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Home My WebLink About2906-MSWLF-1994_DavidsonCountyMSW_GWMReport_DIN26491_20160325MARCH 2016 SEMI-ANNUAL GROUNDWATER MONITORING REPORT DAVIDSON COUNTY PHASE II LANDFILL NORTH CAROLINA SOLIDWASTE PERMIT NUMER 29-06 PREPARED FOR: DAVIDSON COUNTY INTEGRATED SOLID WASTE 1242 OLD HIGHWAY 29 THOMASVILLE,NORTH CAROLINA 27360-0024 PREPARED BY: PILOT ENVIRONMENTAL,INC 743 PARKLAWN COURT KERNERSVILLE, NORTH CAROLINA 27285 MAY 18, 2016 PEI PROJECT NO.1762 Davidson County Phase II Landfill March 2016 Semi-Annual Groundwater Monitoring Report May 18,2016 Davidson County Phase I Lined Landfill NC Solid Waste Permit No 29-06 March 2016 Groundwater Monitoring Report 1.0 INTRODUCTION .....................................................................................................1 2.0 SITE GEOLOGY .......................................................................................................1 3.0 SAMPLING LOCATIONS...........................................................................................1 4.0 SAMPLING PROCEDURES........................................................................................2 5.0 RESULTS ...............................................................................................................2 5.1 FIELD RESULTS ............................................................................................................2 5.2 LABORATORY ANALYSIS..............................................................................................2 5.2.1 Inorganic Constituents .........................................................................................3 5.2.2 Organic Constituents ................................................................................3 5.2.3 Surface Water..........................................................................................3 5.2.4 Leachate .................................................................................................3 6.0 STATISTICAL ANALYSIS ...........................................................................................3 7.0 GROUNDWATER CHARACTERIZATON .....................................................................3 8.0 CONCLUSIONS .......................................................................................................4 9.0 QUALIFICATIONS OF REPORT..................................................................................4 DRAWINGS Drawing 1 Potentiometric Surface Map TABLES Table 1 Groundwater Elevations Table 2 Field Parameters Table 3 Summary of Analytical Results Table 4 Leachate Analytical Data Table 5 Groundwater Velocity Calculations APPENDIX Appendix A Monitoring Well Logs Appendix B Laboratory Data Sheets and Chain of Custody Documents Davidson County Phase II Landfill Semi-Annual Groundwater Monitoring Report May 18,2016 Page 1 1.0 INTRODUCTION Pilot Environmental, Inc. (PEI)was contracted by Davidson County to conduct semi-annual groundwater monitoring at the Davidson County Phase I Lined Landfill, permit number 29-06 as required by 15A NCAC 13B .1600. Sampling was conducted on March 24 and 25, 2016. This report summarizes the sampling procedures, field and laboratory results and groundwater characterization as required by North Carolina Solid Waste Regulations.A potentiometric surface map, summary tables and laboratory analytical reports are included. 2.0 SITE GEOLOGY The Davidson County Phase I Lined Landfill facility is located in the Piedmont Physiographic Province of North Carolina.The Piedmont Physiographic Province generally consists of hills and ridges which are dissected by a system of swales and streams. The Piedmont Physiographic Province is predominantly underlain by metamorphic rock (formed by heat, pressure and/or chemical action) and igneous rock (formed directly from molten material). The topography and relief of the Piedmont Physiographic Province has developed from differential weathering of the igneous and metamorphic rock. Ridges and hills have been developed in areas of less weathered rock. Because of the continued chemical and physical weathering, rock in the Piedmont Physiographic Province is generally covered with a mantle of soil that has weathered in place from the parent bedrock. These soils vary in thickness and are referred to as residuum or residual soils. The residuum is typically finer grained and has higher clay content near the surface because of the advanced weathering. Similarly, the soils typically become coarser grained with increasing depth because of decreased weathering. As the weathering decreases, the residual soils generally retain the overall appearance, texture and foliations of the parent rock. According to the Geologic Map of North Carolina (USGS 1985), the site lies within the Carolina Slate Belt in an area of predominantly volcanic and sedimentary rocks of Late Proterozoic to Cambrian age that have been metamorphosed and intruded by numerous igneous plutons. The boundary zone between the Carolina Slate Belt and the adjacent Charlotte Belt is known as the Gold Hill/Silver Hill shear zone. The site and surrounding property appear to be underlain by volcanic rocks from the Flat Swamp Member of the CID Formation and metavolcanic rocks of the Battleground Formation.The encountered lithology includes sand, silts, partially weathered rock and hard rock (granite). 3.0 SAMPLING LOCATIONS The groundwater monitoring network for the Davidson County Phase II Landfill includes nine monitoring wells (MW-1, MW-2, MW-3S,MW-4S, MW-5, MW-6S, MW-8,MW-9 and MW-10S), two surface water samples (SW-1 and SW-2) and one leachate location (leachate).Monitoring wells MW-3D, MW-4D and MW-10D are designated as water level locations and are not sampled as part of the groundwater monitoring program. Groundwater monitoring wells MW-6D and MW-7 along with surface water sample location SW-3 were removed from the groundwater Davidson County Phase II Landfill Semi-Annual Groundwater Monitoring Report May 18,2016 Page 2 monitoring network in January of 2013.The background well for the Phase II Landfill is MW-1. A trip blank was submitted for quality control purposes. Sample locations are shown on Drawing 1. Available monitoring well logs are included in Appendix A. 4.0 SAMPLING PROCEDURES Sampling procedures followed the protocols outlined in the Water Quality Monitoring Plan and the North Carolina Department of Environmental Quality (NCDEQ) Division of Waste Management Water Quality Monitoring Guidance Document for Solid Waste Facilities. Prior to sampling, PEI personnel measured the depth to groundwater in each well. Following measurement of groundwater depth, each well was purged by removing three to five well volumes or until dry twice.Groundwater elevations are provided in Table 1. Laboratory prepared containers were provided by Research and Analytical Laboratories, Inc.in Kernersville, North Carolina (North Carolina Laboratory Certification Number 34).After being filled, the sample containers were appropriately labeled, placed into a cooler containing ice to maintain temperature control and transported to the laboratory facility within the specified hold time for each analysis. Sampling wells and surface water sample locations were inspected and observed to be in good condition and free of obstruction at the time of sampling. 5.0 RESULTS 5.1 FIELD RESULTS Temperature, pH, specific conductance and turbidity were measured in the field at the time of sampling. The field parameter results are summarized in Table 2. 5.2 LABORATORY ANALYSIS Samples were transported to R&A Laboratories where they were analyzed for metals using EPA Method 200.7 and Volatile Organic Compounds (VOCs) using EPA Method 8260B.The leachate sample was also sampled for BOD, COD, nitrate nitrogen, total phosphorus and sulfate via NCDEQ DWM Solid Waste Section (SWS) approved methods. Analytical results were compared to the NCDEQ DWM SWS Quantitation Limits (SWSLs), 15A NCAC 2L.0200 Groundwater Quality Standards (2L Standards), SWS established Groundwater Protection Standards (GWP) and the Federal Maximum Contaminant Limits (MCLs). Analytical results of surface water samples were compared with the NCAC 2B Standard for Class C waters (2B Standards) Davidson County Phase II Landfill Semi-Annual Groundwater Monitoring Report May 18,2016 Page 3 Most constituents were reported below the method detection limit (MDL) or at non-quantifiable values (J-value) defined by the laboratory as between the MDL and the SWL. 5.2.1 Inorganic Constituents Laboratory analysis detected cobalt (MW-1 and MW-9), chromium (MW-1, MW-2, MW-6S, MW- 8 and MW-10S)and vanadium (MW-1, MW-2, MW-6S, MW-9 and MW-10S)at concentrations above their respective 2L Standards.A summary of laboratory analytical results is provided in Table 3. 5.2.2 Organic Constituents Laboratory analysis did not detect VOCs at concentrations above the method detection limits. A summary of laboratory analytical results is provided in Table 3. 5.2.3 Surface Water Laboratory analysis of surface water samples did not detect constituents at concentrations above the 2B Standards.A summary of laboratory analytical results is provided in Table 3. 5.2.4 Leachate Leachate samples were collected from the leachate collection system. A summary of constituents detected in the leachate sample is provided in Table 4. 6.0 STATISTICAL ANALYSIS No statistical analyses were performed on the analytical data based on 15A NCAC 13B.1632 and .1633, effective April 1, 2011. 7.0 GROUNDWATER CHARACTERIZATON A potentiometric surface map was prepared from groundwater elevation data collected during this sampling event. Based on groundwater elevation data measured during this sampling event, groundwater flow direction was determined to be to the northwest, consistent with historic groundwater flow patterns at the site.The potentiometric surface map is included as Drawing 1. Davidson County Phase II Landfill Semi-Annual Groundwater Monitoring Report May 18,2016 Page 4 Groundwater flow velocities were also calculated for this sampling event. Groundwater flow velocities were calculated for monitoring wells using the equation: V = Ki/n Where:V = average velocity of groundwater flow K = hydraulic conductivity i = groundwater gradient n = porosity Groundwater velocities ranged from 0.1159 ft/day (MW-5) to 0.256 ft/day (MW-9) with an average of 0.0.0906 ft/day. A summary of the measurements and calculations are provided in Table 5. 8.0 CONCLUSIONS Based on the results of the laboratory analysis,PEI concludes the following: Laboratory analysis detected cobalt (MW-1 and MW-9), chromium (MW-1, MW-2, MW-6S,MW- 8 and MW-10S) and vanadium (MW-1, MW-2, MW-6S, MW-9 and MW-10S) at concentrations above their respective 2L Standards.Organic constituents were not detected during this event. The analytical results for the Phase II Lined Landfill are consistent with historic detections. Concentrations detected are likely due to variations in naturally occurring constituents and are not indicative of groundwater impact from the landfill. 9.0 QUALIFICATIONS OF REPORT The activities and evaluative approaches used in this assessment are consistent with those normally employed in groundwater assessment projects of this type. Our evaluation of site conditions has been based on our understanding of the site project information and the data obtained during our field activities. This report was prepared for the express use of Davidson County Integrated Solid Waste. DRAWINGS Drawing 1 Potentiometric Map LEGEND Monitoring Well/Surface Water Sample Waste Boundary Groundwater Surface Contour TOC =Top of Casing DTW = Depth to Water GWE = Groundwater Elevation Monitoring wells MW-6D and MW-7 alongwith SW-3 were removed from the monitoringnetwork in January 2013. Drawing 1 2015 Imagery from Google Earth Scale: 1” =400’ Date: May 12, 2016 Potentiometric Surface Map Davidson County Phase II Landfill Lexington, Davidson County, North Carolina PEI Project 1762 Phase II Landfill SW-1 SW-2 MW-1 TOC = 734.16 DTW = 14.16 GWE = 720.00 MW-10D TOC = 668.76 DTW = 16.48 GWE = 652.28 MW-10S TOC = 668.58 DTW = 16.35 GWE = 652.28 MW-2 TOC = 664.06 DTW = 11.41 GWE = 652.65 MW-4D TOC = 673.54 DTW = 18.77 GWE = 654.77 MW-9 TOC = 683.25 DTW = 21.47 GWE = 661.78 MW-3D TOC = 660.91 DTW = 8.21 GWE = 652.70 MW-4S TOC = 673.82 DTW = 19.70 GWE = 654.12 MW-3S TOC = 660.73 DTW = 8.35 GWE = 652.38 MW-5 TOC = 687.31 DTW = 28.52 GWE = 658.79 MW-6D MW-6S TOC = 703.25 DTW = 36.68 GWE = 666.57 MW-7 MW-8 TOC = 711.14 DTW = 47.58 GWE = 663.56 Leachate TABLES Table 1 Groundwater Elevations Table 2 Field Parameters Table 3 Summary of Groundwater Analytical Results Table 4 Leachate Analytical Data Table 5 Groundwater Velocity Calculations PEI Project 1762 Monitoring Well Well Installation Date Latitude Longitude Well Diamter (Inches) Total Well Depth (feet bgs) Ground Surface Elevation (feet amsl) TOC Elevation (feet amsl) Depth to Water* (feet) Groundwater Elevation (feet) Screen Interval (feet bgs) Screen Geology MW-1 3/25/2008 35.85289 80.17643 2.0 20.0 730.65 734.16 14.16 720.00 10.0-20.0 sandy slit MW-2 8/12/2008 35.84994 80.18351 2.0 14.5 661.05 664.06 11.41 652.65 9.5-14.5 sandy silt/granite MW-3S 3/24/2008 35.84948 80.18486 2.0 18.0 657.87 660.73 8.35 652.38 8.0-18.0 clay and sand MW-3D 3/26/2008 35.84948 80.18484 2.0 40.5 658.08 660.91 8.21 652.70 35.5-40.5 granite MW-4S 3/24/2008 35.84953 80.18559 2.0 21.0 670.74 673.82 19.70 654.12 11.0-21.0 sandy silt with clay MW-4D 3/26/2008 35.84952 80.18557 2.0 37.0 670.60 673.54 18.77 654.77 32.0-37.0 diorite MW-5 3/24/2008 35.84863 80.18713 2.0 38.0 684.59 687.31 28.52 658.79 28.0-38.0 clayey silt MW-6S 3/25/2008 35.84681 80.18525 2.0 40.0 700.00 703.25 36.68 666.57 30.0-40.0 sandy silt with gravel MW-8 3/24/2008 35.84736 80.18404 2.0 58.6 708.21 711.14 47.58 663.56 48.6-58.6 diorite MW-9 8/12/2008 35.84906 80.18614 2.0 30.5 683.68 683.25 21.47 661.78 20.5-30.5 diorite MW-10S 9/21/2004 35.85083 80.18306 2.0 27.0 665.17 668.58 16.35 652.23 12.0-27.0 silty sand clay and gravel MW-10D 9/21/2004 35.85082 80.18305 2.0 44.0 666.02 668.76 16.48 652.28 36.0-44.0 diabase Notes: amsl = above mean sea level bgs = below ground surface TOC = Top of casing *Depth to water measured from TOC Groundwater Elevations 3/24-25/2016 TABLE 1 Davidson County Phase II Landfill PEI Project 1762 Monitoring Well pH (Standard Units) Conductivity (umhos) Temperature (celsius)Turbity (NTU) MW-1 6.26 285 17.5 184.4 MW-2 6.21 161 17.2 21.6 MW-3S 6.74 269 16.6 1.04 MW-4S 6.45 161 18.1 5.92 MW-5 6.36 129 19.4 21.78 MW-6S 6.45 575 18.8 272.8 MW-8 6.92 344 20.1 4.23 MW-9 6.56 271 20.3 24.34 MW-10S 6.37 302 16.9 61.5 SW-1 7.05 268 15.3 7.73 SW-2 7.01 184 15.8 5.79 Notes: TABLE 2 Field Parameters Davidson County Phase II Landfill 3/24-25/2016 PEI Project 1762 Parameter Sample ID MW-1 MW-2 MW-3S MW-4S MW-5 MW-6S MW-8 MW-9 MW-10S SW-1 SW-2 MDL MRL SWSL 2L or GWP Standard MCL 2B Standard All Compounds BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL ------------ antimony BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL 1.9 5 6 1#6 640 arsenic BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL 2.4 10 10 10 10 10 barium 209 31.9J 25.0J 15.8J 10.4J 288 3.48J 72.5J 25.9J 34.3J 27.2J 1.3 40 100 700 2,000 2,000,000 beryllium 0.435J BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL 0.4 1 1 4#4 6.5 cadmium BDL BDL BDL BDL BDL 0.355J 0.330J 10.9 0.345J BDL BDL 0.3 1 1 2 5 2 cobalt 34.6 5.84J BDL BDL 1.84J 14.8 BDL 8.62J 6.06J BDL BDL 1.5 10 10 1#NE 270 copper 95 6.69J BDL BDL 1.77J 28.9 BDL 6.83J 6.92J BDL 3.05J 1.1 10 10 1,000 1,300 7 chromium (total)23 32 1.81J 2.30J 3.82J 16 12.4 9.87J 26.6 BDL BDL 1.3 10 10 10 100 50 lead BDL BDL 2.31J BDL BDL BDL BDL BDL BDL BDL 2.71J 1.7 5 10 15 15 28 nickel 35.5J 9.77J BDL BDL 2.73J 11.8J BDL 24.0J 10.4J BDL 2.32J 1.7 10 50 100 NE 88 selenium BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL 2.5 10 10 20 50 5 silver BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL 2.8 10 10 20 100 0.06 vanadium 140 36.8 8.66J 6.40J 11.7J 59.4 12.2J 37.5 29 BDL BDL 1.8 10 25 0.3#NE NE zinc 96.3 26.6 21.6 16.3 18.4 71.7 22.7 70.9 30.2 21 11.9 2.9 2.9 10 1,000 5,000 50 Notes: MDL = Method Detection Limit MRL = Method Reporting Limit SWSL = Solid Waste Section Quantitation Limits 2L= NCDEQ Groundwater Standards (15A NCAC 2L 0200) GWP = Solid Waste Section Groundwater Protection Standards (noted by#) MCL = Federal Maximum Contaminant Limit 2B = NCAC 2B Standards for Class C waters NE = Standard Not Established Results presented in ug/l, analogous to parts per billion (ppb) BDL = Compound not detected at a concentration above the MDL Bold denotes concentration exceeds the 2L or GWP Standard J = Estimated concentration detected at concentration between the MDL and SWSL Comparison CriteriaGROUNDWATER SAMPLING Volatile Organic Compounds Inorganic Consituents TABLE 3Summary of Analytical ResultsDavidson County Phase II Landfill3/24-25/2016 PEI Project 1762 Parameter Unit Leachate BOD mg/l 82.3 COD mg/l 552 Total Suspended Residue mg/l 54.4 Ammonnia Nitrogen as N mg/l 332 Total Phosphorus as P mg/l 1.12 Sulfate mg/l 50.6 Antimony ug/l BRL Arsenic ug/l BRL Barium ug/l 248 Cobalt ug/l 15.2 Chromium (Total)ug/l 33.2 Copper ug/l 1.24J Lead ug/l 1.79J Nickel ug/l 146 Selenium ug/l BRL Vanadium ug/l 33.7 Zinc ug/l 25.2 Notes: J = estimated concentrations between laboratory MDL and SWSL mg/l = parts per million ug/l = parts per billion TABLE 4 Leachate Analytical Data Davidson County Phase II Landfill 3/24-25/2016 PEI Project 1762 Monitoring Well Aquifer Conductivity (ft/day) Conductivity (ft/min) Assumed Porosity (n)Gradient (i)Velocity (ft/day) MW-2 Sandy Silt 6.75E-02 4.69E-05 0.18 0.0783 0.0294 MW-3S Sand 8.60E-02 5.97E-05 0.20 0.0374 0.0161 MW-4S Sandy Silt 6.22E-02 4.32E-05 0.18 0.0400 0.0138 MW-5 Clayey Silt 4.31E-01 2.99E-04 0.18 0.0484 0.1159 MW-6S Sand and Gravel 4.64E-01 3.22E-04 0.22 0.0125 0.0264 MW-8 Diorite 4.90E-01 3.40E-04 0.10 0.0360 0.1764 MW-9 Diorite 7.20E-01 5.00E-04 0.10 0.0356 0.2563 Notes: Velocity calculated from V=Ki/n V = Velocity K= Hydrulic Conductivity i= gradient n= porosity Hydraulic conductivity data from slug testing performedin 1994. Porosity values assumed from Groundwater & Wells (Driscoll). Gradient calculated from March 2016 potentiometric surface. TABLE 5 Groundwater Velocity Calculations Davidson County Phase II Landfill 3/24-25/2016 APPENDIX Monitoring Well Logs Laboratory Data Sheets and Chain of Custody Documents