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Home My WebLink AboutNC0004774_Seep Charaterization_20200724 tips DUKE James Wells Vice President ENERGY® Environmental,Health and Safety Programs&Environmental Sciences 526 South Church Street Charlotte,NC 28202 (980)373-9646 July 24, 2020 Via Overnight Mail S. Daniel Smith Director of Water Resources E Cr E I�� North Carolina Department of Environmental Quality D 1617 Mail Service Center JUL 2 7 1010 Raleigh, NC 27699-1617 NCDEQ/pWR/NppEs Bob Sledge North Carolina Department of Environmental Quality Division of Water Resources Water Quality Permitting Program 1617 Mail Service Center Raleigh, NC 27699-1617 Subject: Seep Characterization Report submittal and request for formal certification of seep dispositions Duke Energy Carolinas, LLC —Buck Steam Station EMC SOC WQ S 18-004 NPDES Permit NC0004774 Rowan County Dear Messrs. Smith and Sledge: On behalf of Duke Energy Carolinas,LLC(DEC),I am submitting to you the enclosed Buck Steam Station Seep Characterization Report summarizing the findings of the post decant sampling event and requesting formal certification of seep disposition decisions as described in the report. The conclusions from this report and the Department's certifications will be incorporated into the upcoming corrective action plan(CAP) amendment as required by the subject order. Completion of decanting occurred at Buck on March 2, 2020. As outlined in the report, all remaining areas previously identified as "seeps" are proposed for dispositioning based on their characteristics and/or lack of impact to waters of the State. Messrs. Smith and Sledge July 24, 2020 Page 2 Please direct any questions about this submittal to Chris Hallman at(980) 373-7892. I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility offine and imprisonment for knowing violations. Sincerely, ( Ea( James Wells Vice President, Environment, Health & Safety Programs and Environmental Sciences Duke Energy Attachment: Buck Steam Station 2020 Seep Characterization Report CC: Richard Baker, Duke Energy Robert Wylie, Duke Energy Steve Cahoon/FileNet, Duke Energy Shannon Langley, Duke Energy Chris Hallman, Duke Energy Dale Wooten, Duke Energy Paul Draovitch, Duke Energy Matt Hanchey, Duke Energy Corey Basinger, WQ Supervisor, DEQ Mooresville Office synTerra SEEP CHARACTERIZATION REPORT BUCK STEAM STATION EMC SOC WQ S18-004 1555 DUKEVILLE ROAD SALISBURY, NC 28146 JULY 2020 PREPARED FOR (65 DUKE lur ENERGY. CAROLINAS DUKE ENERGY CAROLINAS, LLC i � U John Thao Pr 'ect Scientist Brian Wilker, NC LG #2546 Project Manager Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra EXECUTIVE SUMMARY SynTerra has prepared this Seep Characterization Report pertaining to the Buck Steam Station (Buck or Site) in Salisbury, North Carolina, to evaluate whether the historical storage of coal ash has affected surface waters downgradient of the ash basin Cells 1-3. This report was prepared on behalf of Duke Energy Carolinas, LLC (Duke Energy). ES.1 Introduction A Special Order by Consent (SOC) WQ S18-004, approved on July 12, 2018, addresses management of seeps from coal ash basins at the Site during the process of basin closure under the Coal Ash Management Act (CAMA), G.S. 130A-309.200 through 130A-309.231 and the federal Coal Combustion Residuals (CCR) Rule, 40 CFR Parts 257 and 261. In addition to monitoring requirements, the SOC contains requirements for identifying new seeps and documenting the physical characteristics of previously identified seeps. Compliance requirements specified in the SOC include: • Within 90 days after the completion of decanting, remaining seeps, if not dispositioned in accordance with the SOC, will be characterized and Duke Energy will be required to submit a Final Seep Report identifying new seeps downgradient of the ash basins and detailing the physical characteristics of previously documented seeps. • Within 150 days after the completion of decanting, additional characterization of seeps not dispositioned in the Final Seep Report will be necessary, and a summary of findings (including sampling data and jurisdictional status) provided within a Seep Characterization Report. • Within 210 days after the completion of decanting, if deemed necessary, an amendment to the groundwater Corrective Action Plan and/or Closure Plan describing future seep management must be submitted. Duke Energy provided a Notification of Decanting Completion letter to the North Carolina Department of Environmental Quality (NCDEQ) Division of Water Resources (DWR) on April 2, 2020, indicating decanting was completed on March 2, 2020. A comprehensive survey was completed in April 2020 to identify new seeps and document the physical characteristics of previously documented seeps. No new seeps were identified during this inspection. The findings of the April 2020 comprehensive survey are documented in the 2020 Final Seep Report (SynTerra, May 2020). The Final Seep Report was submitted on May 27, 2020. Page ES-1 Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra Observations duringthe April 2020 physical inspection were evaluated to determine P P Y p whether any remaining seeps are candidates for dispositioning in accordance with the SOC. Samples were collected in May 2020 from the remaining seeps, which had been identified downgradient of the ash basins, to facilitate additional characterization of those seeps. Seep samples were analyzed for constituents consistent with Attachment B of the SOC. The sampling data were evaluated to determine whether constituents are present in non-dispositioned seeps and whether seeps have the potential to be considered for corrective action based on comparison to applicable North Carolina Administrative Code (NCAC) Title 15A, Subchapter 2B Surface Water and Wetland Standards (02B). In addition, a review and preliminary determination of the jurisdictional status of those seeps is included in this report for further characterization. ES.2 Key Findings Key findings regarding the seep characterization presented in this report include: • Nine seeps (S-02, S-03, S-06, S-07, S-09, S-10, S-12, S-13, and S-16) remain in dispositioned status as determined by DWR at the time of the issuance of the SOC. • Pursuant to National Pollutant Discharge Elimination System (NPDES) permit NC0004774, approved September 17, 2018 and effective November 1, 2018, discharge flows from constructed seeps S-11 (Outfall 111) and S-17 (Outfall 117) will be monitored per permit requirements. • Six non-constructed seeps (S-01, S-04, S-05, S-08, S-14, and S-15) remain as non- dispositioned. In accordance with the SOC, they are subject to being addressed in an amendment to the Corrective Action Plan (CAP) and/or the Closure Plan. o S-01 - Seep characterization sampling data indicated that Attachment B constituent values were less than 02B standards. o S-04-Seep characterization sampling data indicated that only the hardness value was greater than 02B standards. However, data collected at the instream monitoring location to evaluate potential impacts from S- 04 indicated 02B standards were being met. o S-05 -Seep characterization sampling data indicated that only the hardness value was greater than 02B standards. However, data collected at the instream monitoring location to evaluate potential impacts from S- 05 indicated 02B standards were being met. Page ES-2 Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra o S-08 - Seep characterization sampling data indicated that Attachment B constituent values were less than 02B standards. o S-14 and S-15 -Monitored via S-05. Seep characterization sampling data indicated that only the hardness value was greater than 02B standards. The data collected at the instream monitoring location to evaluate potential impacts from S-05, S-14, and S-15 indicated 02B standards were being met. • With concurrence from the director of the DWR regarding compliance with 02B standards pertaining to flows from all non-dispositioned seeps, no corrective action may be necessary at the Site. Page ES-3 Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra TABLE OF CONTENTS SECTION PAGE EXECUTIVE SUMMARY 1 1.0 INTRODUCTION 1-1 1.1 Decanting Summary 1-2 1.2 Seep Characterization Evaluation 1-2 2.0 FINDINGS 2-1 2.1 Physical Inspection 2-1 2.1.1 Seep Status 2-1 2.2 Seep Sampling 2-2 2.2.1 Data Results 2-2 2.3 Jurisdictional Status of Seeps 2-2 2.4 Dispositional Status of Seeps 2-3 2.4.1 Dispositioned 2-3 2.4.2 Non-Dispositioned 2-4 2.4.3 Changes of Status 2-5 2.5 Decanting/Dewatering/Ash Basin(s) Status 2-5 2.6 Ash Basin Closure Status/Corrective Action Plan 2-5 3.0 SEEPS TO BE ADDRESSED 3-1 4.0 CONCLUSIONS 4-1 5.0 REFERENCES 5-1 LIST OF FIGURES Figure 1 Seep Locations and Inspection Areas LIST OF TABLES Table 1 Seep Locations and Descriptions—April 2020 Inspection Table 2 Seep Sampling Results—May 2020 LIST OF APPENDICES Appendix A Photographs Pagei r Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra LIST OF ACRONYMS AND ABBREVIATIONS 02B North Carolina Administrative Code Title 15A, Subchapter 2B, Surface Water and Wetland Standards 02L North Carolina Administrative Code Title 15A, Subchapter 2L, Groundwater Classification and Standards CAMA Coal Ash Management Act CAP Corrective Action Plan CCR coal combustion residuals DWR Division of Water Resources EMC Environmental Management Commission USEPA United States Environmental Protection Agency mg/L milligrams per liter NAVD 88 North American Vertical Datum of 1988 NCDEQ North Carolina Department of Environmental Quality NCAC North Carolina Administrative Code NPDES National Pollutant Discharge Elimination System Site Buck Steam Station SOC Special Order by Consent SOP standard operating procedure USACE United States Army Corp of Engineers WOS Waters of the State WOTUS Waters of the United States Page ii Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra 1.0 INTRODUCTION On April 6, 2020, Walter Gerald (NC L.G. #0446) of SynTerra conducted a comprehensive survey of the Buck Steam Station (Buck or Site) for existing and potential new seeps. After the seep inspection, SynTerra prepared a 2020 Final Seep Report (SynTerra, May 2020) documenting the findings of the comprehensive survey as required by the North Carolina Environmental Management Commission (EMC) Special Order by Consent (SOC) WQ S18-004. This requirement can be found in the Additional Compliance Measures (Section 2.c.4) of the SOC. After the submittal of the Final Seep Report, the SOC requires the characterization of seeps which, after the completion of decanting, have not been certified as dispositioned P g� P (Section 2.d). That section of the SOC describes requirements for seep characterization as follows: "Following completion of decanting, if any seeps (including both constructed and non-constructed seeps) have not been certified by the Director of DWR as dispositioned . . . Duke Energy shall conduct a characterization of those seeps. Duke Energy shall submit a report on the findings of these characterizations ("Seep Characterization Report") to the Director of DWR within 150 days of completion of decanting at each Facility (i.e., within 60 days of the submittal of the Final Seep Report). The Seep Characterization Report must include all sampling data for each remaining seep as well as Duke Energy's evaluation of the jurisdictional status of all seeps at the relevant Facility. The determination regarding whether a surface water feature is a classified water of the State rests with DWR." In May 2020, SynTerra collected samples for analysis from non-dispositioned seep locations identified in the 2020 Final Seep Report (Table 1). Seep samples were analyzed for constituents consistent with Attachment B of the SOC. Determination for sampling and collection methods were in accordance with the Standard Operating Procedure (SOP) for Seep Sampling employed by Duke Energy (Duke Energy, March 2016). Several locations were not sampled due to dry or stagnant conditions, insufficient flow, or other observed conditions that would preclude the ability to collect a valid, representative sample as outlined in the March 2016 SOP for seep sampling. Sampling was conducted to facilitate characterization of those seeps as required by the SOC (Section 2.d). The May 2020 seep sampling results are provided in Table 2. Page 1-1 Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra This Seep Characterization Report documents the results of those findings and presents a preliminary evaluation of the jurisdictional status of all remaining seeps at the Site. 1.1 Decanting Summary Decanting (removal) of free water from the ash basins was initiated on February 07, 2019, with the redirection of wastewater inflows from the ash basins into a physical- chemical treatment system designed to the meet the requirements of National Pollutant Discharge Elimination System (NPDES) permit NC0004774. Duke Energy provided a Notification of Decanting Completion letter to the North Carolina Department of Environmental Quality (NCDEQ) Division of Water Resources (DWR) on April 2, 2020, indicating the completion of decanting on March 2, 2020. Decanting of ash basin Cell 1 has reduced flow in constructed seeps S-11 and S-17 downgradient of the basin. No significant reductions in flow were observed at the seeps downgradient of ash basin Cells 2 and 3. 1.2 Seep Characterization Evaluation The purpose of seep characterization is to evaluate whether the historical storage of coal ash has affected surface waters downgradient of the ash basin Cells 1-3. This includes evaluations of the physical status, chemical composition, and jurisdictional determination of the seeps. The following methods were used in this evaluation: Physical Inspection SynTerra conducted a comprehensive survey on April 6, 2020, of areas downgradient of the ash basins to identify new seeps and to document the physical characteristics of previously documented seeps that have not been certified as dispositioned. This survey included identifying the seeps by approximate latitude and longitude and taking date- stamped digital photographs of the appearance of the seeps (Appendix A). The seeps were evaluated based on appearance, current flow conditions, and comparison to historical physical conditions. A summary of the findings of the survey are included in the 2020 Final Seep Report (SynTerra, May 2020). Chemical Composition SynTerra collected samples for analysis from non-dispositioned seep locations in May 2020 for constituents listed in Attachment B of the SOC. Samples were not collected from locations where there were dry or stagnant conditions, insufficient flow, or other observed conditions that would preclude the ability to collect a valid, representative sample as outlined in the SOP for Seep Sampling (Duke Energy, March 2016). Page 1-2 r Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra Jurisdictional Determination At the time of report issuance, the Waters of the United States (WOTUS) delineation at the Site, submitted August 8, 2017, has not been approved by the U.S. Army Corps of Engineers (USACE). SynTerra compared non-dispositioned seep locations to preliminary wetland and stream boundaries (AMEC, 2015) to satisfy requirements within the SOC. The final determination of jurisdictional status of a surface water feature as a classified water of the State (WOS) or WOTUS rests with the DWR and USACE. Page 1-3 Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra 2.0 FINDINGS 2.1 Physical Inspection On April 6, 2020, Walter Gerald (NC L.G. #0446) of SynTerra conducted a comprehensive survey of areas downgradient of the ash basins (Cells 1-3) identifying new seeps and documenting the physical characteristics of previously identified seeps. Inspection activities were performed in accordance with SOC requirements (Section 2.c.3). All locations documented as a seep at the time of the issuance of the SOC, as listed in Table 1, were observed and documented with photographs during the inspection (Appendix A). The inspection included observations in the following areas (Figure 1): • North and east of Ash Basin Cells 2 and 3, along the Yadkin River • Along the tributary located east of Ash Basin Cells 2 and 3 • Along the tributary located west of Ash Basin Cell 1 • Between the Combined Cycle Station and Ash Basin Cell 1, along the dam • Areas along and downgradient of the ash basin dams 2.1.1 Seep Status Seep locations and inspection areas are shown on Figure 1. Observations noted during the April 2020 inspection are summarized on Table 1. A summary of the details of the physical seep inspection are as follows: • New seeps downgradient of the ash basins were not observed during the inspection. • Previously unidentified or unreported pipes were not observed during inspection. • Flow was not observed within the riprap installed along the base of the dam pertaining to ash basin Cells 2 and 3. • Minimal flow was observed from the culvert at S-14, which is below the toe of the dam pertaining to ash basin Cells 2 and 3. Downslope of the S- 15 seep location, the ground was saturated, but flow was not observed. At the S-05 location, low flow was observed in the creek bed, which flows into the cove area of the Yadkin River. These findings are consistent with observations made during the 2019 annual seep inspection. Page 2-1 Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra 2.2 Seep Sampling On May 13, SynTerra collected samples for analysis from non-dispositioned seep locations as identified in the 2020 Final Seep Report (Table 1), except for locations where there were dry or stagnant conditions, insufficient flow, or other observed conditions that would preclude the ability to collect a valid, representative sample as outlined in the SOP for Seep Sampling (Duke Energy, March 2016). Samples were collected in accordance with the March 2016 SOP. Seep sample locations are provided on Figure 1. Seep locations which were not sampled, along with observations that would preclude the ability to collect a valid, representative sample, are provided below: • S-11 —Stagnant conditions/No discernible flow, located inside a manhole covering • S-14—Insufficent flow and volume to collect a respresentative sample (< 1/4 inch of depth over PVC pipe barrier) • S-15 —Insufficent flow and volume to collect a respresentative sample (< 1/4 inch of depth over PVC pipe barrier) 2.2.1 Data Results Seep samples collected at the Site in May 2020 were analyzed for constituents listed in Attachment B of the SOC. Data were collected in order to characterize the potential for corrective action for seeps which were not certified as dispositioned after the completion of decanting as described in SOC (Section 2.d). The analytical results for the seep samples collected at the Site in May 2020 are included in Table 2. Seep sample locations are provided on Figure 1. 2.3 Jurisdictional Status of Seeps At the time of report issuance, the WOTUS delineation at the Site, submitted August 8, 2017, has not been approved by the USACE. SynTerra compared non-dispositioned seep locations to preliminary wetland and stream boundaries to satisfy requirements within the SOC (AMEC, 2015). Stream and wetland data derived from preliminary jurisdictional determinations (JD) are included on Figure 1. Based on this evaluation, non-dispositioned seeps presented in Table 1 (S-01, S-04, S-05, S-08, S-11, S-14, S-15, and S-17) constitute, or flow to, WOS or WOTUS. Page 2-2 r Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra 2.4 Dispositional Status of Seeps During the April 6, 2020 comprehensive survey, Mr. Gerald inspected each seep to evaluate whether it met requirements to be dispositioned in accordance with the SOC (Section 2.c.3). The requirements for dispositioning a seep are as follows: For purposes of this Special Order, "dispositioned" includes the following: (1) the seep is dry for at least three consecutive quarters; (2) the seep does not constitute, and does not flow to, waters of the State or Waters of the United States for three consecutive quarters; (3) the seep is no longer impacted by flow from any coal ash basin as determined by the Director of DWR in accord with applicable law and best professional judgment; or (4) the seep has been otherwise eliminated (e.g., through an engineering solution). If a seep that has been dispositioned through drying up reappears in any subsequent survey, such a seep will no longer be deemed dispositioned and can be subsequently re-dispositioned as specified above. Non-constructed seeps described in paragraph 1(h) of this SOC cannot be dispositioned through option (2) above. A discussion of the dispositional status pertaining to each seep is provided in the following sections. 2.4.1 Dispositioned Seeps have not been certified as dispositioned since the SOC became effective on July 12, 2018. However, several seeps were dispositioned prior to the effective date, as noted in Attachment A of the SOC and on Table 1. These seeps are as follows: • S-02—Location previously investigated as a seep. Monitoring has not indicated the presence of coal combustion residuals (CCRs). • S-03 —Location previously investigated as a seep. Monitoring has not indicated the presence of CCRs. • S-06 —Location previously investigated as a seep. Monitoring has not indicated the presence of CCRs. • S-07—Location previously investigated as a seep. Monitoring has not indicated the presence of CCRs. • S-09 —Seep dispositioned via repair and/or non-flowing condition to potentially reach WOTUS, or other, as noted. Sampling location;not a seep. Page 2-3 Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra • S-10—Location previously investigated as a seep. Monitoring has not indicated the presence of CCRs. • S-12-Seep dispositioned via repair and/or non-flowing condition to potentially reach WOTUS, or other, as noted. • S-13-Seep dispositioned via repair and/or non-flowing condition to potentially reach WOTUS, or other, as noted. • S-16-Seep dispositioned via repair and/or non-flowing condition to potentially reach WOTUS, or other, as noted. 2.4.2 Non-Dispositioned With the exception of the previously dispositioned seeps discussed in Section 2.4.1, remaining seeps listed on Table 1 are currently considered to be non- dispositioned. These seeps include: • S-01 -Seep to unnamed tributary (UT) that flows north to Yadkin River in approximately 2-foot-wide channel. Located northeast of the ash basin Cell 3, north of Leonard Road. • S-04-Seep to approximately 2-foot-wide channel, located northeast of the ash basin Cell 3, north of Leonard Road. Stream flows east to Yadkin River. • S-05 -Seep to small UT below stormwater culvert near toe of ash basin dam. UT may receive flow from S-14 prior to reaching Yadkin River. • S-08-Seep to approximately 1-foot-wide channel, located northwest of the ash basin Cell 1, west of Dukeville Road. Flows northwest to Yadkin River. • S-11 -Seep discharge from terracotta pipe to riprap channel on north dike wall of ash basin Cell 1. Flow conveyed to UT to the Yadkin River. • S-14-Low flow seep near stormwater culvert just above S-05 location. Flow is to UT to Yadkin River near S-05. • S-15 -Low flow seep downgradient of S-05 location. Seep flows to braided, small UT prior to entering Yadkin River. • S-17-Filter blanket discharge from west dike wall of ash basin Cell 1. Flow conveyed to UT to the Yadkin River. Page 2-4 r Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra 2.4.3 Changes of Status An evaluation of seep physical characteristics over time indicate that the non- dispositioned seeps documented in Table 1 are not considered eligible to be dispositioned based on the SOC requirements for dispositioning a seep (Section 2.c.3). In the terms of the SOC, "dispositioned" includes the following: (1) The seep is dry for at least three consecutive quarters. (2) The seep does not constitute, and does not flow to, waters of the State or WOTUS for three consecutive quarters. 1 (3) The seep is no longer impacted by any coal ash basin as determined by the Director of DWR in accordance with applicable law and best professional judgement. (4) The seep has otherwise been eliminated (e.g. through an engineering solution). 2.5 Decanting/Dewatering/Ash Basin(s) Status Decanting (removal) of free water from the ash basins was initiated on February 7, 2019. Duke Energy provided a Notification of Decanting Completion letter to the DWR on April 2, 2020, indicating decanting was completed on March 2, 2020. Dewatering of the ash basins is ongoing. 2.6 Ash Basin Closure Status/Corrective Action Plan Closure plans for the ash basins were submitted to the DWR on December 11, 2019. Revised closure plans for the ash basins, including excavation of the ash basins, were submitted to the DWR on April 2, 2020, and are currently under evaluation. 1 Non-constructed seeps described in paragraph 1(h)of the SOC cannot be dispositioned through option(2)above. Page 2-5 r Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra 3.0 SEEPS TO BE ADDRESSED Seeps were evaluated for disposition based on the physical status, chemical composition, and jurisdictional determination as described in previous sections of this report and listed in Section 2.4.3. Any seep (including constructed and non-constructed seeps) which is not certified as dispositioned after decanting shall be characterized for management in a manner that will be sufficient to protect public health, safety, welfare, the environment and natural resources (SOC Section 2.d). Although non-flowing conditions are often observed, six non-constructed seeps (S-01, S- 04, S-05, S-08, S-14, and S-15) remain in accordance with the recommendations for dispositioning. Page 3-1 Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas, LLC SynTerra 4.0 CONCLUSIONS In accordance with the requirements set forth in the SOC, SynTerra, on behalf of Duke Energy, performed an evaluation of constructed and non-constructed seeps downgradient of the ash basins at Buck. The purpose of this evaluation was to determine seep status with regard to the preliminary JD and characterization of those seeps not dispositioned after the decanting of the ash basins. This evaluation included: • A comprehensive survey in April 2020 to identify new seeps downgradient of the ash basins after decanting and to document the physical characteristics of previously documented seeps. • An evaluation of May 2020 seep sampling data to determine whether constituents listed in Attachment B of the SOC are present in non-dispositioned seeps that have the potential to be considered for corrective action based on comparison to applicable 02B surface water standards. • A review of preliminary jurisdictional stream and wetland determinations at the Site. Based on the findings from these evaluations, the following conclusions have been developed: • Nine seeps (S-02, S-03, S-06, S-07, S-09, S-10, S-12, S-13, and S-16) remain in dispositioned status, as determined by DWR at the time of issuance of the SOC. • Pursuant to National Pollutant Discharge Elimination System (NPDES) permit NC0004774, approved September 17, 2018 and effective November 1, 2018, discharge flows from constructed seeps S-11 (Outfall 111) and S-17 (Outfall 117) will be monitored per permit requirements. • Six non-constructed seeps (S-01, S-04, S-05, S-08, S-14, and S-15) remain as non- dispositioned. In accordance with the SOC, they are subject to being addressed in an amendment to the Corrective Action Plan (CAP) and/or the Closure Plan. o S-01 - Seep characterization sampling data indicated that Attachment B constituent values were less than 02B standards. o S-04—Seepcharacterization sampling data indicated that onlythe P g hardness value was greater than 02B standards. However, data collected at the instream monitoring location to evaluate potential impacts from S- 04 indicated 02B standards were being met. Page 4-1 Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra o S-05 -Seep characterization sampling data indicated that only the hardness value was greater than 02B standards. However, data collected at the instream monitoring location to evaluate potential impacts from S- 05 indicated 02B standards were being met. o S-08 - Seep characterization sampling data indicated that Attachment B constituent values were less than 02B standards. o S-14 and S-15 -Monitored via S-05. Seep characterization sampling data indicated that only the hardness value was greater than 02B standards. The data collected at the instream monitoring location to evaluate potential impacts from S-05, S-14, and S-15 indicated 02B standards were being met. • With concurrence from the director of the DWR regarding compliance with 02B standards pertaining to flows from all non-dispositioned seeps, no corrective action may be necessary at the Site. Page 4-2 I Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra 5.0 REFERENCES AMEC (2015). Natural Resources Technical Report—Buck Steam Station. May 2015. Duke Energy (2016). Standard Operating Procedure for Seep Sampling. March 2016. North Carolina Department of Environmental Quality. (2018). Special Order by Consent EMC SOC WQ S18-004. July 2018. SynTerra (2020). 2020 Final Seep Report—Buck Steam Station. May 2020. Page 5-1 Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra FIGURES s-�4' CELL S fs" / 1 '� LEGEND 9 S 1...- ' \ UPSTREAM IN YADKIN RIVER PER SOC * DOWNSTREAM IN YADKIN RIVER PER SOC •'\ * INSTREAM MONITORING PER SOC I NPDES CONSTRUCTED SEEP(APPROXIMATE) i , _ ®O NON-CONSTRUCTED SEEP(APPROXIMATE) DISPOSITIONED SEEP(APPROXIMATE) i /' ASH BASIN WASTE BOUNDARY DUKE ENERGY CAROLINAS PROPERTY LINE 1 r-- P STREAM(AMEC NRTR 2015) --0.FLOW DIRECTION •.r --�� WETLAND(AMEC NRTR 2015) r - SPECIAL ORDER BY CONSENT(SOC)INSPECTION AREA INOTES —I • 1 I -, 1.SEEP LOCATIONS ARE DESCRIBED IN EMC SOC WO S1B-004 L---�' -• 2.NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM(NPDES)LOCATIONS ARE Imo•-- --.TFSCRIBED IN PERMIT NC0004])4. I —. +AERIAL PHOTOGRAPHY OBTAINED FROM GOGGLE EARTH PRO ON MARCH 19,201a. AERIAL WAS COLLECTED ON OCTOBER 25,2518. 1 NATURAL RESOURCES TECHNICAL REPORT(NRTR)PREPARED BY AMEC FOSTER •— NH EELER INC.,MAY 29,2015. WSP SURVEY CONDUCTED APRIL 17,2014. ti.DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINA STATE PLANE IL°ORDINATE SYSTEM FIPS 3200(NADB3)• FIGURE 1 J LNERGY SEEP LOCATIONS AND INSPECTION AREAS 0.E 0e>0/202s SEEP CHARACTERIZATION REPORT �� DRAWN UV 14O DATE'06/30,2020 BUCK STEAM STATION c�nEO�.V o�:2.TTM� DATE 0w30/2020 SALISBURY,NORTH CAROLINA DATE:OP/30/2020 synTerra Pa9,ER MANAGER'VI GEBwo www.synterracorp.com Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra TABLES TABLE 1 SEEP LOCATIONS AND DESCRIPTIONS-APRIL 2020 INSPECTION SEEP CHARACTERIZATION REPORT BUCK STEAM STATION DUKE ENERGY CAROLINAS,LLC,SALISBURY,NC Location Coordinates Receiving Facility Sample ID Receiving Waterbody Description*** SOC Monitoring Interim Action Notes from 2020 Inspection Latitude Longitude Waterbody Classification Levels Seep to UT that flows north to Yadkin River in Monitoring at point UT to Yadkin prior to any NA-28 Standards Buck S-01 35.70914 -80.36044 River WS-V approximately 2 foot wide channel.Located tributary flow to Apply Water was observed to be clear and flowing. northeast of the ash basin,north of Leonard Road. UT Located northeast of the ash basin,north of UT to Yadkin Leonard Road.Flows north to Yadkin River via NA-SeepNA-SeepSteady moderate flow within well defined tributary to Buck S-02* 35.709414 -80.359441 WS-V Yadkin River.Water is clear.Minor amounts of algae on River approximately 4.5 foot wide stream.From sampling Dispositioned Dispositioned creek bed. -No CCR impacts. Located northeast of the ash basin,north of UT to Yadkin Leonard Road.Flows north to Yadkin River via NA-SeepNA-SeepSteady moderate flow within well defined tributary to Buck S-03* 35.710382 -80.360097 WS-V Yadkin River.Water is clear.Location ID sign has been River approximately 8.5 foot wide stream.From sampling Dispositioned Dispositioned broken off the post and needs to be replaced. -No CCR impacts. Seep to approximately 2 foot wide channel,located Monitoring at point Channel is saturated at the sign location.Flow infiltrates Buck 5-04 35.711273 -80.360796 UT to Yadkin WS-V northeast of the ash basin,north of Leonard Road. prior to entering Hardness 200 mg/L underground and re-emerges twice along channel at River Stream flows east to Yadkin River. Yadkin River Mercury 0.1 pg/L lower elevations before flowing overland towards Yadkin River. Seep to short UT below storm water culvert near Monitoring at Low flow in the creek bed to cove area of the Yadkin UT to Yadkin established Duke pH 6-10 S.U. Buck S-05 35.712239 -80.364595 River WS-V toe of ash basin dam.UT may receive flow from S- Energy S-05 Hardness 200 mg/L River.Minor iron(orange)staining on the creek bottom 14 prior to reaching Yadkin River. monitoring site substrate. Approximately 4 foot wide stream located north of Steady moderate flow in creek at the ID sign location. Buck 5-06* 35.711971 80.369032 UT to Yadkin WS-V ash basin,east of decommissioned Buck Steam NA-Seep NA-Seep Water is flowing clear.Minor biofilm downstream of ID ' River Station facility.Flows north toward Yadkin River. Dispositioned Dispositioned sign.Minor orange iron staining on substrate upstream of From sampling-No CCR impacts. the sign. Approximately 3.5 foot wide stream,located * UT to Yadkin northwest of the ash basin,west of Dukeville Road. NA-Seep NA-Seep Very low flow observed discharging from culvert.Some Buck 5-07 35.708704 -80.378637 WS-V River Flows northwest to Yadkin River.From sampling- Dispositioned Dispositioned clear standing water within the riprap substrate. No CCR impacts. Seep to approximately 1 foot wide channel,located Monitoring at Low flow within the tributary stream leading to the Yadkin UT to Yadkin established Duke River.Water is clear.No discharge from the holding pond Buck S-08 35.708212 -80.378345 River WS-V northwest of the ash basin,west of Dukeville Road. Energy S-08 Hardness 200 mg/L culvert emerging from beneath Dukeville Road where it Flows northwest to Yadkin River. monitoringsite. joins the tributary stream. Moderate flow with much orange biofilm and iron staining Buck S-09** 35.705502 -80.375677 UT to Yadkin WS-V Sampling Location;not a seep NA-Seep NA-Seep on the creek substrate.Relatively wide,shallow channel River Dispositioned Dispositioned at the culvert from beneath Dukeville Rd.Location also receives runoff from S-17 area. UT to Yadkin Approximately 2 foot wide stream,located west of Moderate flow from berm along Dukeville Rd.and the Buck S-10* 35.702188 -80.376455 WS-V the ash basin,west of Dukeville Road.Flow is to NA-Seep NA-Seep Beneficiation Plant.Clear water,some biofilm growth in River Yadkin River.From sampling No CCR impacts. Dispositioned Dispositioned P g P back/stagnant waters. Page 1 of 2 TABLE 1 SEEP LOCATIONS AND DESCRIPTIONS-APRIL 2020 INSPECTION SEEP CHARACTERIZATION REPORT BUCK STEAM STATION DUKE ENERGY CAROLINAS,LLC,SALISBURY,NC Location Coordinates Receiving Facility Sample ID Receiving Waterbody Description*** SOC Monitoring Interim Action Notes from 2020 Inspection Latitude Longitude Waterbody Classification Levels Seepdischarge from terracotta pipe to riprapped NA-Monitoring g p p p pped See Page 4 of Buck Water level in manhole was at the culvert inverts.No Buck S-11 35.707126 -80.374034 UT to Yadkin WS-V channel on north dike wall of ash basin.Flow Established per SOC Document observed flow.Water is relatively clear,with a slight River conveyed to UT to the Yadkin River. Terms of NPDES Attachment A orange tint. Permit Buck 5-12** 35.707429 80.373661 UT to Yadkin WS-V Channeled seep through a terracotta pipe.Pipe has NA-Seep NA-Seep Seep eliminated via engineering controls.Area inspected, River been plugged;discharge eliminated. Dispositioned Dispositioned but seep no longer exists.No issues noted. Minimal AOW with no flow.Identified as a damp UT to Yadkin area near pumphouse;no sufficient flow to NA-SeepNA-SeepSoils were moist at the ID sign and became saturated Buck S-13** 35.711931 -80.364056 WS-V approximately 25 ft southeast of the sign.No overland River perform sampling.Any flow would move to Dispositioned Dispositioned flow observed. adjacent storm drain. Low flow seep near storm water culvert just above Monitoring at UT to Yadkin established Duke Trickle of flow from the culvert.Minor amounts of orange Buck S-14 35.712171 -80.364817 River WS-V S-05 location.Any flow will move to UT to Yadkin Energy S-OS See S-05 bacteria/floc/iron-oxidation on rip-rap substrate. River near S-05. monitoring site Low flow seep downgradient of S-05 location.Seep Monitoring at UT to Yadkin established Duke Saturated ground but no visible flow. Some orange Buck S-15 35.7123 -80.3644 River WS-V flows to braided,short reach UT prior to entering Energy S-05 See S-05 biogrowth and floc on saturated substrate. Yadkin River. monitoring site Static area of wetness along west dike wall of ash ** UT to Yadkin basin.Flow would drain toward S-09 sampling site. NA-Seep NA-Seep Seep eliminated via engineering controls.Area inspected, Buck S-16 35.7044 -80.3746 River WS-V Location has been repaired based on no area of Dispositioned Dispositioned but seep no longer exists. wetness. NA-Monitoring See Page 4 of Buck UT to Yadkin Filter blanket discharge from west dike wall of ash Established per No flow at culvert beneath Dukeville Rd.Some residual Buck S-17 35.7058 -80.3753 River WS-V basin.Flow conveyed to UT to the Yadkin River. Terms of NPDES SOC Document iron staining on riprap. Permit Attachment A Prepared by:WCG Checked by:]VT *-Location previously Investigated as a seep.Monitoring has not Indicated the presence of coal combustion residuals. **-Seep dispositioned via repair and/or non-flowing condition to potentially reach Waters of the U.S.,or other,as noted. ***-Some descriptions have been updated from the original text found in the SOC Attachment A table for accuracy and currency. yg/L-micrograms per liter 28-15A NCAC 02L.0202 Standard CCR-Coal Combustion Residuals mg/L-milligrams per liter NA-Not Applicable NPDES-National Pollutant Discharge Elimination System S.U.-Standard Units SOC-Special Order by Consent UT-Unnamed Tributary Page 2 of 2 I ii . . . ;'\ ; . , . , , „„ W , , , , , .w i � . . , . ! . 1 ; p , , , , I BOO . . . . , 22 _ _ , , , , , ;OM ■ s , � � a . . ■ | , , , , io : . , . . . . ; | , , , , 010 ! ; ; ! ! ! ! ! ! ' , , , , 110 CI ,, ll . 2 . 382 _ _ „ um I . . . . „ . . . „„,, um 1 . . . . . . , , , , KM , , , _ . : ; „ 2 2 2 Z 119: \ : . . . . _ _ _ - - , § ; _ Ili . . . . § ! ! ■ ! , , , , JE� . . . . , Al : . ills: . W� . / ! ! § ! ! ! ! � . . � , , , ` [ !>. %°"| | ! ! ! i - ai . . . . , , , .`21 ; ,}§(E ! .«.2 , . . . . . . . . . , , , : §§�� i _ ! !; | EE ; ; ! | | § ( § § § § �v, ■ _ _ _ . . s . _ _ , , , ; . . o . 8 . . . , . | § A | t ) ) ( § ; . . : ; { ° ; „ s { � I 1 ' § § § | || ! | | | | | | | ! 'Mn! | ; 1 § , f || . h 31 1; AAI1iili, ,1 x \V, AA . _ • . ! I .1 ! • Is § ! _ < | ` | }# ! - - - | ; { / ,\ a ! . 1 ` E ' l \l: § I ; � ` I \ ! ! ; 3 . ! ! | ! I , ! ! . ! § ! _ !! ,! f / , ,(k . , . - \ � \i/ {\��)i{| |! \ ! ,, _ ,, 8sfl ; = l : i i . . . �11A;;;2"1 � . .1,«I� ! |■ evi!#|)it,Ll;! TABLE 2 SEEP SAMPLING RESULTS-MAY 2020 SEEP CHARACTERIZATION REPORT BUCK STEAM STATION DUKE ENERGY CAROLINAS,LLC,SALISBURY,NC ANALYTICAL RESULTS(TOTAL CONCISTEATto5) ANALYTICAL RESULTS(DISSOLVED CONCENTRATION) Total Total AnaMNa Parameter L..e gnesivm Mercury 9,01. sNDrit a Oile: 6.kanium Nate TSaWuns 'weed d nK CMmiWn ChrwnWm Copper leM xkkel zinc e grae Se • Salida (0.653) (0.e.0) (0A ) (.95u1 (0.43u) (0.45u) (0.4591 Reporting Units u9/L m9/L u0/L u9/L mp-NIL lss9/L W/L /L WCL m9/L 1 RN/ 9/L u0/L W/L u9/L W/L W/L u9/L 15A NCAC 02S(Clue Cr WLV) n - 250 x 500 NET O ,Amminilit36 Awdeta0 LOotlen W,<h R.epect to mpu mpMD Leo..ID Loot*Oaglpllen YY Sreundw M•r flow ire<tis n Mee LMRYN L prtude Colln�sn .p An•Miol 3.•u0• Downstream Yadkin Denmm<am Yadkin River --- --- Water 35.71390000 -80.34723600 05/13/2020 0.39 2.15 0.00125 <1 1.1 NA <I 4.3 <0.2 80 NA <5 <I <0.1 <1 <1 <0.2 <1 <5 Instreem 5-01 S-06 Ash Basin --- Water --- --- 05/13/2020 0.968 1.5 0.0018e <1 0.16 NA <l 4.6 <0.2 22 NA <5 1.69 <0.1 <1 <1 <0.2 <1 <5 Instream 5-055-115-15 --- Ash Basin --- Water --- ... 05/13/2020 1.75 3.01 0.00305 1.25 0.1 NA Cl S.9 <0.2 TT NA <5 2.01 <0.1 <1 <1 <0.2 <1 <5 5-01 E of Call 3 Secondary AB Ash Basin --- Water 35.70914000 -80.36044001 05/13/2010 0.443 6.93 0.00103 <I 0.11 <5 Cl 19 <0.2 145 9.6 <5 Cl <0.1 <1 <l <0.1 <1 <5 S-04 NE Of Cell 3 Secondary Al Ash Be. --- Water 35.71127300 -80.36039601 05/13/1020 0.289 13.5 0.00547 1.84 0.03 <5 <1 50 <0.2 294 21 <5 <1 40.1 <l <1 <0.1 2.57 <5 f S-05 N of CNI 2 Primary Al,at toe of dam Ash Basin --- Water 35.71213900 -80.36459501 05/13/1020 0.1 14.5 0.00118 1.15 0.19 <S <1 67 <0.2 203 11 <S <1 <0.1 <I <1 <0.2 Cl <5 S-08 W of Comte.CY.plant,W Of Dutrville Rd A01 Basin --- Weer 35.70021200 -80.37834501 05/13/2020 <0.2 10.1 0.00145 1.8 0.13 <5 <I 71 <0.1 190 9.5 15.1 <1 <0.1 <1 <I <0.2 1.68 9.65 - 5-12 Toed Cell 1 Primary AS Sam,upgredient d 5-09 Ash Basin -- Weber 35.70390000 -80.37530001 05/13/1020 0-01 16.e B2 0.00124 9.04 0.4 <5 <I ea <0.1 252 le <5 <1 <0.1 <I 1.31 <0.2 6.26 <5 upstream vadSn Upstream US.Alves -- --- Water 35.71743000 -80.38702E00 05/13/1020 0.4 1.1 0.00124 <1 1.1 NA <1 4.2 <0.2 l NI NA <5 Cl <0.1 <I Cl <0.2 <1 <5 QC SAMPLE RESULTS ANALYTICAL RESULTS(TOTAL CONCENTRATION) ANALYTICAL RESULTS(DISSOLVED CONCENTRATION) Ng Field Blank Feld BISnk --- --- Water --- --- 05/13/2010 NA SO <0.0005 NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA Filter Blank Filter Wank ... ... Water --- .-. 05/13/2010 NA NA NA NA NA NA NA NA NA NA NA NA <1 <0.1 <1 <1 <0.2 <1 <5 mg Trip Blank Trip Blank -- --- Water --- --- 05/13/2010 NA NA <0.0005 NA NA NA NA NA NA NA Na NA NA NA NA NA NA NA NA 9 Cop Upstream Yadkin Upstream Yadk,,River .-. --- Water 35.71743000 80.38/02800 05/13/1020 NA NA 000143 NA NA NC NA NA NA NA NA NA NA NA NA NA NA NA NA Pr e:a ed., E3W Checked bv.1Y DRIW ® -Bold highlighted mnceocauon indicates the result is greater Man the current respective standard or criteria 115A NUC 028(Ciass C,WS-3),SIDES permit va.el All M1ar0ness-Dependent dissolved metal standards in this table assume 5 25 mg/L in-stream hardness. <-concentrabon not detected at Or above the adjusted reporting limit. Deg C•Degrees Celsius GPM-gallon•per minute map.-milligrams per liter m9-N/L-Milligram nitrogen per liter mV-mllllvotts N available or Not Applicable F�Not established measured NTUS-Nephel5meblc Tut-Licata Units S.U.•mnmm Units owl.-micrograms Per We, umhes/cn-incr..os Per a,roment<r r Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra APPENDIX A PHOTOGRAPHS r Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra r. 137°SE (T) 35°42'32"N, 80°21'37"W ±16ft ♦ 674ft gam },gym . 't` .7�. `S A y r._ �' ;:Y '_ - d ti t•„'�' i`�� ` a. "T, °, _aF^;'"'•;. . 4. s S a , ° , :,- '" w � 7r--A., ,a,_ '-'. •, .....----t-r1.104''' -4. '''':-:.-1;4%-' Ate,..: ,... 7., -- ' • w ,1 t w r r 2> 'C >~. r 14' ' -.._ 1 i r jot* • '"+ )ram ,- 1.g '` , Ya ' ,y,--./ 1 _` • 1n_'_ - a,A, 1 x4 .ram '1 • ;k'• a S-01 Non-Constructed Seep—View facing southeast Page 1 of 18 r Seep Characterization Report July 2020 Buck Steam Station-Duke EnergyCarolinas,LLC SynTerra ynTerra 0 216°SW (T) * 35°42'33"N, 80°21'34"W ±16ft ♦ 693ft •; • da{ • s.. _ ate•. ,1t �' '-*• 1' �!4 ,,r.,. - *..c mot . .- • ¢ .�k - -4, ...?"r- ! .. ' _ ' rs'i f,- f 0 NQ►y r SA •. , q. :-. +t Q s y a „ f ✓.'Y fier y , �. *d. P. ,, n s rt A�" - p }}' r ,b y�.•: y� ":d µ* 1 {% . �.+' . , a `1 Q1 fir= a!rsry l_ ,Y. 'ran �`r..x •• • C' ..yv. i ..+ te ,. :., g. , icr'; Y „„yy • � '"" T'.-or„ � !' ' ! . b `- -,.5 s.:+MT. s , _ . ` .. , . J--. . ** - fi ... ...... ....... # 4 - Dispositioned Seep—View facing southwest Page 2 of 18 r Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra 0102°E (T) OO 35°42'37"N, 80°21'36"W ±16ft ♦ 650ft y ii'liii22 l„ - ,,ch ' y.: .� ' '.. .} w w ".N>ac IV 7� - A . � r. r +q+}r_ !, day S:�'• a + _-� 'ter� ty.. � w_yy X 1 M''o A"te : -.' A— 3 . s►4 � ��yyEE ..r.O' r•.=,. 1 h. w�'-'."" a • P � aCw ti - e, -, . __{ .!_c• 4 'i Ti � "t--��t4 ei,'yam. ity ,, ..„..,.. .„..,,,. . ....„,......,. . .,. .. , , 1 1 ..... ._. „,,. ...... ..., ,,.. , .1/4, ..„....... _ , . .„. ..„ . - ,,, . . . ,4,4,-:: i 1.1":' '';'. ...4,"- .-114104.:444%lr' 7:•'.: ' '..';, . ''''•. ..)- , • _..is _ T_ r`. yam. �",\`\'�F*�'x' �< ,ram i 7`9"' � %. ` .fr 7Lf ""-' v u ' ' 4- ,. n, . - ,.., 1,11.--4-6.-*'-‘.. .,,4`. , ' . IP; ..,,,- . .., ,,,,,„ .._,i. _,„,„ . �., , •w ��. -� Y ... ''.t ° 1 — k ,,,, ,,,, _ .....), , IS-03 Dispositioned Seep—View facing east Page 3 of 18 Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra 11 fl 1 A 265°W (T) O 35°42'40"N, 80°21'38"W ±16ft ♦ 661ft - f -4.. ? ;•. `. .+.e .. t • , Y S-4 I • • 1 ,-,,...4.,..tirtt - - 1 K,'. .* } , ,q t 14* • ,r(y Ir ,'HF �4.° k` * -4,47-0 '•'g: .4 Dili/' ..ic. ,. 1A r !.t `r* i + " ilk % i . 1,4 -- ,;A , '! 9r ` Y r ,M{A if ry"�iril f i�!R 1rz- 'f ..,r{+„ I °� ; ,.. Icy M j, �. ,� + , J x , • { t . .1 .:.." v. 'kid 9Ad .. ;. 4.4A flu ; : , 06 Apr 626, 11:53:38 ' ` S 04 Non-Constructed Seep—View facing west Page 4 of 18 f July 2020 Seep Characterization Report Buck Steam Station-Duke Energy Carolinas,LLC SynTerra Y i 0 21°N (T) OO 35110 °42'44"N , ofr , .• ,. •,. „!.,..,,,,, , 80°21'52"W ±16ft A 638ft �� ..� �- ...),,,,,, 4...1/4.-„c. . ...-itt: it ,_ , -_, „..tets.1 4, , L a i, S t ,•• } ..yy{�r` or', `.,+ `•it •.4,- ` '� ev i l_ y s , _, t ii... .. . , ,,,„ . . #7„ , ,, , ,,.. , ,, =407.' ‘14,41009;'. %Ai:-1- 4.1.14 j '.'4' - ;41• ' ►r � O pr2020. 10:43:17 S-05 Non-Constructed Seep—View facing north Page 5 of 18 r Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra 0 291°W (T) OO 35°42'43"N, 80°22'9"W ±16ft A 679ft } t' l'I� ` } k t'4.4 A F '-(:. .silt.* ,-- -,, ':, _ •r� i , ,7.,'.1.:.";*.a.m.:11t:::411.;";:, ,:1: .,,,.,4.,4 r iv r'z ' i),.::::::Te''''f:: ''''' '-:* r r a ,.;tom}t,. a° ,w ,.•�y 7M a..' ,7 y z 4 • rft. aY ' ; _ '' 71,,,.' • + ,A.O h * '. r. - . tom' �„ :� i y4r' P '*, . _ _� ems+ �wo.- ; -- _� .5. lif � r `,m i, yr ..s. ,. trikiipijk, .0- . .„ - ...: • lak',44.1' 4. A:: :1;':. ir:likt"; '' to 1,..-,....„„,,.* 4-,.. I-40,--''F, 17...;...' ''''.::-.4.- , . . .... •.....:: Or , ,,,,,,,,, .i ,, , , ... , , , ,„,,,,,,,,i.:, .,,,,.,,., , .4 .,,.. ... s. ` � � _ �, ma m t _ rid �..+\ � C • " ` , t t ..� ` aw x ! . - *� r A S. : 06 Apr 2020, :24: Jai. 41.1 "'+. S-06 Dispositioned Seep—View facing west Page 6 of 18 r Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra 0 274°W (T)f*O 35°42'31"N, 80°22'43"W ±16ft ♦ 629ft .` -- A 4 A`�r'�' r;>. .., -ic,'.' '' Kit ,,..., s,�- .. .- ,, At � e.'7 �. k,♦ W ear`ty� a� ..� c � 1+�. �'- [ a' ., , e\ �s z .. . it 7 A. • tr { * yy��. !! x• — ..; W �' y �• ' 1 of ,u , l ... i1frt • - �i r yam � �'re * "'�!� i 9 ; � k" .+^� ~ At ' i , r. '_a �'♦ + ,+1 � , € a`,'Et ,.r . �; , t i ..f„^ i 1. _; `tom i. o .� `t `,� •i,�" '4."•At .r. +A •"!y ;11 '- .0i I" r vfie• , S-07 Dispositioned Seep—View facing west Page 7 of 18 Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra 0 240°SW (T) L 35°42'29"N, 80°22141"W ±16ft ♦ 615ft 4*1 a ., ;tSf4 mot• _ r Sl« 'fi• t tt. • TEA "( f • �^ry Y d' 1 !', t a q . f * ,� it S-Q$ Non-Constructed Seep-View facing southwest Page 8 of 18 Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra li .C) 213°SW (T) • 35°42'19"N,+, ,80°22'32"W ±16ft ♦ 681ft .. ?fp _ a ' +sue `a Y 'r �1 ,,44', r . iiii7r P .r r >a r -\ ..,4- 'a. 4, a�j -`.'4 .a 9 �-' _ '✓ ,fir> 9 �`i ►. > wgyY t ,.4114 4 ter. . ¢ q 4. K � ! 0 Itr:iwe.4, 'gam.. f F, • v^ '!R a4 .....cii aN i �r x f. 1 . J. l e F i m t i • S-09 Dispositioned Seep—View facing southwest 1'ag( ,)of I Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra 0 218°SW (T) 0O 35°42'7"N, 80°22'34"W ±16ft ♦ 673ft " .. -. �. t - P y• _ , .-A. - .„._,-.., ,.,..olt : ,. - v.k. 61W2,1., ..-' '120-11'. _7.:'"si ,___ '1. r -r 'n Nam ...' i ,,-1' _y, '' / .� F • F ors '^',..x+-.* �' . +' M1 -T '4.r 4 ffi• `l• 4y w t ',, T _If d y 33 Y.'"? y �' q„ ♦ Syr �,. .r 1,,r, .......,4:44:,..i.‘tleillPh4;1 I,1115:d ',...:,,,,,,..* ::',,,iz°,•.:.: :1,,-....,_• .,.4. .. tl 4,..,s;... :"::::1 .11,-*2'''--. :- 314i* . ' • ',„ ` ~ 1 �� • �!' - s �` "��"_� F .. �r ,�z.�, �- r • ` sit Ark 0 ',it. qx w t,„ l tt' 1 �i 4 s� f'[l.. "r f •;L fA ii .. t y. lb►,l. y : 6 Apr 202ti, 14 23 41 S-10 Dispositioned Seep-View facing southwest Page 10 of 18 Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra 0 279°W (T) *--- 35°42'25"N, 80°2226"W ±16ft ♦ 692ftfilli. • f ... 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" .. . r,p a&- Y:: S-11 NPDES Constructed Seep(Photo 1 of 2)-View facing west Page 11 of 18 Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra 040' lit 218°SW (T) OO 35°42'25"N, 80°22'26"W ±16ft ♦ 680ft ,� ... s 1 ! x ,.",y ,1 t. a s'.Y' k v , y S-11 NPDES Constructed Seep (Photo 2 of 2) Page 12 of 18 Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra 111 NW N i 0 332°NW (T) `• 35°42'26"N, 80°22'25"W ±26ft ♦ 674ft c ,... - • R ,. a ' ,xp. a e^ub wv bmv u J. r a, " ' ' r- ..,' e • k -„:. , , ,it...,.., , . .. ,„ .„, .. .v. t., „ . .„. . 5froif tii ,,,51„. -14 r f . -- ..tAs . .,,r/ , 2, .,, , jempf,.,,, ''..z..,..i.,0 . ' ' fit ` f , al.,�:¢ ` ° ° +-,. ': .* - 'b /i v x „., i . s , .(.4 . ,. ...) ' ir ..' %�. ��Ky�� s 0.- t i . . , d , S-12 Dispositioned Seep via engineering solution Page 13 of 18 f Seep Characterization Report July 2020 Buck Steam Station-Duke EnergyCarolinas,LLC S Terra yn i. C9 164°S (T) •} 35°42142"N, 80°21'50"W ±16ft ♦ 643ft . • .0 - • � ` �. • .r^ � 'i S'L ''Vi - inn x 6t ;. , '", , 14� 1' ." 1. .£R b[' to rip �, A c , ;! *; •'i „ ;' ' mob. rf.- a ',1. ri ; !b ' (r x• ,Y • i ` it s' Apc 2020, 1 t35;53 S-13 Dispositioned Seep-View facing south Page 14 of 18 Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra c' 310°NW (T) 35°42'43"N, 80°21'53"W ±16ft ♦ 687ft _r ' r ice..04 �f YA v i �y v1 i XR • ' ''''' 4,,,Aire, . ivf.. . a• kg t•, T \a6 Apr 2020, 10:3 L. .w`, S-14 Non-Constructed Seep—View facing northwest Page 15 of 18 Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas, LLC SynTerra �. • , , ; 17°N (T) O 35°42'44"N, 80°21'52"W ±16ft A 6,70ft :.,!A7 b. ti ', zae $ t +y „;ti :k rt ' -xs,> "'^' a..�*�c+#. �;*�f, .,� Y r."' ,dam ' y, ` ,✓ f, 5A ly L R • 1 M tpi g ,-:,' '*77.;..':- - : . ' ' -* * •,,„tick.—i-' i '4,,`' '.:Vg',„' ''',10,,,,,,... 04,4.fr. 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I x 9' 0 351°N (T) 0 35°42'15"N, 80°22128"W ±49ft ♦ 686ft u s t g .w c • • r .. y �" Buck t; „ 2020. 13:25:41 S-16 Dispositioned Seep-View facing north Page 17 of 18 Seep Characterization Report July 2020 Buck Steam Station-Duke Energy Carolinas,LLC SynTerra ,m 0258°W (T) '• 35°42'20"N, 80°22'30"W ±16ft ♦ 626ft ,4., ^ems y - , N P...,^" •_r r ✓ a Y. --'�VA.L,,, t 1. .a .Yr,-+t 'y "C* s'y t ..gyp.. ->•� t T.H . t p n y1 , . .,41011, ,...,,, ..,„....$, ,emp P":4" f:- s ' -rAvii • A.O.W*¶' P. ' -± ' - r'' ,.:-.::, ::',.'t;' S�17 , oi. Aviv •. "° r'i ^' .� •$1....l�'� .,.. 0 NC0 04774 ■ JI NC0006TT6 A„,,,,, „. ..,.., TT ,---. r ',,tilf, 4: .. . --:*' , li---"t"N... ' ''i - - ,.,44 ' , k' � r _ ` l` ,3 of 4a v r w" ` ' °' ►. IL t J. • ' cam' . ., '.)' "w F f t "A .t.I- s„ a " ; " #irP'aK r'1 - ''' .. a S-17 NPDES Constructed Seep-View facing west Page 18 of 18