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Home My WebLink About5503_LincolnCountyMSWLFLined_ASD_DIN27390_20170105Alternate Source Demonstration Lincoln County Landfill Crouse, North Carolina S&ME Project No. 1356-07-004 Prepared for: Lincoln County 5291 Crouse Road Crouse, North Carolina 27777 Prepared by: S&ME, Inc. 8646 W Market Street, Suite 105 Greensboro, NC 27409 January 5, 2017 S&ME, Inc. | 8646 W Market St, Ste 105 | Greensboro, NC 27409 | p 336.288.7180 | f 336.288.8980 | www.smeinc.com January 5, 2017 Lincoln County 5291 Crouse Road Crouse, North Carolina 27777 Attention:Mr. Mark Bivins, Solid Waste Manager Reference:Alternate Source Demonstration Lincoln County Landfill Crouse, North Carolina S&ME Project No. 1356-07-004 Dear Mr. Bivins: S&ME, Inc. (S&ME) has prepared this Alternate Source Demonstration for the lined portions of the Lincoln County Landfill, in accordance with S&ME Proposal No. 43-1600676 dated August 29, 2016. This assessment was conducted in response to the August 8, 2016, letter from the North Carolina Department of Environmental Quality, Division of Waste Management, Solid Waste Section (NCDEQ-SWS) to Lincoln County requiring that facility owner or operator perform one of two actions in response to reported 15A NCAC 2L Standard Exceedances for Appendix I inorganics. Lincoln County elected to pursue the option to “demonstrate that a source other than the MSWLF unit caused the exceedance, or the exceedance resulted from an error in sampling, analysis, statistical evaluation, or natural variation in groundwater quality.” This report documents the findings for our assessment of the natural occurrence of certain Appendix I inorganics in groundwater in the vicinity of the lined portion of the landfill. A copy of this report should be provided to the NCDEQ-SWS and one placed in the operating record. Sincerely, S&ME, Inc. Lyndal Butler Edmund Q.B. Henriques Environmental Scientist Project Manager / Senior Geologist NC Geologist License No. 1216 Jasmine Tayouga, E.I. Staff Professional Alternate Source Demonstration Lincoln County Landfill Crouse, North Carolina S&ME Project No. 1356-07-004 January 5, 2017 ii Table of Contents 1.0 Introduction............................................................................................................1 2.0 Geology & Hydrogeology....................................................................................2 2.1 Site Geology.......................................................................................................................2 2.2 Soil Description.................................................................................................................2 2.3 Groundwater Hydrogeology..........................................................................................2 2.4 Published Data for Metals In Groundwater and Stream Sediments.........................3 3.0 Data Collection ......................................................................................................4 3.1 Soil Sampling.....................................................................................................................5 3.2 Groundwater Sampling...................................................................................................6 4.0 Results......................................................................................................................6 4.1 Soil Sample Analytical Results .......................................................................................6 4.2 Probable Natural Groundwater Concentration Computations.................................6 4.3 Groundwater Analytical Results....................................................................................7 4.4 Time vs Concentration Graphs.......................................................................................8 5.0 Conclusions ............................................................................................................9 6.0 Limitations............................................................................................................13 7.0 References.............................................................................................................13 List of Figures Figure 1 – Site Plan List of Tables Table 1 – 2-Year Summary of Groundwater Analyses Results Table 2 – Summary of Soil Sample Analyses Results Table 3 – Summary of Groundwater Analyses Results Appendices Appendix I – Analytical Reports Appendix II – Time vs Concentration Graphs Appendix III – USGS NURE Data Drawings Alternate Source Demonstration Lincoln County Landfill Crouse, North Carolina S&ME Project No. 1356-07-004 January 5, 2017 1 1.0 Introduction The Lincoln County Landfill is located at 5291 Crouse Road in Crouse, North Carolina. The Facility includes a closed municipal solid waste (MSW) landfill (Existing Area E), a Construction & Demolition (C&D) landfill (Phase 1 and Phase 2), and lined MSW landfill Phases 1 I, II, and III depicted on Figure 1. Lincoln County operates the lined Subtitle D landfill (Phase 1, 2, 3, and 4) under Solid Waste Permit #55-03. The facility’s monitoring network includes one background well (MW-1A), twenty-nine compliance wells, six surface water sample locations. It is our understanding that monitoring wells MW-8, MW-9, MW-10R, MW-12, MW-15, MW-18, MW-19, MW-21, MW-24, MW-25, MW-25A, MW-32R, MW-33, MW-34, and MW-35 comprise the groundwater monitoring system for active lined MSW landfill phases. For detection monitoring, groundwater samples are collected from each monitoring well on a semi-annual basis and submitted for laboratory analysis using the Appendix I list of volatile organic and inorganic constituents. The letter from the North Carolina Department of Environmental Quality, Division of Waste Management, Solid Waste Section (NCDEQ-SWS) to the Lincoln County dated August 18, 2016, required that Lincoln County as owner and operator perform one of two actions in response to reported 15A NCAC 2L groundwater standard exceedances (2L Standards) for certain Appendix I inorganics at compliance monitoring wells associated with the lined MSW landfill. Lincoln County elected to pursue the option to “demonstrate that a source other than the MSWLF unit caused the exceedance, or the exceedance resulted from an error in sampling, analysis, statistical evaluation, or natural variation in groundwater quality.” It is well-known that many inorganics occur naturally in groundwater. Consequently, the 2L Standards contain a provision to exempt naturally occurring inorganic concentrations. Therefore, a direct comparison of detected inorganic constituent concentrations to the 2L Standards is not conclusive evidence of an exceedance. Since naturally occurring inorganic constituents in soils at the Facility can influence inorganic constituent concentrations detected in groundwater samples, this assessment was developed to examine the naturally occurring concentrations of certain Appendix I inorganics (hereafter referred to as metals) in soils within and surrounding the lined MSW landfill. The collected data would then be examine to assess if metals detected groundwater at the facility were indicative of naturally occurring conditions, rather than a result of a release from the Facility. Considering that a method used to develop an Alternate Source Demonstration (ASD) for certain metals occurring in other Piedmont North Carolina landfills was previously successful, a similar approach was used for this ASD. Prior to conducting this ASD, groundwater analytical results for the last two years were reviewed for appendix I inorganic constituents and concentrations which exceed the 2L Standards or the NCDEQ Interim Maximum Allowable Concentrations (IMACs) if no 2L Standards currently exists for these constituents. This review revealed that one or more monitoring wells reported concentrations of antimony, arsenic, chromium, cobalt, lead, and vanadium that exceeded the corresponding 2L Standards or IMACs. No other Appendix I inorganics were reported with concentrations greater than their respective 1 Phase IV is under construction south of Phase III. Alternate Source Demonstration Lincoln County Landfill Crouse, North Carolina S&ME Project No. 1356-07-004 January 5, 2017 2 2L Standards or IMACs, during this time frame. Accordingly, antimony, arsenic, chromium, cobalt, lead, and vanadium were recognized as Constituents Of Potential Concern (COPC) for this ASD. No other Appendix I inorganics were evaluated as part of this ASD.Table 1 summarizes the lined landfill groundwater analytical results for antimony, arsenic, chromium, cobalt, lead, and vanadium over the past two years. This ASD assessment focused on two primary objectives: 1.Assess naturally occurring concentrations of the COPCs in the residual soils within and up- gradient of the landfill. Utilize the observed natural soil concentrations to predict plausible naturally occurring groundwater concentrations. 2.Assess dissolved metals vs total metals in current groundwater samples obtained from the monitoring wells associated with the lined landfill. Utilize this data to determine if suspended or colloidal solids in groundwater samples might influence the reported total metals concentrations, which are used to judge compliance with applicable groundwater standards. The following section provide a summary of local soils, geology, and hydrogeology information. Relevant background information is followed by a discussion of the ASD assessment methods employed, analytical results, findings, and conclusions. 2.0 Geology & Hydrogeology 2.1 Site Geology The Crouse area of North Carolina lies in the Piedmont Physiographic province of the Appalachian Highlands. The Piedmont is comprised of five northeast southwest trending rock belts of various metamorphic grades. According to the Geologic Map of North Carolina, 1985, the subject facility lies within the Charlotte Belt. Bedrock was mapped as mica schist, with possible inclusions of quartzite, calc- silicate rock, biotite gneiss, amphibolite, and phyllite. These rocks were believed to be Cambrian in age. The depth to bedrock rocks varies with topography, but is generally less than 30 feet. When partially weathered, these subsurface materials are generally referred to as saprolite. Saprolite is a residual soil which retains some of the original structural features of the parent rock. The demarcation between the soil and rock materials is transitional, as the difference is one of consistency and degree of weathering between very stiff soil and relatively soft rock. 2.2 Soil Description According to the Soil Survey of Lincoln County, the soil at surrounding the landfill were dominantly classified as Pacolote sandy clay loam (PaB), Pacolet sandy loam (PaD), and Appling sandy loam (ApB). 2.3 Groundwater Hydrogeology In the Piedmont region, groundwater occurs in two hydraulically interconnected zones. The upper zone, or regolith, consists of an unconsolidated or semi-consolidated mixture of clay fragmental material Alternate Source Demonstration Lincoln County Landfill Crouse, North Carolina S&ME Project No. 1356-07-004 January 5, 2017 3 ranging in size from silt to sand boulders. The porosity of the regolith is generally on the order of 20 to 30 percent (Heath, 1984). Because of its high porosity, the regolith functions as a reservoir which slowly feeds water downward into the bedrock. Water is introduced to the regolith by precipitation and stream flow. Once in the regolith, groundwater moves between intergranular pore spaces. This “water table” zone is controlled by climactic factors. Groundwater levels vary seasonally, declining during the summer when atmospheric conditions favor evaporation and plants transpire large amounts of water, and rising during the winter when plants are dormant. Groundwater also occurs below the regolith, in the bedrock zone where it moves through sheet-like openings formed along fractures. Fractures in bedrock are of two types: joints, which are fractures along which there has been no differential movement, and faults, which are fractures along which the adjacent rocks have undergone measurable differential movement. Groundwater in the bedrock zone is generally more stable and less readily influenced by climactic conditions. The regolith and bedrock zones are connected hydraulically. Precipitation generally occurs in the form of rainfall, which is variable throughout the year. Depending on factors such as ground saturation, ground cover, and slope, a portion of the precipitation forms runoff. This natural runoff flows to areas of lower elevation where some of the runoff water infiltrates in the unconsolidated material (i.e. soil) and some flows into local surface waters. The precipitation that does not form runoff infiltrates through the unsaturated zone where it can merge with underlying aquifers, providing aquifer recharge. Most aquifer recharge in the study area takes place in inter-stream areas. In the case of this facility, the lined landfill footprint area limits local aquifer recharge. In general, recharge from precipitation enters the surficial aquifer through the porous regolith. It is believed that much of the recharge water moves laterally through the regolith aquifer and discharges to nearby streams. Near surface groundwater flow generally mimics surface topography, with groundwater moving from topographic highs to topographic lows, with flow lines perpendicular to lines of equal elevation. Indian Creek to the south is the expected dominant discharge area for this Facility. The saprolite regolith and bedrock underlain the Facility could contain antimony, arsenic, chromium, cobalt, lead, and vanadium as natural trace minerals. Dissolution of minerals in the bedrock and residual soils releases naturally occurring constituents to the underlying groundwater. Dissolved concentrations of trace constituents can vary widely based on their occurrence and distribution in the regolith and bedrock. In addition, many site specific factors including but not limited to exact bedrock minerology, the solubility of constituents, and a range of site specific geochemical conditions impact mobility and transport of metals. This preliminary assessment did not attempt to define the vast array of complex site specific variables which could control the natural occurrence of COPC in site groundwater. 2.4 Published Data for Metals In Groundwater and Stream Sediments For this ASD, data published by the United States Geologic Survey (USGS) from the National Uranium Research Evaluation (NURE) program which included an evaluation of certain metals in North Carolina groundwater and stream sediments; was reviewed to provide general knowledge of known or probable background metals concentrations in the vicinity of the landfill. The NURE study did not explore the potential for anthropogenic sources of these metals, which if present, would represent outlier data points Alternate Source Demonstration Lincoln County Landfill Crouse, North Carolina S&ME Project No. 1356-07-004 January 5, 2017 4 relative to natural background levels. The following observations can be made from the NURE data set for the general vicinity of the Lincoln County landfill, in Crouse North Carolina: 1.Groundwater vanadium concentrations could range from between less than 0.3 parts per billion (ppb) to 10 ppb. 2.Stream sediment chromium concentrations could range from approximately 10 to 15 parts per million (ppm). 3.Stream sediment cobalt concentrations could range from approximately 5 to 15 ppm. 4.Stream sediment lead concentrations could range from less than 5 to approximately 5 ppm. Acknowledging potential inherent limitations of the NURE data set, one can conclude that it is probable to find natural groundwater vanadium concentrations in the vicinity of the landfill, which would be greater than the IMAC for vanadium set at 0.3 µg/L. The stream sediment data may provide indications of probable natural metal concentrations in the bedrock and soil in the region, although the data set does not identify potential anthropogenic source influences. Acknowledging this potential limitation, the stream sediment concentrations for chromium and lead were generally less than the concentrations observed in near surface soil samples obtained from the landfill and discussed in Section 4.1. The stream concentrations for cobalt are generally similar to the concentrations observed in near surface soil samples obtained from the landfill. 3.0 Data Collection The US Environmental Protection Agency (EPA’s) developed guidance for predicting what soil concentrations will not cause contamination to groundwater at levels that exceed applicable groundwater cleanup levels. According to the EPA’s Soil Screening Guidance 2 “As contaminants in soil leach and move through soil and groundwater, they are subjected to physical, chemical, and biological processes that tend to reduce the eventual contaminant concentration at the receptor point” (i.e., groundwater monitoring well). This reduction or attenuation in the concentration of parameters as they percolate through the soils to a ground water aquifer is governed by a variety of processes, the sum of which, are referred to as a Dilution/Attenuation Factor. The Dilution/Attenuation Factor (DAF) is defined as “the ratio of contaminant concentration in soil leachate to the concentration in ground water at the receptor point. EPA chose a default DAF of 20 to account for contaminant (parameter) dilution and attenuation during transport through the saturated zone to a compliance point (i.e., a receptor well). 15A NCAC 02L .0411 “Establishing Maximum Soil Contaminant Concentrations” relied substantially upon the EPA’s Soil Screening Guidance for the development of the published equation used to establish the NCDEQ’s “Soil to Groundwater, Maximum Soil Contaminant Concentrations” (Soil-to Groundwater MSCCs) for organic and inorganic constituents. This equation is used by the NCDEQ to predict a maximum concentration of a given constituent in the soil that would not yield a resultant groundwater 2 EPA’s Soil Screening Guidance: Technical Background Document, Second Edition, United States Environmental Protection Agency, EPA/540/R95/128, May 1996 Alternate Source Demonstration Lincoln County Landfill Crouse, North Carolina S&ME Project No. 1356-07-004 January 5, 2017 5 concentration equal to or greater than the associated 15A NCAC 02L groundwater quality standard. As a predictive tool, this equation was generally intended to be conservative (overly protective) of the protection of groundwater quality. For this ASD the equation was reworked to calculate predicted groundwater concentrations relying upon site specific measured soil concentrations. The reworked equation is as follows: GWC (mg/L) = soil concentration (mg/kg) ÷ [(20 x Kd) + 41 + (1.733 x 41 x HLC)} Where: GWC = predicted natural concentration of inorganic constituent in groundwater Soil Concentration = to be measured with site-specific soil sample analytical data Kd = soil/water partitioning coefficient for the inorganic constituent HCL = Henry’s Law Constant for the inorganic constituent Relying on this equation as a conservative tool for predicting plausible naturally occurring concentrations of the COPC, this ASD included the collection of in-situ soils within the immediate vicinity of the affected down-gradient compliance monitoring wells, as well as soil samples collected in the up-gradient and presumed undisturbed portion around Phase 3. The collected soil samples were analyzed for the full Appendix I metals list. The above equation was then used to calculate predicted natural concentrations of the COPC at the landfill. To examine potential influences of suspended solids or colloids in groundwater samples, this ASD included the collection of split groundwater samples from monitoring well locations. For each sample pair, one sample was laboratory filtered and the other unfiltered prior to the analysis for Appendix I metals. Analytical results for each sample pair were evaluated for probable inorganic constituent contributions due to suspended solids in the groundwater sample (e.g. total constituent concentrations) verse true dissolved concentrations for the monitored shallow groundwater. 3.1 Soil Sampling Soil samples were collected at the Facility between October 17 th and 19 th, 2016. Fourteen individual grab samples were obtained. At each of the selected ten groundwater monitoring wells (e.g. sample IDs = MW-1, MW-8/9, MW-10, MW-12, MW-21, MW-24, MW-25, MW-32, MW-33, and MW-35), one sample was collected within no more than fifty feet of the well. Four additional soil samples (e.g. sample IDs = BG-1, BG-2, BG-3, BG-4) were collected at random locations judged to be relatively undeveloped or undisturbed. Historic aerial photographs and other field observations were used to make these judgement calls. These grab soil samples were collected using a properly decontaminated hand-auger, from depths generally ranging from approximately 1-2 feet below the land surface. These sample depths were selected to reduce the chance of obtaining soil samples which could have been influenced by anthropogenic activities. Each soil sample was transferred by hand using disposable nitrile gloves from the hand auger bucket to laboratory-provided containers. Following collection, the soil sample containers were placed in an ice-filled cooler, stored, and transported by courier to ENCO Laboratories under proper chain-of-custody procedures. The collected samples were analyzed for Appendix I metals. Alternate Source Demonstration Lincoln County Landfill Crouse, North Carolina S&ME Project No. 1356-07-004 January 5, 2017 6 Figure 1 depicts the Lincoln County Landfill and the facility monitoring well locations. The fourteen soil sample locations, adjacent to existing monitoring wells provide reasonable spatial coverage for this landfill unit, sufficient to quantify some of the expected natural variations in constituents and concentrations present in the native soils. 3.2 Groundwater Sampling During the routine semi-annual detection monitoring event completed in October 2016, the lined MSW landfill monitoring wells were sampled using the hand bailing and pumping methods generally consistent with those used during prior semi-annual compliance monitoring events. For this event a turbidity meter was used to quantitatively measure the turbidity of groundwater samples obtained, whereas prior monitoring events relied upon a visual and subjective qualitative approach. Split groundwater samples were collected at monitoring wells: MW-1A, MW-8, MW-9, MW-10R, MW-12, MW-21, MW-24, MW-25, MW-25A, MW-32R, MW-33A, MW-34, MW-35 and MW-35A (see Figure 1). Each groundwater sample was transferred from the bailer or well pump tubing directly into laboratory-provided containers. Following collection, the sample containers were placed in an ice-filled cooler, stored, and the shipped by courier to ENCO Laboratories under proper chain-of-custody procedures. The collected samples were analyzed for Appendix I metals. For each sampled location, one split sample was filtered in the laboratory with a 45 micron filter prior to laboratory analysis, to represent total “dissolved” metals in the sample. The other split sample was analyzed for total metals without field or laboratory filtering, representing total metals present in the groundwater sample obtained (dissolved plus suspended solids or colloidal solids). 4.0 Results 4.1 Soil Sample Analytical Results Table 2 summarizes the analytical results for the soil samples collected. Arsenic, chromium, cobalt, lead, and vanadium were detected in each soil sample. Antimony was detected in six of the fourteen soil samples collected.Table 2 also includes some basic statistics for each COPC such as maximum detected concentration, minimum detected concentration, mean concentration, and standard deviation. The standard deviation statistic was particularly valuable since it illustrates the magnitudes of reported concentrations of the COPC; which were expected to vary based on anticipated spatial variations in the underlying parent bedrock mineralogy. The complete Laboratory Analytical Report of the soil sampling results in included in Appendix I. The soil sample results were used in the computation discussed in section 4.2. 4.2 Probable Natural Groundwater Concentration Computations Table 2 includes predicted groundwater concentrations for each COPC using the site-specific soil sample concentrations. The ASD predicted natural groundwater concentrations were calculated utilizing the method outlined in Section 3.0 and site specific values for minimum, maximum, and mean soil concentration for each COPC.Table 2 includes a reference to the corresponding 2L Standard and/or IMAC concentrations for each COPC. Based upon the predicted natural groundwater concentrations calculated utilizing the soil concentration for each COPC, the following observations can be made: Alternate Source Demonstration Lincoln County Landfill Crouse, North Carolina S&ME Project No. 1356-07-004 January 5, 2017 7 •The maximum soil antimony concentration was predicted to yield a groundwater concentration generally equal to the highest groundwater concentration observed in the last two years. The mean soil antimony concentration predicts a groundwater concentration that is equal to the 2L Standard. •The mean soil arsenic concentration was predicted to yield a groundwater concentration that is generally greater than the highest groundwater concentration observed in the last two years. •The mean soil chromium concentration was predicted to yield a groundwater concentration that is generally greater than actual groundwater concentrations which were verified by a report of a similar concentration during one or more subsequent monitoring events over the last two years. •The range based on the minimum and mean soil cobalt concentrations yield predicted groundwater concentrations that are generally consistent with actual concentrations detected over the last two years. Two of the actual groundwater concentrations which exceed the predicted range (e.g. suspect outlier data points) were concentrations that are less than the concentration predicted using the maximum observed soil cobalt concentration. •The maximum soil lead concentrations predicted groundwater concentrations that are less than estimated or quantified groundwater concentrations reported over the last two years. •The calculated mean soil vanadium concentration predicts a groundwater concentration that is generally equal to the vast majority of the detected groundwater concentrations observed in the last two years. Observed groundwater concentrations greater than the concentration predicted using the mean soil concentration do occur; however, these occurrences were typically not substantiated with a detection of a similar concentration at the same well during the subsequent monitoring event. These finding suggests that the COPCs could occur naturally in groundwater at concentrations greater than the corresponding published 2L Standards or IMACs if applicable. Table 2 presents the HLC and Kd values used in the performance of the underlying calculations. It is important to note that generic Kd values for inorganic constituents can vary. To manage this uncertainty mean values for Kd were utilized in the computations, when available. Furthermore, this equation is sensitive to variations in Kd values; therefore, the resultant predicted natural groundwater COPC concentrations should be consider as plausible values rather than as absolute or ceiling values. Other lines of evidence were considered to assess if these predicted concentrations were realistic. 4.3 Groundwater Analytical Results The analytical results for the filtered vs unfiltered groundwater sample pairs obtained were compared to aid in assessing the potential for suspended solids or colloids in the groundwater samples, introducing bias to the conclusions reached regarding groundwater quality. A focus was placed on if a prior 2L Standard or IMAC exceedance might be due to suspended solids or colloids in a groundwater sample, which are not representative of dissolved metals in groundwater quality.Table 3 provides a summary of the groundwater analytical results for total metals (unfiltered) and dissolved metals (filtered). The table also provides the field measured turbidity values for comparison.Appendix I contains the groundwater Alternate Source Demonstration Lincoln County Landfill Crouse, North Carolina S&ME Project No. 1356-07-004 January 5, 2017 8 analytical report for the filtered groundwater samples, whereas the unfiltered sample analytical report was included with the semi-annual water quality monitoring report, for which the data was obtained. As indicated in Table 3: ♦Antimony was detected at five of the twelve monitoring well locations. The differences between reported total metal and dissolved metal concentrations were generally considered insignificant. ♦Arsenic was not detected in the groundwater samples collected from the monitoring wells. ♦Chromium was detected at six monitoring of the twelve monitoring well locations. The differences between reported total metal and dissolved metal concentrations were generally considered insignificant, with the exception of the data for monitoring MW-10R where the total concentration was seven time greater than the dissolved concentration. Monitoring well MW-10R exhibited a field turbidity value of 117.5 NTU, the highest for the twelve wells. ♦Cobalt was detected at two of the twelve monitoring well locations. The differences between reported total metal and dissolved metal concentrations were generally considered insignificant. ♦Lead was detected at one of the twelve monitoring well locations. The differences between reported total metal and dissolved metal concentration was generally considered insignificant. ♦Vanadium was detected at three of the twelve monitoring well locations. The differences between reported total metal and dissolved metal concentrations were generally considered insignificant, with the exception of the data for monitoring MW-10R where the total concentration was approximately ten time greater than the dissolved concentration. Monitoring well MW-10R exhibited a field turbidity value of 117.5 NTU, the highest for the twelve wells. Based a comparison of analytical results for the total metals verses dissolved metals for the sample pairs collected, and giving consideration to measured field turbidity values, the data collected suggests that the samples obtained at monitoring well MW-10R contained suspended or colloidal solids at levels sufficient to influence the reported total metal concentrations for chromium and vanadium. From this finding we can conclude that suspended or colloidal solids could contribute to the prior reported exceedances of the 2L Standards or IMAC at this well, assuming that the prior samples exhibited turbidity values similar or greater than that observed during October 2016. This form of possible sampling and/or analytical errors, could impact decisions made regarding site groundwater quality based on the analytical results. The vast majority of the field turbidity values measured (see Table 3) for the samples collected during October 2016 were greater than a 10 NTU goal often utilized with low-flow sampling procedures. Since prior groundwater sampling practices relied upon qualitative visual assessments of turbidity rather than quantitative field measurements, potential impact of turbidity upon apparent historic exceedances of a 2L Standard or an IMAC can only be judged qualitatively. 4.4 Time vs Concentration Graphs Time vs concentration graphs for historic concentrations of antimony, arsenic, chromium, cobalt, lead, and vanadium in groundwater were reviewed for indications of the natural occurrence of metals in groundwater vs indications of a release from the monitored unit. These graphs are contained in Appendix II. The historic groundwater monitoring data set for the lined MSW landfill contains a few wells which predate the unit’s receiving of waste; therefore, the data set could provide evidence of the natural Alternate Source Demonstration Lincoln County Landfill Crouse, North Carolina S&ME Project No. 1356-07-004 January 5, 2017 9 background concentrations. Unfortunately, historic analytical method reporting limits were higher than they are today, which hindered an evaluation of naturally occurring metals concentrations prior to waste disposal. This is particularly true for constituents detected at relatively low concentrations. Time vs concentration graphs depict both detected concentrations and the changes in the method reporting limits over time. These time vs concentration graphs do not provide definitive evidence for increasing concentrations of antimony, arsenic, chromium, cobalt, lead, and vanadium over time at the lined MSW landfill monitoring wells. Despite the aforementioned limitation associated with the data set, the absence of trends of rising concentrations over time provides an additional line of evidence for the natural occurrence of antimony, arsenic, chromium, cobalt, lead, and vanadium in groundwater associated with Facility. It is noteworthy that: ♦Historically, antimony, chromium, cobalt, and lead have been detected periodically in groundwater at background monitoring well MW-1A. The concentrations detected at monitoring well MW-1A have were generally similar to those detected at other Facility compliance monitoring wells. The groundwater analytical data set does contain periodic detections of higher than average concentrations of these inorganic constituents. For these outlier data points we infer that the elevated concentrations were not indicative of a release from the Facility, based upon the absence of a subsequent confirming elevated concentrations at the same sample point. Rather, sample turbidity is a more probable contributor to the reporting of periodic elevated concentrations. ♦Historically, vanadium has been detected periodically in groundwater at background monitoring well MW-1A. The concentrations detected at monitoring well MW-1A have were generally similar to those detected at other Facility compliance monitoring wells. Furthermore, according to the USGS NURE program database, portions of Lincoln County, North Carolina was found to have elevated vanadium concentrations in wells sampled 1976-1979. Based on USGS NURE database North Carolina diagram, contained in Appendix III, many of the sampled Lincoln County wells were reported to contain vanadium concentrations greater than 1 part per billion (or 1 µg/L), with some wells reported to contain greater than 10 parts per billion vanadium. These assumed natural concentrations are generally consistent with the vanadium groundwater concentrations observed at this Facility. 5.0 Conclusions For this ASD, natural groundwater concentrations for each COPC were predicted using the site-specific soil concentrations and an NCDEQ equation. The ADS also compared total metals concentrations verses dissolved metals in the groundwater sample pairs obtained during the October 2016 monitoring event, to assess if sample turbidity might influence the groundwater analytical results. Although less conclusive, trends in groundwater concentrations over time were also examined. Available USGS NURE data were also considered as an indicator of probable background metals concentrations in groundwater. This ASD assessment finds the following: Alternate Source Demonstration Lincoln County Landfill Crouse, North Carolina S&ME Project No. 1356-07-004 January 5, 2017 10 Antimony ♦The historic data set for groundwater compliance monitoring wells contains a high percentage of non-detect values. When antimony was detected the concentrations were frequently estimated concentrations. ♦The concentrations detected at compliance monitoring wells during the last two years were similar to those detected at background well MW-1A. ♦The maximum soil antimony concentration was predicted to yield a groundwater concentration generally equal to the highest antimony concentration observed in the last two years. ♦Time vs concentration graphs reveal no clear trend of increasing concentrations over time; thus providing no indications of a release from the monitored unit Conclusion: Based on this ASD, the detected antimony concentrations observed over the last two years were assessed to be probably naturally occurring groundwater concentrations. Arsenic ♦The historic data set for groundwater compliance monitoring wells contains a high percentage of non-detect values. Arsenic was detected at compliance wells twice during the last two years and since 1993 it was detected three times at background monitoring well MW-1A. During the last two years the detected concentration exceeding the 2L Standard was not verified with similar concentrations during subsequent monitoring events. ♦The mean soil arsenic concentration was predicted to yield a groundwater concentration that is generally greater than the highest arsenic concentration observed in the last two years. ♦Arsenic was not detected in the groundwater samples collected during October 2016; therefore, the potential impacts of sample turbidity on sample analytical results could not be assessed. Conclusion: Based on this ASD, the detected and substantiated arsenic concentrations observed over the last two years were assessed to be probable naturally occurring groundwater concentrations, or potentially a sampling related error. Chromium ♦The historic data set for groundwater compliance monitoring wells contains a high percentage of non-detect values. When chromium was detected the vast majority of the concentrations were estimated concentrations. ♦Chromium was detected in the background monitoring well at concentrations similar to that detected at the compliance monitoring wells. ♦The mean soil chromium concentration was predicted to yield a groundwater concentration that is generally greater than detected groundwater concentrations observed in the last two years. The two anomalous concentrations greater than 10 µg/L occurred during the October 2015 event, during which one of the anomalous concentrations was detected at background well MW-1. Since these outlier data points were not verified with similar concentrations during subsequent monitoring events, these data points were rejected and assumed to be sampling related errors. Alternate Source Demonstration Lincoln County Landfill Crouse, North Carolina S&ME Project No. 1356-07-004 January 5, 2017 11 ♦The comparison of total vs dissolved chromium groundwater concentrations revealed no significant differences with the exception of the data for monitoring MW-10R where the total concentration was seven time greater than the dissolved concentration. Monitoring well MW-10R exhibited a field turbidity value of 117.5 NTU, the highest for the sample set. For this example, sample turbidity was found to influence the total chromium concentration. ♦Time vs concentration graphs for chromium indicate no clear trend of rising concentrations over time; thus providing no indications of a release from the monitored unit. Conclusion: Based on this ASD, the detected and verified chromium concentrations observed over the last two years were assessed to be probable naturally occurring groundwater concentrations. Cobalt ♦The historic data set for groundwater compliance monitoring wells contains a high percentage of estimated concentrations. ♦Cobalt has been detected in background well MW-1A at concentrations similar to that detected at the compliance monitoring wells. ♦The range represented by the minimum and mean soil cobalt concentrations yield predicted groundwater concentrations that are generally consistent with actual concentrations detected over the last two years. Two of the actual groundwater concentrations which exceed this predicted range were concentrations that are less than the concentration predicted using the maximum observed soil cobalt concentration. These apparent outlier data points were not confirmed with similar concentrations during subsequent monitoring events, therefore these data points were rejected and judge to be sampling related errors. ♦The comparison of total vs dissolved cobalt groundwater concentrations revealed no significant differences between the data sets. It should be noted that cobalt was only detected in two of the twelve sample pairs examined for this ASD. ♦Time vs concentration graphs for cobalt indicate no clear trend of rising concentrations over time; thus providing no indications of a release from the monitored unit. Conclusion: Based on this ASD, the detected and verified cobalt concentrations observed over the last two years were assessed to be probable naturally occurring groundwater concentrations. Lead ♦The historic data set for groundwater compliance monitoring wells contains a high percentage of non-detect concentrations, with most detected concentrations representing estimated values. ♦Lead has been detected in background well MW-1A at concentrations similar to that detected and verified at the compliance monitoring wells. ♦The mean and maximum soil lead concentrations predicted groundwater concentrations that are less than estimated or quantified groundwater concentrations reported over the last two years. The detection of lead at 18 µg/L at monitoring MW-10R during October 2015, represents the only apparent exceedance of the 2L Standard set at 10 µg/L. This apparent outlier data point was not verified with similar concentration during subsequent monitoring events, therefore this data point was rejected and judge to be sampling related error. Well MW-10R is recognized to have groundwater sample turbidity that is higher than other wells. Alternate Source Demonstration Lincoln County Landfill Crouse, North Carolina S&ME Project No. 1356-07-004 January 5, 2017 12 ♦The comparison of total vs dissolved lead groundwater concentrations revealed no significant differences between the data sets. It should be noted that lead was only detected in one of the twelve sample pairs examined for this ASD. ♦Time vs concentration graphs indicate no clear trend of rising concentrations over time; thus providing no indications of a release from the monitored unit. Conclusion: Based on this ASD, the detected and verified lead concentrations observed over the last two years were assessed to be probable naturally occurring groundwater concentrations. Vanadium ♦The historic data set for groundwater compliance monitoring wells contains a high percentage of estimated concentrations. ♦Vanadium has been detected in background well MW-1A at concentrations similar to that detected at the compliance monitoring wells. ♦The calculated mean soil vanadium concentration predicts a groundwater concentration that is generally equal to the vast majority of the detected groundwater concentration observed in the last two years. Observed groundwater concentrations greater than the concentration predicted using the mean soil concentration do occur; however, these occurrences were typically not substantiated with a detection of a similar concentration at the same well during the subsequent monitoring event. These apparent outlier data points were not confirmed with similar concentrations during subsequent monitoring events, therefore these data points were rejected and judge to be sampling related errors. ♦The comparison of total vs dissolved cobalt groundwater concentrations revealed no significant differences between the data sets with the exception of the data for monitoring MW-10R where the total concentration was approximately 10 times greater than the dissolved concentration. Monitoring well MW-10R exhibited a field turbidity value of 117.5 NTU, the highest for the sample set. For this example, sample turbidity was found to influence the total vanadium concentration. It should be noted that vanadium was only detected in three of the twelve sample pairs examined for this ASD. ♦Time vs concentration graphs for vanadium indicate no clear trend of rising concentrations over time; thus providing no indications of a release from the monitored unit. ♦The USGS NURE database indicated that many Lincoln County, North Carolina wells located in the vicinity of the landfill contained vanadium concentrations could range from between less than 0.3 parts per billion (ppb) to 10 ppb. The IMC for vanadium is set at 0.3. The NURE data establishes that it is probable to have naturally occurring vanadium concentrations above the IMAC in the vicinity of the landfill. Conclusion: Based on this ASD, the detected and verified vanadium concentrations observed over the last two years were assessed to be probable naturally occurring groundwater concentrations. These findings suggest that the COPCs could naturally occur at concentrations greater than the corresponding published 2L Standards or IMACs, if applicable. As a result, the prior verified detections of antimony, arsenic, chromium, cobalt, lead and vanadium at concentrations greater than their corresponding 2L Standards or IMACs were not likely due to a release from the landfill, rather they can be reasonably attributed to the natural occurrence of these metals in the native, residual soil. Alternate Source Demonstration Lincoln County Landfill Crouse, North Carolina S&ME Project No. 1356-07-004 January 5, 2017 13 The historic site groundwater database provides evidence of fluctuating; occasionally substantially fluctuating, total metals concentrations over time. This finding together with the ASD finding of sample turbidity influencing chromium and vanadium concentrations at well MW-10R points to the potential for sample turbidity introducing possible error to total metals analytical results at other wells in the past and into the future. This error could impact the conclusions reached regarding site groundwater quality. Based on the above observations and S&ME’s experience with other sites, Lincoln County should consider implementing additional groundwater sampling procedures at the site focused upon reducing sample turbidity. This could include implementing low-flow sampling methods during future compliance monitoring events. The goal of the procedure changes would be to reduce suspended or colloidal solids in future groundwater samples, to the extent practical; thereby, reducing the potential for certain sampling and/or analytical errors. 6.0 Limitations This ASD was conduct to initiate an assessment of the potential natural occurrence of antimony, arsenic, chromium, cobalt, lead and vanadium in shallow groundwater around the lined MSW landfill units. For a larger scale site like this, underlain by a complex metamorphic bedrock unit, the distribution of metals in residual soil can vary spatial due to their natural heterogeneous distributions. This condition can make the use a single background monitoring well, impractical as a definitive tool to define naturally occurring metals concentrations in groundwater. Similarly, a heterogeneous distribution of metals in residual soils and bedrock make it impractical to establish absolute background concentrations of certain metals, present or likely present. Therefore, this assessment has established probable natural concentrations for certain metals in groundwater. Review of this ASD by the NCDEQ-SWS is required to confirm if the regulatory requirements for this matter have been met. 7.0 References Soil Screening Guidance: Technical Background Document, Second Edition, May 1996, United States Environmental Protection Agency (EPA), EPA/540/R95/128, OSWER-9355.4-17A. Geologic Map of North Carolina, 1985. North Carolina Geologic Survey, North Carolina Department of Natural Resources and Community Development USGS National Uranium Resource Evaluation Program Database, http://mrdata.usgs.gov/nure/water/. Accessed April 15, 2015. Date NCAC 2L NCDEQ Analyte Sample MW-1A MW-8 MW-9 MW-10R MW-12 MW-15 MW-18 MW-19 MW-21 MW-24 MW-25 MW-25A MW-32R MW-33 MW-33A MW-34 MW-35 MW-35A Standard IMAC Collected (µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(ug/L) 13 Antimony 10/18/2016 - 10/19/2016 1.42 J dry well <0.220 <0.220 <0.220 <0.220 <0.220 0.849 J <0.220 <0.220 <0.220 0.708 J <0.220 <0.220 4.05 J **<0.220 0.545 J ns 1 4/12/2016 - 4/13/2016 <0.220 0.338 J 0.779 J <0.220 <0.220 <0.220 <0.220 2.79 J <0.220 <0.220 <0.220 1.86 J <0.220 <0.220 3.89 J <0.220 <0.220 1.22 J ns 1 10/6/2015 - 10/7/2015 2.27 J <0.220 3.03 J 0.232 J <0.220 <0.220 <0.220 2.08 J <0.220 <0.220 <0.220 0.981 J <0.220 <0.220 <0.220 <0.220 0.924 J 2.12 J ns 1 4/14/2015 - 4/15/2015 0.647 J 0.440 J 0.563 J 0.641 J <0.220 <0.220 <0.220 0.418 J <0.220 <0.220 <0.220 0.910 J <0.220 <0.220 1.98 J <0.220 0.433 J 0.971 J ns 1 14 Arsenic 10/18/2016 - 10/19/2016 <6.80 dry well <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 **<6.80 <6.80 10 ns 4/12/2016 - 4/13/2016 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 10 ns 10/6/2015 - 10/7/2015 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 10 ns 4/14/2015 - 4/15/2015 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 9.14 J 10.5 10 ns 51 Chromium 10/18/2016 - 10/19/2016 1.52 J dry well 2.69 J 7.58 J <1.40 <1.40 <1.40 <1.40 <1.40 <1.40 1.98 J 4.70 J <1.40 <1.40 <1.40 **<1.40 3.20 J 10 ns 4/12/2016 - 4/13/2016 <1.40 3.66 J 2.43 J 1.52 J <1.40 <1.40 <1.40 <1.40 <1.40 <1.40 0.399 J 4.21 J 1.83 J <1.40 <1.40 <1.40 <1.40 2.83 J 10 ns 10/6/2015 - 10/7/2015 16.0 <1.40 1.95 J 30.4 <1.40 <1.40 2.55 J <1.40 <1.40 <1.40 <1.40 4.91 J <1.40 <1.40 <1.40 <1.40 <1.40 3.11 J 10 ns 4/14/2015 - 4/15/2015 5.91 J 3.90 J 2.95 J 1.78 J <1.40 <1.40 <1.40 <1.40 <1.40 <1.40 7.02 J 5.31 J <1.40 <1.40 <1.40 <1.40 <1.40 3.89 J 10 ns 53 Cobalt 10/18/2016 - 10/19/2016 <1.10 dry well <1.10 2.35 J 17.5 <1.10 1.68 J <1.10 <1.10 <1.10 <1.10 3.56 J <1.10 <1.10 <1.10 **<1.10 <1.10 ns 1 4/12/2016 - 4/13/2016 <1.10 2.38 J <1.10 <1.10 28.9 <1.10 <1.10 <1.10 4.11 J 1.39 J <1.10 5.15 J <1.10 <1.10 <1.10 4.43 J <1.10 <1.10 ns 1 10/6/2015 - 10/7/2015 3.83 J <1.10 <1.10 15.5 2.28 J <1.10 5.06 J 1.33 J 1.15 J <1.10 <1.10 8.91 J 1.16 J <1.10 1.21 J 6.99 J 1.53 J <1.10 ns 1 4/14/2015 - 4/15/2015 1.15 J 2.32 J <1.10 <1.10 14.2 <1.10 1.20 J <1.10 <1.10 1.32 J <1.10 5.03 J <1.10 <1.10 <1.10 6.03 J 1.67 J <1.10 ns 1 131 Lead 10/18/2016 - 10/19/2016 <3.10 dry well <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 **<3.10 <3.10 15 ns 4/12/2016 - 4/13/2016 <3.10 3.89 J <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 3.85 J <3.10 <3.10 <3.10 <3.10 <3.10 15 ns 10/6/2015 - 10/7/2015 5.27 J <3.10 <3.10 18.0 <3.10 <3.10 7.07 J <3.10 <3.10 <3.10 <3.10 <3.10 4.84 J <3.10 <3.10 4.27 J <3.10 <3.10 15 ns 4/14/2015 - 4/15/2015 3.10 J <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 3.41 J <3.10 <3.10 <3.10 <3.10 <3.10 15 ns 209 Vanadium 10/18/2016 - 10/19/2016 <1.40 dry well <1.40 13.9 J <1.40 <1.40 <1.40 <1.40 <1.40 <1.40 <1.40 1.63 J <1.40 <1.40 <1.40 **<1.40 2.15 J ns 0.3 4/12/2016 - 4/13/2016 <1.40 9.40 J 1.70 J 3.10 J <1.40 <1.40 1.44 J 1.59 J 2.24 J <1.40 <1.40 4.07 J 5.58 J <1.40 1.47 J <1.40 <1.40 2.91 J ns 0.3 10/6/2015 - 10/7/2015 10.4 J <1.40 2.20 J 70.7 1.59 J <1.40 7.37 J 2.07 J <1.40 <1.40 <1.40 5.99 J 3.07 J <1.40 1.52 J 2.88 J 5.41 J 4.04 J ns 0.3 4/14/2015 - 4/15/2015 2.77 J 8.69 J 1.56 J 2.42 J <1.40 <1.40 <1.40 1.55 J <1.40 <1.40 <1.40 3.52 J 2.88 J <1.40 1.60 J 2.06 <1.40 1.52 J ns 0.3 µg/L = Concentrations reported in micrograms per liter (µg/L) < = Concentrations is less than the method detection limit shown J = Reported concentration is considered estimated Yellow highligted cells denote detected concentrations, estimate and quantified NCAC 2L Standards = 15A North Carolina Administrative Code 2L .0200, GW Quality Standards for Class GA groundwater. Concentrations in BOLD exceed the corresponding 2L Standard NCDEQ IMAC = NCDEQ Interim Maximum Allowed Concentration. Concentrations in bold print exceed the corresponding IMAC value. ns = no standard ** = Well removed by others due to the construction of new landfill cell Phase IV Solid Waste Section ID # ALTERNATE SOURCE DEMONSTATION - CONSTITUENTS OF POTENTIAL CONCERN TABLE 1 2 YEAR SUMMARY OF GROUNDWATER ANALYSES RESULTS PHASE 3 - PERMIT # 55-03 LINCOLN COUNTY LANDFILL CROUSE, NORTH CAROLINA S&ME PROJECT NO. 1356-07-004 Groundwater Sample Locations TABLE 2 SUMMARY OF SOIL SAMPLE ANALYSES RESULTS AND CALCULATION OF PREDICTED GROUNDWATER CONCENTRATIONS PHASE 3 - PERMIT # 55-03 LINCOLN COUNTY LANDFILL CROUSE, NORTH CAROLINA S&ME PROJECT NO. 1356-07-004 Soil Sample ID Antimony Data Qualifier Arsenic Data Qualifier Chromium Data Qualifier Cobalt Data Qualifier Lead Data Qualifier Vanadium Data Qualifier (mg/kg)(mg/kg)(mg/kg)(mg/kg)(mg/kg)(mg/kg) MW-1 0.293 BRL 17.6 53.5 1.90 J 32.7 113 MW-8/9 0.276 BRL 6.99 J 3.03 J 6.28 J 15.3 16.1 J MW-10 0.272 BRL 8.78 J 23.4 7.69 J 11.9 65.1 MW-12 3.29 J 5.32 J 36.8 8.82 J 25.1 43.5 MW-21 1.54 J 3.52 J 18.5 6.92 J 16.7 41.3 MW-24 3.17 J 4.61 J 24.6 16.6 14.6 84.9 MW-25 0.263 BRL 2.32 J 10.4 3.69 J 11.7 25.4 MW-32 0.229 BRL 3.73 J 17.8 2.42 J 13.3 29.9 MW-33 0.246 BRL 4.10 J 10.8 1.74 J 11.8 26.2 MW-35 0.257 BRL 5.5 J 11.2 2.54 J 13.3 42 BG-1 0.294 BRL 27.4 82.6 15.4 16.9 75.8 BG-2 4.23 J 13.6 104 5.64 J 19.3 119 BG-3 0.994 J 4.82 J 27.0 2.85 J 9.97 J 28.2 BG-4 1.27 J 2.77 J 6.81 J 3.08 J 14.9 21.8 J Maximum 4.23 27.4 104 16.6 32.7 119 Minimum 0.229 2.32 3.03 1.74 9.97 16.1 Mean 1.01 8.80 33.59 6.49 16.88 54.21 Std. Deviation 2.35 13.88 58.57 9.37 11.94 66.58 Alternate Source Demonstration (ASD) Calculations Kd 45 26 180 45 900 1000 HLC 1 0 0 0 0 0 Predicted Natural Groundwater Concentration in mg/L (based on minimum soil concentration)0.0002 0.0044 0.0008 0.0019 0.0006 0.0008 Predicted Natural Groundwater Concentration in mg/L (based on maximum soil concentration)0.0043 0.0523 0.0289 0.0184 0.0018 0.0059 Predicted Natural Groundwater Concentration in mg/L (based on mean soil concentration)0.0010 0.0168 0.0093 0.0072 0.0009 0.0027 2L Standard or IMAC in mg/L 0.001 0.010 0.010 0.001 0.015 0.0003 mg/L = Milligram per liter mg/kg = micrograms per kilogram J = concentration is estimated JD = concentration is estimated and based on sample dilution BRL = Analyte reported as below method detection limit (MDL). Concentrations shown is 1/2 of the MDL. This value used for general statistics computations ASD Calculation Formula: Predicted groundwater conc. (mg/L) = [soil concentration (mg/kg)]÷ [(20 x Kd) + 4 + (1.7333 x 41 x HLC (amt. m3/mole))] Note: 1.733 = conversion factor from organic matter to organic carbon (fom= 1.733 foc) Kd = Soil/water partitioning coefficient (from published literature) HCL = Henry's Law Constant (from published literature) \\charnc\Active\Projects\2007\Energy\1356-07-004 Lincoln Co. Landfill Groundwater\ASD for Metals_Lined Landfill\ASD Tables_FINAL.xlsx MDL NCAC 2L NCDEQ MW-1A MW-9 MW-10R MW-12 MW-21 MW-24 MW-25 MW-25A MW-32R MW-33A MW-35 MW-35A Standard IMAC (µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L)(µg/L) 13 Antimony (total)1.42 J <0.220 <0.220 <0.220 <0.220 <0.220 <0.220 <0.220 <0.220 4.05 J <0.220 0.545 J 0.220 ns 1 (dissolved)1.59 J <0.220 0.437 J <0.220 <0.220 <0.220 <0.220 0.271 J <0.220 3.25J <0.220 0.230 J 0.220 ns ns % change -12%0%-98%0%0%0%0%-23%0%-25%0%-58% 14 Arsenic (total)<6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 6.80 10 ns (dissolved)<6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 <6.80 6.80 ns ns % change 0%0%0%0%0%0%0%0%0%0%0%0% 51 Chromium (total)1.52 J 2.69 J 7.58 J <1.40 <1.40 <1.40 1.98 J <1.40 <1.40 <1.40 <1.40 3.20 J 1.40 10 ns (dissolved)<1.00 2.57 J <1.00 <1.00 <1.00 <1.00 <1.00 4.30 J <1.00 <1.00 <1.00 2.89 J 1.00 ns ns % change 34%-5%86%0%0%0%49%-201%0%0%0%-71% 53 Cobalt (total)<1.10 <1.10 2.35 J 17.5 <1.10 <1.10 <1.10 <1.10 <1.10 <1.10 <1.10 <1.10 1.10 ns 1 (dissolved)<1.10 <1.10 <1.10 17.4 <1.10 <1.10 <1.10 <1.10 <1.10 <1.10 <1.10 <1.10 1.10 ns ns % change 0%0%53%0%0%0%0%0%0%0%0%0% 131 Lead (total)<3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 3.10 15 ns (dissolved)<3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 <3.10 3.10 J <3.10 <3.10 <3.10 3.10 ns ns % change 0%0%0%0%0%0%0%0%0%0%0%0% 209 Vanadium (total)<1.40 <1.40 13.9 J <1.40 <1.40 <1.40 <1.40 <1.40 <1.40 <1.40 <1.40 2.15 J 1.40 ns 0.3 (dissolved)<1.40 <1.40 <1.40 <1.40 <1.40 <1.40 <1.40 1.59 J <1.40 <1.40 <1.40 2.58 J 1.40 ns ns % change 0%0%90%0%0%0%0%-13%0%0%0%-16% 9.81 1.32 117.5 28.45 23.97 2.20 37.12 6.86 14.35 1.71 12.04 12.04 µg/L = Concentrations reported in micrograms per liter (µg/L) < = Concentrations is less than the method detection limit (MDL) shown Shaded cells indicate parameter detected above the MDL SWSL = North Carolina Solid Waste Section Limit J = Concentration reported greater than the MDL but less than the SWSL, thus it is considered estimated NCAC 2L Standards = 15A North Carolina Administrative Code 2L .0200, GW Quality Standards for Class GA groundwater. Concentrations in BOLD exceed the corresponding 2L Standard NCDEQ IMAC = Interim Maximum Allowed Concentration, NCDEQ Analyte (total) = Analyte result for total metal concentration with no field or laboratory filtering of the groundwater sample Analyte (dissolved) = Analyte results for groundwater samples 0.45 micron filtered by the laboratory prior to analysis for total metals % change = Percent change between total concentration and dissolved concentrations reported for each sample pair TABLE 3 SUMMARY OF GROUNDWATER ANALYSES RESULTS PHASE 3 - PERMIT # 55-03 LINCOLN COUNTY LANDFILL CROUSE, NORTH CAROLINA Analytes Field Turbidity (NTUs) S&ME PROJECT NO. 1356-07-004 TOTAL METALS VS DISSOLVED METALS Solid Waste Section ID # Monitoring Well Locations Appendix I Metals (Methods 6010B & 6010D) Well ID Sample ID Date Collected \\charnc\Active\Projects\2007\Energy\1356-07-004 Lincoln Co. Landfill Groundwater\ASD for Metals_Lined Landfill\ASD Tables_FINAL.xlsx G G G G G G < < < < < < < < < < < < < < < < < < < < < < < < < < < < C&D PHASE II C&D PHASE I EXISTING AREA "E"CLOSED LANDFILLEXISTING AREA "D"PHASE IPHASE II PHASE III MW-8 MW-9 MW-12MW-24 MW-25 MW-34 MW-21 MW-15 MW-18MW-19 MW-13 MW-14 MW-20 MW-28 MW-29 MW-36 MW-30 MW-31 MW-26 MW-27 MW-1AMW-17R MW-10R MW-25A MW-32R MW-16R MW-35/MW-35A MW-33/MW-33A SW-4 SW-5 SW-1 SW-2 SW-3 SW-6 856 86 4 8 5 2 8 4 8 8 4 4 8 3 6 8 3 2 828 824 868 872 87 6 816 884 888 812 892 808 804 796 8 9 6 904 9 0 8 912 916 9 2 4 792 788 784 9 2 8 932 9 3 6 864 924 924 904 9 1 6 892 884 7 8 4 936928 796 8 1 2 9 1 2 824 9 3 6 8 7 6 9 1 2 936 844 868 8 9 2 912 808 7 8 8 9 2 8 848 8 8 8 932 8 6 8 904 856 932 8 8 8 856 892 8 6 8 908 8 5 6 896 9 0 4 784 8 7 2 872 848 8 5 2 9 0 8 90 8 9 2 4 876 8 8 4 8 1 2 892 916 836 924 9 3 2 S H O A L R D C R O U S E R D Y O D E R R D SHIRLEY REYNOLDS LN 0 500 1,000Feet LEGEND <GROUNDWATER MONITOR WELLS G SURFACE WATER SAMPLE C&D LANDFILL BOUNDARY MSW BOUNDARY STREAMS 4' CONTOURS ROADS DIRT ROADS SITE ´ 1 S I T E D E T A I L M A P L I N C O L N C O U N T Y L A N D F I L L C R O U S E , N O R T H C A R O L I N A 1 3 5 6 -0 7 -0 0 4 1 " = 5 0 0 ' J A N 2 0 1 7 FIGURE NO. S C A L E : P R O J E C T N O : D A T E : D R A W N B Y : C H E C K E D B Y : N C E N G . L I C E N S E #F -0 1 7 6 3 2 0 1 S P R I N G F O R E S T R D , R A L E I G H , N C 2 7 6 1 6 W W W .S M E I N C .C O M D R A W I N G N U M B E R : B T R B -2 6 8 3 Appendices Appendix I – Analytical Reports Appendix II – Time vs Concentration Graphs Appendix III – USGS NURE Data Drawings Page 1 of 1 10/26/2016https://ncdenr.s3.amazonaws.com/s3fs-public/Water%20Resources/Image%20Files/images/nure_vanadium.gif