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Home My WebLink AboutMayo Ash Basin Soil Sampling Tech Memo_20190125L� synTerra TECHNICAL MEMORANDUM Date: January 25, 2019 File: 1026.105 To: Kim Witt (Duke Energy) Cc: Jerry Wylie (SynTerra) From: Peggy Altman P W A, Subject: Additional Soil Assessment - Mayo Steam Electric Plant Ash Basin Perimeter Soil Assessment Duke Energy Progress, LLC (Duke Energy) owns and operates the Mayo Steam Electric Plant (Mayo, Plant, or Site) in Roxboro, Person County, North Carolina. Additional soil assessment activities proposed for the perimeter of the ash basin 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 detailed assessment of site groundwater and soil within and around the CCR surface impoundments. A primary source of CCR-related constituents was identified during the Comprehensive Site Assessment (CSA) for CAMA to be the ash basin. In response to the October 2017 CSA Update, the North Carolina Department of Environmental Quality (NC DEQ) requested additional evaluation of shallow soil surrounding the ash basin to determine the presence, absence, and/or degree of possible impact from historical coal combustion waste management at Mayo. Site Description The Mayo Plant began operations in 1983 with a single 727-megawatt capacity generating coal-fired unit. CCR have historically been managed in the Plant's on -site ash basin (surface impoundment). CCR were initially deposited in the ash basin by hydraulic sluicing operations until 2013 when the Plant converted to a dry ash system in which 90 percent of CCR was dry. Final system upgrades were completed in October 2016; all CCR collection is currently handled dry. CCR from the Plant is managed in the onsite Industrial Landfill permitted by the NC DEQ Division of Waste Management (DWM) (PN 7305-INDUS) or beneficially reused. Discharge from the ash basin to Mayo Reservoir is permitted by the NCDEQ Division of Water Resources (DWR) under the National Pollutant Discharge Elimination System (NPDES) Permit NC0038377. P: \ Duke Energy Progress.1026 \ 105. Mayo Ash Basin GW Assessment Plan \ Additional Assessment \ Ash Basin Perimeter Soil 2019 \ Mayo Ash Basin Soil Sampling Tech Memo.docx Ash Basin Perimeter Soil Assessment January 25, 2019 Mayo Steam Electric Plant Page 2 of 3 Ash Basin Perimeter Soil Assessment Objectives Objectives of the ash basin perimeter soil assessment include the following: • Characterize inorganic constituent concentrations in shallow soil along the ash basin perimeter • Compare inorganic constituent concentrations in these shallow soils to Site background concentrations Soil Assessment Ash basin perimeter soils will be sampled and analyzed for inorganic parameters to determine the presence, absence, and/or degree of possible impact from the CCR materials in the ash basin. Soil samples are planned to be collected at 24 locations around the perimeter of the ash basin (Figure 1). The sample locations will be field - located and will be located as close to the ash basin as practical with no sample collected closer than five feet from the edge of the ash basin. At Mayo, the extent of the ash basin and CCR material is easily discernable. However, the "water line" of the ash basin does vary by a few feet in some areas in response to heavy precipitation/run-off events. Therefore, the sample locations will be placed no closer than five feet from the edge of the basin defined as the point where CCR material is visually observed. Similarly, unless safety considerations require, no boring will be placed further than 10 feet from the edge of the discernable ash basin limits. GPS coordinates will be recorded for each sample location, and a pin flag with the sample identifier will be placed. Borings will be made using either a hand -auger or manual direct -push probe to a maximum depth of two feet. Samples will be collected between a depth interval of one to two feet. One sample per location will be collected for laboratory analysis. Soil samples will be "grab" samples and will not be composited. Collected soil will be place directly into new bottleware provided by the NC certified analytical laboratory. The hand auger, bucket, and/or direct push probe tip will be decontaminated after sample collection at each location. Soap and water and mechanical scrubbing will be used to clean the equipment, followed by rinsing with deionized water. Soil samples will be analyzed for inorganic parameters listed on Table 1. Ash Basin Perimeter Soil Assessment Report An ash basin perimeter soil assessment report will be included as an appendix in the forthcoming Corrective Action Plan (CAP) update document. The report will be prepared once all soil sample analytical data is received, validated, and evaluated. P: \ Duke Energy Progress.1026 \ 105. Mayo Ash Basin GW Assessment Plan \ Additional Assessment \ Ash Basin Perimeter Soil 2019 \ Mayo Ash Basin Soil Sampling Tech Memo.docx Ash Basin Perimeter Soil Assessment January 25, 2019 Mayo Steam Electric Plant ATTACHMENTS: Figure 1: Proposed Ash Basin Perimeter Soil Assessment Sample Locations Table 1: Soil Analytical Parameters Page 3 of 3 P: \ Duke Energy Progress.1026 \ 105. Mayo Ash Basin GW Assessment Plan \ Additional Assessment \ Ash Basin Perimeter Soil 2019 \ Mayo Ash Basin Soil Sampling Tech Memo.docx Ash Basin Perimeter Soil Assessment January 25, 2019 Mayo Steam Electric Plant ATTACHMENTS P: \ Duke Energy Progress.1026 \ 105. Mayo Ash Basin GW Assessment Plan \ Additional Assessment \ Ash Basin Perimeter Soil 2019 \ Mayo Ash Basin Soil Sampling Tech Memo.docx LEGEND Q� MW-3 EXISTING MONITORING WELL SB-3 EXISTING SOIL BORING LOCATION Q PSB-3 PROPOSED SOIL BORING LOCATION PARCEL LINE DUKE ENERGY (APPROXIMATE) HIGHWAY 501 RIGHT-OF-WAY (DUKE ENERGY PROPERTY) — — — 500 ft COMPLIANCE BOUNDARY APPROXIMATE ASH BASIN WASTE BOUNDARY APPROXIMATE STREAM (NON -JD) SURFACE WATER FLOW DIRECTION — APPROXIMATE POND OR RESERVOIR (NON -JD) APPROXIMATE EFFLUENT CHANNEL ® APPROXIMATE FREE PONDED ASH BASIN WATER CULVERT LOCATION 100' RIGHT OF WAY c 1951 AERIAL PHOTOGRAPH }2(a hil BR .R^107BR FORMER INTERMITTENT STREAM B ON 1968 USGS TOPOGRAPHIC MAP to pp • Our 1j11 11llll��i�l - i �� 0 SOURCE NOTES: NOT ALL UTILITIES ARE IDENTIFIED ON THIS DRAWING. THE UTILITIES SHOWN ON THIS DRAWING ARE VISUAL AIDS TO LOCATE THE STREAMS AND WETLANDS IN THE FIELD. THE HORIZONTAL LOCATION AND THE VERTICAL LOCATIONS HAVE NOT BEEN FIELD LOCATED ON ANY UTILITIES AND THE SHOWN LOCATIONS ARE APPROXIMATE. THE TOPOGRAPHY IS A COMPILATION OF LIDAR DATA OBTAINED FROM FRIS- NORTH CAROLINA FLOOD RISK INFORMATION SYSTEM AT ftp.,//ftpl.ncem.org/Data_Requests/County_LIDAR_Data/Personcounty/ AND AN AERIAL TOPOGRAPHIC SURVEY-MAYO PLANT BY WSP, DATER JULY 24, 2015, JOB NUMBER: 1570002.00, DWG NAME: MAYO OVERALL WK.DWG FOR STREAM JURISDICTIONAL STATUS REFER TO THE STREAM CLASSIFICATION TABLE CONTAINED IN THE CURRENT USACOE MAYO STEAM ELECTRIC PLANT JURISDICTIONAL STREAM AND WETLAND SURVEY. FGD SETTLING vA sti�_a 4so ABMW 4D v /' `POND g, PROPOSED LINED ABMW 46R ABMW 4 a p %' j / 1 RETENTION BASIN AREA a ° \ 5 \ � P / �f MW LRB-1�•o, �\ a \'OOP 5 ///'/ 'Zi yam° 5zo MW-196R SIp "�Y (7 rn dam' S / / � � / �'' � 1 9 �'�s.. o•- f A o�' - PRIMARY AND SECONDARY SETTLING PONDS 200 GRAPHIC SC200 400 FIGURE 1 DUKE IN FEET PROPOSED LOCATIONS 148 RIVER STREET, SUITE 220 ENERGY PHONE 64-421-9999CAROLINA 29601 ASH BASIN PERIMETER SOIL ASSESSMENT PHONE864-421-9999 MAYO STEAM ELECTRIC PLANT ao TerraDRAWNWS Y: C. NEWELL COm PROGRESS 5� ww's C. GER:J. DATE:0122/2019 ROXBORO NORTH CAROLINA PROJECT MANAGER: J. WYLIE � LAYOUT: FIG 1(PROP SOIL LOCI Ol/25/201911:29AM P:\Duke Energy Pro ress.1026105. Mayo Ash Basin GW Assessment Plan 49.EHS-Ex anded CAP Sco a dw DE MAYOSOIL ASSESSMENT -2.dw TABLE 1 SOIL SAMPLE ANALYTICAL METHODS MAYO STEAM ELETRIC PLANT DUKE ENERGY PROGRESS LLC, ROXBORO, 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 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 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: SRW/TCP/VTV 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. Analytical methods and reporting limits as presented were developed for 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 Progress.1026\105. Mayo Ash Basin GW Assessment Plan\Additional Assessment\Coal Pile Assessment 2019\Coal Pile Assessment Work Plan\Tables\Table 1 Soil Sample Analytical Methods Page 1 of 1