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Home My WebLink AboutAdditional Source Area Assessment Workplan3191 Pine Hall Road Walnut Cove, NC 27052 336-445-0610 November 15, 2018 Ms. Shuying Wang Division of Water Resources North Carolina Department of Environmental Quality Winston Salem Regional Office 450 West Hanes Mill Road, Suite 300 Winston-Salem, North Carolina 27105 Subject: Duke Energy Carolinas, LLC Dan River Steam Station Proposed Additional Source Area Assessment Dear Ms. Wang: Duke Energy submits this proposed work plan, prepared by SynTerra Corp., to assess additional sources of groundwater exceedances at the Dan River Steam Station site. Pursuant to the September 8, 2017 DEQ letter and agreed upon during the CSA Update Review comments meeting on June 28, 2018, Duke Energy understands the former coal pile area, CT area, and construction warehouse area soils and underlying groundwater to be a potential “secondary source” of inorganic constituents that will be assessed apart from CAMA. Duke Energy formally requests your concurrence to this Assessment Work Plan. If you have any questions or concerns, please contact Melonie Martin at 336-445-0610 or at Melonie.Martin@duke-energy.com Sincerely, Melonie Martin Environmental Services Electronic cc: John Toepfer, Duke Energy Ed Sullivan, Duke Energy Jerry Wylie, SynTerra Corp. Sherri Knight, NCDEQ Steve Lanter, NCDEQ Eric Smith, NCDEQ ADDITIONAL SOURCE AREA ASSESSMENT DAN RIVER STEAM STATION 900 S. EDGEWOOD ROAD EDEN, NC 27288 NOVEMBER 2018 PREPARED FOR DUKE ENERGY CAROLINAS, LLC Jerry A. Wylie, NC LG 1425 Project Manager Erin N. Kinsey, EIT Project Engineer Additional Source Area Assessment Work Plan November 2018 Dan River Steam Station Page i P:\Duke Energy Carolinas\19. DAN RIVER\Additional Source Areas\Work Plan\FINAL\Dan River Coal Pile Asmt Tech Memo Final.docx LIST OF FIGURES Figure 1 Site Location Map Figure 2 Proposed Monitoring Well & Soil Boring Location Map – South Figure 3 Proposed Monitoring Well & Soil Boring Location Map – West LIST OF TABLES Table 1 Soil Sample Analytical Methods Table 2 Proposed Coal Pile Assessment Soil Samples and Monitoring Wells Table 3 Groundwater Analytical Methods Additional Source Area Assessment Work Plan November 2018 Dan River Steam Station Page 1 P:\Duke Energy Carolinas\19. DAN RIVER\Additional Source Areas\Work Plan\FINAL\Dan River Coal Pile Asmt Tech Memo Final.docx Introduction Duke Energy Carolinas, LLC (Duke Energy) owns and operates the Dan River Energy Complex on the site of the former Dan River Steam Station (Plant or Site) near the town of Eden in Rockingham County, NC. The Site encompasses approximately 380 acres. Coal-fired power generation operations began in 1949 with the construction of the first of three power-generating units. All three coal-fired units along with three 28- megawatt oil-fired combustion turbine units were taken offline in 2012. A Combined Cycle Station was constructed on site and began operation in October 2012. Coal was transported on site by rail and stored on approximately 6.5 acres that constituted the former coal pile area, immediately north of the former steam station on the north bank of the Dan River. Combustion turbines (CTs) were located north of the former coal pile, near the southwest corner of the Combined Cycle Station. Following the retirement of the coal- and oil-fired units, the coal pile and turbines were removed from the Site. A construction warehouse was built where a former baseball field was located. Groundwater and soil assessment activities for the former coal pile area, CT area, and construction warehouse area are described herein. The on-site Land Clearing and Inert Debris (LCID) Landfill, Permit 79B-LCID, is not included in this assessment. The LCID landfill does not contain coal combustion residual (CCR) material. Regulatory Background In 2014, The North Carolina General Assembly passed the Coal Ash Management Act (CAMA). CAMA required owners of a CCR surface impoundment to conduct detailed assessment of Site groundwater within and around the CCR surface impoundment. As indicated in a letter from the North Carolina Department of Environmental Quality (DEQ) dated September 8, 2017 (Zimmerman to Sullivan), it is understood that in addition to CAMA requirements, Duke Energy is also bound by the rules and requirements of the NC General Statutes and NC Administrative Code 02L. These provide requirements for the assessment and abatement of soil and groundwater impacts resulting from Site activities. Therefore, Duke Energy is required to address soil and groundwater impacts resulting from all primary and secondary sources at the coal ash facilities, not just the CCR surface impoundments. Pursuant to technical direction provided by in the September 8, 2017 letter, Duke Energy understands the former coal pile area, CT area, and construction warehouse area soils and underlying groundwater to be a potential “secondary source” of inorganic constituents will be assessed on a separate timeline apart from CCR surface impoundments covered under CAMA. Additional Source Area Assessment Work Plan November 2018 Dan River Steam Station Page 2 P:\Duke Energy Carolinas\19. DAN RIVER\Additional Source Areas\Work Plan\FINAL\Dan River Coal Pile Asmt Tech Memo Final.docx Site Description The Dan River Plant is situated on the north bank of the Dan River, which is the south/southwest property line of the Plant (Figure 1). The Plant is bordered by an unnamed tributary on the west side, which flows into the Service Water Settling pond. Another tributary, locally known as Railroad Branch, flows through the Site east of the Plant operations. The former coal pile is located north of the former steam station (Figure 2). The steam station and former coal pile were separated by a rail line that was used to transport coal onto the Site. This area is south of what is now the Combined Cycle Station and is a large, vacant grass-vegetated area. The land surface surrounding the coal pile is generally flat and is at an elevation of approximately 530 feet North American Vertical Datum of 1988 (NAVD 88). The combustion turbine area is located at the southwest corner of the Combined Cycle Station (Figure 2). The area is now a cleared, grassy area. The elevation of the area is approximately 545 feet NAVD 88. The construction warehouse area is located northeast of the Combined Cycle Station (Figure 3). The area was graded to create a flat, paved area upon which the warehouse and laydown areas were constructed. Beyond the paved area to the south and west, the land surface slopes downward west toward the unnamed tributary on the west of the Site and southwest along the west side of the Combined Cycle Station into a drainage swale. The elevation of the construction warehouse area is about 600 feet NAVD 88. Additional Source Area Assessment Objectives Objectives of the additional source area assessment include the following: • Characterize inorganic constituents associated with coal pile area, CT area, and construction warehouse area soils; • Compare inorganic constituent concentrations in coal pile area, CT area, and construction warehouse area soils and Site background soils; • Characterize inorganic constituent concentrations in groundwater underlying the coal pile area, CT area, and construction warehouse area and just beyond the coal pile area, CT area, and construction warehouse area perimeters; and • Compare inorganic constituent concentrations in coal pile area, CT area, and construction warehouse area groundwater and Site background groundwater. Additional Source Area Assessment Work Plan November 2018 Dan River Steam Station Page 3 P:\Duke Energy Carolinas\19. DAN RIVER\Additional Source Areas\Work Plan\FINAL\Dan River Coal Pile Asmt Tech Memo Final.docx Soil Assessment Coal pile area, CT area, and construction warehouse area soils will be sampled and analyzed for inorganic parameters to determine if they are a secondary source of CCR constituents that may leach into underlying groundwater. Soil samples will be collected at proposed monitoring well locations (CPA-1 through CPA-7; CTA-1, CTA-2 and GWA-7BR; and CWA-1 through CWA-6 and GWA-12) as part of well installation activities. The proposed locations of the monitoring wells are included as Figures 2 and 3. Proposed locations are approximate and may vary slightly based on field observations and locations of underground utilities which will be determined prior to initiation of boring activities. Soil samples will be analyzed for inorganic parameters consistent with assessment of areas used for coal and CCR management (Table 1). Soil samples will be collected from the near ground surface (2 to 3 feet) and at approximately 2- to 5-foot intervals to the top of the groundwater table or bedrock, whichever is encountered first. An additional soil sample will be collected below the water table within the new well screened intervals. SPLP samples will be collected at a frequency of two per well cluster location with one unsaturated sample collected from near ground surface (2 to 3 feet) and a saturated sample collected 2 to 3 feet below the water table (Table 2). Soil samples will also be collected from depths that coincide with the screen intervals of newly installed wells for analysis of metal oxy-hydroxide phases of iron and aluminum (HFO and HAO) to support optimization of the geochemical model for the Site. HFO/HAO samples will be collected at each well. Following the first round of groundwater sampling, wells that are geochemically significant to the Site will be selected for analysis at approximately 15 wells. HFO/HAO analysis will be used in a geochemical modeling approach that combines an aqueous speciation model with a sorption model under a thermochemical framework that will use the site-specific in-situ HFO and HAO results as a proxy of constituent sorption capacity. Groundwater Assessment Groundwater conditions proximate to the three areas of further investigation will be assessed by installing groundwater monitoring wells in and around of the coal pile area, CT area, and construction warehouse and collecting/analyzing representative groundwater samples from the wells. A total of 21 coal pile assessment (CPA) groundwater monitoring wells are proposed to be installed to characterize coal pile area groundwater conditions. Four shallow (“S”), four deep (“D”), and four bedrock (“BR”) groundwater monitoring wells (CPA- Additional Source Area Assessment Work Plan November 2018 Dan River Steam Station Page 4 P:\Duke Energy Carolinas\19. DAN RIVER\Additional Source Areas\Work Plan\FINAL\Dan River Coal Pile Asmt Tech Memo Final.docx 1S/D/BR, CPA-2S/D/BR, CPA-3S/D/BR, and CPA-4S/D/BR) are planned to be installed as well clusters at the proposed locations shown on Figure 2. A total of seven combustion turbine area assessment (CTA) groundwater monitoring wells are proposed to be installed to characterize coal pile area groundwater. Three shallow (“S”), three deep (“D”), and four bedrock (“BR”) groundwater monitoring wells (CTA-1S/D/BR, CTA-2S/D/BR, and GWA-7BR) are planned to be installed as well clusters at the proposed locations shown on Figure 2. A total of 19 construction warehouse area assessment (CWA) groundwater monitoring wells are proposed to be installed to characterize coal pile area groundwater. Seven shallow (“S”), seven deep (“D”), and eight bedrock (“BR”) groundwater monitoring wells (CWA-1S/D/BR, CWA-2S/D/BR, CWA-3S/D/BR, CWA-4S/D/BR, CWA-5S/D/BR, CWA-6S/D/BR, and GWA-12BR) are planned to be installed as well clusters at the proposed locations shown on Figure 3. Well locations may be modified from those shown on Figures 2 and 3 based on field constraints (e.g. underground utility locations, rig stability). Well installation procedures and well construction materials and lengths will be consistent with ongoing CAMA assessment activities in accordance with the approved Proposed Groundwater Assessment Work Plan (Rev. 1) (HDR, 2014). Shallow wells are proposed to be installed so that the top of the screened interval is positioned approximately 5 ft. below the water table, where practical, to avoid potential issues such as biofouling and introduction of artificial redox conditions which are common among monitoring wells with screened intervals that bracket the water table. Rotary sonic drilling will be employed as the primary drilling technology for soil sampling, well drilling, and well installation. In some cases in the unconsolidated surficial materials, hollow stem augers may be employed for borehole stability and unsaturated soil sampling. Rotary sonic drilling allows continuous cores to be retained for subsurface characterization purposes. Continuous soil and rock cores will be collected from the ground surface to the bottom of the exploration to document the underlying stratigraphy; identify the depth encountered and the thickness of the transition zone; identify the depth encountered of competent bedrock; and identify potential water-bearing fractures. Anticipated well depths are provided in Table 2. Groundwater samples will be analyzed for field parameters (e.g., pH, conductivity, and turbidity) and inorganic constituents consistent with ongoing CAMA assessment activities (Table 3). Additional Source Area Assessment Work Plan November 2018 Dan River Steam Station Page 5 P:\Duke Energy Carolinas\19. DAN RIVER\Additional Source Areas\Work Plan\FINAL\Dan River Coal Pile Asmt Tech Memo Final.docx Additional Source Area Assessment Report An additional source area assessment report will be prepared after soil and groundwater sample analytical data is received, validated, and evaluated. Components of the report will include: 1) Brief Site History 2) Description of Source Assessment Activities 3) Observations Concerning Geology and Hydrogeology in Areas of Additional Assessment 4) Soil Analytical Results 5) Groundwater Analytical Results 6) Site Conceptual Model 7) Conclusions and Recommendation Additional Source Area Assessment Work Plan November 2018 Dan River Steam Station FIGURES SOURCE: USGS TOPOGRAPHIC MAP OBTAINED FROM NRCS GEOSPTIAL DATA GATEWAY AT http://datagateway.nrcs.usda.gov/ ,, ROCKINGHAM COUNTY synTena FIGURE 1SITE LOCATION MAP DAN RIVER STEAM STATION DUKE ENERGY CAROLINAS, LLC EDEN, NORTH CAROLINA NORTHEAST & SOUTHEAST EDEN NC QUADRANGLE DRAWN BY: A. ROBINSON PROJECT MANAGER: JERRY WYLIE LAYOUT: FIG 1-1 (2017 USGS MAP) DATE: 12/14/2017 CONTOUR INTERVAL: 20 FEET 1000 MAP DATE: 2017 GRAPHIC SCALE 0 1000 2000 148 RIVER STREET, SUITE 220 GREENVILLE, SOUTH CAROLINA PHONE 864421-9999 www .synterracorp.com P: Duke Ene Carolinas 19. DAN RIVER 018 CSA U ate OWG DE DAN RIVER USGS TOPO MAPS.dw IN FEET <<<<<<<<<<<<<<<<<<<<< &<&<&< &<&<&< &<&<&< &< &<&< &< &<&< &<&< &<&< &<&< &<&< &< &< &< &< &< &< &<&< &<&< &< &<&< &<&< &< &<&< &<&< &<&< &< &< &< &< &< &< &< &< &< &< &< &< &< &< &<&<&< &<&<&< &<&<&< &< &<&< &< &<&< &<&< &<&< &<&< &<&< &< &< &< &< &< &< &<&< &<&< &< &<&< &<&< &< &<&< &<&< &<&< &< &< &< &< DAN RIVERCOMBINEDCYCLE PLANT FORMERSTEAMSTATION DAN RIVER FORMER COMBUSTIONTURBINE AREA FORMERCOAL PILEAREA CTA-2S/D/BR GWA-7BR CPA-5S/D/BR CPA-6S/D/BR CPA-2S/D/BR CTA-1S/D/BR CPA-3S/D/BR CPA-4S/D/BR CPA-7S/D/BR CPA-1S/D/BR AB-30S/D/BR AB-35BR MW-311BR* MW-11/11D CCR-6S/D MW-10*/D* CCR-5S CCR-4S/D MW-310D*/BR* BG-1D/DA BG-5S/D GWA-10S/D GWA-20S/DGWA-6S/D/BR GWA-7S/D MW-22S/D/BR CCR-3S/D 500560520560500 530 520 520 520 5 00 530 530570 520 560 530500 490 530 5 6 0 530 540 530 5 1 0 5 0 0 570 540 520 520 5305 40 560 5 205 7 0 530 530530 5 40550 580 570 51 0520500 5 2 05605605 90 5305 1 0 520 550 53 0 560 580 5905 3 0 520530 56053052 0 5 4 0 5 1 0 530 5 80570 530 510 580 540520 530 5 3 0520 540520 5 60 5405105 7 0 5204 9 0510 570 5 00 52 0 500 520 510 530570 5 0 0 530 5 2 0 560 5 1 0 550 520 530 510 540 490 5 3 0 530 540 FIGURE 2PROPOSED MONITORING WELL & SOIL BORING LOCATION MAP - SOUTH DAN RIVER STEAM STATION DUKE ENERGY CAROLINAS, LLC EDEN, NORTH CAROLINADRAWN BY: A. FEIGLPROJECT MANAGER: J. WYLIECHECKED BY: E. KINSEY DATE: 11/15/2018 148 RIVER STREET, SUITE 220GREENVILLE, SOUTH CAROLINA 29601PHONE 864-421-9999www.synterracorp.com P:\Duke Energy Progress.1026\00 GIS BASE DATA\Dan River\MapDocs\MISC\DANRIVER_ProposedLocations_South_20181114.mxd 150 0 150 300 GRAPHIC SCALE IN FEET &<PROPOSED MONITORING WELL &<MONITORING WELL &<ABANDONED MONITORING WELL ASH BASIN WASTE BOUNDARY ASH BASIN COMPLIANCE BOUNDARY ASH STACK WASTE BOUNDARY CCR LANDFILL BOUNDARY LANDFILL COMPLIANCE BOUNDARY DUKE ENERGY CAROLINAS DAN RIVER PLANTSITE BOUNDARY <STREAM TOPOGRAPHIC CONTOURS (10' INTERVAL) LEGEND NOTES: AERIAL PHOTOGRAPHY OBTAINED FROM GOOGLE EARTH PRO ONSEPTEMBER 11, 2017. IMAGE COLLECTED ON FEBRUARY 18, 2017. DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINASTATE PLANE COORDINATE SYSTEM FIPS 3200 (NAD83). &< &<&< &<&< &<&< &<&< &<&< &<&< &< &< &< &<&< &< &< &< &< &<&< &< &< &< &< &< &< &< &< DAN RIVERCOMBINEDCYCLE PLANT ASHSTACK 2 CONSTRUCTIONWAREHOUSE AREA GWA-7S/D MW-310D/BR OW-303D CWA-1S/D/BR CWA-2S/D/BR GWA-12BR CWA-3S/D/BR CWA-4S/D/BR CWA-5S/D/BR CWA-6S/D/BR BG-5S/D GWA-10S/D GWA-8S/D/BR MW-317BR/BRL MW-23D/BR LF-CW-7S/D AS-12S/D* AS-8D*/BR* MW-315BR* MW-318D* GWA-12S/D 570 560530 540 560 52 0 560 570 580 520 560 5 30520 560510 550 560 580540 530 580 510530520 52 0 560 540 560 5 60570 550 550 590 540560 5 7 0 600 570 5 2 0 560560540540530 540530 600 5305 90520 530520 560 530 600 540 590 FIGURE 3PROPOSED MONITORING WELL & SOIL BORING LOCATION MAP - WEST DAN RIVER STEAM STATION DUKE ENERGY CAROLINAS, LLC EDEN, NORTH CAROLINADRAWN BY: A. FEIGLPROJECT MANAGER: J. WYLIECHECKED BY: E. KINSEY DATE: 11/15/2018 148 RIVER STREET, SUITE 220GREENVILLE, SOUTH CAROLINA 29601PHONE 864-421-9999www.synterracorp.com P:\Duke Energy Progress.1026\00 GIS BASE DATA\Dan River\MapDocs\MISC\DANRIVER_ProposedLocations_West_20181114.mxd 100 0 100 200 GRAPHIC SCALE IN FEET &<PROPOSED MONITORING WELL &<MONITORING WELL &<ABANDONED MONITORING WELL ASH BASIN WASTE BOUNDARY ASH BASIN COMPLIANCE BOUNDARY ASH STACK WASTE BOUNDARY CCR LANDFILL BOUNDARY LANDFILL COMPLIANCE BOUNDARY DUKE ENERGY CAROLINAS DAN RIVER PLANTSITE BOUNDARY <STREAM TOPOGRAPHIC CONTOURS (10' INTERVAL) LEGEND NOTES: AERIAL PHOTOGRAPHY OBTAINED FROM GOOGLE EARTH PRO ONSEPTEMBER 11, 2017. IMAGE COLLECTED ON FEBRUARY 18, 2017. DRAWING HAS BEEN SET WITH A PROJECTION OF NORTH CAROLINASTATE PLANE COORDINATE SYSTEM FIPS 3200 (NAD83). Additional Source Area Assessment Work Plan November 2018 Dan River Steam Station TABLES TABLE 1 SOIL SAMPLE ANALYTICAL METHODS DAN RIVER STEAM STATION DUKE ENERGY CAROLINAS LLC, EDEN NC P:\Duke Energy Carolinas\19. DAN RIVER\Additional Source Areas\Work Plan\FINAL\Table 1 Dan River Coal Pile Asmt Page 1 of 1 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 7471B 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 6010C Sulfate mg/kg EPA 9056A Thallium (low level) (SPLP Extract only)mg/kg EPA 6020B Total Organic Carbon mg/kg EPA 9060 Vanadium mg/kg EPA 6020B Zinc mg/kg EPA 6010C Notes: meq/100g - millequivalents per 100 grams mg/kg - Milligrams per kilogram mV - Millivolts S.U. - Standard Unit Prepared by: RBI Checked by: SRW/TCP/VTV 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. 2. Soil samples collected from near ground surface (2 to 3ft) and from just above water table (field determined) in each boring will also be analyzed for leaching potential using SPLP Extraction Method 1312 in conjunction with USEPA Methods 6010/6020 1. Soil samples to be analyzed for Total Inorganics using USEPA Methods 6010/6020 and pH using USEPA Method 9045, as noted above. TABLE 2 PROPOSED ADDITIONAL SOURCE AREA ASSESSMENT SOIL SAMPLES AND MONITORING WELLS DAN RIVER STEAM STATION DUKE ENERGY CAROLINAS LLC, EDEN NC P:\Duke Energy Carolinas\19. DAN RIVER\Additional Source Areas\Work Plan\FINAL\Table 2 Dan River Addtl Source Area Asmt Page 1 of 3 Monitoring Well ID Estimated Well Depth (feet bgs) Soil Sample ID (Estimated Depth Interval in feet bgs) Comments ----CPA-SB1 (2-3)Unsaturated soil sample ; SPLP ----CPA-SB1 (5-6)Unsaturated soil sample ----CPA-SB1 (11-12)Unsaturated soil sample ----CPA-SB1 (14-15)Unsaturated soil sample(water table ~15 feet bgs) ----CPA-SB1 (20-21)Saturated soil sample; SPLP CPA-1S 30 CPA-SB1 (25-27)Soil sample from shallow well screened interval CPA-1D 50 CPA-SB1 (45-47)Soil sample from deep well screened interval CPA-1BR 100 CPA-SB1 (95-97)Rock sample from bedrock well screened interval ----CPA-SB2 (2-3)Unsaturated soil sample ; SPLP ----CPA-SB2 (5-6)Unsaturated soil sample ----CPA-SB2 (11-12)Unsaturated soil sample ----CPA-SB2 (14-15)Unsaturated soil sample(water table ~15 feet bgs) ----CPA-SB2 (20-21)Saturated soil sample; SPLP CPA-2S 30 CPA-SB2 (25-27)Soil sample from shallow well screened interval CPA-2D 50 CPA-SB2 (45-47)Soil sample from deep well screened interval CPA-2BR 100 CPA-SB2 (95-97)Rock sample from bedrock well screened interval ----CPA-SB3 (2-3)Unsaturated soil sample ; SPLP ----CPA-SB3 (5-6)Unsaturated soil sample ----CPA-SB3 (11-12)Unsaturated soil sample ----CPA-SB3 (14-15)Unsaturated soil sample(water table ~15 feet bgs) ----CPA-SB3 (20-21)Saturated soil sample; SPLP CPA-3S 30 CPA-SB3 (25-27)Soil sample from shallow well screened interval CPA-3D 50 CPA-SB3 (45-47)Soil sample from deep well screened interval CPA-3BR 100 CPA-SB3 (95-97)Rock sample from bedrock well screened interval ----CPA-SB4 (2-3)Unsaturated soil sample ; SPLP ----CPA-SB4 (5-6)Unsaturated soil sample ----CPA-SB4 (11-12)Unsaturated soil sample ----CPA-SB4 (14-15)Unsaturated soil sample(water table ~15 feet bgs) ----CPA-SB4 (20-21)Saturated soil sample; SPLP CPA-4S 30 CPA-SB4 (25-27)Soil sample from shallow well screened interval CPA-4D 50 CPA-SB4 (45-47)Soil sample from deep well screened interval CPA-4BR 100 CPA-SB4 (95-97)Rock sample from bedrock well screened interval ----CPA-SB5 (2-3)Unsaturated soil sample ; SPLP ----CPA-SB5 (5-6)Unsaturated soil sample ----CPA-SB5 (11-12)Unsaturated soil sample ----CPA-SB5 (14-15)Unsaturated soil sample(water table ~15 feet bgs) ----CPA-SB5 (20-21)Saturated soil sample; SPLP CPA-5S 30 CPA-SB5 (25-27)Soil sample from shallow well screened interval CPA-5D 50 CPA-SB5 (45-47)Soil sample from deep well screened interval CPA-5BR 100 CPA-SB5 (95-97)Rock sample from bedrock well screened interval ----CPA-SB6 (2-3)Unsaturated soil sample ; SPLP ----CPA-SB6 (5-6)Unsaturated soil sample ----CPA-SB6 (11-12)Unsaturated soil sample ----CPA-SB6 (14-15)Unsaturated soil sample(water table ~15 feet bgs) ----CPA-SB6 (20-21)Saturated soil sample; SPLP CPA-6S 30 CPA-SB6 (25-27)Soil sample from shallow well screened interval CPA-6D 50 CPA-SB6 (45-47)Soil sample from deep well screened interval CPA-6BR 100 CPA-SB6 (95-97)Rock sample from bedrock well screened interval ----CPA-SB7 (2-3)Unsaturated soil sample ; SPLP ----CPA-SB7 (5-6)Unsaturated soil sample ----CPA-SB7 (11-12)Unsaturated soil sample ----CPA-SB7 (14-15)Unsaturated soil sample(water table ~15 feet bgs) ----CPA-SB7 (20-21)Saturated soil sample; SPLP CPA-7S 30 CPA-SB7 (25-27)Soil sample from shallow well screened interval CPA-7D 50 CPA-SB7 (45-47)Soil sample from deep well screened interval CPA-7BR 100 CPA-SB7 (95-97)Rock sample from bedrock well screened interval Former Coal Pile Area TABLE 2 PROPOSED ADDITIONAL SOURCE AREA ASSESSMENT SOIL SAMPLES AND MONITORING WELLS DAN RIVER STEAM STATION DUKE ENERGY CAROLINAS LLC, EDEN NC P:\Duke Energy Carolinas\19. DAN RIVER\Additional Source Areas\Work Plan\FINAL\Table 2 Dan River Addtl Source Area Asmt Page 2 of 3 Monitoring Well ID Estimated Well Depth (feet bgs) Soil Sample ID (Estimated Depth Interval in feet bgs) Comments ----CTA-SB1 (2-3)Unsaturated soil sample ; SPLP ----CTA-SB1 (5-6)Unsaturated soil sample ----CTA-SB1 (11-12)Unsaturated soil sample ----CTA-SB1 (14-15)Unsaturated soil sample(water table ~15 feet bgs) ----CTA-SB1 (20-21)Saturated soil sample; SPLP CTA-1S 30 CTA-SB1 (25-27)Soil sample from shallow well screened interval CTA-1D 50 CTA-SB1 (45-47)Soil sample from deep well screened interval CTA-1BR 100 CTA-SB1 (95-97)Rock sample from bedrock well screened interval ----CTA-SB2 (2-3)Unsaturated soil sample ; SPLP ----CTA-SB2 (5-6)Unsaturated soil sample ----CTA-SB2 (11-12)Unsaturated soil sample ----CTA-SB2 (14-15)Unsaturated soil sample(water table ~15 feet bgs) ----CTA-SB2 (20-21)Saturated soil sample; SPLP CTA-2S 30 CTA-SB2 (25-27)Soil sample from shallow well screened interval CTA-2D 50 CTA-SB2 (45-47)Soil sample from deep well screened interval CTA-2BR 100 CTA-SB2 (95-97)Rock sample from bedrock well screened interval ----GWA-SB7 (2-3)Unsaturated soil sample ; SPLP ----GWA-SB7 (5-6)Unsaturated soil sample ----GWA-SB7 (11-12)Unsaturated soil sample ----GWA-SB7 (14-15)Unsaturated soil sample(water table ~15 feet bgs) ----GWA-SB7 (20-21)Saturated soil sample; SPLP ----GWA-SB7 (25-27)Soil sample from shallow well screened interval ----GWA-SB7 (45-47)Soil sample from deep well screened interval GWA-7BR 100 GWA-SB7 (95-97)Rock sample from bedrock well screened interval ----CWA-SB1 (2-3)Unsaturated soil sample ; SPLP ----CWA-SB1 (5-6)Unsaturated soil sample ----CWA-SB1 (11-12)Unsaturated soil sample ----CWA-SB1 (14-15)Unsaturated soil sample(water table ~15 feet bgs) ----CWA-SB1 (20-21)Saturated soil sample; SPLP CWA-1S 30 CWA-SB1 (25-27)Soil sample from shallow well screened interval CWA-1D 50 CWA-SB1 (45-47)Soil sample from deep well screened interval CWA-1BR 100 CWA-SB1 (95-97)Rock sample from bedrock well screened interval ----CWA-SB2 (2-3)Unsaturated soil sample ; SPLP ----CWA-SB2 (5-6)Unsaturated soil sample ----CWA-SB2 (11-12)Unsaturated soil sample ----CWA-SB2 (14-15)Unsaturated soil sample(water table ~15 feet bgs) ----CWA-SB2 (20-21)Saturated soil sample; SPLP CWA-2S 30 CWA-SB2 (25-27)Soil sample from shallow well screened interval CWA-2D 50 CWA-SB2 (45-47)Soil sample from deep well screened interval CWA-2BR 100 CWA-SB2 (95-97)Rock sample from bedrock well screened interval ----CWA-SB3 (2-3)Unsaturated soil sample ; SPLP ----CWA-SB3 (5-6)Unsaturated soil sample ----CWA-SB3 (11-12)Unsaturated soil sample ----CWA-SB3 (14-15)Unsaturated soil sample(water table ~15 feet bgs) ----CWA-SB3 (20-21)Saturated soil sample; SPLP CWA-3S 30 CWA-SB3 (25-27)Soil sample from shallow well screened interval CWA-3D 50 CWA-SB3 (45-47)Soil sample from deep well screened interval CWA-3BR 100 CWA-SB3 (95-97)Rock sample from bedrock well screened interval ----CWA-SB4 (2-3)Unsaturated soil sample ; SPLP ----CWA-SB4 (5-6)Unsaturated soil sample ----CWA-SB4 (11-12)Unsaturated soil sample ----CWA-SB4 (14-15)Unsaturated soil sample(water table ~15 feet bgs) ----CWA-SB4 (20-21)Saturated soil sample; SPLP CWA-4S 30 CWA-SB4 (25-27)Soil sample from shallow well screened interval CWA-4D 50 CWA-SB4 (45-47)Soil sample from deep well screened interval CWA-4BR 100 CWA-SB4 (95-97)Rock sample from bedrock well screened interval Combustion Turbine Area Construction Warehouse Area TABLE 2 PROPOSED ADDITIONAL SOURCE AREA ASSESSMENT SOIL SAMPLES AND MONITORING WELLS DAN RIVER STEAM STATION DUKE ENERGY CAROLINAS LLC, EDEN NC P:\Duke Energy Carolinas\19. DAN RIVER\Additional Source Areas\Work Plan\FINAL\Table 2 Dan River Addtl Source Area Asmt Page 3 of 3 Monitoring Well ID Estimated Well Depth (feet bgs) Soil Sample ID (Estimated Depth Interval in feet bgs) Comments ----CWA-SB5 (2-3)Unsaturated soil sample ; SPLP ----CWA-SB5 (5-6)Unsaturated soil sample ----CWA-SB5 (11-12)Unsaturated soil sample ----CWA-SB5 (14-15)Unsaturated soil sample(water table ~15 feet bgs) ----CWA-SB5 (20-21)Saturated soil sample; SPLP CWA-5S 30 CWA-SB5 (25-27)Soil sample from shallow well screened interval CWA-5D 50 CWA-SB5 (45-47)Soil sample from deep well screened interval CWA-5BR 100 CWA-SB5 (95-97)Rock sample from bedrock well screened interval ----CWA-SB6 (2-3)Unsaturated soil sample ; SPLP ----CWA-SB6 (5-6)Unsaturated soil sample ----CWA-SB6 (11-12)Unsaturated soil sample ----CWA-SB6 (14-15)Unsaturated soil sample(water table ~15 feet bgs) ----CWA-SB6 (20-21)Saturated soil sample; SPLP CWA-6S 30 CWA-SB6 (25-27)Soil sample from shallow well screened interval CWA-6D 50 CWA-SB6 (45-47)Soil sample from deep well screened interval CWA-6BR 100 CWA-SB6 (95-97)Rock sample from bedrock well screened interval ----GWA-SB12 (2-3)Unsaturated soil sample ; SPLP ----GWA-SB12 (5-6)Unsaturated soil sample ----GWA-SB12 (11-12)Unsaturated soil sample ----GWA-SB12 (14-15)Unsaturated soil sample(water table ~15 feet bgs) ----GWA-SB12 (20-21)Saturated soil sample; SPLP ----GWA-SB12 (25-27)Soil sample from shallow well screened interval ----GWA-SB12 (45-47)Soil sample from deep well screened interval GWA-12BR 100 GWA-SB12 (95-97)Rock sample from bedrock well screened interval Prepared by: ENK Checked by: JAW Notes: bgs - below ground surface Continuous cores from rotary sonic drilling provide sufficient material for soil sampling and lithologic description. Estimated well and soil sample depths based on data from the GWA-8 and GWA-7 well clusters. Number of soil samples shown is approximate. For example, a shallower water table will result in fewer samples, and a deeper water table will result in additional samples. TABLE 3 GROUNDWATER ANALYTICAL METHODS DAN RIVER STEAM STATION DUKE ENERGY CAROLINAS LLC, EDEN NC P:\Duke Energy Carolinas\19. DAN RIVER\Additional Source Areas\Work Plan\FINAL\Table 3 Dan River Addtl Source Area Asmt Page 1 of 1 PARAMETER RL UNITS METHOD pH NA SU Field Water Quality Meter Specific Conductance NA µS/cm Field Water Quality Meter Temperature NA ºC 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 NA mg/L Field Test Kit 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 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 Radium 226 1 pCi/L EPA 903.1 Modified Radium 228 1 pCi/L EPA 904.0/SW846 9320 Modified Total Uranium NA µg/mL Calculated 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 mg/L SM 2450D Prepared by: RBI Checked by: SRW/TCP Notes: ºC - Degrees Celsius µS/cm = micro-Siemens per centimeter mg/L - Milligrams per liter mg - N/L - Milligrams nitrogen per liter mV - 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 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. INORGANICS FIELD PARAMETERS 1. Select constituents will be analyzed for total and dissolved concentrations. ANIONS/CATIONS RADIONUCLIDES