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Home My WebLink AboutCoal Pile Assessment Technical Memorandum_20181211526 South Church Street DUKE Charlotte, NC 28202 A Mailing Address: ENER Ma E G m Box 10 1 Mail Code C13K Charlotte, NC 28201-1006 December 11, 2018 Ms. Brandy Costner 610 East Center Avenue Suite 301 Mooresville, NC 28115 Re: Soil and Groundwater Assessment - Former Coal Pile at Buck Steam Station Dear Ms. Costner In response to a letter from NCDEQ dated September 8, 2017, Duke Energy Carolinas, LLC. (DEC) is submitting the attached technical memorandum outlining plans to assess potential groundwater and soil impacts from the former coal pile area at Buck Steam Station. Upon concurrence with this assessment plan, Duke will pursue receipt of necessary permits for the installation of fourteen groundwater monitoring wells and perform associated sampling and analysis around the former coal pile area. Please refer to the attached memorandum that provides a detailed description of this assessment plan and let us know if you would like to hold a meeting to discuss the plans further. If you have any questions feel free to contact me at Bristol.Grohol@duke-energy.com or call 980- 373-2693. Bristol Grohol Engineer I ecc: Jay Zimmerman, NC DEQ Andrew Pitner, NC DEQ Joanna Harbison, NC DEQ Steven Lanter, NC DEQ Ed Sullivan, Duke Energy Attachments: Buck Steam Station Former Coal Pile Assessment Work Plan Technical Memorandun L� synTerra TECHNICAL MEMORANDUM Date: December 7, 2018 File: 1026.16 To: Bristol Grohol Cc: Kathy Webb (SynTerra) From: PerrY Waldrep , North Carolina P.G. #2453 Subject: Buck Steam Station Former Coal Pile Assessment Work Plan Duke Energy Carolinas, LLC (Duke Energy) owns and formerly operated the Buck Steam Station (Buck), located on the Yadkin River in Rowan County near Salisbury, North Carolina. The Buck combined cycle station (BCCS) natural gas facility began operating in 2011 and the Buck steam station (BSS) was decommissioned and taken offline in 2013. The Buck plant (Site) encompasses approximately 640 acres. Groundwater and soil assessment activities proposed for the former coal pile area (coal pile) are described herein. Regulatory Background In 2014, The North Carolina General Assembly passed the Coal Ash Management Act (CAMA). CAMA required owners of a coal combustion residuals (CCR) surface impoundment to conduct a detailed assessment of site groundwater within and around the CCR surface impoundments. Primary sources of CCR-related constituents identified during the Comprehensive Site Assessment (CSA) for CAMA (HDR, 2015.) were ash basin cells 1, 2, 3 and the ash storage area. There are currently no groundwater monitoring wells installed in the former coal pile area. Data from the 2015 HDR CSA indicated the presence of boron as well as other metals that are attributed to CCR. Groundwater flow and transport modeling indicates potential flow from ash basin cell 1 to the former coal pile area. The purpose of the assessment of the former coal pile will be to determine if constituents are migrating from ash basin cell 1 and also to delineate the contaminants of interest (COIs) at the perimeter of the former coal pile. Station Description The Site started operations in 1926 as a coal-fired generating station. The BCCS natural gas facility was constructed at the Site and began operating in late 2011. Subsequently, the BSS was decommissioned and taken offline in April 2013. The former coal pile area P: \ Duke Energy Carolinas \ 16.BUCK\ 04.EHS CAMA Compliance Support \ Former Coal Pile \ Work Plan \ Buck - Coal Pile Assessment Work Plan Final v2.docx Former Coal Pile Assessment Work Plan December 7, 2018 Buck Steam Station Page 2 of 3 is downgradient of ash basin cell to the north/northwest of the Site and south of the Yadkin River. The coal pile was removed as part of decommissioning the steam station. The topography at the Site generally slopes downward from the south to the Yadkin River to the north. The site layout is shown on Figure 1. Former Coal Pile Area Assessment Objectives Objectives of the former coal pile area assessment include the following: • Characterize inorganic constituent concentrations in soil and groundwater along the former coal pile area perimeter • Compare inorganic constituent concentrations in the former coal pile area to Site background concentrations Former Coal Pile Soil Assessment Former coal pile area unsaturated soils are proposed to be sampled and analyzed for inorganic parameters to determine if it is a secondary source of coal constituents with potential to impact underlying groundwater. Soil samples can be collected at proposed monitoring well locations at the perimeter of the former coal pile area (CPA-1, CPA-2, CPA-3, CPA-4, and CPA-5) during well installation activities (Figure 1). Soil samples will be collected from 2-feet below ground surface and 2-feet above the water table. An additional soil sample will be collected below the water table within the new well screened intervals for HFO/HAO analyses. Soil samples will be analyzed for inorganic parameters listed on Table 1. Former Coal Pile Groundwater Assessment Existing well cluster GWA-9S/D/BRA, GWA-19S/D, and CCR-26 BR are proposed to be included in the former coal pile groundwater assessment. Proposed well installation locations are shown on Figure 1 and proposed well details are provided in Table 2. Specific well locations may be shifted depending upon access and field conditions at the time of installation. Following completion of well installation, dedicated pumps will be installed in each well, groundwater samples will be collected (initial sampling event), and slug testing activities will be performed. Groundwater samples will be analyzed for the field parameters (e.g., pH, conductivity, and turbidity) and inorganic constituents consistent with ongoing CAMA assessment activities (Table 3). P: \ Duke Energy Carolinas \ 16.BUCK\ 04.EHS CAMA Compliance Support \ Former Coal Pile \ Work Plan \ Buck - Coal Pile Assessment Work Plan Final v2.docx Former Coal Pile Assessment Work Plan December 7, 2018 Buck Steam Station Page 3 of 3 Assessment Report An assessment report is anticipated to include the soil and groundwater analytical data. The report will include the following components: 1) Site History and Source Characterization 2) Site Geology and Hydrogeology 3) Sampling Results 4) Site Conceptual Model 5) Conclusions and Recommendations ATTACHMENTS: Table 1: Soil Analytical Methods Table 2: Proposed Coal Pile Assessment Soil Samples and Monitoring Wells Table 3: Groundwater Analytical Methods Figure 1: Proposed Former Coal Pile Assessment Sample Locations P: \ Duke Energy Carolinas \ 16.BUCK\ 04.EHS CAMA Compliance Support \ Former Coal Pile \ Work Plan \ Buck - Coal Pile Assessment Work Plan Final v2.docx Coal Pile Assessment Work Plan December 7, 2018 Buck Steam Station ATTACHMENTS P:\Duke Energy Carolinas \ 16.BUCK\ 04.EHS CAMA Compliance Support \ Former Coal Pile \ Work Plan \ Buck - Coal Pile Assessment Work Plan Final v2.docx TABLE 1 SOIL ANALYTICAL METHODS BUCK STEAM STATION DUKE ENERGY CAROLINAS, LLC, SALISBURY, NC INORGANIC COMPOUNDS UNITS METHOD Aluminum mg/kg EPA 6010D Antimony mg/kg EPA 6020B Arsenic mg/kg EPA 6020B Barium mg/kg EPA 6010D Beryllium mg/kg EPA 6010D Boron mg/kg EPA 6010D Cadmium mg/kg EPA 6020B Calcium mg/kg EPA 6010D Chloride mg/kg EPA 9056A Chromium mg/kg EPA 6010C Cobalt mg/kg EPA 6020A Copper mg/kg EPA 6010C Iron mg/kg EPA 6010C Lead mg/kg EPA 6020B Magnesium mg/kg EPA 6010D Manganese mg/kg EPA 6010C Mercury mg/kg EPA 7471 B Molybdenum mg/kg EPA 6010D Nickel mg/kg EPA 6010C Nitrate as Nitrogen mg/kg EPA 9056A pH Su EPA 9045D Potassium mg/kg EPA 6010D Selenium mg/kg EPA 6020B Sodium mg/kg EPA 6010D Strontium mg/kg EPA 6010D Sulfate mg/kg EPA 9056A Thallium (total, low level) mg/kg EPA 6020B Total Organic Carbon mg/kg EPA 9060 Vanadium mg/kg EPA 6020B Zinc mg/kgmg/kg EPA 6010C Prepared by: RBI Checked by: WJW Notes: 1. Soil samples to be analyzed for Total Inorganics using USEPA Methods 6010/6020 and pH using USEPA Method 9045, as noted above. 2. Ash samples to be analyzed for Total Inorganics using USEPA Methods 6010/6020 and pH using USEPA Method 9045; select ash samples will also be analyzed for leaching potential using SPLP Extraction Method 1312 in conjunction with USEPA Methods 6010/6020. 3. Analytical methods and reporting limits as presented were applicable at time of CSA field implementation in 2015. Analytical methods and reporting limits are updated periodically and applied as appropriate. meq/100g - millequivalents per 100 grams mg/kg - Milligrams per kilogram my - Millivolts S.U. - Standard Unit P:\Duke Energy Carolinas\16.BUCK\04.EHS CAMA Compliance Support\Former Coal Pile\Work Plan\ Tables.xlsx Page 1 of 1 TABLE 2 PROPOSED COAL PILE ASSESSMENT SOIL SAMPLES AND MONITORING WELLS RIVERBEND STEAM STATION DUKE ENERGY CAROLINAS, LLC, MOUNT HOLLY, NC Monitoring Well ID Estimated Well Depth (feet bgs) Soil Sample ID (Estimated Depth Interval in feet bgs) Comments -- -- -- CPA-1SB 2-3 Near -surface unsaturated soil sample (water table —30 feet bgs) -- CPA-1SB 28-29 Near -top of water table unsaturated soil sample (estimated depth, will be determined in the field) CPA-1S 50 CPA-1SB 45-46 Soil sample from shallow well screened interval CPA-1D 80 CPA-1SB 75-76 Soil sample from deep well screened interval CPA-113R 100 CPA-1SB (95-96) Soil sample from deep well screened interval -- -- CPA-2SB 2-3 Near -surface unsaturated soil sample (water table —30 feet bgs) -- -- CPA-2SB 28-29 Near -top of water table unsaturated soil sample (estimated depth, will be determined in the field) CPA-2S 50 CPA-2SB 45-46 Unsaturated soil sample CPA-21) 80 CPA-2SB 75-76 Soil sample from shallow well screened interval CPA-213R 100 CPA-2SB (95-96) Soil sample from deep well screened interval -- -- CPA-3SB 2-3 Near -surface unsaturated soil sample (water table —30 feet bgs) -- -- CPA-3SB 28-29 Near -top of water table unsaturated soil sample (estimated depth, will be determined in the field) CPA-3S 50 CPA-3SB 45-46 Unsaturated soil sample CPA-31) 80 CPA-3SB 75-76 Soil sample from shallow well screened interval CPA-31311 100 CPA-3SB (95-96) Soil sample from deep well screened interval -- -- CPA-4SB (2-3) CPA-4SB (28-29) Near -surface unsaturated soil sample (water table —30 feet bgs) -- -- Near -top of water table unsaturated soil sample (estimated depth, will be determined in the field) CPA-4S 50 CPA-4SB (45-46) Unsaturated soil sample CPA-41) 80 CPA-4SB (75-76) Soil sample from shallow well screened interval CPA-4BR 100 CPA-4SB (95-96) Soil sample from deep well screened interval -- -- CPA-5SB (2-3) Near -surface unsaturated soil sample (water table —30 feet bgs) -- -- CPA-5SB (28-29) Near -top of water table unsaturated soil sample (estimated depth, will be determined in the field) CPA-5S 50 CPA-5SB (45-46) Unsaturated soil sample CPA-51) 80 CPA-5SB 75-76 Soil sample from shallow well screened interval CPA-513R j 100 1 CPA-5SB (95-96) ISoil sample from deep well screened interval Prepared by:JYT Checked by: Notes: bgs = below ground surface — = Approximately SynTerra recommends rotosonic drilling methods for boring and well installation. Continuous cores from sonic drilling provide sufficient material for soil sampling and lithologic description. Estimated well and soil sample depths based on data from the CCR-26BR, and CCR-27S wells. Number of soil samples shown is approximate. A shallower water table will result in fewer samples, and a deeper water table will result in additional samples. SynTerra recommends each well screen be submerged beneath the water table and have a length of at least 10 feet. P:\Duke Energy Carolinas\16.BUCK\04.EHS CAMA Compliance Support\Former Coal Pile\Work Plan\Tables.xlsx Page 1 of 1 TABLE 3 GROUNDWATER ANALYTICAL METHODS BUCK STEAM STATION DUKE ENERGY CAROLINAS, LLC, SALISBURY, NC PARAMETER RL UNITS I METHOD FIELD PARAMETERS pH NA SU Field Water Quality Meter Specific Conductance NA PS/CM Field Water Quality Meter Temperature NA 0C Field Water Quality Meter Dissolved Oxygen NA mg/L Field Water Quality Meter Oxidation Reduction Potential NA mV Field Water Quality Meter Turbidity NA NTU Field Water Quality Meter Ferrous Iron I NA I mg/L lField Test Kit INORGANICS Aluminum 0.005 mg/L EPA 200.7 or 6010D Antimony 0.001 mg/L EPA 200.8 or 6020B Arsenic 0.001 mg/L EPA 200.8 or 6020A Barium 0.005 mg/L EPA 200.7 or 6010C Beryllium 0.001 mg/L EPA 200.8 or 6020A Boron 0.05 mg/L EPA 200.7 or 6010C Cadmium 0.001 mg/L EPA 200.8 or 6020A Chromium 0.001 mg/L EPA 200.8 or 6010C Cobalt 0.001 mg/L EPA 200.8 or 6020A Copper 0.001 mg/L EPA 200.8 or 6020B Iron 0.01 mg/L EPA 200.7 or 6010C Lead 0.001 mg/L EPA 200.8 or 6020A Manganese 0.005 mg/L EPA 200.7 or 6010C Mercury (low level) 0.005 ng/L 1631 ONLY Molybdenum 0.001 mg/L EPA 200.8 or 6020B Nickel 0.001 mg/L EPA 200.8 or 6020B Phosphorus 0.005 mg/L EPA 365.1 Selenium 0.001 mg/L EPA 200.8 or 6020A Strontium 0.005 mg/L 1 EPA 200.7 or 6010C Thallium (low level) 0.0002 mg/L EPA 200.8 or 6020A Vanadium (low level) 0.0003 mg/L EPA 200.8 or 6020A Zinc 0.005 mg/L EPA 200.7 or 6010C RADIONUCLIDES Radium 226 1 pCi/L EPA 903.1 Modified Radium 228 1 pCi/L EPA 904.0/SW846 9320 Modified Uranium (233, 234, 236, 238) Varies by isotope I µg/mL ISW846 3010A/6020A ANIONS/CATIONS Alkalinity (as CaCO3) 5 mg/L SM 2320B Bicarbonate 5 mg/L SM 2320 Calcium 0.01 mg/L EPA 200.7 Carbonate 5 mg/L SM 2320 Chloride 0.1 mg/L EPA 300.0 or 9056A Magnesium 0.005 mg/L EPA 200.7 Methane 0.01 mg/L RSK 175 Nitrate as Nitrogen 0.01 mg-N/L EPA 353.2 Potassium 0.1 mg/L EPA 200.7 Sodium 0.05 mg/L EPA 200.7 Sulfate 0.1 mg/L EPA 300.0 or 9056A Sulfide 0.1 mg/L SM4500S2-D Total Dissolved Solids 25 mg/L SM 2540C Total Organic Carbon 0.1 mg/L SM 5310C/EPA9060A Total Suspended Solids 2.5 m L SM 2450D Prepared by: RBI Checked by: WJW Notes: 1. Select constituents will be analyzed for total and dissolved concentrations. 2. Analytical methods and reporting limits as presented were applicable at time of CSA field implementation in 2015. Analytical methods and reporting limits are updated periodically and applied as appropriate. OC - Degrees Celsius VS/cm = micro -Siemens per centimeter mg/L - Milligrams per liter mg - N/L - Milligrams nitrogen per liter my - Millivolts NA - Not analyzed NTU - Nephelometric turbidity unit pCi/L - picocuries per liter RL = reporting limit S.U. - Standard Unit ug/mL - micrograms per milliliter P:\Duke Energy Carolinas\16.BUCK\04.EHS CAMA Compliance Support\Former Coal Pile\Work Plan\Tables.xlsx Page 1 of 1 00 NOTES: • � � �.�.• - � �..�...••+�� • .. 4116 1) SAMPLE LOCATIONS WERE DERIVED FROM VARIOUS SOURCES AND - �!�.li'4 ■ yeAS�^�'.�: ARE A MIX OF SURVEYED AND APPROXIMATE LOCATIONS. �;�'•�. ■,+;y„ ••�•• J, "' 1 '� - '-I• I �r - .00. THEREFORE, SAMPLE LOCATIONS ARE TO BE DEEMED APPROXIMATE. r O CCR-27D li' :�.� y .. 1 rid j i•.: { • •i.: d"tiIliff, ♦� 2 AERIAL PHOTOGRAPHY OBTAINED FROM GOOGLE EARTH PRO AND IS a '• `Y# Y �' )DATEDAPRIL8, 2017.IL rl " F{�•�.: 'i. - d'�" �S �.• r �. ky ih IR �J-. ti - _ tA• GWA-18S/D/DA ► � : s b � -� r Y3. _ _ •-. r� _ � GWA-12SIBRU 1."� �, •�1' .rey� .'� of .;�`�II: jf} I i�- ..�; , �•3 4 CPA-1S/D/BR • I 1: •; I� �} ;' �fi ` dd ry r `'`� .# n .'L H CPA-2S/D/BR - • - +� •• � � CPA-4S/D/BR � CPA3S/D/BR •4 5 r�--` f...♦��." '" ` • ��. _ — GWA-6S/BRIBRL/BRU it .�r � • � ' .�� i ir4' ,LAI Aft ' �.+ e GIB - • J 4 ` lot i * - _ CCR-26BR 4 T• • I -'� R■ ' - CPA-SSIDIBR ' J ,•�`rwr-�•3 �'� - � .: ,,. �� ..e ■ CCR-15D - ■ 'F'' �` �� I ., - - '.STY ,yf;=;,.• CCR-9D • ■ k n r S• JOLT - --- � ;. d_• CCR-14S/D - 1 _.4Y ■ GWA-9S/D/BR/BRA f "Pk • CCR-7SID - ``• .� •�..�..�..�..�..�..� .... � • i � q � � � CCR-9S/D �- } � '• LEGEND PROPOSED WELL LOCATION FORME • 150 5 0 150 soo FIGURE 1 MONITORING WELLPIF — FORMER COAL PILE BOUNDARY GWA-22D GRAPHIC SCALE IN FEET R COAL PILE ASSESSMENT � CCR-6S/D 148 RIVER STREET, SUITE 220 SAMPLE LOCATIONS WASTE BOUNDARY MW-9S/D 4; GREENVILLE, SOUTH CAROLINA 29601 BUCK STEAM STATION .`% PHONE 864-421-9999 ASH STORAGE BOUNDARY - COMPLIANCE BOUNDARY ' —•• DUKE ENERGY BUCK PLANT BOUNDARY z) www.s nterracor .com DUKE ENERGY CAROLINAS, LLC mTe r ra PROECT MANAGERNP. WALDREP DATE: 11/08/2018 SALISBURY, NORTH CAROLINA CHECKED BY: B. WYLIE P:\Duke Ener ProI ---s,1026\00 GIB BASE DATA\Buck Combined Cycle Station\Ma Docs\MISC\BUCK Former Coal Pile Assessment 2018.mxd