] -0.89105 2.98375 Effective Stress ZZ[ksf] 0.00339885 6.61297 Effective Stress XX[ksf] 0.116124 7.76694 Effective Stress YY[ksf] -0.707775 9.43122 Total Stress ZZ [ksf] 0.00339885 10.7501 Total Stress XX[ksf] 0.160522 11.904 Total Stress YY[ksf] -0.662316 13.5683 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000168991 0.223328 Pore Water Pressure[ksf] 0 4.13712 Excess Pore Water Pressure [ksf] -0.0176125 0.0201617 Degree of Consolidation [%] 0 100 Pre-consolidation Stress [ksf] 0.0149456 6.61102 Over-consolidation Ratio 1 1.36137 Void Ratio 0 1.09766 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0798428 Stage: 8 Months=243 d Preload_Section I_Z]F_20210205_revl.s3z APC Barry 90&/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 23 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 33.0793 Total Consolidation Settlement[in] 0 28.7568 Virgin Consolidation Settlement[in] 0 28.3617 Recompression Consolidation Settlement[in] 0 0.446858 Immediate Settlement[in] 0 0.374686 Secondary Settlement[in] 0 4.64656 Loading Stress ZZ[ksf] 0.00339885 1.87493 Loading Stress XX[ksf] -0.330855 1.73635 Loading Stress YY[ksf] -0.89105 2.98375 Effective Stress ZZ[ksf] 0.00339885 6.61297 Effective Stress XX[ksf] 0.116124 7.76694 Effective Stress YY[ksf] -0.707775 9.43122 Total Stress ZZ [ksf] 0.00339885 10.7501 Total Stress XX[ksf] 0.160522 11.904 Total Stress YY[ksf] -0.662316 13.5683 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000168991 0.223416 Pore Water Pressure[ksf] 0 4.13712 Excess Pore Water Pressure [ksf] -0.0169327 0.0172169 Degree of Consolidation [%] 0 100 Pre-consolidation Stress [ksf] 0.0149456 6.61102 Over-consolidation Ratio 1 1.36046 Void Ratio 0 1.09766 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0798428 Stage: 9 Months=274 d Preload_Section I_Z]F_20210205_revl.s3z APC Barry91t2/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 24 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 33.4476 Total Consolidation Settlement[in] 0 28.7569 Virgin Consolidation Settlement[in] 0 28.3618 Recompression Consolidation Settlement[in] 0 0.446858 Immediate Settlement[in] 0 0.374686 Secondary Settlement[in] 0 5.07146 Loading Stress ZZ[ksf] 0.00339885 1.87493 Loading Stress XX[ksf] -0.330855 1.73635 Loading Stress YY[ksf] -0.89105 2.98375 Effective Stress ZZ[ksf] 0.00339885 6.61297 Effective Stress XX[ksf] 0.116124 7.76694 Effective Stress YY[ksf] -0.707775 9.43122 Total Stress ZZ [ksf] 0.00339885 10.7501 Total Stress XX[ksf] 0.160522 11.904 Total Stress YY[ksf] -0.662316 13.5683 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000168991 0.223496 Pore Water Pressure[ksf] 0 4.13712 Excess Pore Water Pressure [ksf] -0.0151994 0.0154513 Degree of Consolidation [%] 0 100 Pre-consolidation Stress [ksf] 0.0149456 6.61102 Over-consolidation Ratio 1 1.35984 Void Ratio 0 1.09766 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0798428 Stage: 10 Months=304 d Preload_Section I_Z]F_20210205_revl.s3z APC Barry9192/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 25 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 33.7655 Total Consolidation Settlement[in] 0 28.757 Virgin Consolidation Settlement[in] 0 28.3619 Recompression Consolidation Settlement[in] 0 0.446858 Immediate Settlement[in] 0 0.374686 Secondary Settlement[in] 0 5.43822 Loading Stress ZZ[ksf] 0.00339885 1.87493 Loading Stress XX[ksf] -0.330855 1.73635 Loading Stress YY[ksf] -0.89105 2.98375 Effective Stress ZZ[ksf] 0.00339885 6.61297 Effective Stress XX[ksf] 0.116124 7.76694 Effective Stress YY[ksf] -0.707775 9.43122 Total Stress ZZ [ksf] 0.00339885 10.7501 Total Stress XX[ksf] 0.160522 11.904 Total Stress YY[ksf] -0.662316 13.5683 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000168991 0.223565 Pore Water Pressure[ksf] 0 4.13712 Excess Pore Water Pressure [ksf] -0.0140793 0.0170334 Degree of Consolidation [%] 0 100 Pre-consolidation Stress [ksf] 0.0149456 6.61102 Over-consolidation Ratio 1 1.35973 Void Ratio 0 1.09766 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0798428 Stage: 77 Months=335 d Preload_Section I_Z]F_20210205_revl.s3z APC Barry-6F#4,ggQ91Q/22/2020 [-1S -ence-e Plant Barry Interim Stability: Page 26 of 34 : i Data Type Minimum Maximum Total Settlement[in] 0 34.062 Total Consolidation Settlement[in] 0 28.757 Virgin Consolidation Settlement[in] 0 28.3619 Recompression Consolidation Settlement[in] 0 0.446858 Immediate Settlement[in] 0 0.374686 Secondary Settlement[in] 0 5.78029 Loading Stress ZZ[ksf] 0.00339885 1.87493 Loading Stress XX[ksf] -0.330855 1.73635 Loading Stress YY[ksf] -0.89105 2.98375 Effective Stress ZZ[ksf] 0.00339885 6.61297 Effective Stress XX[ksf] 0.116124 7.76694 Effective Stress YY[ksf] -0.707775 9.43122 Total Stress ZZ [ksf] 0.00339885 10.7501 Total Stress XX[ksf] 0.160522 11.904 Total Stress YY[ksf] -0.662316 13.5683 Modulus of Subgrade Reaction(Total)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Immediate)[ksf/ft] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ff] 0 0 Total Strain 0.000168991 0.223629 Pore Water Pressure[ksf] 0 4.13712 Excess Pore Water Pressure [ksf] -0.00922889 0.0129167 Degree of Consolidation [%] 0 100 Pre-consolidation Stress [ksf] 0.0149456 6.61102 Over-consolidation Ratio 1 1.3596 Void Ratio 0 1.09766 Permeability [ft/min] 0 0.36862 Coefficient of Consolidation[ftA2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undrained Shear Strength 0 0.0798428 Preload_Section I_Z]F_20210205_revl.s3z APC Barry-&PA 91p,2/22/2020 [e1S -ence-e Plant Barry Interim Stability: Page 27 of 34 : i Stage: 12 Months=365 d Data Type Minimum Maximum Total Settlement[in] 0 34.3235 Total Consolidation Settlement[in] 0 28.757 Virgin Consolidation Settlement[in] 0 28.3619 Recompression Consolidation Settlement[in] 0 0.446858 Immediate Settlement[in] 0 0.374686 Secondary Settlement[in] 0 6.08193 Loading Stress ZZ[ksf] 0.00339885 1.87493 Loading Stress XX[ksf] -0.330855 1.73635 Loading Stress YY[ksf] -0.89105 2.98375 Effective Stress ZZ[ksf] 0.00339885 6.61297 Effective Stress XX[ksf] 0.116124 7.76694 Effective Stress YY[ksf] -0.707775 9.43122 Total Stress ZZ [ksf] 0.00339885 10.7501 Total Stress XX[ksf] 0.160522 11.904 Total Stress YY[ksf] -0.662316 13.5683 Modulus of Subgrade Reaction (Total)[ksf/ft] 0 0 Modulus of Subgrade Reaction (Immediate)[ksf/ff] 0 0 Modulus of Subgrade Reaction(Consolidation)[ksf/ft] 0 0 Total Strain 0.000168991 0.223686 Pore Water Pressure[ksf] 0 4.13712 Excess Pore Water Pressure [ksf] -0.00789689 0.0120152 Degree of Consolidation [%] 0 100 Pre-consolidation Stress [ksf] 0.0149456 6.61102 Over-consolidation Ratio 1 1.3595 Void Ratio 0 1.09766 Permeability [tt/min] 0 0.36862 Coefficient of Consolidation[ft"2/min] 0 0.02 Hydroconsolidation Settlement[in] 0 0 Average Degree of Consolidation [%] 0 0 Undreined Shear Strength 0 0.0798428 Embankments Preload_Section I_Z1F_20210205_re,1.s3z APC Barry-6F4499R91¢2/22/2020 t-1%ei ence- Plant Barry Interim Stability: Page 28 of 34 1. Embankment: "Embankment Load 1" Label Embankment Load 1 Center Line (459.52, 0)to (459.52, 500) Near End Angle 18.4 degrees Far End Angle 18.4 degrees Number of Layers 13 Base Width 531.48 Layer Stage Left Bench Left Angle Height Unit Weight Right Angle Right Bench Width (it) (deg) (it) (kips/ft) (deg) Width (it) EoL-Bridge 1 = 6d 0 18.4 3 0.125 18.4 0 2 EoL-1 = 8 d 0 18.4 1 0.125 18.4 0 3 EoL-2= 10 d 0 18.4 1 0.125 18.4 0 4 EoL-3= 12 d 0 18.4 1 0.125 18.4 0 5 EoL-4= 14 d 0 18.4 1 0.125 18.4 0 6 EoL-5= 16 d 0 18.4 1 0.125 18.4 0 7 EoL-0= 18 d 0 18.4 1 0.125 18.4 0 8 EoL-7= 20 d 0 18.4 1 0.125 18.4 0 9 EoL-8=22 d 0 18.4 1 0.125 18.4 0 10 EoL-9= 24 d 0 18.4 1 0.125 18.4 0 11 EoL-10 d 0 18.4 1 0.125 18.4 0 12 EoL-28 d 0 18.4 1 0.125 18.4 0 13 EOL-12 d 0 18.4 1 0.125 18.4 0 Soil Layers Ground Surface Drained: Yes Borehole 1: (193.78,0) Layer 9 Type Thickness [ft] Depth[ft] Drained at Bottom 1 CCR 23.62 -24.47 No 2 Clay 1 C 1.2 -0.85 No 3 Clay 1 M 6.96 0.35 No 4 Clay 1 L 0.99 7.31 Yes 5 Sand 1 11.95 8.3 No 6 Clay 2 3.85 20.25 Yes 7 Sand 2 35.9 24.1 Yes Preload_Section I_Z1F_20210205_re,1.s3z APC Barry 9liQ/22/2030 Rant Barry Interim Stability: Page 29 of 34 24,4P o.es 7,31 ® -21.11 -60 ft Borehole 2: (542.31, 0) Layer# Type Thickness [ft] Depth [ft] Drained at Bottom 1 CCR 21.04 -22.04 No 2 Clay 1 C 1.7 -1 No 3 Clay 1 M 5.9 0.7 No 4 Clay 1 L 1.4 6.6 Yes 5 Sand 1 13.5 8 No 6 Clay 2 4 21.5 Yes 7 Sand 2 34.5 25.5 Yes 24 47 ❑_ 1 ® 16,6 ® -21.5 Go ft Borehole 3: (725.27,0) Layer# Type Thickness [ft] Depth [ft] Drained at Bottom 1 CCR 21.01 -21.29 No 2 Clay 1 C 2.56 -0.28 No 3 Clay 1 M 8.43 2.28 No 4 Clay 1 L 1.61 10.71 Yes 5 Sand 1 5.2 12.32 No 6 Clay 2 7.62 17.52 Yes 7 Sand 2 34.86 25.14 Yes Preload_Section I_Z1F_20210205_re,1.s3z APC Barry 91¢7/22/2030 [elm Plant Barry Interim Stability: Page 30 of 34 ® 24,47 0 0.28 10.71 -17.52 25.14 6o ft Borehole 4: (193.78, 500) Layer# Type Thickness [ft] Depth [ft] Drained at Bottom 1 CCR 23.62 -24.47 No 2 Clay 1 C 1.2 -0.85 No 3 Clay 1 M 6.96 0.35 No 4 Clay 1 L 0.99 7.31 Yes 5 Sand 1 11.95 8.3 No 6 Clay 2 3.85 20.25 Yes 7 Sand 2 35.9 24.1 Yes 2a,aw 0.85 7,31 ® -20.25 -60 ft Borehole 5: (542.31, 500) Layer# Type Thickness [ft] Depth [ft] Drained at Bottom 1 CCR 21.04 -22.04 No 2 Clay 1 C 1.7 -1 No 3 Clay 1 M 5.9 0.7 No 4 Clay 1 L 1.4 6.6 Yes 5 Sand 1 13.5 8 No 6 Clay 2 4 21.5 Yes 7 Sand 2 34.5 25.5 Yes Preload_Section I_2JF_20210205_re,1.s3z APC Barry 911'2/22/2010 Plant Barry Interim Stability: Page 31 of 34 24,47 ❑_ 1 ® -6,6 ® -21.1 Go ft Borehole 6: (725.27, 500) Layer# Type Thickness [ft] Depth [ft] Drained at Bottom 1 CCR 21.01 -21.29 No 2 Clay 1 C 2.56 -0.28 No 3 Clay 1 M 8.43 2.28 No 4 Clay 1 L 1.61 10.71 Yes 5 Sand 1 5.2 12.32 No 6 Clay 2 7.62 17.52 Yes 7 Sand 2 34.86 25.14 Yes ® 24,4➢ 0.28 ®_ -lo.rl -17.52 -Ezs.14 -6o ft Soil Properties Preload_Section I_2JF_20210205_re,1.s3z APC Barry 9lfl2/22/2030 t.',%ei —ence-e Plant Barry Interim Stability: Page 32 of 34 Property CCR Clay 1 M Sand 1 Clay 2 Color 0 M 0 0 Unit Weight [kipsfft3] 0.092 0.096 0.11 0.102 Saturated Unit Weight[kips/ft3] 0.092 0.096 0.11 0.102 KO 1 1 1 1 Immediate Settlement Disabled Disabled Enabled Disabled Es[ksf] - - 2500 Esur[ksf] - - 2500 Primary Consolidation Enabled Enabled Enabled Enabled Material Type Non-Linear Non-Linear Non-Linear Non-Linear Coe 0.05 0.263 0.1 0.14 Cris 0.01 0.019 le-11 0.014 e0 1.1 1.1 1.1 1.1 OCR 1 - 1 1 OCM [ksfJ - 0.3 - Cv[ft2/min] 0.02 0.00083 0.008 0.0008 Cvr[ft2/min] 0.02 0.00083 0.008 0.0008 Bbar 1 1 1 1 Secondary Consolidation Standard Standard Disabled Standard Cae 0.0015 0.035 - 0.03 Care 0.0015 0.035 - 0.03 Undrained Su A[kips/ft2] 0 0 0 0 Undained Su S 0.2 0.2 0.2 0.2 Undrained Su m 0.8 0.8 0.8 0.8 Piezo Line ID 2 2 1 1 Preload_Section I_Z1F_20210205_re,1.s3z APC Barry 91$1/22/2020 [•1�. eience-e Plant Barry Interim Stability: Page 33 of 34 : Property Sand 2 Clay 1 C Clay 7 L Color 0 0 0 Unit Weight [kipsrft3] 0.12 0.1 0.099 Saturated Unit Weight[kipa/ft3] 0.12 0.1 0.099 KO 1 1 1 Immediate Settlement Enabled Disabled Disabled Es[ksf] 3000 - Esur[ksf] 3000 - Primary Consolidation Disabled Enabled Enabled Material Type Non-Linear Non-Linear Coe - 0.263 0.263 Cris - 0.019 0.019 e0 - 1.1 1.1 Pc[ksfJ - 1.3 2.5 Cv[ft2/min] - 0.00083 0.00083 Cvr[ft2/min] - 0.00083 0.00083 B-bar - 1 1 Secondary Consolidation Disabled Standard Standard Cae - 0.035 0.035 Care - 0.035 0.035 Undrained Su A[kips/ft2] 0 0 0 Undrained Su S 0.2 0.2 0.2 Undrained Su m 0.8 0.8 0.8 Piezo Line ID 1 2 1 Groundwater Groundwater method Piezometric Lines Water Unit Weight 0.0624 kips/ft3 Piezometric Line Entities ID Depth(ft) 1 6.3ft 2 22 ft Query Lines Line 9 Query Line Name Start Location End Location Horizontal Divisions Vertical Divisions 1 Query Line 1 193.78, 250 725.26, 250 54 Auto: 75 Preload_Section I_Z1F_20210205_re,1.s3z APC Barry 92111/22/2030 [.1S -ience-e Plant Barry Interim Stability: Page 34 of 34 : Preloac_Section I_Z]F_20210205_re,1.s3z APC Barry 942/22/2020 Geosyntec° consultants Page 145 of 185 CP: ZJF Dale: 2123/21 APC: JMP Date: =2121 CA: WT Date: 3M1 Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 ATTACHMENTS SLIDE OUTPUTS GW7193Nonh_FimlGredea_Stability_Nana ive.da x APC Barry_EPA_000922 Geosynte& consultants Page 1" of 185 CP: ZJF Dale: 2123/21 APC: JNP Date: =2121 CA: WT Date: 3M1 Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 East Section GW7193Nonh_FimlGredea_Stability_Nana ive.da x APC Barry_EPA_000923 Undrained Material Parameters Material Name Color Unit Weight llbs/ft3) Strength Type Cohesion(ps6 Phi(deg) Cohesion Type Cohesion Change(pai Datum(ft) Discrete Functbn Wa[er Surface Ru CCR 92 Mohr Coulomb 0 36 Piezometric Line Clay 1 M Upstream(Up) 92 Undrained 150 FDatum 10.99 19.59 None 0 Clay l M Downstream(Up) 92 Undrained 150 FDatum 11.14 18.56 None 0 Clay 1 L(Local UD) 104 Undrained 830 Constant None 0 Clay M Under Dike(Local U D) 105 Discrete function Clay l Under Dike None 0 Sand 1(Local UD) 107 Undrained 1200 Constant None 0 Sand((Local D) 107 Mohr Coulomb 0 30 Pie0pri LmeI Sand 120 Mohr Coulomb 0 38 Pie.pr is LmeI g U Dike(UD) 120 Undrained 2000 Constant None 0 L Dike(Up) 120 Undrained 2000 Constant None 0 Clay 1 M PKPT-36(UD) 98 Undrained 300 FDatum 9 3 None 0 Clay 1 M(P19-18 UD) 102 Discrete function Clay 1 Preloaded None 0 SCB and Fill(UD) 115 Undrained 600 Constant None 0 Compacted CCR 97 Mohr Coulomb 0 36 Pie0pr is Lme2 CIay1MPOCPT-3](UD) 300 Undrained 150 FDatum 10 SO None 0 Clay 2 PDCPT-3]IUD) 100 Undrained 600 Constant None 0 a -1600 -1400 -1200 -1000 -800 -600 400 -200 0 200 400 vmtct Plant Barry Interim Preload Design Geosyntec° 01 Dike_EDC Pr Master Scenario consultants aaiwi By Zachary Fallert any Geosyntec °D0s 2/5/2021 f-0efa'"e East_EDC_Z]F_20210204_revl.slmd APC Barry_EPA_000924 Drained Material Parameters Material Name Color Unit Weight(lbs/113) Strength Type Cohesion(psf) Phi (deg) Water Surface CCR 92 Mohr-Coulomb 0 36 Piezometric Line 2 Clay 1 M Upstream and Downstream (Local D) 92 Mohr-Coulomb 75 31 Piezometric Line 2 Clay 1 L (Local D) 104 Mohr-Coulomb 75 31 Piezometric Line 1 Clay 1 M Under Dike(Local D) 105 Mohr-Coulomb 75 31 Piezometric Line 2 Sand 1 (Local D) 107 Mohr-Coulomb 0 30 Piezometric Line 1 Sand 2 120 Mohr-Coulomb 0 38 Piezometric Line 1 Dike(D) 120 Mohr-Coulomb 260 29 Piezometric Line 2 Clay 1 M PDCPT-36(D) 98 Mohr-Coulomb 75 31 Piezometric Line 2 Clay 1 M P19-18(D) ♦ 102 Mohr-Coulomb 75 31 Piezometric Line 2 SCB and Fill (D) 115 Mohr-Coulomb 50 27 Piezometric Line 2 Compacted CCR 97 Mohr-Coulomb 0 36 Piezometric Line 2 Clay 1 M PDCPT-37 (D) 100 Mohr-Coulomb 75 31 Piezometric Line 2 Clay 2 PDCPT-37 (D) 100 Mohr-Coulomb 75 31 Piezometric Line 1 -2000 -1800 -1600 -1400 -1200 -1000 -600 -600 400 -200 0 vmtrt Plant Barry Interim Preload Design Geosyntec° Ol_Dike_LongTerm """a' Master Scenario Consultants as By Zachary Fallert ici r Geosyntec 2/5/2021 East_LongTerm_Z1F_20210205_rev4.slmd APC Barry_EPA_000925 Scenario: EoC Sub-Scenario: Existing Dike Only Search Method: Limits 1.36 -------------- ]00 725 750 ]]5 800 825 850 875 900 925 950 9]5 vm/nt Plant Barry Interim Preload Design Geosyntec° Ol_Dike_EoC — Limits consultants Q'a By Zachary Fallert °in"a"r Geosyntec 2/5/2021 East_EoC_Z]F_20210204_rM.slmd APC Barry_EPA_000926 Scenario: EoC Sub-Scenario: Existing Dike Only Search Method: Block 1.35 700 725 750 775 800 825 850 875 900 925 950 9]5 voket Plant Barry Interim Preload Design Geosptec° Ol_Dike_EoC """"O Block consultants Q'a By Zachary Fallert °in"a"r Geosyntec 2/5/2021 East_EoC_ZIF_20210204_rM.slmd APC Barry_EPA_000927 Scenario: EoC Sub-Scenario: All Final Grades Search Method: Limits 5.22 1 2 •-1150 -1500 -1250 -100 -750 -500 -250 0 250 50 750 1000 vm/nt Plant Barry Interim Preload Design Geosynte& 02_Final_EoC Limits consultants Q'aO By Zachary Fallert ICi r Geosyntec 2/5/2021 f-0"`°'"` East_EoC_ZIF_20210204_rM.slmd APC Barry_EPA_000928 Scenario: EoC Sub-Scenario: All Final Grades 3.09 Search Method: Block 1 2 •-1750 -1500 -1250 -1000 -750 -500 -250 0 250 50 750 1000 vm/nt Plant Barry Interim Preload Design Geosyntec° 02_Final_EoC """" Block consultants Q'aO By Zachary Fallert ICi r Geosyntec 2/5/2021 ° ` East_EoC_ZIF_20210204_rM.slmd APC Barry_EPA_000929 Scenario: EoC - Surcharged Sub-Scenario: Dike Only Search Method: Limits 1.29 3DFS = 1.30 Allowable Width of Surcharge in 3rd Dimension = 2950 ft 99A67 131.960 700.001 M2 M 700 725 750 775 800 825 850 875 900 925 950 9]5 vm/nt Geosytltec° Ol Plant Barry Interim Preload Design _Dike_EaC """"O Limits consultants By Zachary Failed °in"a"r Geosyntec 2/5/2021 East_EoC_surcharge_DF_20210204_nNI.slmd APC Barry_EPA_000930 Scenario: EoC - Surcharged Sub-Scenario: Dike Only Search Method: Block 1.28 3DFS = 1.30 Allowable Width of Surcharge in 3rd Dimension = 1450 ft 99.116 132.049 700.001 M2 w A A A A A A A A A ®a.,II __=a 700 725 750 775 B00 825 850 875 900 925 950 9]5 vmµvt Plant Barry Interim Preload Design Geosyntec° Ol_Dike_EoC Black consultants By Zachary Fallert °in"a"r Geosyntec 2/5/2021 f-0"`°'"` East_EoC_surcharge_DF_20210204_nwl.slmd APC Barry_EPA_000931 Scenario: EoC - Surcharged Sub-Scenario: All Final Grades S Search Method: Limits 3.64 N -1]50 -1500 -1250 -1000 -750 -500 -250 0 250 500 ]50 1000 vmkxt Plant Barry Interim Preload Design Geosyntec° 02_Final_EoC Limits consultants a'°"�ar Zachary Fallert Ci r Geosyntec 2/5/2021 f-0"`°'"` East_EoC_surcharge_DF_20210204_nwl.slmd APC Barry_EPA_000932 Scenario: EoC - Surcharged Sub-Scenario: All Final Grades 2.88 S Search Method: Block N -1150 -1500 -1250 -1000 -750 -500 -250 0 250 500 750 1000 vmkxt Plant Barry Interim Preload Design Geosyntec° 02_Final_EoC Block consultants By Zachary Fallert ICi r Geosyntec 2/5/2021 f-0"`°'"` East_EoC_surcharge_DF_20210204_nwl.slmd APC Barry_EPA_000933 Scenario: Seismic Sub-Scenario: Dike Only 0.02 Search Method: Limits 1.23 Ar A A A A A A A A A 11,1141a------- 700 725 750 7]5 800 825 850 65 900 925 950 975 vmtrt GeosYCltec° Ol Plant Barry Interim Preload Design _Dike_EaC """"O Limits consultants By Zachary Fallert °in"a"r Geosyntec 2/5/2021 f-0eNa'"` East_Seismic_Z]F_20210204_mvl.slmd APC Barry_EPA_0009M Scenario: Seismic Sub-Scenario: Dike Only 0.02 Search Method: Block 1.23 411a. ♦AAAA - A T 700 725 750 775 B00 825 850 875 900 925 950 975 voket Geosyntec° Ol Plant Barry Interim Preload Design _Dike_EaC """"O Block consultants By Zachary Fallert °in"a"r Geosyntec 2/5/2021 f-0eNa'"` East_Seismic_Z]F_20210204_mvl.slmd APC Barry_EPA_000935 Scenario: Seismic Sub-Scenario: All Final Grades 002 g Search Method: Limits 3.04 1 2 -1750 -1500 -1250 -1000 -750 -500 -250 0 250 500 750 1000 vmtrt Plant Barry Interim Preload Design Geosyntec° 02_Final_EoC """"O Limits consultants By Zachary Fallert ICi r Geosyntec 2/5/2021 f-0eNa'"` East_Seismic_Z]F_20210204_mvl.slmd APC Barry_EPA_000936 Scenario: Seismic Sub-Scenario: All Final Grades 1.7s Search Method: Block I , o.oz t 2 -1750 -1500 -1250 -100 -70 -50 -250 0 250 50 750 1000• vmtrt GeosyCltec° 02 Plant Barry Interim Preload Design _Final_EoC """"O Block consultants By Zachary Failed ICin r Geosyntec 2/5/2021 f-0eNa'"` East_Seismic_Z]F_20210204_mvl.slmd APC Barry_EPA_000937 Scenario: Long Term 2.69 Sub-Scenario: Dike Only Search Method: Limits .......................:::::::: ............................... ............................... ............................... .............................. 700 725 750 775 800 825 850 875 960 925 950 9]5 vmk� Plant Barry Interim Preload Design Geosyntec° Ol_Dike_LongTerm """"' Limits Consultants Q'a By Zachary Fallert ICi r Geosyntec 2/5/2021 East_LongTerm_Z]F_20210205_rev4.slmd APC Barry_EPA_000938 Scenario: Long Term 2.57 Sub-Scenario: Dike Only Search Method: Block ...............:.:::::::::::::. ............................... ............................... .............................. 700 725 750 775 800 825 850 875 960 925 950 9]5 vmk� Plant Barry Interim Preload Design Geosyntec° 01_Dike_LongTerm Pr Block Consultants By Zachary Fallert ICi r Geosyntec 2/5/2021 f-0"`D'"` East_LongTerm_Z]F_20210205_rev4.slmd APC Barry_EPA_000939 Scenario: Long Term Sub-Scenario: All Final Grades Search Method: Limits a 5.23 .................. SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS.................. „ o mo zoo aoo a00oo soo 000 goo voket Plant Barry Interim Preload Design Geosyntec° 02_Fnal_LongTerm Pr Limits consultants By Zachary Fallert ICi r Geosyntec 2/5/2021 f-0"`D'"` East_LongTerm_Z]F_20210205_rev4.slmd APC Barry_EPA_000W Scenario: Long Term Sub-Scenario: All Final Grades Search Method: Block a 5.20 I . . . . . . . . . . . . . . . . . . . . . . . ................................ ................... ................................................... 0 100 200 300 400 500 600 700 voket Plant Barry Interim Preload Design Geosyntec° 02_Fnal_LongTerm """"O Block consultants Q'a By Zachary Fallert ICi r Geosyntec 2/5/2021 East_LongTerm_Z]F_20210205_rev4.slmd APC Barry_EPA_000W Geosynte& consultants Page 10 of 183 CP: ZJF Dale: 2123/21 APC: JNP Date: =2121 CA: WT Date: 3M1 Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 West Section GW7193Nonh_FimlGredea_Stability_Nana ive.da x APC Barry_EPA_0009 2 Undrained Material Parameters MMII.l Name Color Unit Weight(Ibs/g31 Strength Type Cohesion(pill) Phi(deg) Cohesion Type Cohesion Mange(psf/ft) Datum(ft) Dimmete Funttipn Water Surface go CCR 92 Mohr-Coulomb 0 36 Piezometric Line Clay 1 C PDCPT-02IUD) 100 Undrained 400 Constant None 0 Clay M PDCPT-02(UD) 96 Undrained 150 FWtum 9 5 None 0 Clay 1 LPDCPT-01(UD) 99 Unnamed 60) Constant None 0 Clay l C Under Dike and Dawnstream(U U) 106 Undrained 600 Contant None 0 Clay l M Upuream(UD) 96 Undrained 150 Frahm 9.96 8.8 None 0 ea Clay l M Under Dike DUD) 101 Discrete function Clay l Under Dike None 0 Clay M Downrtream MIN(UD) 96 Undrained 150 Constant None 0 Clay l M Downstream DUD) 96 Unnamed 150 Frahm 9.96 -8.38 None 0 Clay 1 LUnder Dike and Downrtream(UD) 103 Undrained lox Constant None 0 Sand 1(D) 110 Mohr-Coulomb 0 32 Piezometric Line Clay PDCPT-02(LD) 102 Undrained 550 Constant None 0 Send 120 Mohr-Coulomb 0 38 Piezometric Line a UDike DUD) 114 Unnamed! 16M Constant None 0 L Dike(UD) 109 Undrained 250 Consant None 0 Water 614 No strength None 0 Clay 1 POI(LAD) 96 Discrete function Clay l Prelooded None 0 SM and Fill UD) 115 Undrained 600 Constant None 0 Compacted CCR 92 Mohr-Coulomb 0 36 Piezometric Line Clay M PDCPT-37 UD) 100 Undrained 150 FWtum 10 30 None 0 Clay PDCPT-32(U D) 100 Undrained 600 Comtant None 0 -2500 -2000 -1500 -1000 -500 0 500 vm/nt Plant Barry Interim Stability Geosyntec° 01 Dike_EDC Interim Master Scenario COii3UI[HIl[S &,non By Zachary Fallert any Southern Company Amn C 2/5/2021 muaxama West_EDC_ZIF_20210205_revl.slmd A C Barry_EPA_0009 3 Drained Material Parameters Material Name Color Unit Weight(lbs/ft3) Strength Type Cohesion (psf) Phi(deg) Water Surface Ru v CCR 92 Mohr-Coulomb 0 36 Piezometric Line 2 Clay 1 C PDCPT-02(D) 100 Mohr-Coulomb 75 31 Piezometric Line 2 Clay 1 M PDCPT-02(D) 96 Mohr-Coulomb 75 31 Piezometric Line 2 Clay 1 L PDCPT-02 (D) 99 Mohr-Coulomb 75 31 Piezometric Line 1 Clay 1 C Under Dike and Downstream(D) 106 Mohr-Coulomb 75 31 Piezometric Line 2 Clay 1 M Under Dike(D) 101 Mohr-Coulomb 75 31 Piezometric Line 2 Clay 1 M Downstream(D) 96 Mohr-Coulomb 75 31 Piezometric Line 2 Clay 1 L Under Dike and Downstream(D) 103 Mohr-Coulomb 75 31 Piezometric Line 1 Sand 1 (D) 110 Mohr-Coulomb 0 32 Piezometric Line 1 Clay 2 PDCPT-02(D) 102 Mohr-Coulomb 75 31 Piezometric Line 1 Sand 2 120 Mohr-Coulomb 0 38 Piezometric Line 1 U Dike(D) 114 Mohr-Coulomb 260 29 Piezometric Line 2 L Dike(D) 109 Mohr-Coulomb 260 29 Piezometric Line 2 Water 62.4 No strength None 0 SCB and Fill (D) 115 Mohr-Coulomb 50 27 Piezometric Line 2 Compacted CCR 97 Mohr-Coulomb 0 36 Piezometric Line 2 Clay 1 M PDCPT-37(D) 100 Mohr-Coulomb 75 31 Piezometric Line 2 Clay 2 PDCPT-37(D) 100 Mohr-Coulomb 75 31 1 Piezometric Line 1 -1800 -1600 -1400 -1200 -1000 -800 -600 vmtrt Plant Barry Interim Stability Geosyntec° OS—Dike—LT """- Master Scenario consultants °iaiwi By Zachary Fallert icveyanr Southern Company C 2/5/2021 `"`ND'"` West_LongTerm_DF_20210205_rev1.slmd APC Barry_EPA_000944 Scenario: EoC Sub-Scenario: Existing Dike Only Search Method: Limits 1.35 650 700 750 860 850 960 950 1000 vm/nt Plant Barry Interim Stability Geosyntec° Ol_Dike_EoC Limits consultants &r By Zachary Failed ICi r Southern Company C 2/5/2021 f-0eNa'"` West_EoC_ZIF_20210205_rev1.slmd APC Barry_EPA_000945 Scenario: EoC Sub-Scenario: Existing Dike Only Search Method: Block 1.47 650 760 750 860 850 960 950 1000 vm/nt Plant Barry Interim Stability Geosyntec° 01_Dike_EoC Interim Block consultants °iaiwi By Zachary Failed ICi r Southern Company C 2/5/2021 f-0eNa'"` West_EoC_ZIF_20210205_rev1.slmd APC Barry_EPA_0009 6 Scenario: EoC Sub-Scenario: All Final Grades Search Method: Limits a.az ------------------------------------- KK -1750 -1500 -1250 -1000 -]50 -500 -250 0 250 500 750 vm/crt Plant Barry Interim Stability Geospte& 02_Final_EoC """" Limits Consultants °iaiwi By Zachary Failed ICi r Southern Company C 2/5/2021 f-0eNa ` West_EoC_ZIF_20210205_rev1.slmd APC Barry_EPA_00094] Scenario: EoC 2.66 Sub-Scenario: All Final Grades Search Method: Block o — --- ----------------------------- ------ �xxxxxxxxxxxxxxxx -1750 -1500 -1250 -1000 -750 -500 -250 0 250 560 750 vmµrt Plant Barry Interim Stability Geospte& 02_Final_EoC """" Block Consultants °iaiwi By Zachary Failed ICi r Southern Company C 2/5/2021 f-0eNa'"` West_EoC_ZIF_20210205_revl.slmd APC Barry_EPA_ODOM Surcharged Scenario: EoC - Sub-Scenario: Dike Only Search Method: Limits 3D FS = 1.30 Allowable Width of Surcharge in 3rd Dimension = 350 ft 1.2 121.433 155.306 700. Ibs/ft2 650 760 750 860 850 g00 950 1000 vm/nt Plant Barry Interim Stability Geosynte& Ol_Dike_EoC Limits consultants °iaiwi By Zachary Failed ICyr Southern Company C 2/5/2021 f-0eND'"` West_EoC_surcharged_Z]F_20210205_mvl.slmd APC Barry_EPA_000949 Surcharged Scenario: EoC - Sub-Scenario: Dike Only Search Method: Block 3D FS = 1.30 Allowable Width of Surcharge in 3rd Dimension = 350 ft 1.2 11&078 152,224 700. Ibs/ft2 650 700 750 860 850 960 950 1000 vm/nt Plant Barry Interim Stability Geosyntec° Ol_Dike_EoC Block consultants °iaiwi By Zachary Failed ICyr Southern Company C 2/5/2021 f-0eND ` West_EoC_surcharged_Z]F_20210205_mvl.slmd APC Barry_EPA_000950 Scenario: EoC - Surcharged Sub-Scenario: All Final Grades Search Method: Limits 3.36 -1750 -1500 -1250 -1000 -750 -500 -250 0 250 560 750 1&0 vio�r Geosyntec° 02 Plant Barry Interim Stability _Final_EoC """"O Limits °iaiwi By Zachary Failed ICi r Southern Company C 2/5/2021 f-0eND ` West_EoC_surcharged_Z]F_20210205_mvl.slmd APC Barry_EPA_000951 Scenario: EoC - Surcharged 2.48 Sub-Scenario: All Final Grades Search Method: Block --------------- -1750 -1500 -1250 -1600 -750 -500 -250 0 250 560 750 1000 vio�r Plant Barry Interim Stability Geosyntec° 02_Final_EoC """" Block consultants °iaiwi By Zachary Failed ICi r Southern Company C 2/5/2021 f-0eND'"` West_EoC_surcharged_Z]F_20210205_mvl.slmd APC Barry_EPA_000952 Scenario: Seismic Sub-Scenario: Dike Only I ► 0,02 Search Method: Limits IJI"W, N 1.19 550 Boo 650 760 A0 goo 850 goo 950 logo vm/nt Plant Barry Interim Stability Geosynte& Ol_Dike_EoC "" Limits consultants &r By Zachary Fallert °ins"` Southern Company C 2/5/2021 `N° ` West_Seismic_DF_20210205_rw1.slmd APC Barry_EPA_000953 Scenario: Seismic 1.22 Sub-Scenario: Dike Only 0,02 Search Method: Block N Will O 550 600 650 760 750 900 850 900 950 1000 vm/nt Plant Barry Interim Stability Geosyntec° Ol_Dike_EoC """"O Block consultants °iaiwi By Zachary Fallert ICi r Southern Company C 2/5/2021 `"`N°'"` West_Seismic_DF_20210205_nwlslmd APC Barry_EPA_00095 Scenario: Seismic Sub-Scenario: All Final Grades 002 Search Method: Limits 2.41 --------------------------------- -1750 -1500 -1250 -1000 -750 -500 -250 0 250 500 750 10 voket Plant Barry Interim Stability Geosptec° 02_Final_EoC """" Limits consultants °iaiwi By Zachary Fallert ICi r Southern Company C 2/5/2021 `"`N°'"` West_Seismic_DF_20210205_nwl.slmd APC Barry_EPA_000955 Scenario: Seismic 1.53 Sub-Scenario: All Final Grades 0.02 Search Method: Block 1 � -------_ ____ ______ _ xxxxxxxxxxxxxxxxxxxxxx -1750 -1500 -1250 -1000 -750 -500 -AD 0 250 500 750 10 voket Plant Barry Interim Stability Geosptec° 02_Final_EoC Interim Block coitsultallts °iaiwi By Zachary Fallert ICi r Southern Company C 2/5/2021 `"`N°'"` West_Seismic_DF_20210205_nwlslmd APC Barry_EPA_000956 Scenario: Long Term Sub-Scenario: Dike Only Search Method: Limits 2.34 600 650 700 750 800 850 900 950 vm/nt Plant Barry Interim Stability Geosyntec° Ol_Dike_LT -7 Limits consultants &r By Zachary Fallert ICi r Southern Company C 2/5/2021 `"`ND'"` West_LongTerm_DF_20210205_revl.slmd APC Barry_EPA_000957 Scenario: Long Term Sub-Scenario: Dike Only Search Method: Block 2.32 A 600 650 700 750 860 850 960 950 vm/nt Plant Barry Interim Stability Geosyntec° Ol_Dike_LT """"O Block Consultants °iaiwi By Zachary Fallert ICi r Southern Company C 2/5/2021 `"`ND'"` West_LongTerm_DF_20210205_rev1.slmd APC Barry_EPA_000958 Scenario: Long Term Sub-Scenario: Dike Only Search Method: Block a 6.80 -200 -100 0 100 200 300 400 500 600 vor� Plant Barry Interim Stability Geosyntec° 02_Final_LT """" Limits consultants &r By Zachary Fallert ICry Southern Company C 2/5/2021 `"`ND'"` West_LongTerm_DF_20210205_nwl.slmd APC Barry_EPA_000959 Scenario: Long Term Sub-Scenario: All Final Grades Search Method: Block a 7.01 -200 -100 0 100 200 300 400 500 600 vmµrt Plant Barry Interim Stability Geosyntec° 02_Final_LT " Block consultants °iaiwi By Zachary Fallert ICry Southern Company C 2/5/2021 `"`ND'"` West_LongTerm_DF_20210205_rwlslmd APC Barry_EPA_000960 Geosyntec° consultants Page lm of iss CP: ZJF Dale: 2123/21 APC: JMP Date: =2121 CA: WT Date: 3M1 Client: SCS Project: Plant Barry—North Final Grades Stability Project No: GW7193 ATTACHMENT THREE-DIMENSIONAL CORRECTION CALCULATIONS GW7193Nonh_FimlGredea_Stability_Nana ive.da x APC Barry_EPA_000%1 2/5/20213:23 PM 1/1 R aired 3D Factor ofSafctv,F L3 Maximum Minimum Radius of Shear Surface,Rmm Radius of Shear 2-Dimensional Allowable Length Surface,Rm„ Location Scenario Sub-Scenario Factorof Safety, of Failurein3rd (ft) (it) F° Dimension,2L(R) Fast EoC-Surcharged Limits 131.960 99.167 1.29 2950 Block 132.049 99.116 1.28 1450 West EoC-Surcharged Limits 155.306 121433 1.22 350 Block 152.224 118.078 122 350 Plant Barry Final Grades Stability A.S.Aaou;M.A RB1.0 end C C)add,"C—,e dField Vane S,—,S for Emb.kmrnt Duigi,"Jwmul ojGeateeM1eievl Engineering.-1.109,no.5,pp.930-034,1983. Northern Mobile,AL P pR L"a^d w(- 1/P)amd the d�en�of rvw mhe.e saaEace,DR(- Rom, - 3DCorrectionFactorCalculations F. [1+v.��)1................................ �Po��).�and rte and mldmaar.wn of the GW7193 Authored By: A S.Aauu;'n—Dimensional Ar 1,e of Slopes,"M—husells ln.i..fiabn 1"L C—b,A,,1978. Zachary Follett Checked By: See package Date: sheet Egvatiovased i/(F/F'-1 tiovx Date: Rmin 2L�Rme,Rm;,,)/((F/P°-1 1/26/2021 P Geosyntecc�' DR•Rmaa Rmrn cpnstiltants \\Aro-01\prjl$\Alabama Power\Plant Barry\38_Engineering_Support\02_IFC\04_Final_Grade\Northern\Geotech\FinalGradesStability\FinalGrades_3D_ZIF_20 &rFM?ifUO00982 Current Current Month-CAP Current Month-Last Month Milestone Control CAP Last Month Month Completed? Variance Variance Variance Explanations ENGINEERING Detailed Engineering-30%Design Complete-Geosyntec 30-Apr-18 30-Apr-18 30-Apr-18 30-Apr-18 ✓ 0 0 Civil Sitework Design Package Complete-South Evacuation Bridge 11 29-Jun-18 29-Jun-18 29-Jun-18 29-Jun-18 J 0 0 Detailed Engineering-60%Design Complete-Geosyntec 27-Aug-18 27-Aug-18 27-Aug-18 27-Aug-18 ✓ 0 0 Detailed Engineering-90%Design Complete-Geosyntec 3-Dec-18 3-Dec-18 3-Dec-18 3-Dec-18 ✓ 0 0 Dewatering Mobilization Complete 4-Jan-19 4-Jan-19 4-Jan-19 4-Jan-19 ✓ 0 0 Detailed Engineering Complete 28-Feb-20 30-Apr-20 30-Apr-20 30-Apr-20 ✓ 0 0 PROCUREMENT Commitment of Major Bulk Materials Complete-Closure Turf 30-Apr-29 30-Apr-29 30-Apr-29 30-Apr-29 0 0 Commitment of Major Bulk Materials Complete-HDPE Liner 30-Apr-29 30-Apr-29 30-Apr-29 30-Apr-29 0 0 PERMITTING Permitting Complete 30-Nov-20 18-Jun-21 1-Jul-21 1-Jul-21 ✓ -8 0 CONTRACTING Engineering Contract Awarded-Geosyntec 31-Jan-18 31-Jan-18 31-Jan-18 31-Jan-18 ✓ 0 0 Water Treatment Contract Awarded 13-Apr-18 13-Apr-18 13-Apr-18 13-Apr-18 ✓ 0 0 411 Deep Foundations Contract Awarded-South Evacuation Bridge 11 28-Sep-18 28-Sep-18 28-Sep-18 28-Sep-18 ✓ 0 0 Award LOA#2-Prime Contractor-Trans Ash 31-Mar-20 1-Oct-20 1-Oct-20 1-Oct-20 ✓ 0 0 CONSTRUCTION Deep Foundations Installation Complete-South Evacuation Bridge II Construction Complete 5-Aug-19 5-Aug-19 5-Aug-19 5-Aug-19 ✓ 0 0 Dewatering System in Service 6-Apr-20 30-Apr-20 30-Apr-20 30-Apr-20 ✓ 0 0 Westech-Operate and Maintain Dewatering System-Initial Dewatering Complete 5-Jun-20 19-May-20 19-May-20 19-May-20 ✓ 0 0 Ash Handling Start 28-Jan-20 27-May-20 27-May-20 27-May-20 ✓ 0 0 Trans Ash-Prime Mobilization Complete 30-Jun-20 22-Dec-20 22-Dec-20 22-Dec-20 ✓ 0 0 Westech-Operate and Maintain Dewatering System-Water Management Complete 4-Feb-30 11-Apr-30 11-Apr-30 11-Apr-30 0 0 Ash Handling Complete 27-Sep-30 18-Sep-30 18-Sep-30 18-Sep-30 0 0 Cap&Cover Installation Complete 23-Apr-31 7-Apr-31 7-Apr-31 7-Apr-31 0 0 Substantial Completion 23-Apr-31 7-Apr-31 7-Apr-31 7-Apr-31 0 0 Substantial Completion Late Date (445 Days Contingency) 23-Apr-31 20-Dec-32 20-Dec-32 20-Dec-32 0 0 START UP/ CLOSEOUT Trans Ash-Site Demobilization Complete 16-Sep-31 13-Oct-31 13-Oct-31 13-Oct-31 0 0 Final Completion 6-Jan-32 8-Jan-32 8-Jan-32 8-Jan-32 0 0 Certification Complete 6-Jan-32 8-Jan-32 8-Jan-32 8-Jan-32 0 0 Plant Acceptance 6-Jan-32 8-Jan-32 8-Jan-32 8-Jan-32 0 0 Project Complete 9-Apr-32 29-Apr-32 29-Apr-32 29-Apr-32 0 0 APC Barry_EPA_000963 Project Filename:Barry Ash Pond Closure_SCS_BOP... Barry Ash Pond Closure_$C$_BOP... Page l of2 Data Date:01-Jan-23 Project ID:BAR17013_APC_SCS_BOP... Ran Date: 12-Jan-23 15:48 Activity ID Activity Name Rem Dur Start Finish % Complete 2023 1 2024 2025 2026 2027 2028 2029 2030 1 2031 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 TA-C12-530 Pond Prep Area C12-P12B 4 15-Dec-21 A 13Jan-23 77% TA-Civi127O General Fill Soil Import-CY 1599 21-Mar-22A 22Jan-30 0.14% TA-004-696 Preloading Wait Time-C4A-PL54 Months 37 11-May-22A 23-Feb-23 75% TA-C11300 Pond Prep Area C11 -P12A 21 22-Aug-22 A 10-Mar-23 6% TA-CO4-708 Preloading-C4-P6Afrom P5 11 24-Febr23 17-Mar-23 0% ■ TA-C8-105 Preloading-C8-PL613 from P5 28 17-Mar-23 01-May-23 0% ■ ', TA-C8-110 Preloading Wait Time-C8-PLEB 4 Months 83 01-May-23 28-Aug-23 0% TA-MI35 CCR Excavation-C8 PL6B to Elev. 8' 43 28-Aug-23 30-Oct-23 0% IN TA-C8-140 CCR Excavation-C8 P7A to Elev. 8' 43 30-Oc1-23 18Jan-24 0% GEOSYNTEC2110 Geo E7A IFC Design(Excavation/Backfilling) 30 06-Nov-23" 19-Dec-23 0% ■' GEOSYNTEC2180 Geo US IFC Design Excavation/Backfillin 30 O6-Nov-23' 19-Dec-23 0% ' ��', I ' TA-C8-210 CCR Excavation-C8 Remaining to Elev. 8' 85 18Jan-24 14Jun-24 0% TA-C13-10 CCR Excavation-C13 75 14Jun-24 01-Oct-24 0% TA-C9-250 CCR Excavation-C9 P7B to Elev 8' 18 01-Oct-24 25-Oct-24 0% ■ TA-C9-270 CCR Excavation-C9 P8 to Elev 8' 62 25-Oct-24 12-Mar-25 0% �! TA-C9-320 CCR Excavation-C09 Remaining to Elev. 8' 120 12-Mar-25 05-Sep-25 0% ism" TA3920 009-CCR Excavation Elev 9 to Bottom 304 05-Sep-25 11-Nov-26 0% TA-C14-200 CCR Excavation-C14 91 11-Nov-26 12-May-27 0% TA-015-300 CCR Excavation-C15 209 12-May-27 24-Apr-28 0% TA-C10-845 CCR Excavation-C10 Remaining to Elev. 8' 166 24-Apr-28 02Jan-29 0% Elpill"" ti TA-C9-385 CCR Excavation-C9 P9A to Elev. 8 15 02Jan-29 23Jan-29 0% TA-C10-840 CCR Excavation-C10 P913 to Elev. 8' 45 23Jan-29 27-Mar-29 0% TA-C10-850 CCR Excavation -C10 P10 to Elev. 8' 267 27-Mar-29 11-Apr-30 0% TA-C10-800 C10-Structural Fill Containment Bem1 #1 - Inside 0 22Jan-30 22Jan-30 0% q q qI TA-C10-810 C10-CCR Wedge Backfill 0 22Jan-30 22Jan-30 0% I TA-C10-815 C10 Internal Drainage Collection-Structural Fill 0 22Jan 30 22Jan-30 0% q q q ' ' I TA-010-616 CIO Internal Drainage Collection-Aggregate 0 22Jan30 22Jan30 0% I TA-C10-820 C-10 Closure Turf 0 22Jan30 22Jan30 0% .I TA-C10-825 C10-Anchor-Trench 0 22Jan30 22Jan30 0% :I TA-C10-975 C-10 50 Mil Geomembrane 0 22Jan30 22Jan30 0% I TA-010-830 G10 Sand Infill 0 29Jan30 29Jan30 0% . - -- TA-C10-855 C-10 Downchute Rip Rap Placement-CY 0 29Jan30 29Jan30 0% TA-C10-865 C-10 Geocomposite Placement for Downchute 0 29Jan30 29Jan30 0% TA-C10-870 C-10 Geotextile Placement for Bench/IDC 0 29Jan30 29Jan30 00% TA-C10-875 C-10 Geocomposile Placement Buttress -Pilot Channel 0 29Jan30 2"an-30 0% TA-F13-1320 F13 Geocomposite Placement for Downchute-SY 17 29Jan30 22-Feb-30 0% ', ', ', ', : ■ ', TA-F14-1415 F14 Geocomposile Placement for Downchute 30 22-Feb30 05-Apr30 0% Remaining LOE Remaining Work ♦ ♦ Critical Milestone Actual LOE Critical Remaining Work Barry Ash Pond Critical Path Southern Company Actual Work ♦ ♦ Milestone APC Barry_EPA_00 Project Filename:Barry Ash Pond Closure_SCS_BOP... Barry Ash Pond Closure_$C$_BOP... Page 2 of2 Data Date:01-Jan-23 Project ID:BAR17013_APC_SCS_BOP... Ran Date: 12-Jan-23 15:48 Activity ID ActKuy Name Rem Dur Start Finish Complete 2023 1 2024 1 2025 1 2026 1 2027 1 2028 1 2029 1 2030 1 2031 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q4 Q1 Q2 Q3 Q KPM-6.5 Ash Handling Complete 0 11-Apr-30 0% KPM-6.6 Westech-Operate and Maintain Dewatering System-N 0 11-Apr-30 0% » KPM-6.7 Cap& Cover Installation Complete 0 11-Apr-30 0% KPM-6.8 Substantial Completion 0 11-Apr-30 0% • KPM-6.8.1 Substantial Completion Late Dale (445 Days Conlingen 445 11-Apr-30 25-Dec-31 0% TA-MTH-1675 2031 Complete Management 0 30-Sep-31" 0% APC Barry_EPA_000965