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HomeMy WebLinkAbout8401_CityofAlbemarleMSWLF_ASDMetalsRpt_DIN27404_20161123 ALTERNATE SOURCE DEMONSTRATION REPORT INORGANICS CITY OF ALBEMARLE LANDFILL ACTIVE C&D AND CLOSED MSWLF SUBTITLE D LINED MSWLF DSWM PERMIT NO. 84-01 Prepared for: City of Albemarle – Public Works Department Stanly County, North Carolina November 22, 2016 Shield Project 1110192 ALTERNATE SOURCE DEMONSTRATION REPORT INORGANICS CITY OF ALBEMARLE LANDFILL ACTIVE C&D AND CLOSED MSWLF SUBTITLE D LINED MSWLF DSWM PERMIT NO. 84-01 Prepared for: City of Albemarle – Public Works Department Stanly County, North Carolina Prepared by: Shield Engineering, Inc. Charlotte, North Carolina November 22, 2016 Shield Project 1110192 ii TABLE OF CONTENTS Page 1.0 INTRODUCTION ................................................................................................................. 1-1 1.1 BACKGROUND ........................................................................................................... 1-1 1.1.1 Active C&D Closed MSWLF ........................................................................... 1-2 1.1.2 Subtitle D Lined MSWLF ................................................................................. 1-3 1.2 SAMPLING RESULTS ................................................................................................ 1-3 1.3 PURPOSE ..................................................................................................................... 1-4 2.0 SITE DATA AND BACKGROUND DATA FOR AREA.................................................... 2-1 2.1 SITE DATA .................................................................................................................. 2-1 2.1.1 Data Graphs ....................................................................................................... 2-1 2.1.2 Source of Inorganic Exceedances ...................................................................... 2-2 2.2 BACKGROUND DATA ............................................................................................... 2-4 2.2.1 Local Hydrogeology .......................................................................................... 2-4 2.2.2 Background Data ............................................................................................... 2-6 3.0 COMPARISON OF TOTAL AND DISSOLVED CONCENTRATIONS ........................... 3-1 3.1 REVIEW OF SOIL CHARACTERISTICS .................................................................. 3-1 3.2 DISSOLVED CONCENTRATIONS ............................................................................ 3-2 4.0 STATISTICAL ANALYSES ................................................................................................ 4-1 4.1 QUARTILES AND BOX PLOTS ................................................................................. 4-1 4.2 OUTLIER ANALYSIS ................................................................................................. 4-2 4.3 STATISTICAL ANALYSIS ......................................................................................... 4-3 4.4 STATISTICAL RESULTS ........................................................................................... 4-4 4.4.1 Active C&D Closed MSWLF ........................................................................... 4-4 4.4.2 Subtitle D Lined MSWLF ................................................................................. 4-5 4.4.3 Summary............................................................................................................ 4-7 5.0 SUMMARY AND CONCLUSIONS .................................................................................... 5-1 6.0 REFERENCES ....................................................................................................................... 6-1 iii FIGURES Figure 1 Site Vicinity Map Figure 2 Groundwater Contour Map – City of Albemarle Landfill TABLES Table 1 Summary of Inorganic Analyses for 2000-2016 and Exceedances Table 2 Summary of Inorganic Analyses Exceedances per Well for 2000-2016 Table 3 Background Groundwater Data for Carolina Slate Belt Table 4 Background Groundwater Concentrations for Inorganics in Piedmont Table 5 Background Data for Carolina Slate Belt Table 6 Background Geochemical and Hydrogeochemical Data for Stanly County Table 7 Background Groundwater Concentrations for Inorganics in Stanly County Table 8 Soil Types Present at Site Table 9 Analytical Results for Inorganic Constituents (Total and Dissolved) – July 2016, Active C&D and Closed MSWLF Table 10 Analytical Results for Inorganic Constituents (Total and Dissolved) – July 2016, Subtitle D Lined MSWLF Table 11 Summary of Inorganic Analyses for 2000-2016 and Exceedances without Outliers Table 12 Statistical Result Summary, Active C&D and Closed MSWLF Table 13 Statistical Result Summary, Subtitle D Lined MSWLF Table 14 Summary of Statistical Evaluation Table 15 Report Summary for Inorganic Concentrations APPENDICES Appendix A: Analytical Results Appendix B: Graphs Appendix C: Quartiles, Box Plots and Outlier Analyses Appendix D: Statistical Analyses City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 1-1 1.0 INTRODUCTION 1.1 BACKGROUND The City of Albemarle Landfill (DSWM [Division of Solid Waste Management] Permit #84-01) is located on Stony Gap Road (SR 1720), in Stanly County, North Carolina (see Figure 1). Prior to operating as a C&D Landfill, the site formerly operated as an unlined Municipal Solid Waste Landfill (MSWLF) that consisted of two units. The first unit (Unit #1) was closed prior to October 1991 with a 24-inch thick final soil cover. The second unit (Unit #2) was closed with an 18-inch thick cohesive soil cap with a permeability of 10-5 centimeters per second (cm/sec) and an 18-inch thick soil erosive layer prior to June 1999 in accordance with the Transition Plan. The C&D Landfill is constructed and operating on top of the Unit #1 MSWLF. Adjacent to the C&D Landfill, across the unnamed tributary of Jacobs Creek, on the same contiguous property is the active Subtitle D lined MSWLF. The lined MSWLF is comprised of two contiguous phases (Phase 1 and 2) which are combined and treated as a single unit for continuity of the reporting to the SWS. This active MSWLF also operates under DSWM Permit #84-01. A groundwater monitoring system for both the Active C&D and the closed MSWLF and the Subtitle D MSWLF has been installed in accordance with Solid Waste Management Rules as per Title 15A, Subchapter 13B, Rules .1631 of the North Carolina Administrative Code (15A NCAC 13B.1631). Prior to 2015, there were two Sampling and Analysis Plans (SAPs) for the City of Albemarle Landfill, now there is only one document (i.e., WMP dated May 15, 2015) detailing the sampling and analyses procedures for this site. In May 2015 Shield Engineering, Inc. (Shield) completed an updated site- specific Water Monitoring Plan (WMP) for both landfills as specified within Solid Waste Management Rules 15A NCAC 13B.1630. The WMP was dated May 15, 2015 and was submitted to the SWS. This WMP updates the former Sampling and Analysis Plan (SAP) for the Active C&D and closed MSWLF which was contained in the Corrective Action Effectiveness Report (CAER) dated July 1, 2011 for this site; and, follows the SWS Guidelines for Groundwater, Soil, and Surface Water Sampling dated April 2008. This WMP also updates the former Sampling and Analysis Plan dated March 2, 2009 for the Subtitle D lined MSWLF. City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 1-2 The WMP provides details of the sampling procedures. Whereas the semi-annual groundwater monitoring reports provide details of the field measurements, laboratory analytical results, characterization of the groundwater and surface water, and findings from the each of the sampling events. Groundwater and surface water samples have been collected at the Active C&D and closed MSWLF site on a semi-annual basis since 1994, in accordance with Solid Waste Management Rule 15A NCAC 13B.1633(b). Groundwater and surface water samples have been collected at the Subtitle D lined MSWLF site on a semi-annual basis since this MSWLF commenced operations in 1999. The groundwater and surface water sampling has been conducted in accordance with Solid Waste Management Rule .1633(b) [15A NCAC 13B.1633(b)]. As a condition of the water quality monitoring program, semi-annual reports have been submitted to the North Carolina Solid Waste Section (SWS). 1.1.1 Active C&D and Closed MSWLF The semi-annual groundwater sampling at the Active C&D and closed MSWLF typically consists of the following:  Appendix I list constituents, required regulatory constituents for C&D, and turbidity for Monitoring Wells MW-1, MW-2, MW-3, MW-4R, MW-5R, MW-6, MW-7, MW-8D, MW-9, MW-10, MW-11, MW-24 (annual sampling), MW-25 (annual sampling), and MW-29.  Appendix II list constituents and turbidity for Monitoring Wells MW-12, MW-13, and MW-23. The locations of these monitoring wells are shown on Figure 2. The site-specific WMP contains a combination of detection, assessment and corrective action monitoring for the Active C&D and closed MSWLF site. Detection monitoring is required on five monitoring wells (MW-4R, MW-5R, MW-8D, MW-11, and MW-29); and, background monitoring well (MW-1). At a meeting with SWS on June 26, 2013 it was agreed that detection Monitoring Wells MW-24 and MW-25 would be sampled on an annual basis. Corrective action monitoring is required on nine monitoring wells (MW-2, MW-3, MW-6, MW-7, MW-9, MW-10, MW-24, MW-25, and MW-29). Also, at the June 26, 2013 meeting with SWS, it was also agreed to perform monitored natural attenuation (MNA) monitoring on Monitoring Wells MW-3, MW-9, and MW-10 on a biannual cycle. An area downgradient of the Phase 1 Subtitle D lined MSWLF; and, between the unnamed tributary of Jacobs Creek and the Active C&D and closed MSWLF around the Leachate Lagoon has been under City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 1-3 assessment since July 2009. At a meeting with SWS on July 14, 2009 a subset of monitoring wells were selected for assessment monitoring in this area. Therefore, assessment monitoring was performed on Monitoring Wells MW-12, MW-13 and MW-23 around the Leachate Lagoon. These three monitoring well locations are also shown on Figure 2. SWS Rule 15A NCAC 13B.0544(b)(1)(D) requires that detection monitoring at all C&D landfills includes Appendix I of Title 40 Code of Federal Regulations Part 258 (40 CFR Part 258), in addition to mercury, chloride, manganese, sulfate, iron, alkalinity, and total dissolved solids. In addition to the Appendix I inorganics, this report also includes mercury, iron and manganese for the evaluation of inorganics for the Active C&D closed MSWLF Site only. 1.1.2 Subtitle D Lined MSWLF The semi-annual groundwater sampling at the Subtitle D lined MSWLF typically consists of the following:  Appendix I list constituents for Monitoring Wells MW-14, MW-15, MW-16S, MW-16D, MW- 17, MW-18, MW-19, MW-22, MW-26, and MW-27. Based on both the site-specific WMP and interaction with the SWS, the water quality monitoring program for this site consists of detection monitoring. Detection monitoring is typically performed on nine monitoring wells (MW-14, MW-15, MW-16S, MW-16D, MW-17, MW-18, MW-22, MW-26, and MW- 27); and background monitoring well (MW-19). 1.2 SAMPLING RESULTS Since analytical data was first collected at this site in 1994 a significant volume of data has been gathered over the years. During that time the water quality data for both sites at this landfill (i.e., Active C&D and closed MSWLF Site, and the Subtitle D lined MSWLF Site) have occasionally exhibited inorganic concentrations exceeding either the NC 2L Groundwater Standards or the Interim Maximum Allowable Concentrations (IMAC). These exceedances were also often observed in either the background monitoring well or upgradient monitoring wells from the landfill cells. Due to the ongoing nature of these exceedances, they have typically been considered to exhibit natural conditions expected to be encountered within the underlying groundwater and not considered to be a consequence of the material deposited within either the closed unlined landfill cell or the currently used lined landfill cell. City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 1-4 The occurrence of these exceedances have to date been rationalized to be due to natural conditions within the hydrogeologic regime underlying the City of Albemarle Landfill, rather than being caused by the presence of the landfill operations. However, this rationalization has not been technically shown to be the case for the City of Albemarle Landfill. 1.3 PURPOSE The purpose of the this report is to demonstrate that these inorganic exceedances above the NC 2L Groundwater Standards or the IMAC are a result of natural conditions and not the result of the landfill cells located at both sites located at the City of Albemarle Landfill. This demonstration is designed to utilize several approaches to show that these exceedances are natural occurrences within the groundwater underlying the site. These approaches are as follows: 1. Review of background concentrations of inorganics for the area in order to ascertain the range of inorganic concentrations for the local hydrogeologic system (see Section 2); 2. Comparing the dissolved concentrations of metals with the total concentrations of the metals to ascertain the “true” concentration of inorganics within the groundwater (see Section 3); and 3. Applying statistics to compare the inorganic concentrations with those detected within the upgradient monitoring wells (see Section 4). Together these different approaches provide a means to better understand the presence of these inorganic exceedances and their causes within the quality of the groundwater recovered from the monitoring wells located at the site. City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 2-1 2.0 SITE DATA AND BACKGROUND DATA FOR AREA 2.1 SITE DATA The first approach presented for the technical evaluation of the inorganic exceedances is to review the available background data for the area. In so doing, a review of the existing site data would assist in assessing the nature of the presence of inorganics at the City of Albemarle Landfill. The analytical data cumulated over the years from 1994 through to July 2016 from the groundwater sampling at the City of Albemarle Landfill are included in Appendix A. Data for those wells that have been abandoned and not replaced are not included within this database (e.g., MW-20, MW-21R). During that time the water quality data for both sites at this landfill (i.e., Active C&D and closed MSWLF Site, and the Subtitle D lined MSWLF Site) have occasionally exhibited inorganic concentrations exceeding either the NC 2L Groundwater Standards or the Interim Maximum Allowable Concentrations (IMAC). The occurrence of these exceedances have to date been rationalized to be due to natural conditions within the hydrogeologic regime underlying the City of Albemarle Landfill. 2.1.1 Data Graphs The first step in reviewing these analytical data was to graph these data against time for each of the inorganic parameters. Most of the monitoring wells were grouped together for the purposes of graphing these data. The graphical plots for these data are shown in Appendix B and this appendix is subdivided as per the following bullets: Active C&D and closed MSWLF Site  Background wells (MW-1 and MW-8D);  West wells (MW-2, MW-6, and MW-7);  South wells (MW-4R and MW-5R);  Northeast wells (MW-3, MW-9, and MW-10); and  Southeast wells (MW-12, MW-13, and MW-23). Subtitle D lined MSWLF Site  Background well (MW-19);  North wells (MW-17 and MW-18);  South wells (MW-22, MW-26, MW-27); and  West wells (MW-14, MW-15, MW-16S, and MW-16D). City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 2-2 A review of these graphs does indicate that there are numerous spikes (i.e., large data values compared to the majority of the data) within the data set for various inorganics. Issues that may cause such spikes may be related to poor well development, sampling techniques, fine soil infiltrating into the well due to well construction, etc. One notable point that can be observed from these graphs is that more of these spikes occur within the older data values, than in the more recent data. Sometimes this can be a reflection of such occurrences as the lowering of the method detection limits used by the analytical laboratory or the gradual removal of the fine soil particles from the near well formations due to the ongoing well sampling. The latter case is particularly evident upon a review of the graphs for the monitoring wells around the Subtitle D lined MSWLF Site. Numerous of those graphs exhibit elevated values of the inorganics for the initial results that then subsequently declined over time. Overall the general trend exhibited by these graphs for both sites is for a slight downward trend, however, this trend is more likely a reflection of lowered method detection limits in the analytical laboratory rather than groundwater “cleanup”. Therefore the key point from these graphs is that there are no upward trends being exhibited by any wells for these inorganic constituents. This point is important in the assessment of the cause for the presence of the inorganics within the monitoring wells. The lack of an upward trend for constituent concentrations in these graphs does suggest that the cause of the presence of the inorganics is not due to either of the MSWLFs (see Section 2.2.2: [Harden, 2009]). If either of the MSWLFs were contaminating the groundwater the expectation would be to observe an upward trend of the inorganic concentrations in these graphs, particularly in the area around the closed unlined MSWLF units. 2.1.2 Source of Inorganic Exceedances For the purposes of further summarization and discussion of these data, only those data since the beginning of 2000 are reviewed in this section. The reason for this cutoff date is due to the fact that most of those data spikes occur prior to 2000 (see Section 4.2), and the declining trend of the method detection limits for these inorganics. A summary of the groundwater sampling results for inorganics since 2000 through to 2016 is presented in Table 1. Table 1 shows the number of samples collected and analyzed at the site for each of nineteen inorganic constituents (see second column of Table 1). The number of samples collected for each inorganic constituent ranges from a high of 793 down to 65. Fifteen of the inorganic constituents had about 789 analyses completed over the period 2000-16. The analysis for tin was only completed whenever the City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 2-3 Appendix II metal analyses were requested, hence the lower number of analyses since the Appendix II analyses were only performed in a few monitoring wells (e.g., MW-12, MW-13, and MW-23). Similarly, mercury and iron and manganese were only analyzed for the monitoring wells around the active C&D Landfill on top of the closed MSWLF and these analyses have only been completed in the latter part of the 17-year period. The total number of exceedances is shown in the fourth column of Table 1 and the percentage of the analytical results that exceeded the North Carolina Groundwater Standards or the IMACs is shown for each inorganic in the fifth column of Table 1. The most prevalent number of exceedances was exhibited for manganese, iron, cobalt, vanadium, arsenic, and then chromium (i.e., those inorganics with greater than 10% of analyses exhibiting exceedances). However, no exceedances were exhibited for barium, tin, and zinc. Additionally, those exceedances exhibited for beryllium, copper, mercury, selenium, and silver are likely outliers (see Section 4.2). Of the 27 monitoring wells routinely sampled at the City of Albemarle Landfill the number of wells in which exceedances have been recorded are shown in the sixth column of Table 1. Only two inorganics have exhibited at least one exceedance in every one of the 27 monitoring wells located at the site (i.e., cobalt and vanadium). The monitoring wells that exhibit the most exceedances are Monitoring Well MW-2 (antimony, beryllium, cobalt, lead, manganese, and nickel), MW-3 (manganese, mercury, and selenium), followed by MW-1 (antimony and mercury), MW-9 (iron and vanadium), MW-12 (cadmium and nickel), MW-13 (arsenic and thallium), and MW-16D chromium and copper). Monitoring Well MW- 1 is a background monitoring well for the Active C&D and closed MSWLF site. In terms of the total number of exceedances per well, the above results suggest that Monitoring Well MW-2 exhibited the most exceedances of any well (i.e., 113 or 12.9% of the inorganic analyses completed for this well: see last line in Table 1). The total number of exceedances for each inorganic (except for barium, tin and zinc, each of which exhibited no exceedances) at each of the 27 monitoring wells are shown in Table 2. After Monitoring Well MW-2, the next four wells are as follows: MW-16D, MW-12, MW-13, and MW-1 (see highlighted values in last column of Table 2). A secondary point of note from Table 2 is that the upgradient (i.e., background) monitoring wells for both sites (MW-1, MW-8D, and MW-19) at the City of Albemarle Landfill also exhibit a significant number of inorganic exceedances. The average number of exceedances per well across the site is about 58 inorganic exceedances per well (1577 divided by 27 wells). Both Monitoring Wells MW-1 and MW-19 exceed this City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 2-4 average number of exceedances (85 and 60, respectively). Also Monitoring Well MW-8D, with only 33 inorganic exceedances, is located upgradient from the Active C&D and closed MSWLF site, but the monitoring interval is significantly deeper (i.e., mid-point of monitoring interval is at 67-foot depth) than all of the other monitoring wells (i.e., average depth to monitoring interval mid-point is 17.3 feet) across the site. Therefore, the depth to the monitoring interval may be a factor with the number of inorganic exceedances for each of the monitoring wells (Briel, 1997). The deeper the mid-point of the monitoring interval, the more likely the monitoring interval of the well is in bedrock, lessening the potential for fine particles being present within the groundwater samples. Together Tables 1 and 2 encapsulate the results for the inorganic constituents from the analyses of the groundwater samples collected from the City of Albemarle Landfill from 2000 through to 2016. Additionally these tables assist to better understand in which wells these exceedances are occurring and which inorganic constituents are more likely to exhibit exceedances. 2.2 BACKGROUND DATA In evaluating background data for inorganic concentrations the hydrogeology for both the source of the background data and the area of the City of Albemarle Landfill should be similar. 2.2.1 Local Hydrogeology The Site is located in the Piedmont Physiographic Province (Piedmont), an area underlain by ancient igneous and metamorphic rocks. These rocks commonly have a mantle of residual soil (also known as residuum) overlying the bedrock (LeGrand, 1988). The Piedmont is a generally northeast-trending physiographic province. This province is primarily underlain by several geologic zones or belts of plutonic rocks and low-grade to high-grade metamorphic rocks. Geologists have subdivided the Piedmont into four parallel geologic belts from east to west: Carolina Slate, Charlotte, King’s Mountain, and Inner Piedmont. The site is located in the Carolina Slate Belt, a northeast trending band of volcanic, sedimentary, and metamorphic rocks that extend from central Virginia, across North and South Carolina and into eastern Georgia within the eastern and central Piedmont (Floyd, 1965). The group of related formations within this belt comprises the Carolina Terrane, which consists of low-grade meta-igneous and associated meta-sedimentary rocks. City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 2-5 The Carolina Terrane is comprised of four meta-volcanic-dominated sequences: the Albemarle sequence in North Carolina; the South Carolina sequence in South Carolina and southeast Georgia; and the Cary sequence in eastern North Carolina. The area of the site is within the Albemarle sequence that is interpreted to have formed above the continental crust during the Neoproterozoic through the Cambrian Eras. Within this sequence is the Albemarle Group consisting of interbedded meta-mudstones and meta- siltstones (argillites) with lenses of felsic tuff. The Cid Formation portion of this group underlies the site proper and is characterized by thicker-bedded versions of these rocks containing more felsic and mafic volcanic members than underlying formations of the Albemarle Group (Tillery and Uwharrie) (Brown and Parker, 1985). Structurally the Carolina Terrane rock series have been folded in a series of northeastern-trending major and minor synclines and anticlines that show several minor faults and displacements. The Troy anticlinorium, extending from central Randolph County through Union County into South Carolina, is a major structural feature defining the regional geology in the vicinity of the site. These larger structures have wavelengths of ten to fifteen miles, and within them are sub-series of smaller synclines / anticlines (defining the anticlinorium term) all created from the same deformational compressive forces that created the major structures. There are two major faults in the area (Brown and Parker, 1985; Floyd, 1965); ten miles to the west is the Gold Hill Fault and 18 miles to the east is the Jonesboro Fault. The virgin soils encountered in this area are the residual product of in-place chemical weathering of rock, which was similar to the rock presently underlying the Site. In areas not altered by erosion or disturbed by human activities, the typical residual soil profile consists of clayey soils near the surface, where soil weathering is more advanced, underlain by sandy silts and silty sands. The boundary between soil and rock is gradational. These residual soils retain a relic structure within their cross-section and can be identified in soil borings. This gradational zone is termed “partially weathered rock” and is normally found overlying the parent bedrock. Partially weathered rock is defined, for engineering purposes, as residual material with standard penetration resistances in excess of 100 blows per foot. Weathering is facilitated by fractures, joints and by the presence of less resistant rock types. Consequently, the profile of the partially weathered rock and hard rock is quite irregular and erratic, even over short horizontal distances. Also, it is not unusual to find lenses and boulders of hard rock and zones of partially weathered rock within the soil mantle, above the general bedrock surface. The uppermost soils within the flood plains of streams often are alluvial (water-deposited) materials. City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 2-6 A potentiometric contours for the contiguous property (i.e., includes both sites) are shown in Figure 2. The groundwater flow directions based on both the potentiometric map and the aquifer characteristics for the monitoring system in July 2016, are also presented in Figure 2. The estimated average groundwater flow velocity for the Active C&D closed MSWLF Site is approximately 40 feet per year (Shield, 2016). The estimated groundwater flow velocity for the Subtitle D MSWLF Site is approximately 126 feet per year (Shield, 2016). 2.2.2 Background Data The United States Geological Survey have published a number of reports covering the Piedmont Physiographic Province (Piedmont) of North Carolina, some of which provide groundwater quality data general to the Piedmont (e.g., Briel, 1997; and Chapman et al., 2013) and a few (more recent report is Harden et al., 2009) provide groundwater quality data more specific to the Carolina Slate Belt. Tables 3 and 4 provide groundwater data for the Piedmont Physiographic Province. The data presented in Table 3 is solely focused on iron and manganese (Briel, 1997). The groundwater quality data presented in Table 3 are for both total and dissolved analyses of iron and manganese for the same samples. The data does indicate that the results for the dissolved groundwater analyses are lower for the most part compared to the results for the total groundwater analyses. The groundwater quality data presented in Table 4 covers a broader range of inorganics. A total of 17 inorganics are shown in Table 4 (Chapman et al., 2013). Even though the number of samples used for both data sets (i.e., Tables 3 and 4) are extensive, it should be noted that these two tables provide data encompassing the Piedmont region. Additionally, both tables (i.e., Tables 3 and 4) do indicate that iron and manganese routinely exhibit exceedances within the Piedmont. Also, in Table 4 arsenic does exhibit exceedances of the groundwater standards. Table 5 presents groundwater quality data for the Carolina Slate Belt region (see Section 2.2.1) of the Piedmont. These data are for dissolved and total groundwater analyses. Unlike Table 3, these dissolved analyses were for the most part completed on different wells from those used to analyze the total groundwater analyses. Similar to the groundwater quality data shown in Tables 3 and 4, some of the iron and manganese analytical results again exhibit exceedances of the NC 2L Groundwater Standards or the IMACs. In addition to these two inorganics, arsenic and zinc also exhibit exceedances of these City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 2-7 groundwater standards. Two sources for background data for the presence of inorganics within groundwater and sediment in North Carolina are the Geochemical Atlas of North Carolina (Reid, 1993a) and the Hydrogeochemical Atlas of North Carolina (Reid, 1993b). The data for Stanly County from these two references are summarized in Table 6. Unfortunately not many inorganics in groundwater (only manganese and vanadium) were analyzed for the National Uranium Resource Evaluation (NURE) project data presented within the hydrogeochemical atlas (Reid, 1993b). The data in Table 6 does show elevated concentrations for most inorganics within the stream sediments for Stanly County. The presence of inorganics within the stream sediments is an indicator of the presence of these same inorganics within the areawide soils. The finer particles of these same soils make up the sediments that can be extracted from the monitoring wells during the collection of the groundwater samples. These data do support the potential for obtaining elevated analytical results for the inorganics from the analysis of groundwater samples with fine soil particles present in the sample. The Inactive Hazardous Sites Branch (IHSB) of North Carolina Department of Environmental Quality publishes health based and “protection of groundwater remediation goals” for hazardous waste sites located in North Carolina. A “protection of groundwater goal” for a constituent is basically the maximum concentration within the soil above which the constituent could potentially leach into the groundwater and result in constituent concentrations above the IMAC. Though this site is not a hazardous waste site, these goals are a useful tool in evaluating the concentrations of inorganics within the soil medium that may impact groundwater. These protection of groundwater goals are determined specifically for North Carolina. Since there are limited data for cobalt these protection of groundwater goals are used to better understand the natural concentrations of cobalt present within groundwater in Stanly County. Since the IMAC for cobalt in groundwater is 1 microgram per liter (µg/L) the protection of groundwater concentration for cobalt in soil is 0.9 milligrams per kilogram (mg/kg) (IHSB, October 2016). A review of Table 6 shows that 100% of the soil samples collected within Stanly County (minimum cobalt concentration was 2.5 mg/kg: see Table 6) for the NURE project exceeded this concentration of 0.9 mg/kg (Plate 33: Reid, 1993a). In fact 80% of the sediment analyses exhibited cobalt at or above 10 mg/kg (see Table 6), which is more than ten times the IHSB protection of groundwater value of 0.9 mg/kg. Hence, the presence of cobalt within the sediments, and by inference Stanly County soils, is a City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 2-8 strong indicator of the likely presence of cobalt in groundwater above 10 µg/L (i.e., 10 times the IMAC of 1 µg/L for cobalt). The average cobalt concentration for all the analyses completed during the period 2000-2016, without the outliers as per Section 4.2, was 24.9 µg/L (i.e., calculated using half of the Minimum Detection Limit for each of the non-detect results). The average total cobalt concentration for the July 2016 sampling event was 24 µg/L. Therefore, there is no significant difference between these two averages. Also, the average cobalt concentration for the Subtitle D lined MSWLF Site is 29.3 µg/L for July 2016, and 21.8 µg/L for the period 2000-2016. The average cobalt concentration for the Active C&D closed MSWLF Site is 18.5 µg/L for July 2016, and 26.7 µg/L for the period 2000-2016. The highest annual average cobalt concentration for the Active C&D closed MSWLF Site was 37.3 µg/L in 2002, and for the Subtitle D lined MSWLF Site was 49.5 µg/L in 2000. The lowest annual average cobalt concentration for the Active C&D closed MSWLF Site was 18.2 µg/L in 2009, and for the Subtitle D lined MSWLF Site was 11.9 µg/L in 2011. The average cobalt concentration for all of the cobalt analyses in 2016 is 20.5 µg/L. Therefore, the overall trend of the annual average cobalt concentration is downward, as the amount of fine soil particles removed from the monitoring wells declines during subsequent sampling events. The two groundwater data sets from Reid (1993b) for groundwater also exhibit elevated ranges for both manganese and vanadium in the groundwater samples collected from Stanly County. The analytical results for manganese in Table 6 indicate that in Stanly County 55.9% of the groundwater samples have exhibited manganese above the IMAC for manganese of 50 µg/L. Similarly, the analytical results for vanadium in Table 6 indicate that for Stanly County 17% of the groundwater samples have exhibited vanadium above the IMAC for vanadium of 0.3 µg/L. Another resource from which specific data can be obtained for Stanly County is the University of North Carolina (UNC) Gillings School of Public Health. The data available from this data base are shown in Table 7. These data repeat the pattern observed in previous data, with elevated results for the nine inorganic constituents shown on Table 7. More than half of the analytical results for both iron and manganese exceed the NC 2L Groundwater Standards or the IMACs (i.e., average concentrations exceed these groundwater standards). Almost half of the analyses for arsenic exceed the NC 2L Groundwater Standard. Column 6 in Table 7 shows the percentage of the available data that exceeds either the NC 2L groundwater standards or the IMACs. The three inorganics that exhibit large percentages of data exceeding these standards (i.e., manganese, iron and arsenic: see Table 7) are also significant at the City City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 2-9 of Albemarle Landfill (see Table 1). Various factors impact the groundwater quality within bedrock aquifers as follows (Harden, 2009):  Chemical characteristics of the water from the recharge areas;  Lithologic composition of the crystalline bedrock and overlying regolith;  Rate of groundwater flow, which controls the residence time between water and aquifer materials; and  Redox conditions (i.e., measure of the tendency of a chemical species to acquire electrons and thereby be reduced) which influence the distribution of natural and anthropogenic constituents within the groundwater regime. Impact of human activities can often lead to changes of groundwater quality within an aquifer over time (Harden, 2009). In his assessment of the Appalachian Valley and Ridge, Blue Ridge and the Piedmont Physiographic Provinces Briel (1997) found that both iron and manganese exhibited their highest concentrations within the groundwater found within the Piedmont. City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 3-1 3.0 COMPARISON OF TOTAL AND DISSOLVED CONCENTRATIONS The second approach presented in Section 1.3 consists of a comparison of the dissolved and total inorganic concentrations for selected inorganics. This comparison is particularly important at sites located within the Piedmont Physiographic Province of North Carolina. 3.1 REVIEW OF SOIL CHARACTERISTICS The soils within this region consist of an appreciable percentage of fines (i.e., silts and clays). Based on the soil survey for the City of Albemarle Landfill site, the soil types encountered at the Landfill are listed on Table 8. These soils do exhibit significant percentages for the clay fraction. Therefore the installation of monitoring wells in areas with such fine soils is problematic at best, in terms of eliminating the presence of fine particles in the groundwater samples collected from these wells. Shield has worked at several sites located within the same geologic framework (i.e., Carolina Slate Belt) as that underlying the City of Albemarle Landfill. One of these sites was a hazardous waste site also with metal constituents present within the groundwater. This site had been undergoing remediation of these inorganic constituents for a number of years. Shield completed an investigation into the feasibility of using low-flow purging techniques to resolve the issue of sediment/soil particles being extracted with the groundwater samples. The result of this investigation indicated that because of the presence of fine soils (i.e., silts and clays) around the well screens on these monitoring wells, their inability to recharge groundwater to the well, even to meet the minimal flow rates used during low-flow sampling, precluded the effective application of low-flow purging. Hence, the application of low-flow purging did not exhibit any perceptible impact on the reduction of the concentrations for the inorganic constituents. The presence of the elevated concentrations for the inorganics during the first few sampling events (i.e., baseline sampling conducted for the Subtitle D lined MSWLF in 1999 – see Section 4.2), within the monitoring wells around the Subtitle D MSWLF Site (see graphs – Appendix B) is most likely due to initially large amount of fine soil particles being extracted within the groundwater samples. Analytical methods to determine the dissolved metal concentrations have historically used the 0.45- micron filters to separate dissolved and particulate phases within the samples. As a result, the optimal solution for this site was to collect two groundwater samples, one sample for routine inorganic analysis for total concentration and the second sample for filtering at the laboratory within a controlled environment, prior to the same analysis for dissolved concentration. Hence, during the July 2016 City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 3-2 groundwater sampling event dual samples were collected; one for the routine inorganic analyses, and a second sample for laboratory filtering prior to the same inorganic analyses. The laboratory reports for these analytical data were submitted to the SWS with the groundwater sampling report for July 2016 sampling event (Shield, 2016). 3.2 DISSOLVED CONCENTRATIONS These inorganics were selected based on previous occurrences of exceedances for either the NC 2L Groundwater Standards or the IMAC over the past few years. In order to acquire the data in preparation for this report the dissolved concentrations for selected inorganic constituents were analyzed from groundwater samples collected during the previous sampling event completed in July 2016. The results of the total and dissolved analyses for the Active C&D and closed MSWLF are shown in Table 9, and for the Subtitle D lined MSWLF they are shown in Table 10. Of all the 354 (i.e., 15 inorganics at each of 24 monitoring wells, less 6 at MW-3, MW-9 and MW-10) sets (i.e., dissolved and total analytical results) of inorganic results shown in Table 9, only 169 of these data sets exhibited at least one numeric value (either for the dissolved or the total analysis). Only these 169 data sets of results, with at least one numeric value, could be evaluated as to whether the dissolved concentration was lower or higher than the total concentration. About 91% of these 169 sets of results exhibited lower concentrations for the dissolved inorganic analysis compared to the total inorganic concentration. The remaining sixteen of these 169 data sets shown in Table 4 (i.e., 9%) exhibited higher dissolved concentrations for the inorganic analysis compared to the total concentrations. Three of these 16 concentrations were for manganese. Another six of these data sets occurred with thallium, with an equal number (3) occurring at the Active C&D and closed MSWLF site, and three at the Subtitle D lined MSWLF. Together manganese and thallium accounted for over half (9) of those 16 data sets where the dissolved concentrations were higher than the total concentrations (see Table 9). Therefore, for the most part (91%) the dissolved analytical concentrations were less than the total inorganic concentrations. A review of Tables 9 and 10 for the two sites does indicate that based on the total inorganic concentrations nine inorganics (i.e., arsenic, cadmium, chromium, cobalt, iron, lead, manganese, thallium, and vanadium: see Table 9) exhibited exceedances at the Active C&D and closed MSWLF site and five inorganics (i.e., arsenic, chromium, cobalt, thallium, and vanadium: see Table 10) exhibited exceedances City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 3-3 at the Subtitle D lined MSWLF site. Cadmium and lead only had one exceedance each at the Active C&D and closed MSWLF site (MW-7 and MW-1: see Table 9). Hence, for the most part both sites exhibited similar number of exceedances for this July 2016 groundwater sampling event. This characteristic of the July 2016 data for these two sites does suggest that inorganics are present no matter whether the landfill cell is lined or not. Since iron and manganese were analyzed only for the Active C&D and closed MSWLF Site, a comparison between the two sites required the exclusion of these two inorganics. The total number of inorganic exceedances (i.e., without Fe and Mn) at the Active C&D and closed MSWLF site in July 2016 was 33 (14 wells: see Table 9) and at the Subtitle D lined MSWLF site was 25 (10 wells: see Table 10). The ratio of inorganic exceedances per well was 2.4 at the Active C&D and closed MSWLF site and 2.5 at the Subtitle D lined MSWLF site. The data does not indicate any significant difference for occurrence of inorganic exceedances between the two sites for those inorganic data available for both sites. A review of the data in Table 2 indicates that the average number of inorganic exceedances at the Active C&D and closed MSWLF site for the same common set of inorganic constituents (less iron, manganese, mercury and tin) from 2000 through to 2016 was 52 per monitoring well. Whereas for the Subtitle D lined MSWLF site there were 55 inorganic exceedances per monitoring well during the same period. Therefore for both the July 2016 groundwater sampling event and for the whole data set for 2000 through to 2016 the data does indicate slightly higher number of exceedances per monitoring well at the Subtitle D lined MSWLF site. The net result for a comparison of the dissolved and total inorganic concentrations from the July 2016 groundwater sampling event does indicate that all of the inorganics with exceedances are explained by the traces of sediment within the samples, except for cobalt, manganese, thallium and vanadium (see Tables 9 and 10). Detectable concentrations for the dissolved analyses of these four constituents are shown in Tables 9 and 10. These detectable concentrations may be due to one of two things: 1. Either, the results for the dissolved analyses for these four constituents does indicate that these constituents may be present within the groundwater; or 2. The pore size of the filter used to filter the groundwater samples permitted fine particles to pass through during the filtering process. The concentrations for the dissolved inorganics exceeded the IMACs only in Monitoring Wells MW-7 and MW-16S for vanadium; and, in Monitoring Wells MW-16D and MW-17 for thallium. However, of City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 3-4 the total of 23 cobalt exceedances, the dissolved cobalt concentrations were reduced below the IMAC for only five of the monitoring wells (i.e., MW-6, MW-9, MW-18, MW-19, and MW-26). Also, of the total of 12 manganese exceedances, the dissolved manganese concentrations were reduced below the IMAC for only one of the monitoring wells (i.e., MW-6). The remaining 18 monitoring wells still exhibited cobalt concentrations above the IMAC (see Tables 9 and 10). Two of those 18 monitoring wells are upgradient wells (MW-1 and MW-8D). City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 4-1 4.0 STATISTICAL ANALYSES The third approach presented in Section 1.3 consists of a statistical analysis of the data set by comparing the analytical data for the background wells against the analytical data from the downgradient wells at the two sites located at the City of Albemarle Landfill. Prior to the completion of a statistical evaluation of the dataset for the two sites (i.e., Active C&D and closed MSWLF Site, and the Subtitle D lined MSWLF Site) at the City of Albemarle Landfill, a review of these data was completed first as a basis of providing a preliminary understanding of the available data. This review consisted of quartiles and a set of box plots for the full data set for each well and for each inorganic. Subsequently statistical analyses for background comparison of inorganics (metals) were performed utilizing established EPA protocol. 4.1 QUARTILES AND BOX PLOTS Quartiles were produced for the complete data set. These quartiles are included in Appendix C. One set of quartiles were completed for the Active C&D closed MSWLF Site and another set was completed for the Subtitle D lined MSWLF Site. A review the maximum values for a set of quartiles typically will show some elevated concentrations for a number of the wells for several inorganics. For example the quartiles for the antimony results for the Subtitle D lined MSWLF Site show a maximum value of 230 micrograms per liter (µg/L), whereas the remaining maxima are all at 30 µg/L or below. Similar elevated data (i.e., above the other wells) are scattered throughout the quartile results. These quartiles are also exhibited in the form of box plots. The first and third quartiles define the box on the box plot and the minimum and the maximum define the tails of the box plot. Two sets of box plots were prepared for each of the two sites. These box plots are shown in Appendix C. A comparative review of these box plots does show a number of obviously higher values for some the constituents. For example the box plots for antimony at the monitoring wells around the Subtitle D lined MSWLF Site show an unusually high antimony concentration at Monitoring Well MW-19 (i.e., the background well) compared to the box plots shown for the other monitoring wells at this site. Continuing a review of the box plots for the other inorganics for both sites these type of unusually high concentrations are scattered throughout the data set. Some sets of these box plots do not appear to exhibit such elevated concentrations (e.g., antimony for the Active C&D closed MSWLF Site). However, these elevated concentrations are likely outliers for the dataset. For a proper and meaningful statistical City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 4-2 evaluation of these data these outliers were evaluated further. 4.2 OUTLIER ANALYSIS A review of the potential for outliers was performed using Rosner’s Test for outliers (EPA, 2009). The results for the Rosner’s Test are included in Appendix C. The results were completed for the monitoring wells located around each of the two sites. Each of these two sets of results (i.e., one for each site) were compared. These results list the top ten outliers for each inorganic for each group of wells at each site. Care has to be exercised in deciding which data are likely true outliers and which are not. Not all data shown in these results should necessarily be excluded from statistical analyses discussed below. Therefore these results from the Rosner’s Test were individually compared to the box plots (see Section 4.1) and to the graphs discussed in Section 2.1.1. Based on these reviews those data highlighted in the results shown in Appendix C were removed from the data set. The data considered to be outliers was further evaluated in terms of which wells these samples were taken from and when these samples were collected. A total of 134 outlier values were considered for removal from the data set. Fifty-five of these outliers were data collected during the initial baseline quarterly sampling performed in 1999 for the new monitoring wells located around the Subtitle D lined MSWLF Site. The fact that these were collected during the initial sampling of these wells highlights the issue with excessive sediment being withdrawn with the initial groundwater samples from new monitoring wells. These four sampling events with these new wells together produced 41% of the outliers. A total of 72 outliers were identified from the 17 monitoring wells located around the Active C&D closed MSWLF Site over the period 1994 through 2016. Whereas 62 outliers were identified from the ten monitoring wells around the Subtitle D lined MSWLF Site between 1999 and 2016. Together these outliers represent 0.9% of the total data set of 14,864 analytical results for the inorganics at the City of Albemarle Landfill. For the analytical data cumulated from the beginning of 2000 through to the present, 44 outliers were identified (see Appendix C). Outliers can be the cause of many different factors ranging from the field during the sample collection to the laboratory and the sample preparation for the analysis. In each of these situations, outliers in a statistical context represent values that are inconsistent with the distribution of the remaining measurements (EPA, 2009). Tests for outliers thus attempt to infer whether the City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 4-3 suspected outlier could have reasonably been drawn from the same population as the other measurements, based on the sample data observed up to that point. In each of these situations, outliers in a statistical context represent values that are inconsistent with the distribution of the remaining measurements. Tests for outliers thus attempt to infer whether the suspected outlier could have reasonably been drawn from the same population as the other measurements, based on the sample data observed up to that point (EPA, 2009). Due to the ability of outliers to skew results of statistical analyses, these outliers were removed from the 2000-2016 data set and a revised Table 1 is shown in Table 11. Included in Table 11 are the current maximum concentrations for each of the inorganics. The analytical data set used to conduct the statistical analyses discussed in the next section does not have any of the 44 outliers identified within the data set for the period 2000-2016. 4.3 STATISTICAL ANALYSIS The distribution of data was taken into account to determine the required type of statistical analyses. Analytical data that consists of a significant percentage of non-detects is not normally distributed (EPA, 2009) due to the skew within analytical datasets caused by the non-detects. Such is typically the case with groundwater datasets from monitoring wells. Hence these datasets cannot be analyzed using methodologies based on normal distributions. Therefore, the approach toward a statistical analysis should take into account the non-normalized dataset, when statistical methodologies are considered. An added issue are the number of non-detects present within a dataset. The EPA (1992) states that when 90 percent or more of the data values are non-detect, the detected values can often be modeled as "rare events" by using the Poisson distribution. For those data sets with percentages of non-detects greater than 90% (i.e., mercury, selenium and thallium at the Active C&D and closed MSWLF Site; and, silver and thallium at the Subtitle D MSWLF Site). The lack of normality evident from the analytical data collected at this site, resulted in the use of either the Kruskal-Wallis Test or Non-Parametric Tolerance Limits. Hence, non-parametric tolerance limits were used as an alternative to the Kruskal-Wallis Test (EPA, 2009) for those instances where the non-detects are greater than 90%. The Kruskal-Wallis Test is a non-parametric ANOVA (Analysis of Variance). Within each well, the observations are ordered from least to greatest and assigned a rank. Tied observations are assigned the average of the ranks of those observations. Then, the ranks are used for the statistical analysis, rather than City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 4-4 the actual values. This test requires a minimum of three well groups with at least four observations per group; the data base for the City of Albemarle Landfill satisfies these two criteria. For those analytical data from 2000 through to July 2016, the Kruskal-Wallis statistical analysis was run for the inorganics that were analyzed in the downgradient compliance wells. At the Active C&D and closed MSWLF Site, Monitoring Well MW-1 is the background monitoring well. However, MW-8D is also located in an upgradient area from the Active C&D and closed MSWLF Site. The key difference between these two upgradient monitoring wells are the monitoring depths. Hence, groundwater data collected from both Monitoring Wells MW-1 and MW-8D were used as the background monitoring wells for statistical analyses at the Active C&D and closed MSWLF Site. The downgradient compliance monitoring wells for this site used for the statistical analysis for those inorganic constituents consist of Monitoring Wells MW-2, MW-3, MW-4R, MW-5R, MW-6, MW-7, MW-9 through MW-13, MW-23 through MW-25, and MW-29. The background monitoring well for the Subtitle D lined MSWLF Site is Monitoring Well MW-19. The downgradient compliance monitoring wells for this site used for the statistical analysis for those inorganic constituents consist of Monitoring Wells MW-14, MW-15, MW-16D, MW-16S, MW-17, MW-18, MW- 22, MW-26, and MW-27. 4.4 STATISTICAL RESULTS The results of the statistical analyses are presented in Appendix D. The statistical results for the Active C&D closed MSWLF Site are summarized in Table 12, and for the Subtitle D lined MSWLF Site are summarized in Table 13. The results of the statistical analysis are also summarized for each inorganic constituent sampled at each of the two sites in the following subsections. 4.4.1 Active C&D closed MSWLF Site The statistical results for this site are as follows: * Antimony – Statistical analysis indicated that none of the compliance wells were significantly impacted. * Arsenic - Statistical analyses indicated that there was a statistical exceedence at the 5% significance level in Monitoring Wells MW-3, MW-5R and MW-13 above the upgradient background wells (MW-1/MW-8D). * Barium - Statistical analyses indicated that there was a statistical exceedence at the 1% significance level in Monitoring Well MW-13 above the upgradient background wells City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 4-5 (MW-1/MW-8D). * Beryllium – Statistical analysis indicated that none of the compliance wells were significantly impacted. * Cadmium – Statistical analysis indicated that none of the compliance wells were significantly impacted. * Chromium - Statistical analyses indicated that there was a statistical exceedence at the 5% significance level in Monitoring Wells MW-9, MW-11, and MW-25 above the upgradient background wells (MW-1/MW-8D). * Cobalt - Statistical analyses indicated that there was a statistical exceedence at the 5% significance level in Monitoring Wells MW-2, MW-12, MW-13, and MW-23 above the upgradient background wells (MW-1/MW-8D). * Copper - Statistical analyses indicated that there was a statistical exceedence at the 1% significance level in Monitoring Well MW-25 above the upgradient background wells (MW-1/MW-8D). * Iron – Statistical analysis indicated that none of the compliance wells were significantly impacted. * Lead - Statistical analyses indicated that there was a statistical exceedence at the 1% significance level in Monitoring Well MW-2 above the upgradient background wells (MW-1/MW-8D). * Manganese - Statistical analyses indicated that there was a statistical exceedence at the 1% significance level in Monitoring Wells MW-2 and MW-23 above the upgradient background wells (MW-1/MW-8D). * Mercury – Statistical analysis indicated that none of the compliance wells were significantly impacted. * Nickel - Statistical analyses indicated that there was a statistical exceedence at the 1% significance level in Monitoring Wells MW-23 and MW-25; and, at the 5% significance level in Monitoring Wells MW-2, MW-11 and MW-12 above the upgradient background wells (MW-1/MW-8D). * Selenium - Statistical analysis indicated that none of the compliance wells were significantly impacted. * Silver – Statistical analysis indicated that none of the compliance wells were significantly impacted. * Thallium - Statistical analyses indicated that there was a significant impact for one sampling event at Monitoring Well 2; two sampling events at Monitoring Well MW-12 above the upgradient background wells (MW-1/MW-8D). City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 4-6 * Vanadium - Statistical analyses indicated that there was a statistical exceedence at the 1% significance level in Monitoring Well MW-24; and, at the 5% significance level in Monitoring Wells MW-9, MW-11, and MW-25 above the upgradient background wells (MW-1/MW-8D). * Zinc – Statistical analysis indicated that none of the compliance wells were significantly impacted. 4.4.2 Subtitle D lined MSWLF Site The statistical results for this site are as follows: * Antimony – Statistical analysis indicated that none of the compliance wells were significantly impacted. * Arsenic - Statistical analyses indicated that there was a statistical exceedence at the 5% significance level in Monitoring Well MW-16D above the upgradient background well (MW-19). * Barium - Statistical analyses indicated that there was a statistical exceedence at the 1% significance level in Monitoring Well MW-22; and, at the 5% significance level in Monitoring Wells MW-16D and MW-27 above the upgradient background well (MW- 19). * Beryllium – Statistical analysis indicated that none of the compliance wells were significantly impacted. * Cadmium – Statistical analysis indicated that none of the compliance wells were significantly impacted. * Chromium – Statistical analysis indicated that none of the compliance wells were significantly impacted. * Cobalt - Statistical analyses indicated that there was a statistical exceedence at the 5% significance level in Monitoring Well MW-16D above the upgradient background well (MW-19). * Copper - Statistical analyses indicated that there was a statistical exceedence at the 1% significance level in Monitoring Well MW-16S; and, at the 5% significance level in Monitoring Well MW-16D above the upgradient background well (MW-19). * Lead – Statistical analysis indicated that none of the compliance wells were significantly impacted. * Nickel - Statistical analyses indicated that there was a statistical exceedence at the 5% significance level in Monitoring Wells MW-14, MW-16D, and MW-27 above the upgradient background well (MW-19). * Selenium – Statistical analysis indicated that none of the compliance wells were City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 4-7 significantly impacted. * Silver – Statistical analysis indicated that none of the compliance wells were significantly impacted. * Thallium - Statistical analysis indicated that none of the compliance wells were significantly impacted. * Vanadium - Statistical analyses indicated that there was a statistical exceedence at the 1% significance level in Monitoring Well MW-16D above the upgradient background well (MW-19) * Zinc - Statistical analysis indicated that none of the compliance wells were significantly impacted. 4.4.3 Summary In Tables 1 and 11 the inorganics are listed with the total number of analyses that exceeded the NC 2L Groundwater Standards or the IMACs. The most significant inorganic constituent in terms of the percentage of exceedances was manganese, followed by iron, cobalt, vanadium, arsenic, and chromium. In Table 14 these inorganic constituents are listed in that same order with those monitoring wells that are statistically significant for each of the two sites at the City of Albemarle Landfill. The data in the first three columns of Table 14, following the identification of the inorganics, are from Tables 1 and 11. Based on the results of the statistical analyses the inorganic constituent that exhibited the largest percentage of exceedances at this site (i.e., manganese) was statistically significant only at the 1% significance level in Monitoring Wells MW-2 and MW-23 (see Tables 12 and 14) compared to the two upgradient monitoring wells (i.e., MW-1 and MW-8D). The second highest percentage of exceedances was exhibited by iron (see Table 14). Statistically this inorganic constituent was insignificant within the monitoring wells at the Active C&D closed MSWLF Site compared to the background monitoring wells. Neither iron nor manganese were analyzed in the groundwater samples collected from the Subtitle D lined MSWLF Site. Cobalt had the third highest percentage of exceedances above the IMAC and was also statistically significant in Monitoring Wells MW-2, MW-12, MW-13, and MW-23 at the 5% significance level at the Active C&D closed MSWLF Site and in Monitoring Well MW-16D at the 5% significance level at the Subtitle D lined MSWLF Site (see Table 14). Vanadium had exhibited exceedances in 45.9% of the analytical data from 2000 through 2016, but was City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 4-8 statistically significant compared to the background well in Monitoring Wells MW-9, MW-11, and MW- 25 at the 5% significance level and in Monitoring Well MW-24 at the 1% significance level at the Active C&D closed MSWLF Site, and in Monitoring Well MW-16D at the 1% significance level at the Subtitle D lined MSWLF Site. Several monitoring wells are repeated within Table 14 (e.g., MW-2 [four times], MW-16D [three times], MW-9, MW-11, MW-12, MW-13, MW-23, and MW-25 [two times each for these last 6 wells]). City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 5-1 5.0 SUMMARY AND CONCLUSIONS Table 14 provides a good basis upon which the statistical findings of this report can be summarized. This table summarizes the findings for the statistical evaluations described in Section 4. In addition to these findings, the background data cumulated within Section 2 showed that manganese, iron, vanadium, and arsenic are all present within groundwater encountered in both Stanly County, and beyond, within the Carolina Slate Belt (see Table 15). Not only one background data source, but multiple sources consistently show that these constituents are ubiquitous for the area, and are present at concentrations commensurate with those encountered at the City of Albemarle Landfill (see Table 15). There is a lack of background cobalt analyses for groundwater in the area. However, 80% of the sediment analyses on samples from Stanly County exhibited cobalt at or above 10 mg/kg (see Table 6). The presence of cobalt within these fine soil particles that have been washed into the streams of Stanly County is also indicative of its presence within soils around the area (i.e., the source for the sediments). The inherent presence of cobalt in the soils is considered to be a significant factor in the presence of cobalt within the groundwater samples collected from the City of Albemarle Landfill. Based on the IHSB protection of groundwater concentration for cobalt (0.9 mg/kg) and the IMAC for cobalt in groundwater (1 µg/L), these background concentrations for sediment by correlation imply that 80% of the groundwater cobalt concentrations in Stanly County exceed 10 µg/L. The average cobalt concentration at the site in 2016 was 20.5 µg/L. Additionally, the trend for cobalt concentrations at this site has been declining from an average concentration of 38 µg/L in 2001 through to 20.5 µg/L in 2016. This trend is contrary to a rising trend that would be expected from contamination due to a landfill. The continued presence of cobalt within the analytical results for the dissolved samples (see Tables 9 and 10) does suggest that the cobalt is dissolved within the groundwater and natural to the area. Similarly, there are no available background analytical data for thallium. Unlike cobalt, most of the analyses completed on the filtered groundwater samples for thallium, did exhibit a decline in the concentrations to below the IMAC for thallium (except for MW-16D and MW-17). Therefore despite the limited available background data available for either cobalt or thallium, neither of these constituents is considered to be present due to the landfill operations at this site. More importantly, for thallium the statistical analyses do show that neither of the thallium concentrations for these same two monitoring wells (i.e., MW-16D and MW-17) exhibited any statistical significance. City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 5-2 Graphical plots of the inorganic constituent concentrations over time do not exhibit any upward trends, rather more graphs show a downward trend due to lowering of laboratory detection limits, and a reduction of fine particle size material being extracted from the monitoring wells due to ongoing sampling of these wells. The absence of any upward trends in these graphs does support the position that the presence of these inorganics is not due to operations conducted at the site. An additional characteristic of these data is that the number of exceedances recorded on a per monitoring well basis is similar between the Active C&D closed MSWLF Site and the Subtitle D lined MSWLF Site. The former site contains several unlined closed landfill cells, whereas at the latter site the landfill cells are lined. If inorganic constituents were emanating from these unlined cells, the expectation would be for significant differences for the number of exceedances for these inorganics between the two sites. The data does not support that expectation. Because the groundwater underlying the Subtitle D lined MSWLF exhibits inorganic exceedances and the cells are lined; that is, theoretically there should be no leakage from these cells, the contention is that these inorganic exceedances are natural for the groundwater in this area of the Piedmont. The last point is that if the inorganic constituents are emanating from the landfill cells, the statistical evaluation for both sites would exhibit a consistent pattern of the compliance wells being statistical significant from the upgradient background wells. Rather a review of Tables 12 and 13 shows that those wells that are statistically significant are not the same from constituent to constituent. This variation of the well groups that are statistically significant is also evident for each inorganic constituent (i.e., those that exhibit significant percentage of exceedances) listed in Table 14. In conclusion the presence of the inorganic constituents within the groundwater samples collected from the monitoring wells at this site and listed in Table 15 are either natural within the groundwater or present within the soils present in the area. Therefore, other than the continued semi-annual groundwater monitoring, no further action is considered to be justified at this site in regard to the presence of these inorganics. Additionally, the monitoring networks currently in place and sampled around each of the two landfill sites owned and operated by City of Albemarle are capable of detecting the migration of inorganic constituents for the landfill cells in future groundwater sampling events. City of Albemarle Landfill November 22, 2016 Alternate Source Demonstration Report Shield Project 1110192 6-1 6.0 REFERENCES Briel, L. I., 1997; Water Quality in the Appalachian Valley and Ridge, the Blue Ridge, and the Piedmont Physiographic Provinces, Eastern United States – Regional Aquifer-System Analysis- Appalachian Valley and Piedmont, United States Geological Survey, Professional Paper 1422-D, Washington, DC Brown, Phillip M., and John M. Parker, 1985; Geologic Map of North Carolina, North Carolina Geologic Survey, Division of Land Resources, Raleigh, NC. Chapman, Melinda J.; Charles A. Crovotta III, Zoltan Szabo, and Bruce D. Lindsey, 2013; Naturally Occurring Contaminants in the Piedmont and Blue Ridge Crystalline-Rock Aquifers and Piedmont Early Mesozoic Basin Siliclastic-Rock Aquifers, Eastern United States, 1994-2008, United States Geological Survey, Scientific Investigations Report 2013-5072, Washington, DC Environmental Protection Agency, 1992; Statistical Analysis of Groundwater Monitoring Data at RCRA Facilities – Addendum to Interim Final Guidance, US EPA Office of Solid Waste, Washington, DC. Environmental Protection Agency, 2009; Statistical Analysis of Groundwater Monitoring Data at RCRA Facilities – Unified Guidance, US EPA Office of Resource Conservation and Recovery Program Implementation and Information Division, US EPA, EPA 530-R-09-007, Washington, DC. Floyd, Edwin O., 1965; Geology and Ground-Water Resources of the Monroe Area, North Carolina, North Carolina Department of Water Resources, Raleigh, NC. Harden, Stephen L.; Melinda J. Chapman, and Douglas A. Harned, 2009; Characterization of Groundwater Quality Based on Regional Geologic Setting in the Piedmont and Blue Ridge Physiographic Provinces, North Carolina, United States Geological Survey, Scientific Investigations Report 2009-5149, Washington, DC Inactive Hazardous Sites Branch (IHSB), 2016; Preliminary Soil Remediation Goals (PSRG) Table, North Carolina Department of Environmental Quality, October 2016, Raleigh, NC LeGrand, Harry E., 1988; Region 21, Piedmont and Blue Ridge, in Back, W., Rosenhein, J.S. and P.R. Seaber, (Editors), Hydrogeology – The Geology of North America, Volume O-2, The Geological Society of America, Boulder, Colorado. Reid, Jeffrey C., 1993a; A Geochemical Atlas of North Carolina, North Carolina Geological Survey, Bulletin 93, Raleigh, NC. Reid, Jeffrey C., 1993b; A Hydrogeochemical Atlas of North Carolina, North Carolina Geological Survey, Bulletin 94, Raleigh, NC. Shield Engineering, Inc, 2016; Semi-Annual Groundwater Monitoring Report, City of Albemarle Landfill, Charlotte – DSWM Permit No. 84-01, North Carolina, 2016. TABLES Inorganic Constituent Total Number of Analyses NC 2L or IMAC (µg/L) Total Number of Exceedances Percentage of Analyses exceeding Standard No. of Wells in which Exceedances Occur Well with most exceedances (No. of exceedances) Antimony 789 1 17 2.2% 8 MW-1, MW-2 and MW-15 (3 each) Arsenic 789 10 194 24.6% 20 MW-13 (30) Barium 789 700 -- 0% -- -- Beryllium 789 4 4 0.5% 3 MW-2 (2) Cadmium 789 2 33 4.2% 15 MW-12 (7) Chromium 789 10 122 15.5% 21 MW-11 and MW-16D (11 each) Cobalt 789 1 577 73.1% 27 MW-2 (36) Copper 789 1000 1 0.1% 1 MW-16D Iron 119 300 92 77.3% 16 MW-9 (12) Lead 789 15 56 7.1% 13 MW-2 (11) Manganese 71 50 55 77.5% 15 MW-2, MW-3, and MW-7 (6 each) Mercury 120 1 2 1.7% 2 MW-1 and MW-3 Nickel 789 100 19 2.4% 7 MW-2 and MW-12 (6 each) Selenium 793 20 6 0.8% 4 MW-3 and MW-10 (2 each) Silver 789 20 1 0.1% 1 MW-19 Thallium 789 0.2 36 4.6% 17 MW-13 (5) Tin 65 2000 -- 0% -- -- Vanadium 789 0.3 362 45.9% 27 MW-9 (23) Zinc 789 1000 -- 0% -- -- TOTAL 12214 -- 1577 12.9% -- MW-2 (113) NOTE:NC 2L - Title 15A, Subchapter 2L, Rules .0202 of the North Carolina Administrative Code (North Carolina Groundwater Standards) IMAC - Interim Maximum Allowable Concentrations µg/L - Microgram per liter TABLE 1 SUMMARY OF INORGANIC ANALYSES FOR 2000-2016 AND EXCEEDANCES CITY OF ALBEMARLE LANDFILL STANLY COUNTY, NORTH CAROLINA Mo n i t o r i n g W e l l A n t i m o n y A r s e n i c B e r y l l i u m C a d m i u m C h r o m i u m C o b a l t C o p p e r I r o n L e a d M a n g a n e s e M e r c u r y N i c k e l S e l e n i u m S i l v e r T h a l l i u m V a n a d i u m Total Nu m b e r o f Ex c e e d a n c e s pe r w e l l MW - 1 3 3 7 2 8 9 1 0 4 1 1 2 1 7 8 5 MW - 1 0 2 1 2 5 6 6 2 1 8 5 1 MW - 1 1 2 1 1 1 9 3 2 1 9 5 6 MW - 1 2 1 4 7 8 3 2 4 4 6 3 1 3 9 1 MW - 1 3 3 0 6 3 3 3 3 5 8 8 8 MW - 1 4 1 3 3 8 2 4 1 1 8 6 7 MW - 1 5 3 1 3 4 1 5 3 1 7 5 5 MW - 1 6 D 2 4 1 1 3 3 1 5 1 1 2 2 2 1 0 0 MW - 1 6 S 8 2 2 9 3 2 1 1 5 5 MW - 1 7 1 8 1 2 7 1 3 1 0 5 1 MW - 1 8 2 2 5 1 6 1 1 9 4 5 MW - 1 9 24 1 2 6 2 4 5 2 1 1 2 1 0 6 0 MW - 2 3 7 2 9 3 6 1 1 1 1 6 6 1 2 1 1 1 3 MW - 2 2 3 2 7 2 7 1 2 2 6 2 MW - 2 3 6 1 3 3 2 3 2 3 2 8 6 0 MW - 2 4 3 3 1 3 7 1 2 1 5 4 4 MW - 2 5 3 1 1 1 0 1 4 7 7 3 1 1 4 6 1 MW - 2 6 2 2 1 1 1 1 3 2 9 MW - 2 7 2 1 6 8 2 6 MW - 2 9 5 2 5 1 2 MW - 3 2 8 1 2 7 7 6 1 2 2 7 8 1 MW - 4 R 2 1 3 3 1 1 0 2 9 MW - 5 R 1 3 1 8 2 8 2 8 2 2 1 9 8 3 MW - 6 1 1 1 0 9 1 2 6 3 0 MW - 7 3 4 1 5 4 6 1 1 4 3 MW - 8 D 2 3 1 7 3 8 3 3 MW - 9 6 1 9 8 1 2 1 5 2 2 3 6 7 Nu m b e r o f W e l l s wi t h E x c e e d a n c e s 82 0 3 1 5 2 1 2 7 1 1 6 1 3 1 5 2 7 4 1 1 7 2 7 - - To t a l o f Ex c e e d a n c e s 17 1 9 4 4 3 3 1 2 2 5 7 7 1 9 2 5 6 5 5 2 1 9 6 1 3 6 3 6 2 1 5 7 7 TA B L E 2 SU M M A R Y O F I N O R G A N I C A N A L Y S E S E X C E E D A N C E S P E R W E L L F O R 2 0 0 0 - 2 0 1 6 CI T Y O F A L B E M A R L E L A N D F I L L ST A N L Y C O U N T Y , N O R T H C A R O L I N A 5t h 2 5 t h 5 0 t h 7 5 t h 9 5 t h Di s s o l v e d 4 . 0 1 2 . 0 5 0 . 0 1 9 0 . 0 3 2 0 1 . 0 3 , 4 7 8 To t a l 1 7 . 0 1 0 0 . 0 2 0 0 . 0 1 0 0 0 . 0 1 2 0 0 0 . 0 3 , 1 0 9 Di s s o l v e d 2 . 0 1 0 . 0 3 8 . 0 1 7 0 . 0 1 4 0 0 . 0 2 , 8 6 9 To t a l 0 . 1 5 0 . 0 5 0 . 0 2 0 0 . 0 3 9 5 8 . 0 2 , 1 7 5 SO U R C E : T a b l e 5 ( B r i e l , 1 9 9 7 ) NO T E : Al l D a t a a r e i n u n i t s o f M i c r o g r a m s p e r L i t e r ( µ g / L ) Hi g h l i g h t - D a t a e x c e e d s t h e N C 2 L o r t h e I M A C NC 2 L - T i t l e 1 5 A , S u b c h a p t e r 2 L , R u l e s . 0 2 0 2 o f t h e N o r t h C a r o l i n a A d m i n i s t r a t i v e C o d e ( N o r t h C a r o l i n a G r o u n d w a t e r S t a n d a r d s ) IM A C - I n t e r i m M a x i m u m A l l o w a b l e C o n c e n t r a t i o n s Number of Analyses ST A N L Y C O U N T Y , N O R T H C A R O L I N A CI T Y O F A L B E M A R L E L A N D F I L L BA C K G R O U N D G R O U N D W A T E R D A T A F O R C A R O L I N A S L A T E B E L T TA B L E 3 Pe r c e n t i l e s : Gr o u n d w a t e r D a t a ( µ g / L ) Ir o n Ma n g a n e s e Co n s t i t u e n t NC 2 L o r IM A C 30 0 50 Number of Samples Number of Detections Number of Detections greater than HHB value Antimony 6 1 202 11 1 Arsenic 10 10 206 59 5 Barium 2,000 700 206 204 0 Beryllium 4 4 202 48 0 Cadmium 5 2 206 33 0 Chromium 100 10 206 122 0 Cobalt -- 1 202 88 0 Copper 1,300 1,000 206 163 0 Iron 300 300 249 160 46 Lead 15 15 206 88 0 Manganese 300 50 264 225 22 Nickel 100 100 202 134 0 Selenium 50 20 206 56 0 Silver 100 20 206 1 0 Thallium 2 0.2 102 13 0 Vanadium -- 0.3 102 89 0 Zinc 2,000 1,000 206 194 1 SOURCE: Chapman et alia, 2013 NOTE:All Data are in units of Micrograms per Liter (µg/L) for groundwater data Highlight - Data exceeds the NC 2L or the IMAC NC 2L - Title 15A, Subchapter 2L, Rules .0202 of the North Carolina Administrative Code (North Carolina Groundwater Standards) IMAC - Interim Maximum Allowable Concentrations CITY OF ALBEMARLE LANDFILL FOR INORGANICS IN PIEDMONT TABLE 4 BACKGROUND GROUNDWATER CONCENTRATIONS Constituent Human- Health Benchmark (HHB) Crystalline Lithologies (Piedmont, Blue Ridge, and Early Mesozoic Basins Provinces)NC 2L or IMAC STANLY COUNTY, NORTH CAROLINA Constituent NC 2L or IMAC Minimum Maximum Antimony 1 Dissolved <0.06 2 Dissolved <0.12 38.3 Total <5.0 <5.0 Dissolved <10 245 Total <10 24 Beryllium 4 Dissolved <0.01 <1 Dissolved <0.04 <1 Total <1 <1 Dissolved <0.12 4 Total <10.0 <10.0 Cobalt 1 Dissolved <0.04 0.33 Dissolved <0.4 11.6 Total <2.0 <2.0 Dissolved <6 9860 Total <50 240 Dissolved <0.12 <10 Total <10.0 <10.0 Dissolved 0.1J 1490 Total 45 440 Dissolved <0.2 <10.0 Total <10.0 <10.0 Dissolved <0.08 7.5 Total <5 <5 Dissolved <0.10 <5 Total <5 <5 Dissolved 1.4 4770 Total 310 4200 SOURCE: Harden, Stephen L.; Melinda J. Chapman and Douglas A. Harned, 2009 NOTE:NC 2L - Title 15A, Subchapter 2L, Rules .0202 of the North Carolina Administrative Code (North Carolina Groundwater Standards) IMAC - Interim Maximum Allowable Concentrations All Data are in units of Micrograms per Liter (µg/L) µg/L - Microgram per liter Highlight - Analytical result exceeds the NC 2L or the IMAC Nickel Selenium Silver Zinc Arsenic Barium Cadmium Chromium Copper Iron 100 20 20 1000 10 700 2 10 1000 300 STANLY COUNTY, NORTH CAROLINA TABLE 5 BACKGROUND DATA FOR CAROLINA SLATE BELT CITY OF ALBEMARLE LANDFILL 15 50 Lead Manganese Constituent Total Number of Sampling Locations in Stanly County Range 1 - 25 26 - 50 51 - 88 89 - 3,758 Percent 20.6 23.5 14.7 41.2 Range -- -- 0.05 - 0.2 0.3 - 42.9 Percent -- -- 82.9 17.1 Range 0.2 - 0.25 0.5 - 0.9 1 - 1.4 1.5 - 84 Percent 2.3 13.6 36.4 47.7 Range < 0.25 5 - 6 7 - 11 12 - 3010 Percent 13.3 17.8 28.9 40 Range -- 2.5 - 6 7 - 9 > 10 Percent -- 15.6 4.4 80 Range 1 - 2 3 - 5 6 - 8 9 - 215 Percent 0 2.3 20.5 77.2 Range -- < 5 10 - 12 13 - 2,597 Percent -- 0 31.1 68.9 Range -- 2.5 - 3 5 - 9 10 - 422 Percent -- 15.9 27.3 56.8 Range 0.05 - 0.1 0.2 0.3 - 0.7 0.8 - 2.5 Percent 0 0 93.3 6.7 Range 10 - 20 30 - 40 50 - 80 90 - 1570 Percent 2.6 18.4 52.7 26.3 NOTE:All Data are in units of Micrograms per Liter (µg/L) for groundwater data and milligrams per kilogram (mg/Kg) for sediment data. Highlight - The larger percentage of values for that constituent with the corresponding data range. Groundwater Data (µg/L) Beryllium TABLE 6 BACKGROUND GEOCHEMICAL AND HYDROGEOCHEMICAL DATA FOR STANLY COUNTY CITY OF ALBEMARLE LANDFILLSTANLY COUNTY, NORTH CAROLINA 44 Silver Vanadium 44 45 44 45 38 Lead Nickel Copper 45 45 Sediment Data (mg/Kg) Sources: "A Geochemical Atlas of North Carolina" (Reid, 1993a) and "A Hydrogeochemical Atlas of North Carolina" (Reid, 1993b) Manganese 34 Chromium Cobalt Vanadium 41 Mi n i m u m A v e r a g e M a x i m u m Pe r c e n t a g e o f we l l s a b o v e NC 2 L o r I M A C Ar s e n i c 1 0 0 . 5 9 . 7 8 0 6 2 0 . 2 9 3 3 Ca d m i u m 2 0 . 5 0 . 6 5 N A 2 3 4 Ch r o m i u m 1 0 0 . 5 5 1 0 0 . 0 2 3 4 Co p p e r 1 0 0 0 2 5 5 1 . 9 2 , 6 7 0 0 . 5 8 9 0 Ir o n 3 0 0 2 5 4 1 2 . 6 4 1 , 4 4 0 2 2 . 4 8 6 9 Le a d 1 5 2 . 5 3 . 5 1 8 3 1 . 4 9 0 0 Ma n g a n e s e 5 0 1 5 1 6 8 . 1 1 2 , 1 8 0 3 2 . 2 8 7 6 Se l e n i u m 2 0 2 . 5 2 . 7 1 2 0 . 0 2 3 4 Zi n c 1 0 0 0 2 5 7 7 . 2 1 , 9 4 0 N A 8 8 0 NO T E : Co u n t y - l e v e l a v e r a g e s r e p o r t e d f o r e a c h i n o r g a n i c a r e b a s e d s o l e l y o n p r i v a t e w e l l t e s t s f r o m t h e N o r t h C a r o l i n a S t a t e L a b o r a t o r y o f P u b l i c H e a l t h f r o m 1 9 9 8 - 2 0 1 0 . NA - N o t A v a i l a b l e ( U N C G i l l i n g s S c h o o l o f G l o b a l P u b l i c H e a l t h u s e d E P A M C L f o r c a l c u l a t i o n o f P e r c e n t a g e ) Al l D a t a a r e i n u n i t s o f M i c r o g r a m s p e r L i t e r ( µ g / L ) FO R I N O R G A N I C S I N S T A N L Y C O U N T Y To t a l N u m b e r o f We l l s T e s t e d i n St a n l y C o u n t y Co n s t i t u e n t NC 2 L o r IM A C (µ g / L ) TA B L E 7 BA C K G R O U N D G R O U N D W A T E R C O N C E N T R A T I O N S CI T Y O F A L B E M A R L E L A N D F I L L ST A N L Y C O U N T Y , N O R T H C A R O L I N A So u r c e : U N C G i l l i n g s S c h o o l o f G l o b a l P u b l i c H e a l t h So i l T y p e N a m e A c r e s Pe r c e n t a g e o f S o i l Ty p e a t S i t e Cl a y ( p e r c e n t a g e ) Ba d i n - C h a n n e r y s i l t l o a m ( 2 t o 8 % s l o p e s ) 5 0 . 2 1 7 . 8 % 3 5 - 5 5 % Ba d i n - C h a n n e r y s i l t l o a m ( 8 t o 1 5 % s l o p e s ) 3 2 . 6 1 1 . 6 % 3 5 - 5 5 % En o n c o b b l y l o a m ( 8 t o 1 5 % s l o p e s ) 8 . 4 3 . 0 % 3 5 - 6 0 % En o n v e r y c o b b l y l o a m ( 4 t o 1 5 % s l o p e s ) 1 3 4 . 6 % 3 5 - 6 0 % Go l d s t o n v e r y C h a n n e r y s i l t l o a m ( 4 t o 1 5 % sl o p es ) 40 . 8 1 4 . 5 % 5 - 2 7 % Go l d s t o n v e r y C h a n n e r y s i l t l o a m ( 1 5 t o 45 % s l o p es ) 89 . 2 3 1 . 6 % 5 - 2 7 % Oa k b o r o s i l t l o a m ( 0 t o 2 % s l o p e s ) 2 2 . 7 8 . 0 % 1 8 - 3 5 % Di s t u r b e d S o i l s 2 5 . 2 8 . 9 % N o t A v a i l a b l e TO T A L 2 8 2 . 1 1 0 0 . 0 % SO U R C E S : Na t i o n a l R e s o u r c e C o n s e r v a t i o n S e r v i c e W e b s i t e - W e b S o i l S u r v e y (WS S ) h t t p :/ / w e b s o i l s u r v e y .s c . e g ov . u s d a . g ov / A pp /W e b S o i l S u r v e y .a s p x S o i l C o n s e r v a t i o n S e r v i c e , 1 9 8 9 ; S o i l S u r v e y o f S t a n l y C o u n t y , N o r t h C a r o l i n a , S o i l C o n s e r v a t i o n S e r v i c e , U n i t e d S t a t e s D e p a r t m e n t o f A g r i c u l t u r e , W a s h i n g t o n D . C . TA B L E 8 SO I L T Y P E S P R E S E N T A T S I T E CI T Y O F A L B E M A R L E L A N D F I L L ST A N L Y C O U N T Y , N O R T H C A R O L I N A Co n s t i t u e n t N C 2 L o r IM A C (µ g / L ) MW - 1 M W - 2 M W - 3 M W - 4 R M W - 5 R M W - 6 M W - 7 M W - 8 D M W - 9 M W - 1 0 M W - 1 1 M W - 1 2 M W - 1 3 M W - 2 3 To t a l 0 . 4 3 J 0 . 2 6 9 J 0 . 2 7 7 J N D 0 . 7 0 6 J N D 0 . 2 6 4 J 0 . 4 0 9 J N D 0 . 5 6 6 J N D N D N D N D Di s s o l v e d 0 . 2 4 2 J N D N D N D 0 . 4 6 J N D N D 0 . 4 0 3 J N D 0 . 2 4 1 J N D N D N D N D To t a l N D N D 8 . 7 8 J N D N D N D N D N D N D N D N D 48 . 9 1 3 . 3 ND Di s s o l v e d N D N D N D N D N D N D N D N D N D N D N D N D N D N D To t a l 1 . 6 4 N D N D N D N D N D N D N D 0 . 7 2 4 J N D N D N D N D N D Di s s o l v e d N D N D N D N D N D N D N D N D N D N D N D N D N D N D To t a l N D N D N D N D N D N D 2. 0 4 0.3 8 1 J N D N D N D N D N D N D Di s s o l v e d N D N D 0 . 3 6 1 J N D N D N D 1 . 8 0 . 4 7 9 J N D N D N D N D N D N D To t a l 11 . 2 3.3 5 J N D N D N D 7 . 4 2 J 7 . 9 J N D 3 . 9 8 J N D 10 . 1 ND 2 . 1 6 J N D Di s s o l v e d N D N D N D N D N D N D N D N D N D N D N D N D N D N D To t a l 24 . 2 4 0 . 5 2 9 . 3 ND 7. 1 5 J 6 . 3 3 J 7 . 9 8 J 4 . 0 J 3 . 4 2 J 8 . 0 6 J 4 . 7 9 J 7 5 . 4 2 4 . 4 2 2 . 2 Di s s o l v e d 4. 2 7 J 3 4 . 1 2 3 . 8 ND 4.7 J ND 2. 9 3 J 3 . 4 J ND 8. 0 8 J 2 . 8 9 J 6 4 . 5 1 9 . 3 2 0 . 6 To t a l 1 0 0 1 1 . 1 2 2 . 1 2 . 1 4 J 8 . 0 8 J 1 1 . 5 1 7 3 . 0 6 J 1 8 . 2 4 . 8 5 J 4 . 7 6 J 1 . 7 7 J 9 . 7 2 J 6 . 6 1 J Di s s o l v e d 9 . 7 8 J 3 . 4 5 J 4 . 6 4 J N D 3 . 3 9 J 1 . 7 1 J 2 . 8 1 J 2 . 1 2 J N D 3 . 5 5 J N D N D N D 2 . 1 6 J To t a l 17 , 1 0 0 1 7 , 9 0 0 20 4 J 84 1 6 4 6 8 , 0 1 0 6 , 9 8 0 65 . 5 J 1,3 9 0 1 , 4 6 0 3 , 4 9 0 3 7 , 9 0 0 8 , 8 4 0 1 2 , 4 0 0 Di s s o l v e d 1 4 2 J 3, 8 5 0 -- N D N D N D N D N D - - - - N D 23 , 7 0 0 2 , 5 7 0 106J To t a l 92 . 8 7.2 9 J N D N D N D N D N D N D 7 . 8 5 J N D N D N D N D N D Di s s o l v e d N D N D N D N D N D N D N D N D N D N D N D N D N D N D To t a l 96 4 4 , 2 2 0 4 9 1 18 . 1 J 76 . 8 2 2 2 1 , 1 6 0 23 . 9 J 41 1 1 0 0 0 1 5 8 1 7 , 6 0 0 8 , 0 5 0 7 , 2 1 0 Di s s o l v e d 31 9 4 , 2 5 0 -- 1 1 . 2 J 65 . 7 23 . 8 J 92 5 21 J - - - - 14 6 1 7 , 7 0 0 8 , 2 3 0 7 , 1 4 0 To t a l 4 1 . 1 J 2 3 . 7 J 5 . 7 1 J 1 1 . 3 J N D 1 0 . 7 J 1 2 . 0 J 2 . 9 7 J 9 . 8 J 3 2 . 2 J 3 7 . 7 J 3 4 . 6 J 3 . 1 3 J 8 . 4 6 J Di s s o l v e d 3 . 0 2 J 1 7 . 7 J 5 . 9 J 3 . 0 7 J N D 2 . 4 5 J 5 . 7 4 J 2 . 6 J 5 . 1 1 J 3 2 . 1 J 3 3 . 2 J 2 9 . 1 J N D 5 . 8 1 J To t a l N D N D N D N D N D N D N D N D N D N D N D N D N D N D Di s s o l v e d N D N D N D N D N D N D N D N D N D N D N D N D N D N D To t a l N D N D N D N D N D N D N D N D N D N D N D 2 . 8 3 J N D N D Di s s o l v e d N D N D N D N D N D N D N D N D N D N D N D N D N D N D To t a l 0. 2 1 7 J 0. 1 3 9 J 0. 2 J 0. 1 4 3 J 0 . 1 5 3 J 0 . 1 4 J 0 . 1 5 6 J 0 . 1 4 6 J 0. 2 8 7 J 0 . 3 3 5 J 0.1 6 6 J 0 . 1 6 7 J 0 . 1 8 3 J 0 . 1 4 5 J Di s s o l v e d N D 0 . 1 5 6 J 0 . 1 8 J 0 . 1 3 9 J 0 . 1 3 7 J 0 . 1 3 3 J 0 . 1 3 3 J 0 . 1 5 4 J 0 . 1 4 1 J 0 . 1 2 J 0 . 1 2 6 J 0 . 1 6 J 0 . 1 6 6 J 0 . 1 4 7 J To t a l 21 . 7 J 5 . 6 2 J ND 1. 4 8 J 2 . 0 2 J 8 . 8 J 1 9 . 8 J ND 13 . 9 J ND 7. 5 2 J 2 . 7 8 J 2 . 6 3 J ND Di s s o l v e d N D N D N D N D N D N D 2. 9 1 J ND N D N D N D N D N D N D NO T E : NC 2 L - T i t l e 1 5 A , S u b c h a p t e r 2 L , R u l e s . 0 2 0 2 o f t h e N o r t h C a r o l i n a A d m i n i s t r a t i v e C o d e ( N o r t h C a r o l i n a G r o u n d w a t e r S t a n d a r d s) IM A C - I n t e r i m M a x i m u m A l l o w a b l e C o n c e n t r a t i o n s -- N o A v a i l a b l e D a t a J - E s t i m a t e d c o n c e n t r a t i o n ND - N o t D e t e c t e d µg / L - M i c r o g r a m p e r l i t e r Al l D a t a a r e i n u n i t s o f M i c r o g r a m s p e r L i t e r ( µ g / L ) Bo l d - A n a l y t i c a l r e s u l t e x c e e d s t h e N C 2 L o r t h e I M A C Hi g h l i g h t - T h o s e r e s u l t s f o r w h i c h t h e t o t a l e x c e e d e d t h e N C 2 L o r I M A C an d t h e d i s s o l v e d w a s l e s s t h a n t h e N C 2 L o r t h e I M A C . Be r y l l i u m Ca d m i u m Ir o n 3 0 0 Ma n g a n e s e 5 0 TA B L E 9 AN A L Y T I C A L R E S U L T S F O R I N O R G A N I C C O N S T I T U E N T S ( T O T A L A N D D I S S O L V E D ) - J U L Y 2 0 1 6 CI T Y O F A L B E M A R L E L A N D F I L L ST A N L Y C O U N T Y , N O R T H C A R O L I N A 10 0 0 Ni c k e l An t i m o n y 1 10 4 AC T I V E C & D A N D C L O S E D M S W L F 20 Co b a l t 10 0 152 Le a d Ch r o m i u m 1 0 Ar s e n i c 20 Co p p e r 0.3 Va n a d i u m Th a l l i u m 1 0.2 Se l e n i u m Sil v e r Co n s t i t u e n t NC 2 L o r IM A C (µg/ L ) MW - 1 4 M W - 1 5 M W - 1 6 S M W - 1 6 D M W - 1 7 M W - 1 8 M W - 1 9 M W - 2 2 M W - 2 6 M W - 2 7 To t a l N D N D 0 . 5 9 9 J N D 0 . 4 7 9 J N D 0 . 7 5 5 J N D N D N D Di s s o l v e d N D N D 0 . 3 7 6 J 0 . 2 7 5 J 0 . 4 4 4 J N D 0 . 5 2 8 J N D N D N D To t a l N D N D N D 20 . 7 ND N D N D N D N D N D Di s s o l v e d N D N D N D N D N D N D N D N D N D N D To t a l N D N D N D N D N D N D N D N D N D N D Di s s o l v e d N D N D N D N D N D N D N D N D N D N D To t a l N D N D N D N D N D N D N D N D N D 0 . 3 8 9 J Di s s o l v e d N D N D N D N D N D N D N D N D N D 0 . 4 9 4 J To t a l N D N D N D 10 . 4 ND 22 . 3 ND 60 . 7 4. 1 9 J N D Di s s o l v e d N D N D N D N D N D N D N D N D N D N D To t a l 1. 4 J 1 . 8 4 J 1 7 . 3 9 9 . 2 8 9 . 5 1 3 . 9 2 . 7 9 J 4 3 . 2 1 . 2 7 J 2 2 . 5 Di s s o l v e d 1. 2 4 J 1 . 6 J 1 1 . 4 8 5 . 3 8 8 ND N D 30 . 3 ND 21.9 To t a l N D 4 . 2 1 J 5 . 4 6 J 5 1 . 8 3 . 6 7 J 1 6 . 9 N D 5 1 4 . 0 4 J 1 . 9 1 J Di s s o l v e d N D N D 3 . 1 4 J 8 . 2 J 3 . 1 8 J N D N D N D N D N D To t a l N D N D N D N D N D 3 . 8 8 J N D 5 . 3 J N D N D Di s s o l v e d N D N D N D N D N D N D N D N D N D N D To t a l 1 5 . 6 J 3 . 8 4 J 2 . 3 4 J 1 3 . 8 J 5 . 5 J 1 5 . 8 J N D 4 0 . 1 J 5 . 0 J 1 6 . 3 J Di s s o l v e d 1 5 . 1 J N D 2 . 8 1 J 4 . 9 8 J 5 . 3 3 J 2 . 3 2 J N D 1 2 . 9 J 3 . 3 J 1 5 . 7 J To t a l N D N D N D N D N D N D N D N D N D N D Di s s o l v e d N D N D N D N D N D N D N D N D N D N D To t a l N D N D N D 2 . 0 6 J N D N D N D 2 . 5 5 J N D N D Di s s o l v e d N D N D N D N D N D N D N D N D N D N D To t a l 0 . 1 8 8 J 0. 2 J 0. 1 6 4 J 0 . 1 8 6 J 0. 2 1 9 J 0 . 2 3 8 J 0. 1 6 7 J 0. 2 1 6 J ND 0 . 1 1 6 J Di s s o l v e d 0 . 1 6 4 J 0 . 1 6 4 J 0 . 1 7 3 J 0. 2 2 8 J 0 . 2 1 3 J 0. 1 7 7 J 0 . 1 3 5 J 0 . 1 5 5 J N D 0 . 1 1 7 J To t a l 1. 4 8 J ND 6. 6 7 J 2 0 . 5 J ND 21 . 6 J ND 66 . 1 4 . 5 9 J 1 . 5 6 J Di s s o l v e d N D N D 2. 1 4 J ND N D N D N D N D N D N D NO T E : NC 2 L - T i t l e 1 5 A , S u b c h a p t e r 2 L , R u l e s . 0 2 0 2 o f t h e N o r t h C a r o l i n a A d m i n i s t r a t i v e C o d e ( N o r t h C a r o l i n a G r o u n d w a t e r S t a n d a r d s) IM A C - I n t e r i m M a x i m u m A l l o w a b l e C o n c e n t r a t i o n s J - E s t i m a t e d c o n c e n t r a t i o n µg / L - M i c r o g r a m p e r l i t e r Al l D a t a a r e i n u n i t s o f M i c r o g r a m s p e r L i t e r ( µ g / L ) Bo l d - A n a l y t i c a l r e s u l t e x c e e d s t h e N C 2 L o r t h e I M A C Hi g h l i g h t - T h o s e r e s u l t s f o r w h i c h t h e t o t a l e x c e e d e d t h e N C 2 L o r I M A C a n d t h e d i s s o l v e d w a s l e s s t h a n t h e N C 2 L o r t h e I M A C. AN A L Y T I C A L R E S U L T S F O R I N O R G A N I C C O N S T I T U E N T S (TO T A L A N D D I S S O L V E D ) - J U L Y 2 0 1 6 1 10 CI T Y O F A L B E M A R L E L A N D F I L L SU B T I T L E D L I N E D M S W L F ST A N L Y C O U N T Y , N O R T H C A R O L I N A 10 1 Th a l l i u m An t i m o n y Ar s e n i c Si l v e r 2 Ch r o m i u m TA B L E 1 0 20 Ca d m i u m Le a d Co b a l t Be r y l l i u m Se l e n i u m 10 0 0 Ni c k e l 4 0. 3 Co p p e r 0. 2 10 0 20 Va n a d i u m 15 Inorganic Constituen t NC 2L or IMAC (µg/L) Total Number of Exceedances (includes outliers: Table 1) Total Number of Exceedances (without outliers) Maximum Concentration (without outliers) (µg/L) No. of Wells in which Exceedances Occur (without outliers) Well with most exceedances (No. of exceedances) Antimony 1 17 16 5.8 8 MW-1, MW-2 and MW-15 (3 each) Arsenic 10 194 189 89 20 MW-13 (29) Barium 700 -- -- 653 -- -- Beryllium 4 4 3 12 2 MW-2 (2) Cadmium 2 33 28 6.54 14 MW-12 (5) Chromium 10 122 121 250 21 MW-11 and MW- 16D (11 each) Cobalt 1 577 574 380 27 MW-2 (34) Copper 1000 1 -- 450 -- MW-16D Iron 300 92 87 39100 16 MW-9 (12) Lead 15 56 55 240 13 MW-2 (11) Manganese 50 55 51 9180 15 MW-2, MW-3, MW-7, and MW- 10 (6 each) Mercury 1 2 2 1.23 2 MW-1 and MW-3 Nickel 100 19 16 270 6 MW-12 (6) Selenium 20 6 2 21.1 2 MW-3 and MW- 16D Silver 20 1 -- 1 MW-19 Thallium 0.2 36 28 14 16 MW-12, MW-15, and MW-8D (3 each) Tin 2000 -- -- -- -- Vanadium 0.3 362 361 260 27 MW-9 (23) Zinc 1000 -- -- -- -- TOTAL -- 1577 1533 -- -- MW-2 (106) NOTE:NC 2L - Title 15A, Subchapter 2L, Rules .0202 of the North Carolina Administrative Code (North Carolina Groundwater Standards) IMAC - Interim Maximum Allowable Concentrations µg/L - Microgram per liter TABLE 11 SUMMARY OF INORGANIC ANALYSES FOR 2000-2016 AND EXCEEDANCES WITHOUT OUTLIERS CITY OF ALBEMARLE LANDFILL STANLY COUNTY, NORTH CAROLINA Pa r a m e t e r M W - 2 M W - 3 M W - 4 R M W - 5 R M W - 6 M W - 7 M W - 9 M W - 1 0 M W - 1 1 M W - 1 2 M W - 1 3 M W - 2 3 M W - 2 4 M W - 2 5 M W - 2 9 An t i m o n y Ar s e n i c XX X Ba r i u m O Be r y l l i u m Ca d m i u m Ch r o m i u m XX X Co b a l t X XX X Co p p e r O Ir o n Le a d O Ma n g a n e s e O O Me r c u r y * Ni c k e l XX X O O Se l e n i u m * Si l v e r Th a l l i u m * 1 v a l u e 2 V a l u e s Va n a d i u m XX O X Zi n c NO T E : * N o n - P a r a m e t r i c T o l e r a n c e I n t e r v a l T e s t A n a l y s i s p e r f o r m e d f o r t h i s I n o r g a n i c ( n u m b e r o f v a l u e s e x h i b i t i n g s t a t i s t i c a l i m p a c t a re reported). X St a t i s t i c a l a n a l y s i s i n d i c a t e s c o n c e n t r a t i o n s a b o v e t h e b a c k g r o u n d a t a 9 5 % s i g n i f i c a n c e l e v e l O St a t i s t i c a l a n a l y s i s i n d i c a t e s c o n c e n t r a t i o n s a b o v e t h e b a c k g r o u n d a t a 9 9 % s i g n i f i c a n c e l e v e l TA B L E 1 2 AC T I V E C & D C L O S E D M S W L F S I T E CI T Y O F A L B E M A R L E L A N D F I L L ST A N L Y C O U N T Y , N O R T H C A R O L I N A ST A T I S T I C A L R E S U L T S U M M A R Y Pa r a m e t e r M W - 1 4 M W - 1 5 M W - 1 6 D M W - 1 6 S M W - 1 7 M W - 1 8 M W - 2 2 M W - 2 6 M W - 2 7 An t i m o n y Ar s e n i c X Ba r i u m XO X Be r y l l i u m Ca d m i u m Ch r o m i u m Co b a l t X Co p p e r XO Le a d Ni c k e l XX X Se l e n i u m Si l v e r * Th a l l i u m * Va n a d i u m O Zi n c NO T E : * N o n - P a r a m e t r i c T o l e r a n c e I n t e r v a l T e s t A n a l y s i s p e r f o r m e d f o r t h i s I n o r g a n i c ( n u m b e r o f v a l u e s e x h i b i t i n g s t a t i t s t i c a l i m p a c t a r e r e p o r t e d ) . X St a t i s t i c a l a n a l y s i s i n d i c a t e s c o n c e n t r a t i o n s a b o v e t h e b a c k g r o u n d a t a 9 5 % s i g n i f i c a n c e l e v e l O St a t i s t i c a l a n a l y s i s i n d i c a t e s c o n c e n t r a t i o n s a b o v e t h e b a c k g r o u n d a t a 9 9 % s i g n i f i c a n c e l e v e l TA B L E 1 3 ST A T I S T I C A L R E S U L T S U M M A R Y SU B T I T L E D L I N E D M S W L F S I T E CI T Y O F A L B E M A R L E L A N D F I L L ST A N L Y C O U N T Y , N O R T H C A R O L I N A Ac t i v e C & D c l o s e d M S W L F S i t e Su b t i t l e D l i n e d M S W L F Site Ma n g a n e s e 7 7 . 4 6 % 5 0 5 5 M W - 2 & M W - 2 3 ( 1 % S i g ) - - Ir o n 7 7 . 3 1 % 3 0 0 9 2 N on e - - Co b a l t 7 3 . 1 3 % 1 5 7 7 MW - 2 , M W - 1 2 , M W - 1 3 & MW - 2 3 (5% S i g) MW - 1 6 D ( 5 % S i g ) Va n a d i u m 4 5 . 8 8 % 0 . 3 3 6 2 MW - 9 , M W - 1 1 , & M W - 2 5 ( 5 % Si g ) ; a n d M W - 2 4 ( 1 % S i g ) MW - 1 6 D ( 1 % S i g ) Ar s e n i c 2 4 . 5 9 % 1 0 1 9 4 MW - 3 , M W - 5 R , & M W - 1 3 (5% S i g) MW - 1 6 D ( 5 % S i g ) Ch r o m i u m 1 5 . 4 6 % 1 0 1 2 2 MW - 9 , M W - 1 1 , & M W - 2 5 (5 % S i g ) No n e Le a d 7 . 1 0 % 1 5 5 6 M W - 2 ( 1 % S i g ) N o n e Th a l l i u m 4 . 5 6 % 0 . 2 3 6 MW - 2 , M W - 1 2 ( 1 a n d 2 v a l u e s , re s p .) No n e Ca d m i u m 4 . 1 8 % 2 3 3 N o n e N o n e NO T E : N C 2 L - T i t l e 1 5 A , S u b c h a p t e r 2 L , R u l e s . 0 2 0 2 o f t h e N o r t h C a r o l i n a A d m i n i s t r a t i v e C o d e ( N o r t h C a r o l i n a G r o u n d w a t e r S t a n d a r d s ) IM A C - I n t e r i m M a x i m u m A l l o w a b l e C o n c e n t r a t i o n s µg / L - M i c r o g r a m p e r l i t e r Si g - S i g n i f i c a n c e L e v e l - - - N o A n a l y s e s f o r t h i s c o n s t i t u e n t TA B L E 1 4 SU M M A R Y O F S T A T I S T I C A L E V A L U A T I O N CI T Y O F A L B E M A R L E L A N D F I L L ST A N L Y C O U N T Y , N O R T H C A R O L I N A Mo n i t o r i n g W e l l s t h a t a r e s t a t i s t i c a l l y s i g n i f i c a n t NC 2 L or IM A C (µ g / L ) Pe r c e n t a g e o f An a l y s e s Ex c e e d i n g St a n d a r d s In o r g a n i c Co n s t i t u e n t To t a l N u m b e r of Ex c e e d a n c e s (s e e T a b l e 1 ) Ma n g a n e s e 7 7 . 4 6 % 5 0 5 5 1 2 , 1 8 0 T a b l e 7 9 , 1 8 0 Ir o n 7 7 . 3 1 % 3 0 0 9 2 4 1 , 4 4 0 T a b l e 7 3 9 , 1 0 0 Co b a l t 7 3 . 1 3 % 1 5 7 7 - - - - 3 8 0 Va n a d i u m 4 5 . 8 8 % 0 . 3 3 6 2 4 2 . 9 T a b l e 6 2 6 0 Ar s e n i c 2 4 . 5 9 % 1 0 1 9 4 8 0 6 T a b l e 7 8 9 Ch r o m i u m 1 5 . 4 6 % 1 0 1 2 2 - - - - 2 5 0 Le a d 7 . 1 0 % 1 5 5 6 1 8 3 T a b l e 7 2 4 0 Th a l l i u m 4 . 5 6 % 0 . 2 3 6 - - - - 1 4 Ca d m i u m 4 . 1 8 % 2 3 3 5 T a b l e 7 6 . 5 4 NO T E : N C 2 L - T i t l e 1 5 A , S u b c h a p t e r 2 L , R u l e s . 0 2 0 2 o f t h e N o r t h C a r o l i n a A d m i n i s t r a t i v e C o d e ( N o r t h C a r o l i n a G r o u n d w a t e r S t a n d a r d s ) IM A C - I n t e r i m M a x i m u m A l l o w a b l e C o n c e n t r a t i o n s µg / L - M i c r o g r a m p e r l i t e r So u r c e Ac t u a l S i t e D a t a - Ma x i m u m V a l u e (s e e T a b l e 1 1 ) TA B L E 1 5 RE P O R T S U M M A R Y F O R I N O R G A N I C C O N C E N T R A T I O N S CI T Y O F A L B E M A R L E L A N D F I L L ST A N L Y C O U N T Y , N O R T H C A R O L I N A In o r g a n i c Co n s t i t u e n t Pe r c e n t a g e o f An a l y s e s E x c e e d i n g St a n d a r d s NC 2 L o r IM A C ( µ g / L ) To t a l N u m b e r o f Ex c e e d a n c e s ( s e e Ta b l e 1 ) Ba c k g r o u n d D a t a - Ma x i m u m V a l u e FIGURES APPENDIX A ANALYTICAL RESULTS APPENDIX B GRAPHS APPENDIX B - 1 ACTIVE C&D CLOSED MSWLF GRAPHS: BACKGROUND WELLS (MW-1 & MW-8D) APPENDIX B - 2 ACTIVE C&D CLOSED MSWLF GRAPHS: WEST WELLS (MW-2, MW-6 & MW-7) APPENDIX B - 3 ACTIVE C&D CLOSED MSWLF GRAPHS: SOUTH WELLS (MW-4R & MW-5R) APPENDIX B - 4 ACTIVE C&D CLOSED MSWLF GRAPHS: NORTHEAST WELLS (MW-3, MW-9 & MW-10) APPENDIX B - 5 ACTIVE C&D CLOSED MSWLF GRAPHS: SOUTHEAST WELLS (MW-12, MW-13 & MW-23) APPENDIX B - 6 SUBTITLE D LINED MSWLF GRAPHS: BACKGROUND WELL (MW-19) APPENDIX B - 7 SUBTITLE D LINED MSWLF GRAPHS: NORTH WELLS (MW-17 & MW-18) APPENDIX B - 8 SUBTITLE D LINED MSWLF GRAPHS: SOUTH WELLS (MW-22, MW-26 & MW-27) APPENDIX B - 9 SUBTITLE D LINED MSWLF GRAPHS: WEST WELLS (MW-14, MW-15, MW-16S & MW-16D) APPENDIX C QUARTILES, BOX PLOTS AND OUTLIER ANALYSES APPENDIX C - 1 ACTIVE C&D CLOSED MSWLF QUARTILES APPENDIX C - 2 SUBTITLE D LINED MSWLF QUARTILES APPENDIX C - 3 ACTIVE C&D CLOSED MSWLF BOX PLOTS APPENDIX C - 4 SUBTITLE D LINED MSWLF BOX PLOTS APPENDIX C - 5 ACTIVE C&D CLOSED MSWLF OUTLIER ANALYSES APPENDIX C - 6 SUBTITLE D LINED MSWLF OUTLIER ANALYSES APPENDIX D STATISTICAL ANALYSES APPENDIX D STATISTICAL ANALYSES APPENDIX D - 1 ACTIVE C&D CLOSED MSWLF APPENDIX D - 2 SUBTITLE D LINED MSWLF