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HomeMy WebLinkAbout7906_Duke_DanRiver_Area1SoilSamplingPlan_DIN26909_20161025Belews Creek Steam Station 3195 Pine Hall Road Belews Creek, NC 27009 336-445-0610 336-669-2994 www.duke-energy.com Page 1 of 2 October 25, 2016 North Carolina Department of Environmental Quality Division of Waste Management Solid Waste Section 2090 U.S. Highway 70 Swannanoa, North Carolina 28778 Attn: Mr. Larry Frost (electronic delivery only) Re: Excavation Soil Sampling Plan For Area 1 Dry Stack Duke Energy Dan River Steam Station Permit No. 7906-INDUS-2016 Rockingham County Eden, North Carolina 27288 Dear Mr. Frost, On October 11, 2016, Duke Energy received Guidance for Area 1 Dry Stack at the Dan River Steam Station (DIN 26815). In response to that guidance, an Excavation Soil Sampling Plan has been prepared and is being submitted for review by the Solid Waste Section. Duke Energy is committed to excellent environmental stewardship and cooperation with the Division regarding the operation, maintenance, safety, and integrity of all of its facilities. We look forward to continuing to work with you regarding environmental concerns. If there are any questions regarding this request, please contact Melonie Martin at (336) 445-0610. Respectfully submitted, Melonie Martin Environmental Services Attachment: Excavation Soil Sampling Plan www.duke-energy.com Page 2 of 2 cc (via e-mail): Elizabeth Warner, NCDEQ Shawn McKee, NCDEQ Shannon Aufman, NCDEQ Ellen Lorscheider, NCDEQ Melonie Martin, Duke Energy Ed Sullivan, Duke Energy EXCAVATION SOIL SAMPLING PLAN FOR AREA 1 DRY STACK DUKE ENERGY DAN RIVER STEAM STATION DUKE ENERGY CAROLINAS, LLC. 526 SOUTH CHURCH STREET/EC13K CHARLOTTE, NORTH CAROLINA 28202 Waste & Groundwater Programs Revision 0 October 2016 Area 1 Dry Stack Soil Sampling Plan October 2016 Duke Energy Carolinas, LLC Revision 0 Page i TABLE OF CONTENTS SECTION PAGE 1.0 PURPOSE ................................................................................................................................1 2.0 SOIL SAMPLING METHODOLOGY .............................................................................................1 2.1 Method Summary 1 2.1.1 Equipment 1 2.1.2 Sample Locations 2 2.1.3 Collection of Representative Samples 2 2.1.4 Sample Preservation, Containers, Handling and Storage 3 2.1.5 Decontamination 4 3.0 VISUAL CONFIRMATION OF ASH REMOVAL ..............................................................................4 3.1 Pre-Excavation Documentation 4 3.2 Ash Removal Verification Protocol 4 3.2.1 Field Documentation 5 3.2.2 Fill Evaluation Criteria 5 3.3 Visual Removal Not Applicable 6 4.0 SOIL SAMPLING AND ANALYSIS ...............................................................................................6 4.1 Soil Sampling 6 4.1.1 Scenario 1 6 4.1.2 Scenario 2 7 4.2 Fate and Transport Modeling 7 LIST OF TABLES Table 1 - Soil Parameters and Analytical Methods Area 1 Dry Stack Soil Sampling Plan October 2016 Duke Energy Carolinas, LLC Revision 0 Page 1 1.0 PURPOSE The purpose of this Excavation Soil Sampling Plan is to provide a standardized method for collecting soil samples at Duke Energy Dan River Steam Station Area 1 Dry Stack. Soil samples are being collected to verify removal of CCR material per the NCDEQ Guidance (DIN 26815) provided on October 11, 2016. This Excavation Soil Sampling Plan is applicable to the collection of representative soil samples. Analysis of soil samples may be chemical or physical in nature and may be used to determine the following: • Extent and magnitude of constituent occurrence • Input concentrations for groundwater fate and transport model The methodologies discussed in this Excavation Soil Sampling Plan are applicable to the sampling of soil in the Area 1 Dry Stack at Dan River Steam Station. For the purposes of this plan, soils are those mineral and organic materials remaining (above bedrock and above the groundwater surface) after all visible ash has been excavated. 2.0 SOIL SAMPLING METHODOLOGY 2.1 Method Summary This Excavation Soil Sampling Plan has been adapted from Environmental Protection Agency (EPA) Standard Operating Procedures (SOPs) #2012 and #2006; and North Carolina Department of Environmental Quality (DEQ) Attachment 1 Coal Combustion Residuals Surface Impoundment Closure Guidelines for Protection of Groundwater, September 2016. Soil samples are collected directly using stainless steel or plastic trowel, spade, shovel, or scoops. Following collection, soil is transferred from the sampling device to a stainless steel or plastic bowl to be homogenized. Once homogenized, the soil is transferred into Duke Energy Laboratory supplied sample bottles. Soil samples will be submitted for total metals analysis. Analytical methods for total metals are described in Table 1. CCR material presence is quantitatively determined by polarized light microscopy (PLM) by RJ Lee Laboratory (or other approved vendor). PLM analysis passes visible light through a pair of polarizing filters to create optical effects used in identifying unknown materials. This method is commonly used in asbestos and coal ash identification. 2.1.1 Equipment • Stainless steel or plastic trowel, scoop, spade or shovel – used for collecting soil samples from surface locations. • Sample containers – To be supplied by Duke Energy Laboratory with appropriate cooler(s). Estimated that 5-8 ounce samples bottles with Teflon-lined lids will be required for each sample location and sample depth. For return of cooler to the lab, ice will be required. Area 1 Dry Stack Soil Sampling Plan October 2016 Duke Energy Carolinas, LLC Revision 0 Page 2 • Gloves – used for personal protection and to prevent cross-contamination of samples – nitrile, disposable, powderless. • Field clothing and Personal Protective Equipment – used as specified in the site Health and Safety Plan. • Sampling flags – used for identifying soil sampling locations. • Field notebook – a bound book used to record progress of sampling effort and record any problems and field observations during sampling. • Three-ring binder book – used to store necessary forms and record and track samples collected at the site. • Permanent marking pen – used to label sample containers, document field logbooks and data sheets. • Stainless steel or plastic spoon – used for homogenizing soil samples within a stainless steel or plastic bowl. • Stainless steel or plastic bowl – used for homogenizing soil samples, when applicable. • Camera – used for photo-documentation of sample locations and samples. • GPS – device used to obtain elevation, latitude and longitude of sample location. • Trash bag – used to dispose of gloves and any other non-hazardous waste generated during sampling. • Decontamination supplies and equipment. 2.1.2 Sample Locations General locations for soil sampling are determined by the soil scientist in the field at a rate of one soil sample for every 1 acre of area excavated. Actual sampling locations on-site may vary to account for site conditions and to allow collection of representative samples. Collection of Representative Samples For the purpose of this plan, surface soil is considered to range from 0 to 6 inches in depth while deeper samples are considered to two feet below ground surface (unless bedrock, refusal, or the water table are encountered). A surface soil sample and deeper samples will be collected at each location for every 1 acre of area excavated. A new pair of nitrile gloves is worn at each sampling location and each depth. Each sampling location is recorded on the site map prior to collecting the sample if location is not already noted on the map. The GPS location of each sampling location (i.e. elevation, latitude and longitude), sample descriptions, and area photographs are also recorded. All sampling and homogenizing equipment is decontaminated prior to use irrespective of depth. The following procedure will be used to collect representative soil samples with a scoop, shovel, or trowel: Area 1 Dry Stack Soil Sampling Plan October 2016 Duke Energy Carolinas, LLC Revision 0 Page 3 • Locate general sampling locations. • Determine suitability of sampling location for a representative sample. • If sampling location appears to reflect conditions that are representative of the subject grid cell, proceed with sampling procedure. If location is not representative of the grid cell, notify the project manager so an alternate location can be identified. • Using a decontaminated sampling instrument, remove the desired thickness and volume of soil from the sampling area. Will require enough soil to fill five 8- ounce sample bottles. • Transfer the sample into an appropriate sample or homogenization bowl. Non- dedicated containers should be adequately decontaminated. Stir for approximately one minute until there appears to be a uniform color and consistency. • Transfer homogenized sample to a labeled container(s) of appropriate size and construction for the analyses requested. • Secure sample container tightly. 2.1.3 Sample Preservation, Containers, Handling and Storage Chemical preservation of soils is generally not recommended. Cooling to 4oC on wet ice is usually the best approach, supplemented by the appropriate holding time for the analyses requested. The Duke Energy Laboratory will supply the appropriate sample bottles for the collected soil samples. The sample volume is a function of the analytical requirements and the Duke Energy Laboratory will ensure the appropriate number of bottles is supplied. Table 1 contains a list of parameters to be analyzed with corresponding reporting units and analytical methods. If a parameter or group of parameters is not included in Table 1, the laboratory performing the analysis should be contacted to determine the appropriate sample bottles, volumes, and preservatives. All non-dedicated sampling/homogenizing devices should be decontaminated and wrapped in plastic. The sampling device should remain in this wrapping until it is needed. Each sampling/homogenizing device should be used for only one sample and then decontaminated or disposed of. Non dedicated sampling/homogenizing devices should be cleaned in the field using the decontamination procedure described below. 2.1.4 Decontamination Decontamination procedures can be time consuming; having a sufficient quantity of sampling tools available is recommended. All non-dedicated sampling/homogenizing equipment must be decontaminated prior to reuse. Equipment decontamination consists of: Area 1 Dry Stack Soil Sampling Plan October 2016 Duke Energy Carolinas, LLC Revision 0 Page 4 1. Detergent wash and brush cleaning 2. Tap water rinse 3. Deionized water rinse 4. Air dry 5. Wrap sampling tools with plastic 3.0 VISUAL CONFIRMATION OF ASH REMOVAL 3.1 Pre-Excavation Documentation Closure by removal is defined herein as removing the primary source (primary source of potential constituents of interest) to the point that CCR material is not visible to the unaided eye at the ground surface. This method is intended solely to verify and document CCR material removal and is not intended to validate environmental quality standards of the subsurface (considered the secondary source of potential constituents of interest). Pre-excavation documentation would consist of: • Review topographic mapping, aerial photography, construction drawings, and boring logs to estimate the pre-CCR placement topography and/or CCR/soil interface • Preparation of a figure illustrating a grid spacing of 100 feet. Each grid point (node) will be assigned a unique identifier. Each node of the grid spacing (grid point) will represent a visual verification location. 3.2 CCR Material Removal Verification Protocol CCR material excavation will be considered complete based on visual confirmation that all CCR material has been removed. CCR material removal will be based on sampling of the CCR/soil interface and analysis by PLM. Soil samples will be examined utilizing methods outlined in American Society for Testing and Materials (ASTM) D2488, Standard Practice for Description and Identification of Soils (Visual- Manual Procedure). Vertical and horizontal excavation of CCR material can terminate when the remaining material can be documented using PLM to contain less than 50% CCR. Project will excavate CCR material until a visible change in color or texture confirms removal. This location shall be referred to as the CCR/soil interface. If visual evaluation is inconclusive, then request additional evaluation to confirm CCR removal. Area 1 Dry Stack Soil Sampling Plan October 2016 Duke Energy Carolinas, LLC Revision 0 Page 5 3.2.1 Field Documentation Evaluate the excavated surface elevation relative to the pre-CCR placement topography. Periodically check bottom elevation to evaluate if fill is present above historic bottom elevation. Visual confirmation will be performed on a 100 foot grid system. Soil sampling will be performed on an acre grid system and will be analyzed using PLM. • Personnel will locate each node by GPS or survey control, determine elevation and evaluate whether that point is above or below the historic bottom elevation. • Personnel will then observe the surface area represented by the node to note if visible CCR is present at the surface. If present, the location should be documented and excavation will need to continue. If the evaluation indicates the surface soils are residuum or bedrock, then hand auger to two feet below surface (or refusal) and perform visual-manual classification of the soils at the surface and depth according to ASTM method D2488. Submit sample from depth (or shallower if refusal) for PLM analysis. The conditions shall be documented by taking photographs. • If the node point elevation is near the historic bottom elevation, soil is confirmed by visual manual classification (ASTM D2488), and PLM analysis is less than 50% CCR, then personnel can conclude the CCR material is removed. 3.3 Visual Removal Not Applicable If possible, excavation of ash should continue even if groundwater is encountered. If Duke Energy cannot complete visual removal because of site conditions or other restricting factors, documentation shall be presented to DEQ. 4.0 SOIL SAMPLING AND ANALYSIS 4.1 Soil Sampling Soil sampling of the remaining soils (less than 50% CCR per PLM analysis) will be necessary to evaluate the extent any potential for the soil to act as a secondary source of contamination. Soil samples for laboratory analysis must be collected in a manner that will ensure a relatively uniform distribution of particles throughout the six inch sample. The systematic approach and design for soil sampling and analysis is based upon NCDEQ Guidance (DIN 26815) provided on October 11, 2016: Confirmation sampling will include discrete surface samples collected from the first six inches of the soil. Sampling will be performed on an acre grid system. This sample collection methodology shall be sufficient to characterize the horizontal extent of any remaining potential secondary source impacts for comparison with the DEQ Preliminary Soil Remediation Goals (PSRG). The samples shall be analyzed by a North Carolina certified laboratory for total concentrations for the following parameters: antimony, aluminum, arsenic, barium, beryllium, boron, cadmium, calcium, chloride, chromium (total and hexavalent), cobalt, copper, iron, lead, magnesium, manganese, mercury, molybdenum, nickel, nitrate as nitrogen, pH, potassium, Area 1 Dry Stack Soil Sampling Plan October 2016 Duke Energy Carolinas, LLC Revision 0 Page 6 selenium, silver, sodium, strontium, sulfate, thallium, vanadium and zinc. No SPLP testing is required. 4.2 Fate and Transport Modeling Site specific fate and transport modeling may be used to evaluate the impact of any contamination found in excess of the applicable soil screening values. Excavation Soil Sampling Plan October 2016 Duke Energy Carolinas, LLC. & Duke Energy Progress, LLC. Revision 0 Table Excavation Soil Sampling Plan October 2016 Duke Energy Carolinas, LLC. Revision 0 TABLE 1 SOIL PARAMETERS AND ANALYTICAL METHODS TOTALS AND SPLP ANALYSIS AREA 1 DRY STACK DUKE ENERGY DAN RIVER STEAM STATION INORGANIC COMPOUNDS UNITS METHOD1 Aluminum mg/kg or µg/l EPA 6010D Antimony mg/kg or µg/l EPA 6020B Arsenic mg/kg or µg/l EPA 6020B Barium mg/kg or µg/l EPA 6010D Beryllium mg/kg or µg/l EPA 6020B Boron mg/kg or µg/l EPA 6010D Cadmium mg/kg or µg/l EPA 6020B Calcium mg/kg or µg/l EPA 6010D Chloride mg/kg or µg/l EPA 9056A Chromium mg/kg or µg/l EPA 6010D Cobalt mg/kg or µg/l EPA 6020B Copper mg/kg or µg/l EPA 6010D Hexavalent Chromium mg/kg or µg/l EPA Method 7199/218.7 Iron mg/kg or µg/l EPA 6010D Lead mg/kg or µg/l EPA 6020B Magnesium mg/kg or µg/l EPA 6010D Manganese mg/kg or µg/l EPA 6010D Mercury mg/kg or µg/l EPA Method 7470A/7471B Molybdenum mg/kg or µg/l EPA 6010D Nickel mg/kg or µg/l EPA 6010D Nitrate as Nitrogen mg/kg or µg/l EPA 9056A pH SU EPA 9045D Potassium mg/kg or µg/l EPA 6010D Selenium mg/kg or µg/l EPA 6020B Silver mg/kg or µg/l EPA 6020B Sodium mg/kg or µg/l EPA 6010D Strontium mg/kg or µg/l EPA 6010D Sulfate mg/kg or µg/l EPA 9056A Thallium (low level) (SPLP Extract only) mg/kg or µg/l EPA 6020B Vanadium mg/kg or µg/l EPA 6020B Zinc mg/kg or µg/l EPA 6010D Notes: 1. Soil samples to be analyzed for Total Inorganics using USEPA Methods 6010/6020 and pH using USEPA Method 9045, as noted above (or similar approved methods). Soil samples will also be analyzed for leaching potential using SPLP Extraction Method 1312 in conjunction with USEPA Methods 6010/6020 (or similar approved methods).