Annual Groundwater Monitoring Report

Transcription

1 Annual Groundwater Monitoring Report Southwestern Electric Power Company John W. Turk Power Plant Landfill CCR Management Unit Fulton, Arkansas January 218 Prepared by: American Electric Power Service Corporation 1 Riverside Plaza Columbus, Ohio 43215

2 Page Table of Contents I. Overview... 1 II. Groundwater Monitoring Well Locations and Identification Numbers... 3 III. Monitoring Wells Installed or Decommissioned... 4 IV. Groundwater Quality Data and Static Water Elevation Data, With Flow Rate and Direction and Discussion... 4 V. Discussion About Transition Between Monitoring Requirements or Alternate Monitoring Frequency... 4 VI. Statistical Evaluation of Previous Year s Events... 4 VII. Other Information Required... 4 VIII. Description of Any Problems Encountered in 217 and Actions Taken... 5 IX. A Projection of Key Activities for the Upcoming Year... 5 Appendix I Appendix II i

3 I. Overview This Annual Groundwater Monitoring Report (Report) has been prepared to report the status of activities for the preceding year for an existing CCR unit at Southwestern Electric Power Company s, a wholly-owned subsidiary of American Electric Power Company (AEP), Turk Power Plant. The USEPA s CCR rules require that the Annual Groundwater Monitoring Report be posted to the operating record for the preceding year no later than January 31, 218. In general, the following activities were completed: Monitoring wells were installed and developed to establish a certified groundwater monitoring system around each CCR unit, in accordance with the requirements of 4 CFR pursuant AEP s Groundwater Monitoring Network Design Report (3/9/217); Groundwater samples were collected and analyzed for Appendix III and Appendix IV constituents, as specified in 4 CFR et seq. and AEP s Groundwater Sampling and Analysis Plan (216); Groundwater data underwent various validation tests, including tests for completeness, valid values, transcription errors, and consistent units; Background groundwater quality data was collected for each Appendix III and Appendix IV constituent; Detection Monitoring sampling was initiated; A statistical process in accordance with 4 CFR to evaluate groundwater data was prepared, certified, and posted to AEP s CCR website in April 217. AEP s Statistical Analysis Plan (AEP 217). The statistical process was guided by USEPA s Statistical Analysis of Groundwater Monitoring Data at RCRA Facilities, Unified Guidance ( Unified Guidance, USEPA, 29). Data evaluation is complete for the second half 217 sample. No statistically significant increases were determined. The major components of this annual report, to the extent applicable at this time, are presented in sections that follow: A map, aerial photograph or a drawing showing the CCR management unit(s), all groundwater monitoring wells and monitoring well identification numbers; Identification of any monitoring wells that were installed or decommissioned during the preceding year, along with a statement as to why that happened; All of the monitoring data collected, including the rate and direction of groundwater flow, plus a summary showing the number of samples collected per monitoring well, the dates the samples were collected and whether the sample was collected as part of detection monitoring or assessment monitoring programs is included in Appendix I; 1

4 A summary of any transition between monitoring programs or an alternate monitoring frequency, for example the date and circumstances for transitioning from detection monitoring to assessment monitoring, in addition to identifying the constituents detected at a statistically significant increase over background concentrations is included in Appendix II; Other information required to be included in the annual report such as alternate source demonstration or assessment of corrective measures, if applicable. In addition, this report summarizes key actions completed, and where applicable, describes any problems encountered and actions taken to resolve those problems. The report includes a projection of key activities for the upcoming year. 2

5 II. Groundwater Monitoring Well Locations and Identification Numbers The figure that follows depicts the PE-certified groundwater monitoring network, the monitoring well locations and their corresponding identification numbers. Landfill Monitoring Wells Up Gradient Down Gradient MW-1 MW-1 3

6 III. Monitoring Wells Installed or Decommissioned There were no monitoring wells installed or decommissioned in 217. The network design, as summarized in the Groundwater Monitoring Network Design Report (3/9/217) and as posted at the CCR web site for Turk Power Plant, did not change. That design report, viewable on the AEP CCR web site, discusses the facility location, the hydrogeological setting, the hydrostratigraphic units, the uppermost aquifer, downgradient monitoring well locations and the upgradient monitoring well locations. IV. Groundwater Quality Data and Static Water Elevation Data, With Flow Rate and Direction and Discussion Appendix I contains tables showing the groundwater quality data collected during the establishment of background quality. Static water elevation data from each monitoring event also are shown in Appendix I, along with the groundwater velocity, groundwater flow direction and potentiometric maps developed after each sampling event. V. Discussion About Transition Between Monitoring Requirements or Alternate Monitoring Frequency As of this first annual groundwater report date there has been no transition between detection monitoring and assessment monitoring. Detection monitoring will continue in 218. The sampling frequency of twice per year will be maintained for the Appendix III parameters (boron, calcium, chloride, fluoride, ph, sulfate and total dissolved solids). Regarding defining an alternate monitoring frequency, the groundwater velocity and monitoring well production is high enough at this facility that no modification of the twice-per-year detection monitoring effort is needed. VI. Statistical Evaluation of Previous Year s Events The statistical analysis report is included in Appendix II. The CCR unit is in detection monitoring. No statistically significant increases were determined. VII. Other Information Required The landfill is permitted in the state of Arkansas as a Class 3 industrial waste landfill. The landfill began receiving waste on November 2, 212. At the appropriate time the geochemical analyses, coupled with the statistical analyses of the groundwater quality data, will determine whether an alternate source or alternate sources are affecting groundwater chemistry. In those cases where an alternate source demonstration is made, those analyses and supporting information will be presented as well. 4

7 VIII. Description of Any Problems Encountered in 217 and Actions Taken No significant problems were encountered. The low flow sampling effort went smoothly and the schedule was met to support this first annual groundwater report preparation. IX. A Projection of Key Activities for the Upcoming Year Key activities for 218 include: Detection monitoring on a twice per year schedule; Evaluation of detection monitoring results from a statistical analysis viewpoint, looking for any statistically significant increases, or decreases when ph is considered; Responding to any new data received in light of what the CCR rule requires; Preparation of the second annual groundwater report. 5

8 APPENDIX I Tables follow, showing the groundwater monitoring data collected, the rate and direction of groundwater flow, and a summary showing the number of samples collected per monitoring well. The dates that the samples were collected also is shown.

9 Table 1: Groundwater Data Summary Turk Plant - Landfill MW-1 Parameter Unit 6/1/216 7/25/216 9/1/216 11/2/216 12/15/216 2/1/217 2/21/217 5/2/217 6/29/217 7/19/217 8/1/217 Background Detection Antimony <.93 U <.93 U.146 J.35 J.951 J <.93 U <.93 U <.93 U <.93 U <.93 U - Arsenic <.15 U <.15 U <.15 U <.15 U <.15 U <.15 U <.15 U <.15 U <.15 U <.15 U - Barium Beryllium.89 J.16 J.166 J <.2 U <.2 U <.2 U <.2 U <.2 U <.2 U <.2 U - Boron Cadmium <.7 U <.7 U.811 J <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U - Calcium Chloride Chromium J.9 J <.23 U <.23 U <.23 U <.23 U <.23 U.24 J - Cobalt.19 J.125 J.951 J.11 J.65 J.688 J.564 J.57 J.33 J.78 J - Combined Radium pci/l Fluoride J J J Lead.116 J <.68 U <.68 U <.68 U <.68 U <.68 U <.68 U.74 J <.68 U.71 J - Lithium Mercury.199 J.18 J.1 J <.5 U <.5 U.122 J.711 J <.5 U <.5 U <.5 U - Molybdenum.254 J.31 J.413 J.157 J.158 J.143 J.172 J.215 J.168 J.182 J - Selenium.29 J.31 J.388 J.333 J <.99 U <.99 U.252 J.343 J <.99 U <.99 U - Total Dissolved Solids Sulfate Thallium.124 J <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U - ph SU Notes: : milligrams per liter pci/l: picocuries per liter SU: standard unit U: Non-detect value. Parameters which were not detected are shown as less than the method detection limit (MDL). J: Estimated value. Parameter was detected in concentrations below the reporting limit. -: Not sampled For statistical analysis, parameters which were not detected were replaced with the reporting limit. Page 1 of 6

10 Table 1: Groundwater Data Summary Turk Plant - Landfill Parameter Unit 6/1/216 7/25/216 9/1/216 11/2/216 12/15/216 2/1/217 2/21/217 5/2/217 6/29/217 7/19/217 8/1/217 Background Detection Antimony <.93 U <.93 U J.173 J <.93 U <.93 U.146 J <.93 U <.93 U - Arsenic.176 J.139 J <.15 U <.15 U <.15 U <.15 U <.15 U.137 J <.15 U <.15 U - Barium Beryllium.123 J.131 J.142 J.819 J <.2 U <.2 U <.2 U <.2 U <.2 U.2 J - Boron Cadmium <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U - Calcium Chloride Chromium J.3.3 <.23 U <.23 U <.23 U <.23 U <.23 U.76 J - Cobalt.94 J.121 J.113 J.154 J.356 J.218 J.233 J.32 J.58 J.71 J - Combined Radium pci/l Fluoride.56 J.478 J.481 J.493 J.523 J.59 J <.83 U.52 J.443 J.469 J.451 J Lead.22 J <.68 U.123 J.127 J <.68 U <.68 U <.68 U <.68 U <.68 U.114 J - Lithium Mercury.115 J.71 J.138 J.947 J <.5 U <.5 U <.5 U <.5 U <.5 U.5 J - Molybdenum.283 J.469 J J.292 J.263 J.18 J.87 J.118 J - Selenium.115 J <.99 U.392 J.145 J.168 J <.99 U <.99 U.132 J <.99 U <.99 U - Total Dissolved Solids Sulfate Thallium <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U - ph SU Notes: : milligrams per liter pci/l: picocuries per liter SU: standard unit U: Non-detect value. Parameters which were not detected are shown as less than the method detection limit (MDL). J: Estimated value. Parameter was detected in concentrations below the reporting limit. -: Not sampled For statistical analysis, parameters which were not detected were replaced with the reporting limit. Page 2 of 6

11 Table 1: Groundwater Data Summary Turk Plant - Landfill Parameter Unit 6/1/216 7/25/216 9/1/216 11/2/216 12/15/216 2/1/217 2/21/217 5/2/217 6/29/217 7/19/217 8/1/217 Background Detection Antimony <.93 U <.93 U.19 J.191 J.137 J.139 J.176 J <.93 U <.93 U <.93 U - Arsenic <.15 U <.15 U <.15 U.232 J.184 J <.15 U <.15 U.237 J <.15 U <.15 U - Barium Beryllium.194 J.138 J.186 J.958 J.262 J.158 J.239 J.1 J.13 J.15 J - Boron Cadmium <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U - Calcium Chloride Chromium J.955 J.571 J.471 J.97 J.4.31 J J - Cobalt.665 J.786 J.84 J.134 J.396 J.762 J.121 J.35 J.89 J.72 J - Combined Radium pci/l Fluoride.393 J.44 J.429 J.585 J.65 J <.83 U <.83 U.37 J.348 J <.83 U.438 J Lead.94 J <.68 U <.68 U.152 J <.68 U <.68 U.219 J <.68 U.112 J <.68 U - Lithium Mercury.151 J <.5 U <.5 U <.5 U <.5 U.71 J.692 J <.5 U <.5 U <.5 U - Molybdenum.949 J.117 J.114 J.169 J.39 J.13 J.551 J <.29 U <.29 U <.29 U - Selenium <.99 U <.99 U.126 J <.99 U <.99 U <.99 U <.99 U <.99 U <.99 U <.99 U - Total Dissolved Solids Sulfate Thallium <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U.919 J <.86 U <.86 U <.86 U - ph SU Notes: : milligrams per liter pci/l: picocuries per liter SU: standard unit U: Non-detect value. Parameters which were not detected are shown as less than the method detection limit (MDL). J: Estimated value. Parameter was detected in concentrations below the reporting limit. -: Not sampled For statistical analysis, parameters which were not detected were replaced with the reporting limit. Page 3 of 6

12 Table 1: Groundwater Data Summary Turk Plant - Landfill Parameter Unit 6/1/216 7/25/216 9/1/216 11/2/216 12/15/216 2/1/217 2/21/217 5/2/217 6/29/217 7/19/217 8/1/217 Background Detection Antimony <.93 U <.93 U.144 J.265 J <.93 U.115 J.987 J.226 J <.93 U <.93 U - Arsenic.184 J <.15 U.176 J.141 J.22 J <.15 U <.15 U <.15 U <.15 U.244 J - Barium Beryllium.237 J.454 J.57 J.976 J.335 J <.2 U.171 J.3 J.5 J.7 J - Boron Cadmium <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U - Calcium Chloride Chromium J.266 J.9.33 J Cobalt.335 J J.944 J.772 J.418 J.12 J.164 J.164 J - Combined Radium pci/l Fluoride.62 J <.83 U.561 J.374 J.4 J <.83 U <.83 U.44 J.461 J <.83 U.512 J Lead.147 J.482 J J <.68 U <.68 U.277 J <.68 U <.68 U.134 J - Lithium Mercury.163 J.192 J.28 <.5 U <.5 U.591 J.148 J.6 J <.5 U.13 J - Molybdenum.299 J.139 J.39 J.18 J.377 J.343 J.253 J.141 J.265 J.36 J - Selenium J <.99 U J <.99 U.118 J - Total Dissolved Solids Sulfate Thallium <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U - ph SU Notes: : milligrams per liter pci/l: picocuries per liter SU: standard unit U: Non-detect value. Parameters which were not detected are shown as less than the method detection limit (MDL). J: Estimated value. Parameter was detected in concentrations below the reporting limit. -: Not sampled For statistical analysis, parameters which were not detected were replaced with the reporting limit. Page 4 of 6

13 Table 1: Groundwater Data Summary Turk Plant - Landfill Parameter Unit 6/1/216 7/25/216 9/1/216 11/2/216 12/15/216 2/1/217 2/21/217 5/2/217 6/29/217 7/19/217 8/1/217 Background Detection Antimony <.93 U.42 J.949 J <.93 U <.93 U <.93 U <.93 U.12 J <.93 U <.93 U - Arsenic <.15 U <.15 U <.15 U <.15 U <.15 U <.15 U <.15 U <.15 U <.15 U <.15 U - Barium Beryllium.62 J.165 J.141 J <.2 U <.2 U <.2 U <.2 U <.2 U <.2 U <.2 U - Boron Cadmium <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U - Calcium Chloride Chromium.663 J.2.56 J.372 J.559 J.862 J.1.42 J <.23 U.46 J - Cobalt.611 J.138 J.97 J.683 J.495 J.547 J.734 J.6 J.68 J.81 J - Combined Radium pci/l Fluoride.487 J.494 J.48 J.52 J.294 J.722 J <.83 U.54 J <.83 U <.83 U <.83 U Lead <.68 U.136 J <.68 U <.68 U <.68 U <.68 U <.68 U <.68 U <.68 U.95 J - Lithium Mercury.212 J.123 J.14 J <.5 U <.5 U.15 J.912 J.16 J.11 J.26 - Molybdenum.145 J.413 J.331 J.761 J <.29 U.862 J.957 J.111 J.22 J.97 J - Selenium.23 J.8.16 J.157 J <.99 U <.99 U <.99 U <.99 U <.99 U <.99 U - Total Dissolved Solids Sulfate Thallium <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U - ph SU Notes: : milligrams per liter pci/l: picocuries per liter SU: standard unit U: Non-detect value. Parameters which were not detected are shown as less than the method detection limit (MDL). J: Estimated value. Parameter was detected in concentrations below the reporting limit. -: Not sampled For statistical analysis, parameters which were not detected were replaced with the reporting limit. Page 5 of 6

14 Table 1: Groundwater Data Summary Turk Plant - Landfill MW-1 Parameter Unit 6/1/216 7/25/216 9/1/216 11/2/216 12/15/216 2/1/217 2/21/217 5/2/217 6/29/217 7/19/217 8/1/217 Background Detection Antimony <.93 U <.93 U <.93 U.18 J <.93 U <.93 U <.93 U <.93 U <.93 U <.93 U - Arsenic <.15 U <.15 U <.15 U <.15 U <.15 U <.15 U <.15 U <.15 U <.15 U <.15 U - Barium Beryllium.421 J.79 J.6 J <.2 U <.2 U <.2 U <.2 U <.2 U <.2 U <.2 U - Boron Cadmium <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U <.7 U - Calcium Chloride Chromium J J Cobalt.69 J.89 J.877 J.996 J.642 J.671 J.951 J.74 J.61 J.77 J - Combined Radium pci/l Fluoride.526 J.462 J.516 J.373 J.342 J 1.25 <.83 U.52 J J Lead <.68 U <.68 U <.68 U.773 J <.68 U <.68 U.871 J <.68 U.83 J.11 J - Lithium Mercury.193 J.766 J.756 J <.5 U <.5 U.911 J.135 J <.5 U <.5 U.7 J - Molybdenum.88 J.139 J.118 J.13 J.73 J.775 J.26 J.59 J.59 J.87 J - Selenium.128 J.17 J <.99 U <.99 U <.99 U <.99 U <.99 U <.99 U <.99 U <.99 U - Total Dissolved Solids Sulfate Thallium <.86 U.913 J <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U <.86 U - ph SU Notes: : milligrams per liter pci/l: picocuries per liter SU: standard unit U: Non-detect value. Parameters which were not detected are shown as less than the method detection limit (MDL). J: Estimated value. Parameter was detected in concentrations below the reporting limit. -: Not sampled For statistical analysis, parameters which were not detected were replaced with the reporting limit. Page 6 of 6

15 Turk landfill MW monitoring wells Distance between wells. MW-9D is in a different aquifer and will not be used for groundwater seepage rates. MW1 MW2 MW3 MW4 MW5 MW6 MW7 MW8 MW-9D MW1 MW11 MW MW MW MW MW MW MW MW MW-9D MW MW11 - MW-1 MW-6 MW-7 MW-8 MW-9D MW-1 MW-11 Total depth of well, TOC Depth to water in feet, TOC Date 9/2/ Dry 5.1 Dry 12/3/ /28/ /17/ /8/ /7/ /28/ /2/ /6/ /4/ /1/ /5/ /5/ /5/ /3/ /5/ /19/ /18/ /23/ /26/ /1/ /25/ /1/ /2/ /15/ /1/ /21/ /2/ /29/ /19/ /1/

16 v (dh / dl) = k n ft cm (dh / dl) 1in 1ft 6 sec* 6 min* 876hr yr sec cm 12in min* hr * yr 5 v = 6.47e * * * * Hydraulic gradient. Use row 62 8/1/217 Gradient seepage rate (ft/ft) (ft/yr) MW1 MW2 MW3 MW4 MW5 MW6 MW7 MW8 MW1 MW11 Max gradient MW MW MW mean gradient MW MW MW median gradient MW MW MW-9D Min gradient MW MW11 - Turk landfill MW monitoring wells MW-1 MW-6 MW-7 MW-8 MW-9D MW-1 MW-11 Top of casing elevation, ft (ft/yr) Potentiometric surface, feet NAVD88 (dh/dl) seepage rate Date gradient max 9/2/ < < /3/ /28/ /17/ /8/ /7/ /28/ /2/ /6/ /4/ /1/ /5/ /5/ /5/ /3/ /5/ /19/ /18/ /23/ /26/ /1/ /25/ /1/ /2/ /15/ /1/ /21/ /2/ /29/ /19/ /1/

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28 APPENDIX II The statistical analysis report is presented in the appendix.

29 Purpose of Statistical Analysis Summary Report During the initial phase of ground water monitoring, the CCR rule requires AEP to collect at least eight independent samples from at least one up-gradient and three downgradient wells for 21 substances listed in the CCR rule. The CCR rule also requires us to select a statistical method that will be used to evaluate the samples in the later phases of the ground water monitoring program. The Statistical Plan, which has been posted to AEP s CCR website, describes the methods selected by AEP. See AEP s Statistical Analysis Plans. Each Statistical Analysis Summary Report is based on the results of the 8 independent samples that were collected by October 17, 217, and reported in the Annual Groundwater Monitoring Report. Using the statistical methods chosen by AEP, the samples were evaluated to eliminate outliers, determine variability and general trends in the data, and establish background values for: boron, calcium chloride, fluoride, ph, sulfate, and total dissolved solids. Appendix IV substances were evaluated for purposes of identifying outliers and understanding data trends. A subsequent sample taken during the first detection monitoring sampling event was also compared using the proper statistical methods to the background values that were established for these seven substances from the eight independent samples. A second or third re-sampling event occurred, and the results compared using the same methods. This work is reported in the memorandum included in attachment A. If confirmed, AEP will be required to enter the next phase of monitoring. The results of future sampling will be further analyzed to target any specific substances for which ongoing monitoring or potential corrective action is required.

30 STATISTICAL ANALYSIS SUMMARY LANDFILL John W. Turk, Jr. Power Plant Fulton, Arkansas Submitted to 1 Riverside Plaza Columbus, Ohio Submitted by 15 East Wilson Bridge Road Suite 232 Worthington, Ohio 4385 December 27, 217 CHA8423

31 Statistical Analysis December 27, 217 TABLE OF CONTENTS SECTION 1 Executive Summary... ES-1 SECTION 2 Landfill Evaluation Data Validation & QA/QC Statistical Analysis Background Outlier Evaluation Establishment of Background Levels Detection Monitoring Certification by Qualified Professional Engineer Conclusions SECTION 3 References CHA Turk LF Report i

32 Statistical Analysis December 27, 217 LIST OF TABLES Table 1 Table 2 Table 3 Table 4 Table 5 Background Sampling Summary Groundwater Data Summary Historical Groundwater Data Summary Outlier Analysis Summary Detection Monitoring Data Evaluation LIST OF ATTACHMENTS Attachment A Attachment B Evaluation of Detection Monitoring Data Statistical Analysis Output 217 CHA Turk LF Report ii

33 Statistical Analysis December 27, 217 LIST OF ACRONYMS AND ABBREVIATIONS AEP ANOVA CCR CCV CFR EPA LFB LPL LRB NELAP PQL QA QC SSI SWFPR TDS UPL USEPA American Electric Power Analysis of Variance Coal Combustion Residuals Continuing Calibration Value Code of Federal Regulations Environmental Protection Agency Laboratory Fortified Blanks Lower Prediction Limit Laboratory Reagent Blanks National Environmental Laboratory Accreditation Program Practical Quantitation Limit Quality Assurance Quality Control Statistically Significant Increase Site-Wide False-Positive Rate Total Dissolved Solids Upper Prediction Limit United States Environmental Protection Agency 217 CHA Turk LF Report iii

34 Statistical Analysis December 27, 217 SECTION 1 EXECUTIVE SUMMARY In accordance with the United States Environmental Protection Agency s (USEPA s) regulations regarding the disposal of coal combustion residuals (CCR) in landfills and surface impoundments (4 CFR , CCR rule ), groundwater monitoring has been conducted at an active CCR Landfill at the John W. Turk, Jr. Power Plant located in Fulton, Arkansas. Ten monitoring events were completed prior to October 17, 217 to establish background concentrations for Appendix III and Appendix IV parameters under the CCR rule. Groundwater data underwent several validation tests, including those for completeness, sample tracking accuracy, transcription errors, and consistent use of measurement units. No data quality issues were identified which would impact the usability of the data. The monitoring data were submitted to Groundwater Stats Consulting, LLC for statistical analysis. Additional data, including data collected prior to the start of operations at the Turk Power Plant and placement of CCR at the Turk Landfill, were also included in the statistical analysis. The background data were reviewed for outliers, which were removed (when appropriate) prior to calculating upper prediction limits (UPLs) for each Appendix III parameter to represent background values. Oversight on the use of statistical calculations was provided by Dr. Kirk Cameron of MacStat Consulting, Ltd. The first detection monitoring event was completed on August 1, 217. The results of detection monitoring were compared to the corresponding UPLs for all Appendix III parameters. No UPL exceedances were observed. Therefore, no statistically significant increases (SSIs) over background were identified, and the groundwater monitoring program for the Turk Landfill CCR unit will remain in a detection monitoring regime. 217 CHA Turk LF Report ES-1

35 Statistical Analysis December 27, 217 SECTION 2 LANDFILL EVALUATION 2.1 Data Validation & QA/QC During the background monitoring program, ten sets of samples were collected for analysis from each upgradient and compliance well. A summary of data collected during background sampling may be found in Table 1. Chemical analysis was completed by an analytical laboratory certified by the National Environmental Laboratory Accreditation Program (NELAP). Quality assurance and quality control (QA/QC) samples completed by the analytical laboratory included the use of laboratory reagent blanks (LRBs), continuing calibration verification (CCV) samples, and laboratory fortified blanks (LFBs). The analytical data were imported into a Microsoft Access database, where checks were completed to assess the accuracy of sample location identification and analyte identification. Where necessary, unit conversions were applied to standardize reported units across all sampling events. Exported data files were created for use with the Sanitas v statistics software. The export was checked against the analytical data for transcription errors and completeness. No QA/QC issues were noted which would impact data usability. 2.2 Statistical Analysis The background data used to conduct the statistical analyses are summarized in Table 2. Additional data were collected prior to background monitoring for the CCR Rule at the Turk Landfill. Portions of these data were collected prior to the start of operations at the Turk Plant in December 212 and prior to the placement of CCR at the Turk Landfill. The sampling and analysis procedures used to collect these data met the requirements of 4 CFR , including the requirement to conduct analyses for total recoverable metals. The historical data collected for boron, chloride, fluoride, ph, sulfate, and total dissolved solids (TDS) were also included in the statistical evaluation described below. (Calcium data were not collected during this period.) Historical data are summarized in Table 3. Statistical analyses for the landfill were conducted in accordance with the January 217 Statistical Analysis Plan (AEP, 217), except where noted below. Results for all completed statistical tests are provided in Attachment A. Time series plots of Appendix III and IV parameters are included in Attachment A. Mann-Kendall analyses (α =.1) were conducted to evaluate trends in the background data. The following statistically significant trends were observed: 217 CHA Turk LF Report 2-1

36 Statistical Analysis December 27, 217 Barium was found to be significantly decreasing at upgradient well MW-1. Boron was found to be significantly decreasing at upgradient well MW-1 and at compliance wells,,,, and MW-1. Chloride was found to be significantly decreasing at upgradient well MW-1 and at compliance wells,,,, and MW-1. Fluoride was found to be significantly increasing at upgradient well MW-1 and at compliance wells,,, and MW-1. Lithium was found to be significantly decreasing at upgradient well MW-1. ph was found to be significantly increasing at compliance wells and. Sulfate was found to be significantly decreasing at upgradient well MW-1 and at compliance wells,,,, and MW-1. TDS was found to be significantly decreasing at upgradient well MW-1 and at compliance wells,,, and MW-1. No other significant increasing or decreasing trends were observed for other parameters or at other monitoring wells. Where the magnitude of the trend was low relative to absolute concentrations, the background value was calculated as if no trend were present; i.e., the dataset was not limited to more recent data nor was the prediction interval constructed around a trendline. However, some datasets were truncated based on significant trends. The background dataset for fluoride at MW-1 excluded the most recent result (collected in July 217), which was higher than the other historical results. The datasets for chloride at and, sulfate at and, and TDS at were limited to more recent data due to the significant decreasing trends observed. Limiting these datasets resulted in the generation of more conservative (i.e., lower) background values. The timeframes of data used for the statistical evaluation are included in Appendix A Background Outlier Evaluation Potential outliers were identified using Tukey s outlier test. Accordingly, data points were considered potential outliers if they met one of the following criteria: x i < x.25 3 IQR (1) or x i > x.75 3 IQR (2) 217 CHA Turk LF Report 2-2

37 Statistical Analysis December 27, 217 where: x i = x.25 = x.75 = IQR = individual data point first quartile third quartile the interquartile range = x.75 x.25 Data that were evaluated as potential outliers are summarized in Attachment A. Tukey s outlier test indicated one potential outliers, which are summarized in Table 4. Next, the data were reviewed to identify possible sources of errors or discrepancies, including data recording errors, unusual sampling conditions, laboratory quality indicators, or inconsistent sample turbidity. Based on the data review described above, the reported sulfate value of 2,3 for the November 5, 211 sample collected at compliance well was identified as a potential outlier. This value was removed from the dataset as an outlier as recommended by USEPA s Unified Guidance (USEPA, 29), resulting in the generation of more conservative (i.e., lower) calculated background values Establishment of Background Levels Since the historical dataset includes data collected prior to the placement of CCR at the Turk Landfill, analysis of variance (ANOVA) was conducted on the historical data to determine whether spatial variation was present among upgradient and compliance wells. ANOVA indicated no significant variation among the monitoring wells for ph. Significant variation was observed for boron, chloride, fluoride, sulfate, and TDS. (ANOVA was not conducted for calcium since calcium data were not collected prior to background monitoring for the CCR Rule.) Further analyses were conducted to evaluate the appropriateness of using intrawell tests at the Turk Landfill. Intrawell tests presume that the groundwater quality in the compliance wells was not initially impacted by the CCR unit. To test this presumption, data from each compliance well were compared to a background value based on data collected from upgradient well MW-1, specifically a parametric upper (and, in the case of ph, lower) tolerance limit with 99% confidence and 95% coverage. Confidence intervals were calculated for each Appendix III parameter at each compliance monitoring well. If the lower confidence limit from a compliance well exceeded the upper tolerance limit for the background data, it was concluded that groundwater concentrations at compliance wells were above background concentrations. However, the analyses indicated no significant exceedances for boron, calcium, fluoride, ph, sulfate, and total dissolved solids (TDS). Chloride concentrations were significantly higher at compliance well relative to upgradient well MW-1. However, the historical data and the ANOVA result described above indicated that chloride concentrations at were elevated prior to placement of CCR at the Landfill. If an interwell test was selected for chloride, SSIs would likely be observed at and would likely be attributable to natural spatial variation instead of a release from the CCR unit. Given the spatial 217 CHA Turk LF Report 2-3

38 Statistical Analysis December 27, 217 variability observed and the availability of data that were collected prior to placement of CCR at the Landfill, intrawell tests were used for all Appendix III parameters at the Turk Landfill. After identified outliers were removed (where appropriate), a parametric or non-parametric analysis was selected based on the distribution of the data and the frequency of non-detect data. Estimated results less than the practical quantitation limit (PQL) i.e., J-flagged data were considered detections and the estimated results were used in the statistical analyses. Nonparametric analyses were selected for datasets with at least 5% non-detect data or datasets that could not be normalized. Parametric analyses were selected for datasets (either transformed or untransformed) that passed the Shapiro-Wilk / Shapiro-Francía test for normality. The Kaplan- Meier non-detect adjustment was applied to datasets with between 15% and 5% non-detect data. For datasets with fewer than 15% non-detect data, non-detect data were replaced with one half of the PQL. The selected analysis (i.e., parametric or non-parametric) and transformation (where applicable) for each background dataset are shown in Attachment A. Upper prediction limits (UPLs) were calculated for each Appendix III parameter to represent background values. A lower prediction limit (LPL) was also calculated for ph. To conduct the intrawell tests, a separate UPL was calculated for each compliance well for each Appendix III parameter. The background data used for the UPL calculations are summarized in Tables 2 and 3. UPLs were calculated for a one-of-two retesting procedure; i.e., if at least one sample in a series of two does not exceed the UPL, then it can be concluded that an SSI has not occurred. In practice, where initial results did not exceed the UPL, a second sample was not collected. The one-of-two retesting procedure allowed achieving an acceptably high statistical power while maintaining a site-wide false-positive rate (SWFPR) of 1% per year or less. Power curves were constructed for the intrawell parametric tests and are compared with the EPA Reference Power Curve in Appendix A. The power curves associated with the statistical tests for the Turk Plant Landfill exceed the EPA Reference Power Curve at 3 and 4 standard deviations; this is considered a good level of statistical power according to EPA s Unified Guidance (USEPA, 29) Detection Monitoring A sampling event for detection monitoring was conducted on August 1, 217. The results of this detection monitoring event are summarized in Table 5 and were used to evaluate potential SSIs. Exceedances of background UPLs were not observed. Increasing trends in fluoride concentrations at compliance wells,,, and MW-1 and in ph at compliance wells and were also observed. However, the fluoride concentrations at,,, and MW-1 were lower than or similar to fluoride concentrations at upgradient well MW-1, and the ph results at and were similar to ph results at upgradient well MW-1. An increasing trend in fluoride concentrations was also observed at upgradient well MW-1. For these reasons, these increasing trends are not currently considered indicative of a release from the CCR unit. 217 CHA Turk LF Report 2-4

39

40 Statistical Analysis December 27, Conclusions Ten background monitoring events and one detection monitoring event were completed in accordance with the CCR Rule. The laboratory and field data were reviewed prior to statistical analysis, with no QA/QC issues identified that impacted data usability. Background levels were calculated using data from the ten background monitoring events and from historical monitoring events conducted prior to background monitoring for the CCR Rule. A review of outliers identified one potential outlier, which was removed from the dataset. Prediction intervals were constructed based on the remaining background data and a one-of-two retesting procedure. Because of the natural spatial variability observed and the availability of historical data collected prior to placing CCR at the Landfill, intrawell tests were selected for all Appendix III parameters. The detection monitoring results were compared to the intrawell background concentrations to evaluate potential SSIs. No SSIs were observed, and the Turk Landfill will remain in a detection monitoring program. 217 CHA Turk LF Report 2-6

41 Statistical Analysis December 27, 217 SECTION 3 REFERENCES American Electric Power (AEP) Statistical Analysis Plan John W. Turk Plant. January 217. United States Environmental Protection Agency (USEPA). 29. Statistical Analysis of Groundwater Monitoring Data at RCRA Facilities Unified Guidance. EPA 53/R-9-7. March CHA Turk LF Report 3-1

42 TABLES

43 Table 1: Background Sampling Summary Turk Plant - Landfill Geosyntec Consultants, Inc. Well ID Jun-16 Jul-16 Sep-16 Nov-16 Dec-16 Metals Radium ph Metals Radium ph Metals Radium ph Metals Radium ph Metals Radium ph MW-1 X NS X X NS X X X X X X X X X X MW-1 X NS X X NS X X X X X X X X X X X NS X X NS X X X X X X X X X X X NS X X NS X X X X X X X X X X X NS X X NS X X X X X X X X X X X NS X X NS X X X X X X X X X X Well ID 1-Feb Feb-17 May-17 Jun-17 Jul-17 Metals Radium ph Metals Radium ph Metals Radium ph Metals Radium ph Metals Radium ph MW-1 X X X X X X X X X X X X X X X MW-1 X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X Notes: X: Sampled NS: Not Sampled

44 Table 2 - Groundwater Data Summary Turk Plant - Landfill Geosyntec Consultants, Inc. MW-1 Parameter Unit 6/1/216 7/25/216 9/1/216 11/2/216 12/15/216 2/1/217 2/21/217 5/2/217 6/29/217 7/19/217 8/1/217 Background Detection Antimony.5U.5U.146J.35J.95J.5U.5U.5U.5U.5U - Arsenic.5U.5U.5U.5U.5U.5U.5U.5U.5U.5U - Barium Beryllium.8J.16J.17J.1U.1U.1U.1U.1U.1U.1U - Boron Cadmium.1U.1U.81J.1U.1U.1U.1U.1U.1U.1U - Calcium Chloride Chromium J.9J.1U.1U.1U.1U.1U.24J - Cobalt.19J.125J.95J.11J.61J.69J.56J.57J.33J.78J - Combined Radium pci/l Fluoride J J J Lead.116J.5U.5U.5U.5U.5U.5U.74J.5U.71J - Lithium Mercury.2J.1J.1J.2U.2U.1J.1J.2U.2U.2U - Molybdenum.254J.31J.413J.157J.158J.143J.172J.215J.168J.182J - Selenium.29J.31J.388J.333J.5U.5U.252J.343J.5U.5U - Total Dissolved Solids Sulfate Thallium.124J.2U.2U.2U.2U.2U.2U.2U.2U.2U - ph SU Notes: : milligrams per liter pci/l: picocuries per liter SU: standard unit U: Component was not present in concentrations above method detection limit and is reported as the reporting limit J: Estimated value. Component was detected in concentrations below the reporting limit -: Not sampled

45 Table 2 - Groundwater Data Summary Turk Plant - Landfill Geosyntec Consultants, Inc. Parameter Unit 6/1/216 7/25/216 9/1/216 11/2/216 12/15/216 2/1/217 2/21/217 5/2/217 6/29/217 7/19/217 8/1/217 Background Detection Antimony.5U.5U.5.192J.173J.5U.5U.146J.5U.5U - Arsenic.176J.139J.5U.5U.5U.5U.5U.137J.5U.5U - Barium Beryllium.12J.13J.14J.8J.1U.1U.1U.1U.1U.2J - Boron Cadmium.1U.1U.1U.1U.1U.1U.1U.1U.1U.1U - Calcium Chloride Chromium.2.86J.3.3.1U.1U.1U.1U.1U.76J - Cobalt.9J.121J.113J.154J.36J.22J.23J.32J.58J.71J - Combined Radium pci/l Fluoride.564J.4781J.4811J.493J.5233J.586J 1U.52J.4428J.4694J.451J Lead.22J.5U.123J.127J.5U.5U.5U.5U.5U.114J - Lithium Mercury.1J.1J.1J.1J.2U.2U.2U.2U.2U J - Molybdenum.283J.469J J.292J.263J.18J.87J.118J - Selenium.115J.5U.392J.145J.168J.5U.5U.132J.5U.5U - Total Dissolved Solids Sulfate Thallium.2U.2U.2U.2U.2U.2U.2U.2U.2U.2U - ph SU Notes: : milligrams per liter pci/l: picocuries per liter SU: standard unit U: Component was not present in concentrations above method detection limit and is reported as the reporting limit J: Estimated value. Component was detected in concentrations below the reporting limit -: Not sampled

46 Table 2 - Groundwater Data Summary Turk Plant - Landfill Geosyntec Consultants, Inc. Parameter Unit 6/1/216 7/25/216 9/1/216 11/2/216 12/15/216 2/1/217 2/21/217 5/2/217 6/29/217 7/19/217 8/1/217 Background Detection Antimony.5U.5U.19J.191J.137J.139J.176J.5U.5U.5U - Arsenic.5U.5U.5U.232J.184J.5U.5U.237J.5U.5U - Barium Beryllium.19J.14J.19J.1J.26J.16J.24J.1J.13J.15J - Boron Cadmium.1U.1U.1U.1U.1U.1U.1U.1U.1U.1U - Calcium Chloride Chromium.1.49J.96J.57J.47J.91J.4.31J J - Cobalt.66J.79J.8J.134J.4J.76J.121J.35J.89J.72J - Combined Radium pci/l Fluoride.3926J.443J.4288J.5852J.647J 1U 1U.37J.3475J 1U.438J Lead.94J.5U.5U.152J.5U.5U.219J.5U.112J.5U - Lithium Mercury.2J.2U.2U.2U.2U.1J.1J.2U.2U.2U - Molybdenum.95J.117J.114J.169J.31J.13J.55J.5U.5U.5U - Selenium.5U.5U.126J.5U.5U.5U.5U.5U.5U.5U - Total Dissolved Solids Sulfate Thallium.2U.2U.2U.2U.2U.2U.92J.2U.2U.2U - ph SU Notes: : milligrams per liter pci/l: picocuries per liter SU: standard unit U: Component was not present in concentrations above method detection limit and is reported as the reporting limit J: Estimated value. Component was detected in concentrations below the reporting limit -: Not sampled

47 Table 2 - Groundwater Data Summary Turk Plant - Landfill Geosyntec Consultants, Inc. Parameter Unit 6/1/216 7/25/216 9/1/216 11/2/216 12/15/216 2/1/217 2/21/217 5/2/217 6/29/217 7/19/217 8/1/217 Background Detection Antimony.5U.5U.144J.265J.5U.115J.99J.226J.5U.5U - Arsenic.184J.5U.176J.141J.22J.5U.5U.5U.5U.244J - Barium Beryllium.24J.45J.51J.1J.3J.1U.17J.3J.5J.7J - Boron Cadmium.1U.1U.1U.1U.1U.1U.1U.1U.1U.1U - Calcium Chloride Chromium J.27J.9.33J Cobalt.335J J.94J.77J.418J.12J.164J.164J - Combined Radium pci/l Fluoride.623J 1U.5614J.374J.3995J 1U 1U.44J.465J 1U.512J Lead.147J.482J.6.227J.5U.5U.277J.5U.5U.134J - Lithium Mercury.2J.2J.3.2U.2U.1J.1J.1J.2U.1J - Molybdenum.299J.139J.39J.18J.377J.34J.253J.141J.265J.36J - Selenium.6.382J U J.5U.118J - Total Dissolved Solids Sulfate Thallium.2U.2U.2U.2U.2U.2U.2U.2U.2U.2U - ph SU Notes: : milligrams per liter pci/l: picocuries per liter SU: standard unit U: Component was not present in concentrations above method detection limit and is reported as the reporting limit J: Estimated value. Component was detected in concentrations below the reporting limit -: Not sampled

48 Table 2 - Groundwater Data Summary Turk Plant - Landfill Geosyntec Consultants, Inc. Parameter Unit 6/1/216 7/25/216 9/1/216 11/2/216 12/15/216 2/1/217 2/21/217 5/2/217 6/29/217 7/19/217 8/1/217 Background Detection Antimony.5U.42J.95J.5U.5U.5U.5U.12J.5U.5U - Arsenic.5U.5U.5U.5U.5U.5U.5U.5U.5U.5U - Barium Beryllium.6J.17J.14J.1U.1U.1U.1U.1U.1U.1U - Boron Cadmium.1U.1U.1U.1U.1U.1U.1U.1U.1U.1U - Calcium Chloride Chromium.66J.2.56J.37J.56J.86J.1.42J.1U.46J - Cobalt.61J.138J.97J.68J.49J.55J.73J.6J.68J.81J - Combined Radium pci/l Fluoride.4866J.4938J.48J.523J.2941J.7224J 1U.54J 1U 1U 1U Lead.5U.136J.5U.5U.5U.5U.5U.5U.5U.95J - Lithium Mercury.2J.1J.1J.2U.2U.1J.1J.2J.1J.3 - Molybdenum.145J.413J.331J.76J.5U.86J.96J.111J.22J.97J - Selenium.23J.8.16J.157J.5U.5U.5U.5U.5U.5U - Total Dissolved Solids Sulfate Thallium.2U.2U.2U.2U.2U.2U.2U.2U.2U.2U - ph SU Notes: : milligrams per liter pci/l: picocuries per liter SU: standard unit U: Component was not present in concentrations above method detection limit and is reported as the reporting limit J: Estimated value. Component was detected in concentrations below the reporting limit -: Not sampled

49 Table 2 - Groundwater Data Summary Turk Plant - Landfill Geosyntec Consultants, Inc. MW-1 Parameter Unit 6/1/216 7/25/216 9/1/216 11/2/216 12/15/216 2/1/217 2/21/217 5/2/217 6/29/217 7/19/217 8/1/217 Background Detection Antimony.5U.5U.5U.18J.5U.5U.5U.5U.5U.5U - Arsenic.5U.5U.5U.5U.5U.5U.5U.5U.5U.5U - Barium Beryllium.4J.8J.6J.1U.1U.1U.1U.1U.1U.1U - Boron Cadmium.1U.1U.1U.1U.1U.1U.1U.1U.1U.1U - Calcium Chloride Chromium.2.84J.1.84J Cobalt.61J.89J.88J.1J.64J.67J.95J.74J.61J.77J - Combined Radium pci/l Fluoride.5264J.4623J.5157J.373J.3419J U.52J J Lead.5U.5U.5U.77J.5U.5U.87J.5U.83J.11J - Lithium Mercury.2J.1J.1J.2U.2U.1J.1J.2U.2U.1J - Molybdenum.81J.139J.118J.13J.73J.78J.26J.59J.59J.87J - Selenium.128J.17J.5U.5U.5U.5U.5U.5U.5U.5U - Total Dissolved Solids Sulfate Thallium.2U.91J.2U.2U.2U.2U.2U.2U.2U.2U ph SU Notes: : milligrams per liter pci/l: picocuries per liter SU: standard unit U: Component was not present in concentrations above method detection limit and is reported as the reporting limit J: Estimated value. Component was detected in concentrations below the reporting limit -: Not sampled

50 Table 3: Historical Groundwater Data Summary Turk Plant - Landfill Geosyntec Consultants, Inc. Parameter Unit MW-1 9/19/211 12/29/211 2/28/212 5/16/212 8/8/212 11/7/212 2/28/213 5/2/213 8/6/213 11/4/213 2/1/214 5/5/214 8/5/214 11/5/214 2/3/215 3/23/216 5/5/215 8/19/215 11/18/215 Boron Chloride Fluoride.5U ph SU Sulfate Total Dissolved Solids Notes: : milligrams per liter SU: standard p unit p method detection limit and is reported as the reporting limit *: Component was not present in concentrations above method detection limit and is reported as the method J: Component was detected in concentrations below the reporting limit -: Not sampled Page 1 of 6

51 Table 3: Historical Groundwater Data Summary Turk Plant - Landfill Geosyntec Consultants, Inc. Parameter Boron Chloride Fluoride ph Sulfate Total Dissolved Solids Unit SU 9/19/211 12/29/211 2/28/212 5/16/212 8/7/212 11/7/212 2/28/213 5/2/213 8/6/213 11/4/213 2/1/214 5/5/214 8/5/214 11/5/214 2/3/215 3/23/216 5/5/215 8/19/215 1/9/21511/18/ U.2U.2U.41.2U U Notes: : milligrams per liter SU: standard p unit p method detection limit and is reported as the reporting limit *: Component was not present in concentrations above method detection limit and is reported as the method J: Component was detected in concentrations below the reporting limit -: Not sampled Page 2 of 6

52 Table 3: Historical Groundwater Data Summary Turk Plant - Landfill Geosyntec Consultants, Inc. Parameter Boron Chloride Fluoride ph Sulfate Total Dissolved Solids Unit SU 9/19/211 12/29/211 2/28/212 5/16/212 8/7/212 11/7/212 2/28/213 5/2/213 8/6/213 11/4/213 2/1/214 5/5/214 8/5/214 11/5/214 2/3/215 3/23/216 5/5/215 8/19/215 1/9/215 11/18/ U.2U.2.2U.2U.2U.257.2U U Notes: : milligrams per liter SU: standard p unit p method detection limit and is reported as the reporting limit *: Component was not present in concentrations above method detection limit and is reported as the method J: Component was detected in concentrations below the reporting limit -: Not sampled Page 3 of 6

53 Table 3: Historical Groundwater Data Summary Turk Plant - Landfill Geosyntec Consultants, Inc. Parameter Boron Chloride Fluoride ph Sulfate Total Dissolved Solids Unit SU 9/2/211 12/3/211 2/28/212 5/17/212 8/7/212 11/7/212 2/28/213 5/2/213 8/6/213 11/4/213 2/1/214 5/5/214 8/5/214 11/5/214 2/3/215 3/23/216 5/5/215 8/19/215 11/18/ U Notes: : milligrams per liter SU: standard p unit p method detection limit and is reported as the reporting limit *: Component was not present in concentrations above method detection limit and is reported as the method J: Component was detected in concentrations below the reporting limit -: Not sampled Page 4 of 6

54 Table 3: Historical Groundwater Data Summary Turk Plant - Landfill Geosyntec Consultants, Inc. Parameter Boron Chloride Fluoride ph Sulfate Total Dissolved Solids Unit SU 9/2/211 12/29/211 2/27/212 5/17/212 8/8/212 11/7/212 2/28/213 5/2/213 8/6/213 11/4/213 2/1/214 5/5/214 8/5/214 11/5/214 2/3/215 3/23/216 5/5/215 8/19/215 11/18/ U.2U.2U.2U.37.2U.2U U U Notes: : milligrams per liter SU: standard p unit p method detection limit and is reported as the reporting limit *: Component was not present in concentrations above method detection limit and is reported as the method J: Component was detected in concentrations below the reporting limit -: Not sampled Page 5 of 6

55 Table 3: Historical Groundwater Data Summary Turk Plant - Landfill Geosyntec Consultants, Inc. Parameter Boron Chloride Fluoride ph Sulfate Total Dissolved Solids Unit SU MW-1 12/29/211 2/27/212 5/16/212 8/8/212 11/7/212 2/28/213 5/2/213 8/6/213 11/4/213 2/1/214 5/5/214 8/5/214 11/5/214 2/3/215 3/23/216 5/5/215 8/19/215 11/18/ U U.34.2U.2U U Notes: : milligrams per liter SU: standard p unit p method detection limit and is reported as the reporting limit *: Component was not present in concentrations above method detection limit and is reported as the method J: Component was detected in concentrations below the reporting limit -: Not sampled Page 6 of 6

56 Table 4: Outlier Analysis Summary Turk Plant - Landfill Geosyntec Consultants, Inc. Location Well ID Sample Date Parameter Reported Value Units Conclusions Downgradient 11/5/214 Sulfate 23 This value was conservatively removed from the dataset as an outlier per the Unified Guidance.

57 Parameter Boron Calcium Chloride Fluoride ph Total Dissolved Solids (TDS) Sulfate Notes: * Indicates resample NS: Not sampled UPL: Upper prediction limit LPL: Lower prediction limit Bold values exceed the background value. Background values are shaded gray. Table 5: Detection Monitoring Data Evaluation Turk Plant - Landfill Geosyntec Consultants, Inc. Unit Description MW-1 8/1/217 8/1/217 8/1/217 8/1/217 8/1/217 Intrawell Background Value (UPL) Detection Monitoring Result Intrawell Background Value (UPL) Detection Monitoring Result Intrawell Background Value (UPL) Detection Monitoring Result Intrawell Background Value (UPL) Detection Monitoring Result SU Intrawell Background Value (UPL) SU Intrawell Background Vlaue (LPL) SU Detection Monitoring Result Intrawell Background Value (UPL) Detection Monitoring Result Intrawell Background Value (UPL) Detection Monitoring Result

58 ATTACHMENT A Evaluation of Detection Monitoring Data

59 15 E.Wilson Bridge Road, Suite 232 Columbus, Ohio 4385 PH FAX Memorandum Date: March 1, 218 To: Copies to: From: Subject: David Miller (AEP) Terence Wehling (AEP) Allison Kreinberg and Bruce Sass, Ph.D. (Geosyntec) Evaluation of Detection Monitoring Data at Turk Plant s Landfill (LF) In accordance with the United States Environmental Protection Agency s (USEPA s) regulations regarding the disposal of coal combustion residuals (CCR) in landfills and surface impoundments (4 CFR , CCR rule ), detection monitoring events were completed on August 1, 218 at the Landfill (LF), an existing CCR unit at the Turk Power Plant located in Fulton, Arkansas. Ten background monitoring events were conducted at the Turk LF prior to these detection monitoring events, and upper prediction limits (UPLs) were calculated for each Appendix III parameter to represent background values. A lower prediction limit (LPL) was also calculated for ph. Details on the calculation of these background values are described in Geosyntec s Statistical Analysis Summary report, dated December 27, 217. To achieve an acceptably high statistical power while maintaining a site-wide false-positive rate (SWFPR) of 1% per year or less, prediction limits were calculated based on a one-of-two retesting procedure. With this procedure, a statistically significant increase (SSI) is only concluded if both samples in a series of two exceeds the UPL. In practice, if the initial result did not exceed the UPL, a second sample was not collected or analyzed. Detection monitoring results and the relevant background values are summarized in Table 1. No SSIs were observed at the Turk LF CCR unit, and as a result the Turk LF will remain in detection monitoring. CHA Turk LF Addendum Memo

60