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HomeMy WebLinkAboutNC0004961_RBSS CSA Report_Appendix A_Introduction_20150818Introduction • NCDENR NORR Letter • Summary of Work Plan Submittals and NCDENR-Duke Energy Correspondence • Revised Groundwater Assessment Work Plan NCDENR NORR Letter A 4 A=(WA 4AF1 NCDENR North Carolina Department of Environment and Natural Resources Pat McCrory John E. Skvarla, III Governor Secretary August 13, 2014 CERTIFIED MAIL 7004 2510 0000 3651 1168 RETURN RECEIPT REQUESTED Paul Newton Duke Energy 526 South Church Street Charlotte, NC 28202 Subject: Notice of Regulatory Requirements Title 15A North Carolina Administrative Code (NCAC) 02L .0106 14 Coal Ash Facilities in North Carolina Dear Mr. Newton: Chapter 143, North Carolina General Statutes, authorizes and directs the Environmental Management Commission of the Department of Environment and Natural Resources to protect and preserve the water and air resources of the State. The Division of Water Resources (DWR) has the delegated authority to enforce adopted pollution control rules. Rule 15A NCAC 02L .0103(d) states that no person shall conduct or cause to be conducted any activity which causes the concentration of any substance to exceed that specified in 15A NCAC 02L .0202. As of the date of this letter, exceedances of the groundwater quality standards at 15A NCAC 02L .0200 Classifications and Water Quality Standards Applicable to the Groundwaters of North Carolina have been reported at each of the subject coal ash facilities owned and operated by Duke Energy (herein referred to as Duke). Groundwater Assessment Plans No later than September, 26 2014 Duke Energy shall submit to the Division of Water Resources plans establishing proposed site assessment activities and schedules for the implementation, completion, and submission of a comprehensive site assessment (CSA) report for each of the following facilities in accordance with 15A NCAC 02L .0106(g): Asheville Steam Electric Generating Plant Belews Creek Steam Station Buck Steam Station Cape Fear Steam Electric Generating Plant Cliffside Steam Station 1636 Mail Service Center, Raleigh, North Carolina 27699-1636 Phone: 919-807-64641 Internet: www.ncdenr.gov An Equal Opportunity 1 Affirmative Action Employer— Made in part by recycled paper Mr. Paul Newton August 12, 2014 Page 2 of 3 Dan River Combined Cycle Station H.F. Lee Steam Electric Plant Marshall Steam Station Mayo Steam Electric Generating Plant Plant Allen Steam Station Riverbend Steam Station Roxboro Steam Electric Generating Plant L.V. Sutton Electric Plant Weatherspoon Steam Electric Plant The site assessment plans shall include a description of the activities proposed to be completed by Duke that are necessary to meet the requirements of 15A NCAC 02L .0106(g) and to provide information concerning the following: (1) the source and cause of contamination; (2) any imminent hazards to public health and safety and actions taken to mitigate them in accordance to 15A NCAC 02L .0106(f); (3) all receptors, and significant exposure pathways; (4) the horizontal and vertical extent of soil and groundwater contamination and all significant factors affecting contaminant transport; and (5) geological and hydrogeological features influencing the movement,. chemical, and physical character of the contaminants. For your convenience, we have attached guidelines detailing the information necessary for the preparation of a CSA report. The DWR will review the plans and provide Duke with review comments, either approving the plans or noting any deficiencies to be corrected, and a date by which a corrected plan is to be submitted for further review and comment or approval. For those facilities for which Duke has already submitted groundwater assessment plans, please update your submittals to ensure they meet the requirements stated in this letter and referenced attachments and submit them with the others. Receptor Survey No later than October 14t', 2104 as authorized pursuant to 15A NCAC 02L .0106(g), the DWR is requesting that Duke perform a receptor survey at each of the subject facilities and submitted to the DWR. The receptor survey is required by 15A NCAC 02L .0106(g) and shall include identification of all receptors within a radius of 2,640 feet (one-half mile) from the established compliance boundary identified in the respective National Pollutant Discharge Elimination System (NPDES) permits. Receptors shall include, but shall not be limited to, public and private water supply wells (including irrigation wells and unused or abandoned wells) and surface water features within one-half mile of the facility compliance boundary. For those facilities for which Duke has already submitted a receptor survey, please update your submittals to ensure they meet the requirements stated in this letter and referenced attachments and submit them with the others. If they do not meet these requirements, you must modify and resubmit the plans. Mr. Paul Newton August 12, 2014 Page 3 of 3 The results of the receptor survey shall be presented on a sufficiently scaled map. The map shall show the coal ash facility location, the facility property boundary, the waste and compliance boundaries, and all monitoring wells listed in the respective NPDES permits. Any identified water supply wells shall be located on the map and shall have the well owner's name and location address listed on a separate table that can be matched to its location on the map. Failure to comply with the State's rules in the manner and time specified may result in the assessment of civil penalties and/or the use of other enforcement mechanisms available to the State. We appreciate your attention and prompt response in this matter. If you have any questions, please feel free to contact S. Jay Zimmerman, Water Quality Regional Operations Section Chief, at (919) 807-6351. 2hn ierely, E. Skvarla, III Attachment enclosed cc: Thomas A. Reeder, Director, Division of Water Resources Regional Offices — WQROS File Copy August 12, 2014 GUIDELINES FOR COMPREHENSIVE SITE ASSESSMENT This document provides guidelines for those involved in the investigation of contaminated soil and/or groundwater, where the source of contamination is from: ■ Incidents caused by activities subject to permitting under G.S. 143-215.1 ■ Incidents caused by activities subject to permitting under G.S. 87-88 ■ Incidents arising from agricultural operations, including application of agricultural chemicals, but not including unlawful discharges, spills or disposal of such chemicals Comprehensive Site Assessment (CSA) NOTE: Regional Offices may request additional information in support of the CSA to aid in their review and will not approve the CSA if any of the elements specified below have not been included or have not been sufficiently addressed Minimum Elements of the Comprehensive Site Assessment Report: A. Title Page • Site name, location and Groundwater Incident number (if assigned) and Permit Number; • Date of report; • Responsible Party and/or permiee, including address and phone number; • Current property owner including address and phone number; • Consultant/contractor information including address and phone number; • Latitude and longitude of the facility; and • Seal and signature of certifying P.E. or P.G., as appropriate. B. Executive Summary The Executive Summary should provide a brief overview of the pertinent site information (i.e., provide sufficient information to acquaint the reader with the who, what, when, where, why and how for site activities to date). 1. Source information: Type of contaminants 2. Initial abatement/emergency response information. 1 August 12, 2014 3. Receptor information: • Water supply wells; • Public water supplies (wells, surface water intakes); • Surface water bodies; • Wellhead protection areas; • Deep aquifers in the Coastal Plain physiographic region; • Subsurface structures; and • Land use. 4. Sampling/investigation results: • Nature and extent of contamination; • Maximum contaminant concentrations; • Site hydrogeology. 5. Conclusions and recommendations. C. Table of Contents • First page number for each section listed. • List of figures (all referenced by number and placed in a single section following contents text). • List of tables (all referenced by number and placed in a single section following contents text). • List of appendices. D. Site History and Source Characterization • Provide a history of property ownership and use. Indicate dates of ownership, uses of the site, and potential sources of contaminants. • Discuss the source(s) of contamination, including primary and secondary sources. • For permitted activities, describe nature of activity, permitted waste, application of all instances of over-application/irrigation of wastes or water • Summarize assessment activities and corrective actions performed to date including emergency response, initial abatement, primary and secondary source removal. • Discuss geographical setting and present/future surrounding land uses. E. Receptor Information Provide a site map showing labeled well locations within a August 12, 2014 minimum of 1500 feet of the known extent of contamination. Key to the table and maps described. NOTE: As the known extent of contamination changes, the receptor survey must be updated to reflect the change. This applies throughout the Receptor Information section. • In table format, list all water supply wells, public or private, including irrigation wells and unused wells, (omit those that have been properly abandoned in accordance with 15A NCAC 2C .0100) within a minimum of 1500 feet of the known extent of contamination. Note whether well users are also served by a municipal water supply. • For each well, include well number, well owner and user names, addresses and telephone numbers, use of the well, well depth, well casing depth, well screen interval, and distance from source of contamination; NOTE: It will often be necessary to conduct any or all of the following in order to ensure reliability in a water supply well survey. o Call the city/county water department to inquire about city water connections, o Visit door-to-door (make sure that you introduce yourself and state your purpose to residents prior to examining their property) to obtain accurate description of water usage, and if some residents are not at home, ask surrounding neighbors who are home about the water usage at those residences. Even if a public water line is available, some residents still use their well water and are not connected to the public water system; and o Search for water meters and well houses. • Site map showing location of subsurface structures (e.g., sewers, utility lines, conduits, basements, septic tanks, drain fields, etc.) within a minimum of 1,500 feet of the known extent of contamination; • Table of surrounding property owner addresses; • Discuss the availability of public water supplies within a minimum of 1,500 feet of the source area, including the distance and location to the nearest public water lines and the source(s) of the public water supply; 3 August 12, 2014 • Identify all surface water bodies (e.g., ditch, pond, stream, lake, river) within a minimum of 1,500 feet of the source of contamination; • Determine the location of any designated wellhead protection areas as defined in 42 USC 300h-7(e) within a minimum of 1,500 feet of the source of contamination. Identify and discuss the location of the water supply well(s) for which the area was designated a wellhead protection area, and the extent of the protected area. Include information about the well owner, well -construction specifications (especially at screened intervals), pumping rate and pumping schedule. Information regarding designated wellhead. protection areas may be obtained by contacting the Public Water Supply Section at (919) 707-9083; • Discuss the uses and activities (involving possible human exposure to contamination) that could occur at the site and adjacent properties. Examples of such activities and uses include but are not limited to use of a property for an office, manufacturing operation, residence, store, school, gardening or farming activities, recreational activities, or undeveloped land; • Determine whether the contaminated area is located in an area where there is recharge to an unconfined or semi -confined deeper aquifer that is being used or may be used as a source of drinking water. Based on a review of scientific literature on the regional hydrogeology and well construction records and lithological logs for deeper wells in the area, identify and describe the deep aquifers underlying the source of contamination. Include information on the depth of the deep aquifer in relation to the surficial saturated zone, the lithology and hydraulic conductivity of the strata between the surficial aquifer and the deeper aquifer, and the difference in groundwater head between the surficial aquifer and the deeper aquifer. Discuss the local and regional usage of the deep aquifer and the draw down from major pumping influences. Also, specify the distance from the source of contamination to major discharge areas such as streams and rivers. Cite all sources and references used for this discussion. NOTE: This requirement (last bullet) only pertains to 4 August 12, 2014 contamination sources in the Coastal Plain physiographic region as designated on a map entitled "Geology of !North Carolina" published by the Department in 1985. However, recharge/discharge, hydraulic conductivity, lithology, head difference, etc. is also important information at mountains and piedmont sites. F. Regional Geology and Hydrogeology Provide a brief description of the regional geology and hydrogeology. Cite all references. G. Site Geology and Hydrogeology • Describe the soil and geology encountered at the site. Use the information obtained during assessment activities (e.g., lithological descriptions made during drilling, probe surveys, etc.). This information should correspond to the geologic cross sections required in N. below; and • Based on the results of the groundwater investigation, describe the site hydrogeology, including a discussion of groundwater flow direction, hydraulic gradient, hydraulic conductivity and groundwater velocity. Discuss the effects of the geologic and hydrogeological characteristics on the migration, retardation, and attenuation of contaminants. H . Soil Sampling Results Using figures and tables to the extent possible, describe all soil sampling performed to date and provide the rationale for sample locations, number of samples collected, etc. Include the following information: • Location of soil samples; • Date of sampling; • Type of soil samples (from excavation, borehole, Geoprobe, etc.); • Soil sample collection procedures (split spoon, grab, hand auger, etc.) • Depth of soil samples below land surface; • Soil sample identification • Soil sample analyses; • Soil sample analytical results (list any contaminant detected above the method detection limit); and 5 August 12, 2014 • Identify any sample analytical results that exceed the applicable cleanup levels. NOTE: Information related to H. above should correspond to the sampling location and sampling results maps required in N. below. I . Groundwater Sampling Results Using figures and tables to the extent possible describe the groundwater sampling performed to date and provide the rationale for sample locations (based on source and contaminant type), number of samples collected, etc. Include the following information: • Location of groundwater samples and monitoring wells; • Date of sampling; • Groundwater sample collection procedures (bailer, pump, etc.); • Groundwater sample identification and whether samples were collected during initial abatement, CSA, etc.; • Groundwater sample analyses; • Groundwater sample analytical results (list any contaminant detected above the method detection limit; and • Identify all sample analytical results that exceed 15A NCAC 2L or interim standards. NOTE: Information related to 1. above should correspond to the sampling location and sampling results maps required in N. below. J. Hydrogeological Investigation Describe the hydrogeological investigation performed including all methods, procedures and calculations used to characterize site hydrogeological conditions. The following information should be discussed and should correspond to the maps and figures required below: • Groundwater flow direction; • Hydraulic gradient (horizontal and vertical); • Hydraulic conductivity; • Groundwater velocity; • Contaminant velocity; • Slug test results; * • Aquifer test results; • Plume's physical and chemical characterization; and • Fracture trace study if groundwater in bedrock is impacted. 6 August 12, 2014 * Check with the Regional Office prior to performing these tests and study to see if necessary for the site. K. Groundwater Modeling Results Groundwater modeling or predictive calculations may be necessary at some sites (source area proximate to surface water, source area located within wellhead protection area or source area overlying semi -confined or unconfined deeper Coastal Plain aquifer) to verify, based on site specific hydrogeological conditions, whether groundwater contamination poses a risk to receptors. For contamination shown to pose a risk to receptors, groundwater modeling may be necessary to determine an appropriate cleanup level for contaminated groundwater. Modeling should illustrate the input data used to complete the model and will generally be required for natural attenuation proposals (see Groundwater Modeling Policy at http://portal. ncdenr.org/web/wq/aps/a-wr)ro/policy). NOTE: Input data for models should be derived from site specific information with limited assumptions or estimates. All assumptions and estimated values including biodegradation rates must be conservative (predict reasonable worst -case scenarios) and must be well documented. L. Discussion • Nature and extent of contamination, including primary and secondary source areas, and impacted groundwater and surface water resources; • Maximum contaminant concentrations; • Contaminant migration and potentially affected receptors M. Conclusions and Recommendations If corrective action will be necessary, provide a preliminary evaluation of remediation alternatives appropriate for the site. Discuss the remediation alternatives likely to be selected. Note that for impacts to groundwater associated with permitted activities, corrective action pursuant to 15A NCAC 2L .0106(k), (1) and (m) is not applicable, unless provided for pursuant to 15A NCAC 2L .0106(c) and (e) or through a variance from the Environmental Management Commission (EMC). N. Figures 9 71/2 minute USGS topographic quadrangle map showing an area August 12, 2014 within a minimum of a 1,500-foot radius of the source of contamination and depicting the site location, all water supply wells, public water supplies, surface water intakes, surface water bodies, designated well head protection areas, and areas of recharge to deeper aquifers in the Coastal Plain that are or may be used as a source for drinking water; Site map locating source areas, site boundaries, buildings, all water supply wells within a minimum of 1,500 feet, named roads/easements/right-of-ways, subsurface utilities, product or chemical storage areas, basements and adjacent properties, scale and north arrow; At least two geologic cross sections through the saturated and unsaturated zones intersecting at or near right angles through the contaminated area using a reasonable vertical exaggeration. Indicate monitoring well/sample boring/sample locations and analytical results for soil samples. Identify the depth to the water table. Provide a site plan showing the locations of the cross sections; ■ Site map(s) showing the results of all soil sampling conducted. Indicate sampling identifications, sampling depths, locations and analytical results; ■ Site map(s) showing the results of all groundwater sampling conducted. Indicate sampling locations, monitoring well identifications, sample identifications, and analytical results; Separate groundwater contaminant iso-concentration contour maps showing total volatile organic compound concentrations, total semi -volatile organic compound concentrations and concentrations for the most extensive contaminant. Maps should depict the horizontal and vertical extent. Contour line for applicable 2L standard should be shown in bold; ■ Site map(s) showing the elevation of groundwater in the monitoring wells and the direction of groundwater flow. Contour the groundwater elevations. Identify and locate the datum (arbitrary 8 August 12, 2014 1000, USGS, NGVD) or benchmark. Indicate the dates that water level measurements were made. There should be one map for each series of water level measurements obtained; ■ Groundwater contaminant iso-concentration contour cross-section; and ■ Site map(s) showing the monitoring wells. NDTE: If possible, use a single base map to prepare site maps using a map scale of 9 inch = 40 feet (or a smaller scale for large sites, if necessary). Maps and figures should include conventional symbols, notations, labeling, legends, scales, and north arrows and should conform to generally accepted practices of map presentation such as those enumerated in the US Geological Survey pamphlet, "Topographic Maps". O. Tables List all water supply wells, public or private, including irrigation wells and unused wells, (omit those that have been properly abandoned in accordance with 15A NCAC 2C .0100) within a minimum of 1500 feet of the known extent of contamination For each well, include the well number (may use the tax map number), well owner and user names, addresses and telephone numbers, use of the well, well depth, well casing depth, well screen interval and distance from the source of contamination; List the names and addresses of property owners and occupants within or contiguous to the area containing contamination and all property owners and occupants within or contiguous to the area where the contamination is expected to migrate; ■ List the results for groundwater samples collected including sample location; date of sampling; sample collection procedures (bailer, pump, etc.); sample identifications; sample analyses; and sample analytical results (list any contaminant detected above the method detection limit in bold); and List for each monitoring well, the monitoring well identification 9 August 12, 2014 numbers, date water levels were obtained, elevations of the water levels, the land surface, top of the well casing, screened interval and bottom of the well. P Appendices • Boring logs and lithological descriptions; • Well construction records; • Standard procedures used at site for sampling, field equipment decontamination, field screening, etc.; • Laboratory reports and chain -of -custody documents; • Copies of any permits or certificates obtained, permit number, permitting agency, and • Modeling data and results; • Slug/pumping test data; and • Certification form for CSA 10 August 12, 2014 DIVISION OF WATER RESOURCES Certification for the Submittal of a Comprehensive Site Assessment Responsible Party and/or Permittee: Contact Person: Address: City: State: Zip Code: Site Name: Address: City: State: Zip Code: Groundwater Incident Number (applicable): I, , a Professional Engineer/Professional Geologist (circle one) for (firm or company of employment) do hereby certify that the information indicated below is enclosed as part of the required Comprehensive Site Assessment (CSA) and that to the best of my knowledge the data, assessments, conclusions, recommendations and other associated materials are correct, complete and accurate. (Each item must be initialed by the certifying licensed professional) 1. The source of the contamination has been identified. A list of all potential sources of the contamination are attached. 2. Imminent hazards to public health and safety have been identified. 3. Potential receptors and significant exposure pathways have been identified. 4. Geological and hydrogeological features influencing the movement of groundwater have been identified. The chemical and physical character of the contaminants have been identified. 5. The CSA sufficiently characterizes the cause, significance and extent of groundwater and soil contamination such that a Corrective Action Plan can be developed. If any of the above statements have been altered or items not initialed, provide a detailed explanation. Failure to initial any item or to provide written justification for the lack thereof will result in immediate return of the CSA to the responsible party. (Please Affix Seal and Signature) 11 Summary of Work Plan Submittals and NCDENR-Duke Energy Correspondence NCDENR North Carolina Department of Environment and Natural Resources Pat McCrory Governor February 19, 2015 Mr. Harry Sideris Senior Vice -President Environment, Health, and Safety Duke Energy 526 South Church Street Mail Code EC3XP Charlotte, NC 28202 Re: Riverbend Steam Station NPDES Permit No. NC0004961 — Gaston County, North Carolina Conditional Approval of Revised Groundwater Assessment Work Plan Dear Mr. Sideris: Donald R. van der Vaart Secretary On December 31, 2014, the Division of Water Resources (Division) received the revised Groundwater Assessment Plan (GAP) for the above listed facility. The revised GAP was submitted in response to the DWR's Review of Groundwater Assessment Work Plan letter dated November 4, 2014. A review of the plan has been completed and several deficiencies or items requiring clarification were noted. Therefore, in order to keep the site assessment activities on a timely schedule, the Division has approved the revised GAP under the condition that the following deficient items are addressed in the Groundwater Assessment Report: • Comment Section 5.3 Hydrogeologic Site Characteristics: The initial site conceptual site model (ISCM) section of the revised GAP does not provide a clear, cohesive description of how constituents of potential concern (COPCs) may migrate from the source(s) to the receptors through various pathways. It is acknowledged that there is information available to develop an ICSM, but data are not presented in a manner such as groundwater elevation maps, geologic maps, cross -sections that depict detailed site conditions, flow diagrams, or in a tabulated format to illustrate where data gaps may exist. Duke Energy should incorporate all existing data at the site and be prepared to collect additional data if the Division determines that additional data gaps exist. Continued site conceptual model development should follow guidelines similar to those presented in the American Standards Testing Measures E1689 - 95(2014) Standard Guide for Developing Conceptual Site Models for Contaminated Sites to direct data collection, data interpretation, and model development efforts. 1636 Mail Service Center, Raleigh, North Carolina 27699-1636 Phone: 919-807-64641Internet: http://www.ncwater.org An Equal Opporlunity1Affirrnative Action Employer — Made in pad by recycled paper Riverbend Steam Station February 19, 2015 Page 2 of 3 • Comment 7.1.3 Deep Monitoring Wells and Comment Section 7.1.4 Bedrock Monitoring Wells: The Division suggests installing a cluster of monitoring wells that are screened across various flowpaths (shallow aquifer, transition zone/partially weathered bedrock and within bedrock) near the compliance boundary at a location approximately 200 feet north of existing monitoring well MW-9. Additional monitoring wells that are screened within the transition zone/partially weathered rock and within bedrock are also suggested in the immediate vicinity of existing monitoring well MW-15. These locations will provide more data adjacent to the Catawba River for assessment of multiple flowpath transects across the site. • Comment Section 7.2 Groundwater Sampling and Analysis: Direction provided in the EPA Region 1 Low Stress Purging and Sampling Procedure for the Collection of Groundwater Samples from Monitoring Wells (2010) should be followed strictly and any deviations from the procedure must be approved by the Division and documented accordingly. For example, samples should not be collected until pH is stabilized within t 0.1 for three consecutive readings rather than t 0.2 written in the GAP. Temperature and specific conductivity readings should stabilize within 3% for three consecutive readings before samples are collected instead of 10% noted in the GAP. Also note that if the pumping rate is so low that the flow-through-cell/chamber volume cannot be replaced in a 5 minute interval, the time between measurements should be increased accordingly. • Table 10 — Groundwater, Surface Water, and Seep Parameters and Constituent Analytical Methods: Low level Vanadium listed as having a detection limit unit of mg/L. This is likely a typographical error but the units should be in µg/L rather than mg/L • Comment Section 7.2.3 Speciation of Select Inorganics and 7.3.3 Seep Samples: The GAP text indicates that review of the Division's March 2014 seep and surface water sampling analytical data will be incorporated into assessment plans to evaluate seep and surface water sample locations at the facility. Locations where the Division's March 2014 seep and surface water sampling data indicated exceedances or elevated concentrations of iron, manganese and other constituents of concern should be incorporated into the assessment's seep/surface water sampling plans with speciation of analytical data sufficient to support delineation and modeling efforts. In addition, technical direction that will serve as the basis of expectations for completion of the site assessment is provided at Attachment 1. Failure to address the deficient items stated above will result in Duke Energy not being in compliance with the stated statutes. Per G.S. 130A-309.209(a) (3) and (4), you must begin implementation of the revised GAP on March 1, 2015 and the Groundwater Assessment Report is due on August 18, 2015. It is our understanding that Duke Energy may have to obtain additional permits to facilitate installation of certain monitoring wells. In the event permits are needed for this purpose, Duke Energy should take all steps necessary consistent with the law to avoid delaying completion of the assessment report. If you have any questions, please contact Bruce Parris at (704) 235-2185. Riverbend Steam Station February 19, 2015 Page 3 of 3 Sincerely, > I pow S. Jay Zimmerman, P.G., Acting Director Division of Water Resources cc: WQROS—MRO WQROS Central Files DENR Secretary - Don van der Vaart HDR (Attn: William Miller) 440 South Church Street, Suite 1000, Charlotte, NC 28202 Attachment 1 Page 1 of 6 Duke Energy GAP Review Issues The items identified in this Groundwater Assessment Plan (GAP) review summary are provided for general discussion for the various parties to agree upon technical direction and content in the revised GAPs, comprehensive site assessments (CSAs), and corrective action plans (CAPs). Groundwater Monitoring 1. A schedule for continued groundwater monitoring is mandated by the Coal Ash Management Act 2014. An interim plan should include at least two rounds of groundwater samples collected and analyzed in 2015. The analytical results of the first round of data collected in 2015 would be included in the CSA report, while the results of the second round would be submitted as a CSA addendum. After CSA data can be evaluated, a plan for continued groundwater monitoring can be developed for implementation in 2016. 2. Sites impacted by inorganics are typically managed using a tiered site analysis which includes four elements as referenced in EPA/600/R-07/139: • Demonstration of active contaminant removal from groundwater & dissolved plume stability; • Determination of the mechanism and rate of attenuation; • Determination of the long-term capacity for attenuation and stability of immobilized contaminants, before, during, and after any proposed remedial activities; and • Design of performance monitoring program, including defining triggers for assessing the remedial action strategy failure, and establishing a contingency plan. This reference and the framework described above should be used as applicable to meet the corrective action requirements found in 15A NCAC 02L .0106. 3. Because of uncertainty concerning the site's ability to attenuate contaminants over the long term given potentially changing geochemical conditions, there is a need to address the elements of the tiered site analysis described above and collect appropriate samples as part of the CSA, CAP development, and continued groundwater monitoring. 4. The Division of Water Resources (Division) Director is responsible for establishing background levels for COPCs in groundwater. This determination is based on information and data provided by the responsible party and may include formal statistical testing using background wells with at least four rounds of data. Wells identified as "background" are subject to periodic review based on a refined understanding of site chemistry and hydrogeologic conditions. In general, each facility must have a background well or wells screened or open to each of the dominant flow systems that occur at the site and are associated with groundwater contamination. Any questions concerning adequacy of background monitoring locations or conditions at the facilities should be directed to the Regional offices. Attachment 1 Page 2 of 6 5. Delineation of the groundwater contaminant plume associated with coal combustion residuals is a requirement of the investigation and if off -site monitoring wells are ultimately required to perform this task, then it is expected that these activities will be completed as part of the groundwater assessment activities and included in the final report. Documentation of the effort to gain off -site access, or right of way permits, will be provided if off -site access is denied or alternate means of assessing the area were not available within the allocated timeframe (such as within right-of-ways). Site Assessment Data Requirements and Sampling Strategy 1. Robust data collection is warranted to support timely completion of site assessments and subsequent corrective action plans because of the impending deadlines for completion of CSAs and CAPs, scale and geologic complexity of the sites, the challenges of modeling heterogeneous systems, and site proximity to potential human and sensitive ecosystem receptors. 2. Robust data collection will be focused along strategically positioned flowpath transect(s) - from ash pond source to potential receptor —as an efficient approach for model development (analytical, geochemical, groundwater flow, and transport) in support of risk assessment and CAP development. Data collected to support evaluation of site conditions along the flowpath transects should be located along or defensibly proximate to the modeled transects. 3. The dataset developed along proposed flowpath transects will include any information needed to determine constituent concentrations, conduct Kd tests, and perform batch geochemical modeling in multiple flow horizons as appropriate. This data will include a) solid phase sample collection for Kd measurement and batch geochemical modeling, inorganic analysis and speciation, and other parameters identified in General Comment#4 of the November4, 2014 GAP comments issued by DWR, b) solution phase sample collection for total and dissolved inorganic analysis of total concentrations, small pore filtration for dissolved samples, etc., and c) slug, constant/falling head, and packer testing. The solid phase sample mineralogy, total concentration results, re-dox measurements, and other geochemical parameters will be used as input for equilibrium speciation calculations of redox sensitive constituents calculated by PHREECIC or similar program (EPA/540/5-92/018). This geochemical modeling will be performed to identify potential mineral phases, estimated species speciation and concentrations, and will be performed varying key solubility controlling parameters to predict mineral phases, speciation, and concentrations under varying conditions. Solid samples for Kd tests from locations where moderately to strongly reducing conditions are anticipated shall be frozen upon collection and tested in glove box conditions (EPA/600/R-06/112). Refer to EPA/600/R-07/139 Section III for the data collection and characterization needed to support the four -tiered analysis discussed above. 4. Speciations forgroundwater and surface water samples should include Fe, Mn, and any COPCs whose speciation state may affect toxicity or mobility (e.g. As, Cr, Se, or others if applicable). This speciation will apply for groundwater samples collected at wells located along proposed Attachment 1 Page 3 of 6 flowpath transects and in wells where these constituents exceed 2L groundwater standards as well as for surface water samples collected within ash impoundments. 5. Solid phase samples shall be analyzed for: minerals present, chemical composition of oxides, hydrous Fe, Mn, and AL oxides content; moisture content; particle size analysis; plasticity; specific gravity; porosity, permeability, or other physical properties or analyses needed to provide input to a chosen model. The Division reserves the right to request analysis for organic carbon content, organic carbonate content (as appropriate if site conditions warrant), or ion exchange capacities, if needed to complete the site assessment process. 6. In addition to conducting the SPLP leachable inorganic compounds analysis for selected ash samples to evaluate the potential for leaching of constituents to groundwater, the leachable analysis should also be conducted for some soil samples from locations beneath the ash ponds, within the plume, and outside the plume to evaluate potential contributions from native soils. 7. In addition to collecting solid phase samples onsite for Kd procedures, soil samples should be also collected from unaffected soils within groundwater flow pathway to evaluate Kd(s) or hydrous ferrous oxide. 8. Rock samples for laboratory analyses should be collected as commented in General Comment 4 of the November 4, 2014 GAP comments issued by DWR. This GAP review comment indicated that the sample(s) collected from bedrock well soil and rock cores shall be analyzed, at a minimum, for the following: type of material, formation from which it came, minerals present, chemical composition as oxides, hydrous Fe, Mn, and Al oxides content, surface area, moisture content, etc.; however, these analyses were not mentioned in the GAP. The Division reserves the right to request analysis for organic carbon content, organic carbonate content, and ion exchange capacity if needed to complete the site assessment process. 9. The coal ash and soil analyte lists should match the groundwater analyte lists. 10. Total uranium analysis should be analyzed where total radium is analyzed for groundwater. 11. If analytical results from a seep sample exceed 2L standards, then the area in the vicinity of the sample location should be investigated for groundwater contamination. If analytical results from a surface water sample exceed 2B standards, then the area in the vicinity of the sample location should be investigated for groundwater contamination. 12. Surface water/seep samples should be collected during baseflow conditions and that the groundwater monitoring (WLs and sampling) should occur at about the same time. 13. Measurement of streamflow in selected perennial streams is expected as needed in support of simulation/calibration of flow and transport models; major rivers that serve as groundwater divides are not included in this expectation. Conceptual Model Elements 1. In the CSA report, data gaps remaining should be specifically identified and summarized. 2. Site heterogeneities should be identified and described with respect to: a) their nature, b) their scale and density, c) the extent to which the data collection successfully characterizes them, d) how the modeling accounts for them, e) and how they affect modeling uncertainty. Attachment 1 Page 4 of 6 3. The impact of data gaps and site heterogeneities should be described in relation to the elements developed in the Site Hydrogeologic Conceptual Model and Fate and Transport Model subsections. 4. For sites in the Piedmont or Mountains, the CSA Report should include a subsection within the Site Geology and Hydrogeology Section titled 'Structural Geology'. This section should describe: a) foliations, b) shear zones, c) fracture trace analysis, and d) other structural components anticipated to be relevant to flow and contaminant transport at the site. S. Duke Energy will include a poster -sized sheet(s) (ANSI E) combining tabulated analytical assessment results (groundwater, surface water, and leachate samples); multiple sheets may be needed to present the data. This should be provided in addition to the individual analytical results tables that will be prepared for the CSA reports. Any questions concerning format or content of the analytical result summaries should be directed to the Regional offices. Geochemical Modeling 1. The Division agrees that a geochemical model "coupled" to a 3-D fate and transport model is inappropriate given the size and complexity of the sites and the extremely large amount of data required to calibrate such a model. Rather, a "batch" geochemical model approach should be sufficient for successfully completing the site assessment and/or corrective action plan. 2. Samples collected for "batch" geochemical analysis should be focused along or defensibly proximate to flowpath transects. 3. To support successful batch geochemical modeling, dissolved groundwater samples collected along a contaminant flowpath transect should be obtained using a 0.1 um filter. This will help ensure a true dissolved phase sample. Note that the dissolved samples are for assessment purposes only and may not be used for purposes of compliance monitoring. If there is uncertainty about which areas/wells will be used in the batch geochemical modeling, the initial round of assessment sampling at the facility can utilize the 0.45 um filter until the contaminant flow path transects are selected. Once determined, Duke Energy can go back and re -sample the wells needed for geochemical modeling using the 0.1 um filter. It is recognized that the use of a 0.1 um filter will be difficult for wells with elevated turbidity; in this case, it is recommended that Duke Energy use two filters in series (the water initially passes through a 0.45 um filter to remove larger particles prior to passing through the 0.1 um filter). Information for a disposable 0.1um field filter designed specifically for sampling groundwater for metal analysis is provided at the following link: http://www.vosstech.com/index.pho/­products/filters. If field comparisons of 0.1 versus 0.45 micron filtration at several transect wells at a given site show no significant differences between the two methods, then 0.45 micron filters may be used for evaluating the dissolved phase concentrations at that site. 4. In support of the objectives of General Comment #2 of the November 4, 2014 GAP comments issued by DWR, Duke Energy should add a column titled 'relative redox'to the analytical results tables to record the geochemical conditions for that location/sample date. The redox determination should be based on observed DO, ORP, and any other relevant measures and presented for historic and new samples (wells, ash pore water, surface waters, etc.). Relative Attachment 1 Page 5 of 6 redox designations may include "iron reducing", "sulfate reducing", mildly oxidizing, moderately oxidizing, etc. and should be footnoted with a statement about the degree of confidence in the designation based on amount and quality of available data. 5. Duke Energy shall also evaluate: a) spatial geochemical trends across the facility and along selected flow paths, b) temporal geochemical trends where observable (such as for compliance boundary wells), along with the likely reason for the change (e.g. increase in seasonal recharge, pond de -watering and subsequent reversal of groundwater flow direction, inundation of well from river at flood stage, etc.) in support of the CAP. This evaluation step will require a comparison of geochemical conditions overtime with rainfall data, notable ash capping, dewatering, disposal/removal, or other plant operations, etc. The quality of existing geochemical data will be evaluated using field notes, calibration records, and consistency in redox measurements (e.g. eH vs. raw ORP). Groundwater Models 1. The technical direction for developing the fate and transport modeling will follow guidelines found in Groundwater Modeling Policy, NCDENR DWO, May 31, 2007, and discussions conducted between Duke Energy and their consultants with the Division. Ultimate direction for completion of fate and transport models will be provided by the Division. The CAP Report should include a subsection within Groundwater Modeling Results titled 'Site Conceptual Model' that succinctly summarizes, for purposes of model construction, the understanding of the physical and chemical setting of the site and shall include, at a minimum: a) the site setting (hydrogeology, dominant flow zones, heterogeneities, areas of pronounced vertical head gradients, areas of recharge and discharge, spatial distribution of geochemical conditions across the site, and other factors as appropriate), b) source areas and estimated mass loading history, c) receptors, d) chemical behavior of COPCs, and f) likely retention mechanisms for COPCs and how the mechanisms are expected to respond to changes in geochemical conditions. 3. Modeling will be included in the Corrective Action Plan (CAP). The four -tiered analysis previously referenced and appropriate modeling should be conducted, and the mass flux calculations described in the EPA/600/R-07/139 should be performed. 4. The CAP Report shall provide separate subsections for reporting groundwater flow models and fate and transport models. 5. The CAP Report should include subsections within Groundwater Modeling Results titled 'Groundwater Model Development' that describes, for each chosen model: a) purpose of model, built-in assumptions, model extent, grid, layers, boundary conditions, initial conditions, and others as listed in Division guidance. Include in this section a discussion of heterogeneities and how the model(s) account for this (e.g. dual porosity modeling, equivalent porous media approach, etc.). Separate subsections should be developed for the groundwater flow model, fate and transport model, and batch geochemical models, respectively. 6. CAP Reports should include a subsection within Groundwater Modeling Results titled 'Groundwater Model Calibration' that describes, for each model used, the process used to Attachment 1 Page 6 of 6 calibrate the model, the zones of input and calibration variables (for example, hydraulic conductivities) that were used, the actual (measured) versus modeled results for all key variables, and others. Separate subsections should be developed for the groundwater flow model, fate and transport model, and batch geochemical model(s), respectively. CAP Reports should include a subsection within Groundwater Modeling Results titled 'Groundwater Model Sensitivity Analysis' that describes, for each model used, the process used to evaluate model uncertainty, variable ranges tested, and the key sensitivities. Separate subsections should be developed for the groundwater flow model, fate and transport model, and batch geochemical model(s), respectively. Development of Kd Terms 1. Kd testing and modeling in support of CAP development should include all COPCs found above the NCAC 15A 02L .0106(g) standards in ash leachate, ash pore water, or compliance boundary well groundwater samples. 2. The selected Kd used in transport modeling often will profoundly affect the results. Duke Energy should acknowledge this concept and document within the transport modeling section(s) of the CAP all widely recognized limitations inherent in the estimation of the Kd term. Risk Assessment Provide references for guidance and potential sampling methodology related to conducting a baseline ecological risk assessment or habitat assessment, if warranted. CSA GUIDELINE ADJUSTMENTS DWR Review June 2015 Tracked Changes Version, May 14, 2015 Reviewers & Users: See Document End Note Note to NCDENR Reviewers: Proposed CSA Guideline Adjustments are indicated as follows: • Proposed deletions are shown as crimson colored strike through text • Proposed additions are shown as blue -colored text. NCDENR Division of Water Resources Position: Clarification of certain items in the Comprehensive Site Assessment (CSA) Guidelines submitted on August 13, 2014 is provided by the Division of Water Resources (Division) in order to facilitate completion of the groundwater assessments at the Duke Energy Coal Ash Impoundments. The Division does not intend to change the CSA Guidelines, which were provided to Duke Energy to ensure compliance with NCAC 2L standards and technical direction presented in the Coal Act Management Act Senate Bill 729 (CAMA). If a change to the CSA Guidelines proposed by Duke Energy leads to more clarity, the Division will consider the merit of the proposed changes on a site -by -site basis while reviewing the CSA report document. If the Division determines the data and related reporting are inadequate, then additional information may be requested to complete the site assessments. This document provides guidelines for those involved in the investigation of contaminated soil and/or groundwater, where the source of contamination is from: • Incidents caused by activities subject to permitting under G.S. 143-215.1. • Incidents caused by activities subject to permitting under G.S. 87-88. • Incidents arising from agricultural operations, including application of agricultural chemicals, but not including unlawful discharges, spills or disposal of such chemicals. COMPREHENSIVE SITE ASSESSMENT (CSA) NOTE: Regional Offices may request additional information in support of the CSA to aid in their review and will not approve the CSA if any of the elements specified below have not been included or have not been sufficiently addressed. Minimum Elements of the Comprehensive Site Assessment Report: A. Title Page • Site name, location and Groundwater Incident number (if assigned) and Permit Number; • Date of report; • Responsible Party and/or permittee, including address and phone number; • Current property owner including address and phone number; • Consultant/contractor information including address and phone number; • Latitude and longitude of the facility; and • Seal and signature of certifying P.E. or P.G., as appropriate. Page 1 of 15 CSA GUIDELINE ADJUSTMENTS DWR Review June 2015 Tracked Changes Version, May 14, 2015 Reviewers & Users: See Document End Note B. Executive Summary The Executive Summary should provide a brief overview of the pertinent site information (i.e., provide sufficient information to acquaint the reader with the who, what, when, where, why and how for site activities to date). 1. Source Information: • Type of contaminants 2. Initial abatement/emergency response information. 3. Receptor Information: • Water supply wells; • Public water supplies (wells, surface water intakes); • Surface water bodies; • Wellhead protection areas; • Deep aquifers in the Coastal Plain physiographic region; • Subsurface structures; and • Land use. 4. Sampling/Investigation Results: • Nature and extent of contamination; • Maximum contaminant concentrations; • Site Hydrogeology. S. Conclusions and Recommendations. C. Table of Contents • First page number for each section listed. • List of figures (all referenced by number and placed in a single section following contents text). • List of tables (all referenced by number and placed in a single section following contents text). • List of appendices. D. Site History and Source Characterization • Provide a history of property ownership and use. Indicate dates of ownership, uses of the site, and potential sources of contaminants. • Discuss the source(s) of contamination, including primary and secondary sources. • For permitted activities, describe nature of activity, permitted waste, application of all instances of over-application/irrigation of wastes or water • Summarize assessment activities and corrective actions performed to date including emergency response, initial abatement, primary and secondary source removal. Page 2 of 15 CSA GUIDELINE ADJUSTMENTS DWR Review June 2015 Tracked Changes Version, May 14, 2015 Reviewers & Users: See Document End Note Discuss geographical setting and present/future surrounding land uses. E. Receptor Information Note to NCDENR Reviewers: With respect, the language as -is versus as -proposed of Section E did not lend itself well to "internal" editing. Respectfully again, please receive/review as presented, with the languages at least in close proximity, to hopefully help facilitate your review. L. Armstrong FoF each well, include well nun4beF, weil owner and useF narnes, addFesses and telephone nuniber-s, use of the well, well depth, well casing depth, weil scFeen interval, sta P Ee-fyA-PA seurrEeavf eeirtamination; AO Page 3 of 15 CSA GUIDELINE ADJUSTMENTS DWR Review June 2015 Tracked Changes Version, May 14, 2015 Reviewers & Users: See Document End Note activities,• Di-se-u-s-s the u-se-S -and -activities (involving possible human expesuFe to C-AptAmipAtien) that eauld- eeeur _At the Site and- adjaeent pFeper-ties. Examples of h activities and uses include but aFe not limited to use of a pFeper-ty for an office, ve-Atien-al _Ae.ivities, or- undeveloped land; the stFata between the sur-ficial aquifeF and the deeper- aquifeF, and the diffeFenee gFE)undwater head thP_ SUFficial aquifer -And the deepeF aquifer. -Pi-seuss, t influenees. Also, specify the distance from the sour-ee of contamination to major - discharge areas sueh as stFeams and FiveFs. Cite all souFees and Fefer-ences used foT- t h i S, ,l; d�ffiFenee, etc-. is also important inoFmGtien Gt mountains 6ind piedment sites. • Consistent with the DWR's August 13, 2014 Notice of Regulatory Requirement: The CSA Report will include information obtained from the Drinking Water Well and Receptor Survey Report submitted September 2014, the Supplement to Drinking Water Supply Well and Receptor Survey Report submitted November 2014, and updated information obtained between these noted reports and submittal of the CSA Report. The receptor survey is required by 15A NCAC 02L .0106(g) and shall include identification of all receptors within a radius of 2,640 feet (one-half mile) from the established compliance boundary identified in the respective National Pollutant Discharge Elimination System (NPDES) permits. Receptors shall include, but shall not be limited to, public and private water supply wells (including irrigation wells and unused or abandoned wells) and surface water features within one-half mile of the facility compliance boundary. The results of the receptor survey shall be presented on a sufficiently scaled map. The map shall show the coal ash facility location, the facility property boundary, the waste and compliance boundaries, and all monitoring wells listed in the respective NPDES permits. Any identified water supply wells shall be located on the map and shall have the well owner's name and location address listed on a separate table that can be matched to its location on the map. • Consistent with Senate Bill 729: Page 4 of 15 CSA GUIDELINE ADJUSTMENTS DWR Review June 2015 Tracked Changes Version, May 14, 2015 Reviewers & Users: See Document End Note • The CSA Report will identify all drinking water supply wells within one-half mile down -gradient from the established compliance boundary of the impoundment and submit the Survey to the Department. Information including well locations, the nature of water uses, available well construction details, and information regarding ownership of the wells will be provided for the above noted wells. • The CSA Report will include the Duke Energy Laboratory analytical results from the drinking water supply wells required to be sampled by the Department. NCDENR Division of Water Resources Position: The Division does not intend to change the CSA Guidelines. Specific information is expected in order to evaluate site conditions at and in the vicinity of the coal ash ponds that are germane to significant exposure pathways and potential receptors. Several of sub -elements proposed for deletion in Section E are related to identification and characterization of potential environmental receptors (human and ecological) and determination of the limits of the study area or system boundaries, which are key elements of a conceptual model as stated in standard industry practice reference ASTM E1689 Guide for Developing Conceptual Site Models for Contaminated Sites. The Division will evaluate the content of Section E Receptor Information along with components of the refined conceptual site models presented in the CSA reports with respect to receptor and exposure pathway information to determine if the data are adequate to meet CAMA requirements for groundwater assessment and corrective action. If the Division considers the data provided in the CSA reports are inadequate, additional data may be requested. Data presentation -does not have to follow a prescriptive format; however, documentation of relevant water supply well receptor information is expected by the Division to support evaluation of potential risk to receptors and conceptual site models. Data requirements related to Section E Receptor Information that should be considered include: The Division acknowledges the difficulty with determining the known extent of contamination at this time since potential plume assessments are not complete. With this in mind, the Division expects all drinking water wells located 2,640-feet downgradient from the established compliance boundary be documented in the CSA reports as specified in the CAMA requirements. The Division may request additional data after review of well receptor and water quality data in a CSA report. In general, subsurface utilities are expected to be mapped within 1500-ft of the known extent of contamination in order to evaluate the potential for preferential pathways. An explanation must be provided in the CSA report if the subsurface utility mapping requirements are modified. Details concerning site conditions such the possibility of a shallow, perched, or fluctuating water table resulting from site operations intercepting subsurface utilities must be documented. If the utility mapping requirements are modified, Duke Energy must be able to document that the subsurface utilities are not potential preferential pathways for contaminant migration in the CSA reports. Page 5 of 15 CSA GUIDELINE ADJUSTMENTS DWR Review June 2015 Tracked Changes Version, May 14, 2015 Reviewers & Users: See Document End Note • A determination of whether the contaminated area is located in an area where there is recharge to an unconfined or semi -confined deeper aquifer that is being used or may be used as a source of drinking water is expected by the Division. The groundwater assessment findings may indicate a continuous confining unit cannot be delineated beneath across the Coastal Plain sites; therefore, potential impacts to deeper aquifers should be evaluated. • The Division maintains that all surface water bodies (e.g., ditch, pond, stream, lake, river) within a minimum of 1,500 feet of the source of contamination be identified as these features relate to identification of potential receptors and exposure points, both key elements of a conceptual site model. F. Regional Geology and Hydrogeology • Provide a brief description of the regional geology and hydrogeology. Cite all references. G. Site Geology and Hydrogeology • Describe the soil and geology encountered at the site. Use the information obtained during assessment activities (e.g., lithological descriptions made during drilling, probe surveys, etc.). This information should correspond to the geologic cross sections required in N. below; and • Based on the results of the groundwater investigation, describe the site hydrogeology, including a discussion of groundwater flow direction, hydraulic gradient, hydraulic conductivity and groundwater velocity. Discuss the effects of the geologic and hydrogeological characteristics on the migration, retardation, and attenuation of contaminants. H. Soil Sampling Results • Using figures and tables to the extent possible, describe all soil sampling performed to date and provide the rationale for sample locations, number of samples collected, etc. Include the following information: • Location of soil samples; • Date of sampling; • Type of soil samples (from excavation, borehole, Geoprobe, etc.); • Soil sample collection procedures (split spoon, grab, hand auger, etc.) • Depth of soil samples below land surface; • Soil sample identification • Soil sample analyses; • Soil sample analytical results (list any contaminant detected above the method detection limit); and, • Identify any sample analytieal Fesults that exceed the applicable eleanup levels. Page 6 of 15 CSA GUIDELINE ADJUSTMENTS DWR Review June 2015 Tracked Changes Version, May 14, 2015 Reviewers & Users: See Document End Note • Identify any soil sample analytical results that exceed the EPA Region 9 Regional Screening Levels. NOTE. Information related to H. above should correspond to the sampling location and sampling results maps required in N. below. NCDENR Division of Water Resources Position: The Division does not agree with the proposal to identify soil analytical results that exceed EPA Region 9 soil screening levels. Instead, the Division is in the process of finalizing clean closure guidelines for cleanup that will meet protection of groundwater criteria for 2L standards, which will include soil screening levels. Details related to the partial draft guidelines are provided below: Clean Closure Guidelines The Division's goal is that facilities remediate all discharges or releases of constituents to unrestricted use levels. • For groundwater, the unrestricted use level is the North Carolina Division of Water Quality, 2L groundwater standard (2L) or site -specific background concentration. • For soil, the unrestricted use level is either the site -specific background concentration or the lowest of a soil screening level (SSL) protective of groundwater. Determining Soil Screening Levels for Clean Closure Soil Remediation Goals The methodology the Division recommends for calculating unrestricted use levels or soil screening levels (SSLs) for contaminant migration to groundwater was developed in the Preliminary Soil Remediation Goals (PSRG) document (identified below)to identify chemical concentrations in soil with the potential to migrate and contaminate groundwater. • SSLs protective of groundwater are calculated with a soil leachate model using default values from 15A NCAC 21, groundwater standard or the 2L groundwater interim maximum allowable concentration as target groundwater concentrations and take into consideration fate and transport parameters. • The Preliminary Soil Remediation Goals (PSRG) table contains a column with soil remediation goals titled (Protection of Groundwater PSRG) that should be used in evaluating soil -to -groundwater values that meet and are protective of the 15A NCAC 2L groundwater quality standards. A link to the IHSB PSRG table can be found here: http://portal.ncdenr.org/c/document librarylget file?uuid=Of601ffa-574d-4479-bbb4- 253af0665bf5&groupId=38361. Please note that the Division of Waste Management updates this table during the first and third quarter of each calendar year. • A transport model is included in the PSRG table for calculating other soil values not specifically listed in the table in order to meet Protection of Groundwater Criteria. Rule 15A NCAC 2L .0202 (c) does specify substances that are not permitted in groundwater and indicates that even those which are not specifically listed in the rule are not allowed above the practical quantitation limit (PQL), unless they are naturally occurring. The approved laboratory method PQL for the substance can be used in the equation if there is no specifically listed 15A NCAC 21, standard. Page 7 of 15 CSA GUIDELINE ADJUSTMENTS DWR Review June 2015 Tracked Changes Version, May 14, 2015 Reviewers & Users: See Document End Note • Background concentrations of naturally occurring metals in soil at a site can be established using EPA guidance for comparing background and chemical concentrations in soil for CERCLA sites: httl2://www.epa.gov/oswer/riskassessment/12df/background.pdf I. Groundwater Sampling Results Using figures and tables to the extent possible describe the groundwater sampling performed to date and provide the rationale for sample locations (based on source and contaminant type), number of samples collected, etc. Include the following information: • Location of groundwater samples and monitoring wells; • Date of sampling; • Groundwater sample collection procedures (bailer, pump, etc.); • Groundwater sample identification and whether samples were collected during initial abatement, CSA, etc.; • Groundwater sample analyses; • Groundwater sample analytical results (list any contaminant detected above the method detection limit; and, • Identify all sample analytical results that exceed 15A NCAC 2L or interim standards. NOTE. Information related to L above should correspond to the sampling location and sampling results maps required in N. below. J. Hydrogeological Investigation Describe the hydrogeological investigation performed including all methods, procedures and calculations used to characterize site hydrogeological conditions. The following information should be discussed and should correspond to the maps and figures required below: • Groundwater flow direction; • Hydraulic gradient (horizontal and vertical); • Hydraulic conductivity; • Groundwater velocity; • Contaminant velocity; • Slug test results*; • Aquifer test results*; • Plume's physical and chemical characterization; and • Fracture trace study if groundwater in bedrock is impacted*. NOTE. Check with the Regional Office prior to performing these tests and study to see if necessary for the site. Page 8 of 15 CSA GUIDELINE ADJUSTMENTS DWR Review June 2015 Tracked Changes Version, May 14, 2015 Reviewers & Users: See Document End Note NOTE: Contaminant velocity will be addressed in the Groundwater Model Report portion of the Corrective Action Plans. NCDENR Division of Water Resources Position: The Division agrees with the proposed change in content. Discussion of contaminant velocity is appropriate for inclusion in the Groundwater Modeling Report portion of the Corrective Action Plans rather than the CSAs. This is consistent with direction provided in the NCDENR Groundwater Assessment Plan (GAP) Conditional Letters of Approval. K. Groundwater Modeling Results Groundwater modeling or predictive calculations may be necessary at some sites (source area proximate to surface water, source area located within wellhead protection area or source area overlying semi -confined or unconfined deeper Coastal Plain aquifer) to verify, based on site specific hydrogeological conditions, whether groundwater contamination poses a risk to receptors. For contamination shown to pose a risk to receptors, groundwater modeling may be necessary to determine an appropriate cleanup level for contaminated groundwater. Modeling should illustrate the input data used to complete the model and will generally be required for natural attenuation proposals (see Groundwater Modeling Policy at http://portal.ncdenr.org/web/wo/apskiwpro/oolicv). NOTE: Input data for models should be derived from site specific information with limited assumptions or estimates. All assumptions and estimated values including biodegradation rates must be conservative (predict reasonable worst -case scenarios) and must be well documented. NOTE: Groundwater Modeling Results will be included in the Corrective Action Plans per NCDENR DWR Conditional Approval of Revised Groundwater Assessment Work Plan letters. NCDENR Division of Water Resources Position: The Division agrees with the proposed change in content. Direction has been given by the Division to include groundwater modeling results in the Corrective Action Plans per NCDENR Conditional Approval of Revised GAP letters. Some discussion related to how site assessment data and the resulting refined site conceptual model will be incorporated into the groundwater models is appropriate and should be presented in the CSAs. L. Discussion • Nature and extent of contamination, including primary and secondary source areas, and impacted groundwater and surface water resources; • Maximum contaminant concentrations; and, • Contaminant migration and potentially affected receptors. M. Conclusions and Recommendations If corrective action will be necessary, provide a preliminary evaluation of remediation alternatives appropriate for the site. Discuss the remediation alternatives likely to be selected. Note that for Page 9 of 15 CSA GUIDELINE ADJUSTMENTS DWR Review June 2015 Tracked Changes Version, May 14, 2015 Reviewers & Users: See Document End Note impacts to groundwater associated with permitted activities, corrective action pursuant to 15A NCAC 2L .0106(k), (I) and (m) is not applicable, unless provided for pursuant to 15A NCAC 2L .0106(c) and (e) or through a variance from the Environmental Management Commission (EMC). N. Figures Note to NCDENR Reviewers: With respect, the language as -is versus as -proposed of Section N did not lend itself well to "internal" editing. However, we have attempted to place language relative to certain figures (i.e., the USGS Map and the Site Maps) at least in close proximity, to hopefully help facilitate your review. Respectfully again, we request your receipt/review as presented. • The CSA Report Figures will include a 71/2 minute USGS topographic quadrangle map showing an area within a minimum of 2,640 feet (one-half mile) from the established compliance boundary identified in the respective National Pollutant Discharge Elimination System (NPDES) permits. This map will include depiction of the following, as applicable: • the fossil station property boundary; • ash basin compliance boundaries; • 2,640 feet (one-half mile) offset of the ash basin compliance boundaries; • water supply wells identified in the Drinking Water Well and Receptor Survey Report submitted September 2014, the Supplement to Drinking Water Supply Well and Receptor Survey Report submitted November 2014, and updated information obtained between these noted reports and submittal of the CSA Report; • public water supplies; • surface water intakes; • surface water bodies; • designated well head protection areas; and, • areas of recharge to deeper aquifers in the Coastal Plain that are or may be used as a source for drinking water. within a minimum of 1,900 feet, named Feads/easements/Fight of ways, subsuFfa utilities, pFeduet E)F chem-Jeal ster-age aFeas, basements -and adjacent • Site map leeating seuFee areas, site boundaries, buildings, all water- supply wells leeations and analytical results for- sail samples. identify the depth to thp watiav table. PFevide a site plan showing the locations of the eFess inteFseeting at OF near- Fight angles thFough the eopt-arnin-ated- -area usin Page 10 of 15 CSA GUIDELINE ADJUSTMENTS DWR Review June 2015 Tracked Changes Version, May 14, 2015 Reviewers & Users: See Document End Note ------- — ------- . . . . ... ..... .. ... The CSA Report Figures (plan views), as applicable, will be based on like or similar base maps developed from 2014 aerial photography, with associated photogrammetric topography. Considered collectively, the CSA Report Figures will include the following information: • ash basins and associated compliance boundaries; • fossil station property boundaries within the limits of the particular map, • buildings within the limits of the particular map; • named roads within the limits of the particular map; • subsurface utilities having a significant impact on groundwater flow and/or transport from the ash basin; • product or chemical storage areas associated with ash basin operations; and, • scale and north arrow. NOTE: The CSA Report will include adjacent property information obtained from the Drinking Water Well and Receptor Survey Report submitted September 2014, the Supplement to Drinking Water Supply Well and Receptor Survey Report submitted November 2014, and updated information obtained between these noted reports and submittal of the CSA Report. • soil sample locations and analytical results (subjectively as supportive of conveying findings while affording depiction clarity); Page 11 of 15 CSA GUIDELINE ADJUSTMENTS DWR Review June 2015 Tracked Changes Version, May 14, 2015 Reviewers & Users: See Document End Note • groundwater sample locations and analytical results (subjectively as supportive of conveying findings while affording depiction clarity); • separate groundwater contaminant iso -concentration contour maps for constituents exceeding 2L standards with contour line for applicable 2L standard shown bold (or otherwise demarcated); • separate groundwater elevation contour maps for each holistic series of water level measurements obtained with: • elevation of groundwater in the monitoring wells; • direction of groundwater flow indicated; • identification of the elevation datum; and, • date(s) that the water level measurements were made. • the monitoring wells. • The CSA Report Figures will include at least two geologic cross sections through the saturated and unsaturated zones intersecting at or near right angles through the ash basin(s) as proposed in the approved Proposed Groundwater Assessment Work Plan. The cross -sections will comprise: • a reasonable vertical exaggeration; • boring, monitoring well, soil sample, and/or groundwater sample locations and analytical results (sample locations and analytical results subjectively as supportive of conveying findings while affording depiction clarity); • groundwater contaminant iso-concentrationcontours for constituents exceeding 2L standards; • depiction of the water table; and, • a site map showing the locations of the cross sections. NCDENR Division of Water Resources Position: The Division does not intend to change the CSA Guidelines. Proposed changes in data presentation in Section N will be considered during the Division's review of the CSA reports. If the Division's review of a CSA report indicates data presentation related to the figures provided in Section N is inadequate, then additional data and/or data presentation may be requested. Technical direction related to data presentation in Section N that should be considered includes : • The direction for data presentation in site assessment deliverables outlined in Comment 23 from the November 2014 Review of Groundwater Assessment Work Plan letters sent to Duke Energy. Strike out the caveats that read "(subjectively as supportive of conveying findings while affording depiction clarity)" from proposed text revisions. Direction provided in Sections H. Soil Sampling Results and I. Groundwater Sampling Results, respectively, gives specific instruction related to presentation of both soil and groundwater analytical results detected above PQLs along with those results above numeric regulatory limits. This approach is suggested in order to allow the Page 12 of 15 CSA GUIDELINE ADJUSTMENTS DWR Review June 2015 Tracked Changes Version, May 14, 2015 Reviewers & Users: See Document End Note Division Regional offices to have sufficient information in a format that promotes an effective review of the CSA documents. In addition, the Division Regional Offices may request additional information in support of the CSA to aid in their review. • Map groundwater analytical results related to detection monitoring constituents and inorganic parameters as identified in the USEPA April 2015 Final Ruling 40 CFR Parts 257 and 261, including boron, calcium, chloride, conductivity, pH, sulfate, and total dissolved solids. Map groundwater analytical results related to assessment monitoring constituents as identified in the USEPA April 2015 Final Ruling 40 CFR Parts 257 and 261, including aluminum, antimony, arsenic, barium, beryllium, cadmium, chromium, copper, iron, lead, manganese, mercury, molybdenum, selenium, sulfate, sulfide, and thallium. In addition, map the distribution of vanadium as an assessment monitoring constituent. O. Tables • List all water supply wells, public or private, including irrigation wells and unused wells, (omit those that have been properly abandoned in accordance with 15A NCAC 2C .0100) within a minimum of 1500 feet of the known extent of contamination For- depth,each Nye!!, inelude the %reall nu-m-h-ear- (may use the tax map numbeF), Nye!] Awnevand user- names, add-resses and telephone numbeFs, use of the well, Nvell contamination;casing depth, Nvell screen interval and distance 49M the SOUFGe of List the na nn es a nd ad-d-resses of pro moo,-ty ewneFs and e ntsyAt-h;n . ce tiguous to the area containing C0Ht_ArAin_At_jA_14 -and all pFoper-ty owners occupants within OF COntigUOUS tO the area Nvher-e the contamination is expected t& migr-ate; 2,640 feet (one-half mile) from the established ash basin compliance boundaries. For each well, include that information obtained during and since the formerly noted Receptor Surveys. • List the results for groundwater samples collected including sample location; date of sampling; sample collection procedures (briefly/concisely as "bailer", "pump", etc.); sample identifications; sample analyses; and sample analytical results (4s-t demarcate (bold or otherwise) any contaminant detected above the method detection limit in bold); and, • List for each monitoring well, the monitoring well identification number, date water levels were obtained, elevations of the water levels, the land surface, top of the well casing, screened interval and bottom of the well. Page 13 of 15 CSA GUIDELINE ADJUSTMENTS DWR Review June 2015 Tracked Changes Version, May 14, 2015 Reviewers & Users: See Document End Note NCDENR Division of Water Resources Position: The Division does not intend to change the CSA Guidelines. Proposed changes in tables in Section 0 will be considered during the Division's review of the CSA reports. If the Division's review of a CSA report indicates tables provided in Section 0 is inadequate, then revised tables may be requested. Documentation of specific water supply well receptor information is expected to be presented in a certain format to facilitate review and as indicated below: Direction outlined in Comments 22 and 23, respectively, from the November 2014 Review of Groundwater Assessment Work Plan letters sent to Duke Energy for data presentation in site assessment deliverables will be followed. Highlight groundwater analytical results that exceed numeric regulatory values in some manner that distinguishes those results from those below the limits. Note the numeric regulatory value for a constituent in the table. P. Appendices • Boring logs and lithological descriptions; • Well construction records; • Standard procedures used at site for sampling, field equipment decontamination, field screening, etc.; • Laboratory reports and chain -of -custody documents; • Copies of any permits or certificates obtained, permit number, permitting agency, and • Modeling data and results-, • Slug/pumping test data; and Certification fOr-M f9F GSA. • The CSA Reports will be sealed and signed by a groundwater -experienced Professional Engineer or Professional Geologist registered in North Carolina. NOTE. Modeling data and results will be included in the Corrective Action Plans per NCDENR DWR Conditional Approval of Revised Groundwater Assessment Work Plan letters. NCDENR Division of Water Resources Position: The Division accepts the proposed change in Section P to not include groundwater modeling results and related data in the CSA Reports; instead, providing information related to groundwater modeling in the Corrective Action Plans. The Division does require relevant information provided in the Certification Form for the CSA Reports and does not accept the proposed change for the CSA Guidelines. Page 14 of 15 CSA GUIDELINE ADJUSTMENTS DWR Review June 2015 Tracked Changes Version, May 14, 2015 Reviewers & Users: See Document End Note Document End Note: This Microsoft Word file was generated from a PDF version of the August 12, 2014 Guidelines for Comprehensive Site Assessment attached to NCDENR's August 14, 2015 Notice of Regulatory Requirements letter. Generation comprised saving the PDF file as a Microsoft Word file using PDF Converter Assistant within PDF Converter Enterprise 8.2, with post -conversion manual formatting. Any discrepancy/disparity between the original PDF file and this Word file are unintentional. Page 15 of 15 Clarification of Attachment 1 Groundwater Assessment Plan Conditional Letters of Approval Items Related to Speciation - May 22, 2015 e-mail Duke Energy GAP Attachment Clarification Request Background: Division of Water Resources Position "Comment 4 of "Site Assessment: Data Requirements and Sampling Strategy" found in Attachment 1 of the GWAP Since speciation of groundwater and surface water samples is a critical component of both the site assessments and corrective Conditional Approval Letters states the following: action, the Division expects a geochemical site conceptual site model (CSM) developed as a subsection in the Comprehensive "Speciations for groundwater and surface water samples should include Fe, Mn, and any COPCs whose speciation state Site Assessment (CSA) Reports. The geochemical CSM should provide a summary of the geochemical interactions between the may affect toxicity or mobility (e.g. As, Cr, Se, or others if applicable). This speciation will apply for groundwater solution and solid phases along the groundwater flowpath that impact the mobility of metal constituents. At a minimum, the samples collected at wells located along proposed flowpath transects and in wells where these constituents exceed 2L geochemical CSM will describe the adsorption/desorption and mineral precipitation/dissolution processes that are believed to groundwater standards as well as for surface water samples collected within ash impoundments." impact dissolved concentrations along the aquifer flowpaths away from the ash basin sources. The model descriptions should After conversations with risk assessors and other technical leads with our consulting agencies, Duke Energy plans the include the data upon which the conceptual model is based and any calculations (such as mineral saturation indices) that are following as it relates to speciation sampling for the groundwater assessments:" made to develop the site -specific model. Metal speciation analyses cover a broad aspect of metals' geochemistry, including solution complexation with other dissolved species and specific association with aquifer solids, such as a metal adsorbed onto HFO or precipitated as a sulfate mineral. A comprehensive speciation analysis that requires a relatively complete groundwater analysis is expected that includes use of an ion speciation computer code (such as PHREEQC) capable of calculating solution complexes, surface complexation onto HFO, and mineral saturation indices. This type of speciation calculation is necessary for the development of a geochemical SCM and understanding metal mobility in an aquifer. Duke Energy Proposal Division of Water Resources Position For the sampling to be reported in the CSA (Round 1 of Samples) The Division agrees with the overall approach presented for Round 1 of groundwater sampling since it is consistent with the • At wells located along proposed flow -path transects and at surface water sample locations within the ash basins: direction provided in Attachment 1 of the GAP Conditional Approval Letters. However as stated in the GAP Conditional Letters o Collect samples and perform speciation for the following constituents and oxidation states: Fe(II, III), Mn(Il,lll), of Approval, the Division reserves the right to request additional data to complete the CSA if a determination is made that As(III,V), Cr(III,VI), Se (-II,IV,VI). there is insufficient data to evaluate site conditions, including speciation of groundwater samples. • At compliance wells where 2L exceedances have been measured (and are not related to turbidity): Clarification of the Division's expectations with respect to the specific proposed direction for CSA Round 1 groundwater o Perform speciation for the constituent with the measured exceedance if the constituent has a speciation state(s) that sampling is provided below: may affect toxicity or mobility. • Existing background wells that have historically had 2L exceedances of speciation constituents and all newly installed First bullet: Add Mn (IV) to the speciation list for wells along the flow -path transects. background wells o Collect samples and perform speciation for the following constituents and oxidation states: Fe(II, III), Mn(II,III), Second bullet: The Division acknowledges that turbidity is problematic with respect to obtaining representative groundwater As(III,V), Cr(III,VI), Se (-II,IV,VI). samples for analysis at some wells at the coal ash facilities, particularly when the wells are completed in coal ash. However, the Division expects that an intent to comply with the requirements of 15A NCAC 02C .0108 (p) is made: "Each non -water supply well shall be developed such that the level of turbidity or settleable solids does not preclude accurate chemical analyses of any fluid samples collected or adversely affect the operation of any pumps or pumping equipment." The rules do not specify a minimum filter pack or levels of turbidity or settable solids applicable to monitoring wells; however, proper well development must be conducted for each well such that there is no interference with subsequent sample analysis. Any well that does not provide a water quality sample that meets the requirements of the well construction code may need to be replaced. Third bullet: Add Mn (IV) to the speciation list for background wells. Duke Energy Proposal Division of Water Resources Position For the sampling to be reported in the Supplement to the CSA (Round 2 of Samples) The Division agrees with the overall approach presented for Round 2 of groundwater sampling since it is consistent with the • Any well where 2L exceedances were measured in the sampling reported in the CSA: direction provided in Attachment 1 of the GAP Conditional Approval Letters. However as stated in the GAP Conditional Letters o Collect samples and perform speciation for the following constituents and oxidation states: Fe(II, III), Mn(II,III), of Approval, the Division reserves the right to request additional data to complete the CSA if a determination is made that As(III,V), Cr(III,VI), Se (II,IV,VI) or for constituents with the measured exceedances from Round 1 if the constituent has a there is insufficient data to evaluate site conditions, including speciation of groundwater samples. speciation state(s) that may affect toxicity or mobility. Clarification of the Division's expectations with respect to the specific proposed direction for CSA Round 2 groundwater • Existing background wells that have historically had 2L exceedances of speciation constituents and all newly installed sampling is provided below: background wells o Collect samples and perform speciation for constituents with the measured exceedances from Round 1 if the First bullet: Sample wells and surface water locations situated on groundwater flow -paths as well as wells that exhibited constituent has a speciation state(s) that may affect toxicity or mobility. exceedances of 2L reported in the CSA. Add Mn (IV) to the speciation list for wells sampled. In addition, plan to sample a subset of existing compliance and new site assessment wells two (2) additional times during 2015 as part of an anticipated corrective action measure to support EPA tiered site analysis. The timeframe for these suggested additional groundwater sample collection events should be such that the samples collected are not auto -correlated. Second bullet: Add Mn (IV) to the speciation list for background wells. Plan to sample the existing and newly installed background wells two (2) additional times during 2015 as part of an anticipated corrective action measure to support EPA tiered site analysis and statistical analysis. The timeframe for these suggested additional groundwater sample collection events should be such that the samples collected are not auto -correlated. Revised Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin Proposed Groundwater Assessment Work Plan (Rev. 1 ) NPDES Permit NC0004961 December 30, 2014 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin FN Table of Contents Table of Contents Tableof Contents.........................................................................................................................i ExecutiveSummary..............................................................................................................ES-1 1.0 Introduction.......................................................................................................................... 1 2.0 Site Information.................................................................................................................... 4 2.1 Plant Description...................................................................................................... 4 2.2 Ash Basin Description............................................................................................... 4 2.3 Regulatory Requirements......................................................................................... 5 3.0 Receptor Information............................................................................................................ 7 4.0 Regional Geology and Hydrogeology................................................................................... 8 5.0 Initial Conceptual Site Model...............................................................................................10 5.1 Physical Site Characteristics....................................................................................10 5.1.1 ASH BASIN..................................................................................................11 5.1.2 ASH STORAGE AREA.................................................................................12 5.1.3 CINDER STORAGE AREA..........................................................................12 5.2 Source Characteristics.............................................................................................12 5.3 Hydrogeologic Site Characteristics............................................................................14 6.0 Compliance Groundwater Monitoring..................................................................................17 7.0 Assessment Work Plan.......................................................................................................18 7.1 Subsurface Exploration............................................................................................19 7.1.1 Ash and Soil Borings....................................................................................19 7.1.2 Shallow Monitoring Wells and Observation Wells.........................................22 7.1.3 Deep Monitoring Wells.................................................................................24 7.1.4 Bedrock Monitoring Wells.............................................................................24 7.1.5 Well Completion and Development..............................................................25 7.1.7 Compliance and Voluntary Monitoring Wells................................................27 7.1.8 Onsite Water Supply Wells...........................................................................27 7.2 Groundwater Sampling and Analysis.......................................................................27 7.2.1 Compliance and Voluntary Monitoring Wells................................................29 7.2.2 Onsite Water Supply Wells...........................................................................29 7.2.3 Speciation of Select Inorganics....................................................................29 7.3 Surface Water, Sediment, and Seep Sampling........................................................29 7.3.1 Surface Water Samples...............................................................................29 7.3.2 Sediment Samples.......................................................................................30 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin �� Table of Contents 7.3.3 Seep Samples..............................................................................................30 7.4 Field and Sampling Quality Assurance/Quality Control Procedures .........................30 7.4.1 Field Logbooks.............................................................................................31 7.4.2 Field Data Records......................................................................................31 7.4.3 Sample Identification....................................................................................31 7.4.4 Field Equipment Calibration.........................................................................31 7.4.5 Sample Custody Requirements....................................................................32 7.4.6 Quality Assurance and Quality Control Samples..........................................33 7.4.7 Decontamination Procedures.......................................................................34 7.5 Site Hydrogeologic Conceptual Model.....................................................................35 7.6 Site -Specific Background Concentrations................................................................36 7.7 Groundwater Fate and Transport Model..................................................................36 7.7.1 MODFLOW/MT3DMS Model........................................................................36 7.7.2 Development of Kd Terms............................................................................38 7.7.3 MODFLOW/MT3DMS Modeling Process.....................................................39 7.7.4 Hydrostratigraphic Layer Development........................................................41 7.7.5 Domain of Conceptual Groundwater Flow Model.........................................41 7.7.6 Boundary Conditions for Conceptual Groundwater Flow Model....................42 7.7.7 Groundwater Impacts to Surface Water.......................................................42 8.0 Risk Assessment.................................................................................................................44 8.1 Human Health Risk Assessment..............................................................................44 8.1.1 Site -Specific Risk -Based Remediation Standards........................................45 8.2 Ecological Risk Assessment....................................................................................46 9.0 CSA Report.........................................................................................................................49 10.0 Proposed Schedule...........................................................................................................51 11.0 References........................................................................................................................52 Appendix A — Notice of Regulatory Requirements Letter from John E. Skvarla, III, Secretary, State of North Carolina, to Paul Newton, Duke Energy, dated August 13, 2014. Appendix B — Review of Groundwater Assessment Work Plan Letter from S. Jay Zimmerman, Chief, Water Quality Regional Operations Section, NCDENR, To Harry Sideris, Duke Energy, dated November 4, 2014. Appendix C — Site Plan with Cross -sections Riverbend Steam Station Ash Basin Duke Energy Carolinas, LLC Gaston County, NC, Figures 4.1-3, 4.1-4, and 4.1-5, May 31, 2013; Cross -sections A -A', B-B', C-C' Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin Table of Contents List of Figures 1. Site Location Map 2. Site Layout Map 3. Proposed Monitoring Well and Sample Location Map List of Tables 1. Groundwater Monitoring Requirements 2. Exceedances of 2L Standards 3. SPLP Leaching Analytical Results 4. Groundwater Analytical Results 5. Ash Analytical Results 6. Surface Water Analytical Results 7. Seep Analytical Results 8. Environmental Exploration and Sampling Plan 9. Soil and Ash Parameters and Constituent Analytical Methods 10. Groundwater, Surface Water, and Seep Parameters and Constituent Analytical Methods Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin EXECUTIVE SUMMARY Executive Summary Duke Energy Carolinas, LLC (Duke Energy), owns and formerly operated the Riverbend Steam Station (RBSS), located in Gaston County near the town of Mt. Holly, North Carolina (see Figure 1). RBSS began operation in 1929 as a coal-fired generating station. Subsequently, RBSS was decommissioned and taken offline in April 2013. The coal ash residue from RBSS's coal combustion process was historically disposed of in the station's ash basin located adjacent to the station and Mountain Island Lake. The discharge from the ash basin is permitted by the North Carolina Department of Environment and Natural Resources (NCDENR) Division of Water Resources (DWR) under the National Pollutant Discharge Elimination System (NPDES) Permit NC0004961. Duke Energy has performed voluntary groundwater monitoring around the ash basin from December 2008 until June 2010. The voluntary groundwater monitoring wells were sampled two times each year and the analytical results were submitted to DWR. Groundwater monitoring as required by the NPDES permit began in December 2010. The system of compliance groundwater monitoring wells required for the NPDES permit is sampled three times a year and the analytical results are submitted to the DWR. The compliance groundwater monitoring is performed in addition to the normal NPDES monitoring of the discharge flows from the ash basin. It is Duke Energy's intention that the assessment will collect additional data to validate and expand the knowledge of the groundwater system at the ash basin. The proposed assessment plan will provide the basis for a data -driven approach to additional actions related to groundwater conditions if required by the results of the assessment and for closure. On August 13, 2014, NCDENR issued a Notice of Regulatory Requirements (NORR) letter to Duke Energy, pursuant to Title 15A North Carolina Administrative Code Chapter (15A NCAC) 02L.0106 (Appendix A). The NORR stipulates that for each coal -fueled plant owned, Duke Energy will conduct a comprehensive site assessment (CSA) that includes a Groundwater Assessment Work Plan (Work Plan) and a receptor survey. In accordance with the requirements of the NORR, HDR completed a receptor survey to identify all receptors within a 0.5-mile radius (2,640 feet) of the RBSS ash basin compliance boundary. This receptor survey also addressed the requirements of the General Assembly of North Carolina Session 2013 Senate Bill 729 Ratified Bill (SB 729). Similar requirements to perform a groundwater assessment are found in SB 729, which revised North Carolina General Statute 130A- 309.209(a). In accordance with the NORR, Duke Energy submitted a Groundwater Assessment Work Plan (GAWP) to the NCDENR on September 25, 2014. Subsequent to their review, the NCDENR provided comments to the GAWP in a letter dated November 4, 2014 (Appendix B). The letter included general comments that pertained to each of the work plans prepared for Duke Energy's 14 coal ash sites in North Carolina, as well as comments specific to the RBSS work plan and Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin EXECUTIVE SUMMARY site. This Revised GAWP has been prepared to address the general and site -specific comments made by NCDENR in the November 4, 2014, letter. Soil and groundwater sampling will be performed to provide information pertaining to the horizontal and vertical extent of potential soil and groundwater contamination. This will be performed by sampling existing wells, installing and sampling approximately 30 ]nested monitoring well pairs (shallow and deep), 4 wells in the ash basin with the screens located bracketing the porewater surface and at the bottom of the ash, 2 observation wells (no water quality samples collected), 11 bedrock monitoring wells, and collecting soil and ash samples. This work will provide information on the chemical and physical characteristics of site soils and ash, as well as the geological and hydrogeological features of the site that influence groundwater flow and direction and transport of constituents from the ash basin and ash storage area. Samples of ash basin surface water will be collected and used to evaluate potential impacts to groundwater and surface water. Seep samples will be collected from locations identified in April 2014 (as part of Duke Energy's NPDES permit renewal application) to evaluate potential impacts to groundwater and surface water. The information obtained through implementation of this Work Plan will be utilized to prepare a CSA report in accordance with the requirements of the NORR. If it is determined that additional investigations are required during the review of existing data or data developed from this assessment, Duke Energy and HDR will notify the NCDENR regional office prior to initiating additional sampling or investigations. HDR will also perform an assessment of risks to human health and safety and to the environment. This assessment will include the preparation of a conceptual site model illustrating potential pathways from the source to possible receptors. ES-2 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin 1.0 INTRODUCTION 1.0 Introduction Duke Energy Carolinas, LLC (Duke Energy), owns and formerly operated the Riverbend Steam Station (RBSS), located in Gaston County near the town of Mt. Holly, North Carolina (see Figure 1). RBSS began operation in 1929 as a coal-fired generating station. Subsequently, RBSS was decommissioned and taken off line in April 2013. The coal ash residue from RBSS's coal combustion process was historically disposed of in the station's ash basin located adjacent to the station and Mountain Island Lake. The discharge from the ash basin is permitted by the North Carolina Department of Environment and Natural Resources (NCDENR) Division of Water Resources (DWR) under the National Pollutant Discharge Elimination System (NPDES) Permit NC0004961. Duke Energy has performed voluntary groundwater monitoring around the ash basin from December 2008 until June 2010. The voluntary groundwater monitoring wells were sampled two times each year and the analytical results were submitted to DWR. Groundwater monitoring as required by the NPDES permit began in December 2010. The system of compliance groundwater monitoring wells required for the NPDES permit is sampled three times a year and the analytical results are submitted to the DWR. The compliance groundwater monitoring is performed in addition to the normal NPDES monitoring of the discharge flows from the ash basin. It is Duke Energy's intention that the assessment will collect additional data to validate and expand the knowledge of the groundwater system at the ash basin. The proposed assessment plan will provide the basis for a data -driven approach to additional actions related to groundwater conditions if required by the results of the assessment and for closure. On August 13, 2014, NCDENR issued a Notice of Regulatory Requirements (NORR) letter to Duke Energy, pursuant to Title 15A North Carolina Administrative Code (15A NCAC) Chapter 02L.0106. The NORR stipulates that for each coal -fueled plant owned, Duke Energy will conduct a comprehensive site assessment (CSA) that includes a Groundwater Assessment Work Plan (Work Plan) and a receptor survey. In accordance with the requirements of the NORR, HDR has completed a receptor survey to identify all receptors within a 0.5-mile radius (2,640 feet) of the RBSS ash basin compliance boundary. The NORR letter is included as Appendix A. The Coal Ash Management Act 2014 — General Assembly of North Carolina Senate Bill 729 Ratified Bill (Session 2013) (SB 729) revised North Carolina General Statute 130A-309.209(a) to require the following: (a) Groundwater Assessment of Coal Combustion Residuals Surface Impoundments. — The owner of a coal combustion residuals surface impoundment shall conduct groundwater monitoring and assessment as provided in this subsection. The requirements for groundwater monitoring and assessment set out in this subsection are in addition to any other groundwater monitoring and assessment requirements applicable to the Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin FN 1.0 INTRODUCTION owners of coal combustion residuals surface impoundments. (1) No later than December 31, 2014, the owner of a coal combustion residuals surface impoundment shall submit a proposed Groundwater Assessment Plan for the impoundment to the Department for its review and approval. The Groundwater Assessment Plan shall, at a minimum, provide for all of the following: a. A description of all receptors and significant exposure pathways. b. An assessment of the horizontal and vertical extent of soil and groundwater contamination for all contaminants confirmed to be present in groundwater in exceedance of groundwater quality standards. C. A description of all significant factors affecting movement and transport of contaminants. d. A description of the geological and hydrogeological features influencing the chemical and physical character of the contaminants. e. A schedule for continued groundwater monitoring. f. Any other information related to groundwater assessment required by the Department. (2) The Department shall approve the Groundwater Assessment Plan if it determines that the Plan complies with the requirements of this subsection and will be sufficient to protect public health, safety, and welfare; the environment; and natural resources. (3) No later than 10 days from approval of the Groundwater Assessment Plan, the owner shall begin implementation of the Plan. (4) No later than 180 days from approval of the Groundwater Assessment Plan, the owner shall submit a Groundwater Assessment Report to the Department. The Report shall describe all exceedances of groundwater quality standards associated with the impoundment. This work plan addresses the requirements of 130A-309.209(a)(1) (a) through (f) and the requirements of the NORR. On behalf of Duke Energy, HDR submitted to NCDENR a proposed Work Plan for the RBSS site dated September 25, 2014. Subsequently, NCDENR issued a comment letter dated November 4, 2014, containing both general comments applicable to all 14 of Duke Energy ash basin facilities and site -specific comments for the RBSS. In response to these comments, HDR has prepared this revised work plan for performing the groundwater assessment as prescribed in the NORR. If it is determined that additional investigations are required during the review of existing data or data developed from this assessment, Duke Energy and HDR will notify the NCDENR regional office prior to initiating additional sampling or investigations. HDR will also perform an assessment of risks to human health and safety and to the environment. This assessment will include the preparation of a conceptual site model illustrating potential pathways from the source to possible receptors. 2 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin FN 1.0 INTRODUCTION The purpose of the work plan contains a description of the activities proposed to meet the requirements of 15A NCAC 02L .0106(g). This rule requires: (g) The site assessment conducted pursuant to the requirements of Paragraph (c) of this Rule, shall include: (1) The source and cause of contamination; (2) Any imminent hazards to public health and safety and actions taken to mitigate them in accordance with Paragraph (0 of this Rule; (3) All receptors and significant exposure pathways; (4) The horizontal and vertical extent of soil and groundwater contamination and all significant factors affecting contaminant transport; and (5) Geological and hydrogeological features influencing the movement, chemical, and physical character of the contaminants. The work proposed in this plan will provide the information sufficient to satisfy the requirements of the rule. However, uncertainties may still exist due to the following factors: • the natural variations and the complex nature of the geological and hydrogeological characteristics involved with understanding the movement, chemical, and physical character of the contaminants; • the size of the site; and the time frame mandated by the Coal Ash Management Act (CAMA). Site assessments are most effectively performed in a multi -phase approach where data obtained in a particular phase of the investigation can be reviewed and used to refine the subsequent phases of investigation. The mandated 180-day time frame will prevent this approach from being utilized. The 180-day time frame will limit the number of sampling events that can be performed after well installation and prior to report production. Effectively, this time frame will likely reduce the number of sampling events within the proposed wells to a single sampling event. Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan _ Riverbend Steam Station Ash Basin 2.0 SITE INFORMATION 2.0 Site Information 2.1 Plant Description RBSS is a former coal-fired electricity generating facility with a capacity of 454 megawatts located near the town of Mt. Holly in Gaston County, North Carolina. As of April 2013, all of the coal-fired units have been retired. The site is located between the south bank of the Catawba River on Mountain Island Lake and the north side of Horseshoe Bend Beach Road. The surrounding area generally consists of residential properties, undeveloped land, and Mountain Island Lake. Horseshoe Bend Beach Road runs from west to east in the vicinity of the site and is located along a topographic divide. The topography at the site slopes downward from that divide toward Mountain Island Lake. The seven -unit station began commercial operation in 1929 with two units and then expanded to seven by 1954. During its final years of operation, RBSS was considered a cycling station and was brought online to supplement energy supply when electricity demand was at its highest. The entire RBSS site is approximately 340.7 acres in area. In addition to the power plant property, Duke Energy operates Mountain Island Lake as part of the Catawba-Wateree Hydroelectric Project (FERC Project No. 2232). Mountain Island Lake is part of the Catawba- Wateree project and is used for hydroelectric generation, municipal water supply, and recreation. Duke Energy has performed a review of property ownership of the FERC project boundary property within the ash basin compliance boundary (described in Section 2.3). The review indicated that Duke Energy owns the lake bottom of Mountain Island within the FERC project boundary and within the compliance boundary, as shown on Figure 2. 2.2 Ash Basin Description The ash basin system at the plant was used to retain and settle ash generated from coal combustion at RBSS. The ash basin system consists of a Primary and a Secondary Cell, separated by an intermediate dike. The ash basin at RBSS originally consisted of a single -cell basin commissioned in 1957 and was expanded in 1979. The single basin was divided by constructing a divider dike to form two separate cells in 1986. The ash basin is located approximately 2,400 feet to the northeast of the power plant, adjacent to Mountain Island Lake, as shown on Figure 2. The Primary Cell is impounded by an earthen embankment dike, referred to as Dam #1 (Primary), located on the west side of the Primary Cell. The Secondary Cell is impounded by an earthen embankment dike, referred to as Dam #2 (Secondary), located along the northeast side of the Secondary Cell. The toe areas for both dikes are in close proximity to Mountain Island Lake. The surface area of the Primary Cell is approximately 41 acres with an approximate maximum pond elevation of 724 feet. The Primary Cell contains approximately 1,924,679 cubic yards of coal combustion product (CCP) material. The surface area of the Secondary Cell is approximately 28 acres with an approximate maximum pond elevation of 714 feet. The Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin 2.0 SITE INFORMATION Secondary Cell contains approximately 677,600 cubic yards of CCP material. The full pond elevation of Mountain Island Lake is approximately 646.8 feet. During operation of the coal-fired units, the ash basin system was operated as an integral part of the site's wastewater treatment system which predominantly received inflows from the ash removal system, station yard drain sump, and stormwater flows. During station operations, inflows to the ash basin were highly variable due to the cyclical nature of station operations. The inflows from the ash removal system and the station yard drain sump are discharged through sluice lines into the Primary Cell. The discharge from the Primary Cell to the Secondary Cell is through a concrete discharge tower located near the divider dike. Although the station is retired, wastewater effluent from other non -ash -related station discharges to the ash basin is discharged from the Secondary Cell, through a concrete discharge tower, to Mountain Island Lake. The concrete discharge tower drains through a 30- inch-diameter corrugated metal pipe into a concrete -lined channel that discharges to Mountain Island Lake. The ash basin pond elevation is controlled by the use of concrete stop logs. 2.3 Regulatory Requirements The NPDES program regulates wastewater discharges to surface waters to ensure that surface water quality standards are maintained. The RBSS site is permitted to discharge wastewater under NPDES Permit NC0004961, which authorizes discharge from the ash basin to the Catawba River (Mountain Island Lake) in accordance with effluent limitations, monitoring requirements, and other conditions set forth in the permit. The NPDES permitting program requires that permits be renewed every five years. The most recent NPDES permit renewal for the RBSS site became effective on March 1, 2011, and expires February 28, 2015. In addition to surface water monitoring, the NPDES permit requires groundwater monitoring. Groundwater monitoring has been performed in accordance with the permit conditions beginning in December 2010. The existing compliance groundwater monitoring system for the ash basin consists of the following monitoring wells: MW-7SR, MW-7D, MW-8S, MW-81, MW- 8D, MW-9, MW-10, MW-11 SR, MW-11 DR, MW-13, MW-14, and MW-15. All the compliance wells were installed in 2010. NPDES Permit Condition A (11), Version 1.1, dated June 15, 2011, lists the parameters and constituents measured and analyzed, and the requirements for sampling frequency and reporting results (Table 1). The compliance boundary for groundwater quality at the RBSS ash basin site is defined in accordance with Title 15A NCAC 02L .0107(a) as being established at either 500 feet from the waste boundary or at the property boundary, whichever is closer to the waste. The location of the ash basin compliance monitoring wells, the ash basin waste boundary, and the compliance boundary are shown on Figures 2 and 3. Note that monitoring wells MW-1 S, MW-1 D, MW-2S, MW-2D, MW-3S, MW-3D, MW-4S, MW-4D, MW-5S, MW-5D, MW-6S, and MW-6D were installed by Duke Energy in 2006 as part of a voluntary monitoring system. Samples are Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin 2.0 SITE INFORMATION currently being collected from monitoring wells MW-4S, MW-4D, MW-5S, and MW-5D as part of groundwater assessment efforts. No samples are currently being collected from the other voluntary wells. The locations for the compliance groundwater monitoring wells were approved by the NCDENR DWR Aquifer Protection Section (APS). All of these existing compliance monitoring wells are sampled three times per year (in February, June, and October). Analytical results are submitted to the DWR before the last day of the month following the date of sampling for all compliance monitoring wells except MW-9, MW-10, and MW-13. One or more groundwater quality standards (21L Standards) have been exceeded in groundwater samples collected at monitoring wells MW-7SR, MW-7D, MW-8S, MW-81, MW-8D, MW-9, MW-10, MW-11 SR, MW-11 DR, MW-13, MW-14, and MW-15. Exceedances have occurred for pH, iron, and manganese. MW-7D also has had an exceedance of the interim maximum allowable concentration (IMAC) groundwater quality standard for antimony. Table 2 presents exceedances measured from March 2011 through July 2014 Monitoring wells MW-9, MW-10, and MW-13 are located inside of the compliance boundary as it was not possible to access the compliance boundary at these three locations. Therefore, these monitoring wells are installed inside of the 500-foot compliance boundary. These monitoring wells are also sampled three times per year, and compliance with 2L Standards is determined by using predictive calculations or a groundwater model to demonstrate compliance. For these three monitoring wells, the NPDES permit allows prediction of the concentrations at the compliance boundary to be performed by use of a groundwater model. Monitoring wells MW-7SR and MW-7D are located to the southeast of the Primary Cell and are considered to represent back groundwater quality. Monitoring wells MW-8S, MW-81, and MW- 8D are located to the south of an ash storage area and to the north of Horseshoe Bend Beach Road. Monitoring well MW-9 is located to the north of a cinder storage area. MW-10 is located downgradient of the Primary Cell. Monitoring wells MW-11 SR and MW-11 DR are located northwest of the dike dividing the Primary Cell and the Secondary Cell. Monitoring wells MW- 13, MW-14, and MW-15 are located downgradient of the Secondary Cell. With the exception of monitoring wells MW-9, MW-10, and MW-13, the ash basin compliance monitoring wells were installed at or near the compliance boundary. Monitoring wells MW-7SR, MW-8S, MW-9, MW-10, MW-11 SR, MW-13, MW-14, and MW-15 were installed by rotary drilling methods using hollow stem augers, with the well screen installed above auger refusal to monitor the shallow aquifer within the saprolite layer. The screen lengths for these wells range from 15 feet to 20 feet. Monitoring well MW-81 was also installed by rotary drilling methods using hollow stem augers, with the well screen installed at an intermediate depth in the surficial aquifer at 98 feet to 118 feet below ground surface (bgs). The screen for monitoring well MW-8D was installed above auger refusal. The 5-foot long screen for monitoring well MW-11 DR was installed in the fractured bedrock zone immediately below auger refusal (MACTEC, 2011). Monitoring well MW-7D was installed using hollow stem augers and mud rotary drilling techniques to complete the well with a 5-foot long well screen from 95 feet bsto 100 feet bgs within the fractured bedrock zone (ARCADIS G&M of North Carolina, 2007). Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 3.0 RECEPTOR INFORMATION 3.0 Receptor Information The August 13, 2014, NORR states: No later than October 14th, 2014 as authorized pursuant to 15A NCAC 02L .0106(g), the DWR is requesting that Duke perform a receptor survey at each of the subject facilities and submitted to the DWR. The receptor survey is required by 15A NCAC 02L .0106(g) and shall include identification of all receptors within a radius of 2,640 feet (one-half mile) from the established compliance boundary identified in the respective National Pollutant Discharge Elimination System (NPDES) permits. Receptors shall include, but shall not be limited to, public and private water supply wells (including irrigation wells and unused or abandoned wells) and surface water features within one-half mile of the facility compliance boundary. For those facilities for which Duke has already submitted a receptor survey, please update your submittals to ensure they meet the requirements stated in this letter and referenced attachments and submit them with the others. If they do not meet these requirements, you must modify and resubmit the plans. The results of the receptor survey shall be presented on a sufficiently scaled map. The map shall show the coal ash facility location, the facility property boundary, the waste and compliance boundaries, and all monitoring wells listed in the respective NPDES permits. Any identified water supply wells shall be located on the map and shall have the well owner's name and location address listed on a separate table that can be matched to its location on the map. In accordance with the requirements of the NORR, HDR completed and submitted the receptor survey to NCDENR (HDR, 2014A) in September 2014. HDR subsequently submitted to NCDENR a supplement to the receptor survey (HDR, 201413) in November 2014. The supplementary information was obtained from responses to water supply well survey questionnaires mailed to property owners within a 0.5-mile radius of the RBSS ash basin compliance boundary requesting information on the presence of water supply wells and well usage. The receptor survey includes a map showing the coal ash facility location, the facility property boundary, the waste and compliance boundaries, and all monitoring wells listed in the NPDES permit. The identified water supply wells are located on the map and the well owner's name and location address are listed on a separate table that can be matched to its location on the map. During completion of the CSA, HDR will update the receptor information as necessary, in general accordance with the CSA receptor survey requirements Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 4.0 REGIONAL GEOLOGY AND HYDROGEOLOGY 4.0 Regional Geology and Hydrogeology North Carolina is divided into distinct regions by portions of three physiographic provinces: the Atlantic Coastal Plain, Piedmont, and Blue Ridge (Fenneman, 1938). The RBSS site is located in the Charlotte terrane within the Piedmont province. The Piedmont province is bounded to the east and southeast by the Atlantic Coastal Plain and to the west by the escarpment of the Blue Ridge Mountains, covering a distance of 150 miles to 225 miles (LeGrand, 2004). The topography of the Piedmont region is characterized by low, rounded hills and long, rolling, northeast -southwest trending ridges (Heath, 1984). Stream valley to ridge relief in most areas ranges from 75 feet to 200 feet. Along the Coastal Plain boundary, the Piedmont region rises from an elevation of 300 feet above mean sea level, to the base of the Blue Ridge Mountains at an elevation of 1,500 feet (LeGrand, 2004). The Charlotte terrane consists primarily of igneous and metamorphic bedrock. The fractured bedrock is overlain by a mantle of unconsolidated material known as regolith. The regolith includes residual soil and saprolite zones and, where present, alluvium. Saprolite, the product of chemical weathering of the underlying bedrock, is typically composed of clay and coarser granular material and reflects the texture and structure of the rock from which it was formed. The weathering products of granitic rocks are quartz -rich and sandy textured. Rocks poor in quartz and rich in feldspar and ferro-magnesium minerals form a more clayey saprolite. The groundwater system in the Piedmont Province, in most cases, is comprised of two interconnected layers, or mediums: 1) residual soil/saprolite and weathered fractured rock (regolith) overlying 2) fractured crystalline bedrock (Heath, 1980; Harned and Daniel, 1992). The regolith layer is a thoroughly weathered and structureless residual soil that occurs near the ground surface with the degree of weathering decreasing with depth. The residual soil grades into saprolite, a coarser grained material that retains the structure of the parent bedrock. Beneath the saprolite, partially weathered/fractured bedrock occurs with depth until sound bedrock is encountered. This mantle of residual soil, saprolite, and weathered/fractured rock is a hydrogeologic unit that covers and crosses various types of rock (LeGrand, 1988). This layer serves as the principal storage reservoir and provides an intergranular medium through which the recharge and discharge of water from the underlying fractured rock occurs. Within the fractured crystalline bedrock layer, the fractures control both the hydraulic conductivity and storage capacity of the rock mass. A transition zone at the base of the regolith has been interpreted to be present in many areas of the Piedmont. The zone consists of partially weathered/fractured bedrock and lesser amounts of saprolite that grades into bedrock and has been described as "being the most permeable part of the system, even slightly more permeable than the soil zone" (Harned and Daniel, 1992). The zone thins and thickens within short distances and its boundaries may be difficult to distinguish. It has been suggested that the zone may serve as a conduit of rapid flow and transmission of contaminated water (Harned and Daniel, 1992) The igneous and metamorphic bedrock in the Piedmont consist of interlocking crystals and primary porosity is very low, generally less than 3 percent. Secondary porosity of crystalline Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan ��� Riverbend Steam Station Ash Basin 4.0 REGIONAL GEOLOGY AND HYDROGEOLOGY bedrock due to weathering and fractures ranges from 1 to 10 percent (Freeze and Cherry, 1979); but, porosity values of 1 percent to 3 percent are more typical (Daniel and Sharpless, 1983). Daniel (1990) reported that the porosity of the regolith ranges from 35 percent to 55 percent near land surface but decreases with depth as the degree of weathering decreases. LeGrand's (1988; 1989) conceptual model of the groundwater setting in the Piedmont incorporates the above two medium system into an entity that is useful for the description of groundwater conditions. That entity is the surface drainage basin that contains a perennial stream (LeGrand, 1988). Each basin is similar to adjacent basins and the conditions are generally repetitive from basin to basin. Within a basin, movement of groundwater is generally restricted to the area extending from the drainage divides to a perennial stream (Slope -Aquifer System; LeGrand, 1988; 1989). Rarely does groundwater move beneath a perennial stream to another more distant stream or across drainage divides (LeGrand, 1989). The crests of the water table undulations represent natural groundwater divides within a slope -aquifer system and may limit the area of influence of wells or contaminant plumes located within their boundaries. The concave topographic areas between the topographic divides may be considered as flow compartments that are open-ended down slope. Therefore, in most cases in the Piedmont, the groundwater system is a two medium system (LeGrand, 1988) restricted to the local drainage basin. The groundwater occurs in a system composed of two interconnected layers: residual soil/saprolite and weathered rock overlying fractured crystalline rock separated by the transition zone. Typically, the residual soil/saprolite is partially saturated and the water table fluctuates within it. Water movement is generally through the weathered/fractured and fractured bedrock. The near -surface fractured crystalline rocks can form extensive aquifers. The character of such aquifers results from the combined effects of the rock type, fracture system, topography, and weathering. Topography exerts an influence on both weathering and the opening of fractures, while the weathering of the crystalline rock modifies both transmissive and storage characteristics. Groundwater flow paths in the Piedmont are almost invariably restricted to the zone underlying the topographic slope extending from a topographic divide to an adjacent stream. Under natural conditions, the general direction of groundwater flow can be approximated from the surface topography (LeGrand, 2004). Groundwater recharge in the Piedmont is derived entirely from infiltration of local precipitation. Groundwater recharge occurs in areas of higher topography (i.e., hilltops) and groundwater discharge occurs in lowland areas bordering surface water bodies, marshes, and floodplains (LeGrand, 2004). Average annual precipitation in the Piedmont ranges from 42 inches to 46 inches. Mean annual recharge in the Piedmont ranges from 4.0 inches to 9.7 inches per year (Daniel, 2001). 9 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 5.0 INITIAL CONCEPTUAL SITE MODEL 5.0 Initial Conceptual Site Model The following Initial Conceptual Site Model (ICSM) has been developed for the RBSS site using available regional data and site -specific data (e.g., boring logs, well construction records, etc.). Although the groundwater flow system at the site is not fully understood and heterogeneities exist, the available data indicates that the LeGrand Slope -Aquifer hydrogeologic conceptual model for sites within the Piedmont, as described in Section 4.0, is a reasonable preliminary representation of site conditions. The ICSM served as the foundation for the development of proposed field activities and data collection presented in Section 7.0. The ICSM will be refined as needed as additional site -specific information is obtained during the site assessment process. The ICSM serves as the basis for understanding the hydrogeologic characteristics of the site, as well as the characteristics of the ash sources and will serve as the basis for the Site Conceptual Model (SCM) discussed in Section 7.5. In general the ICSM identified the need for the following additional information concerning the site and ash: • Delineation of the extent of possible soil and groundwater contamination; • Additional information concerning the direction and velocity of groundwater flow; • Information on the constituents and concentrations found in the site ash; • Properties of site materials influencing fate and transport of constituents found in ash; and • Information on possible impacts to seeps and surface water from the constituents found in the ash. The assessment work plan found in Section 7.0 was developed in order to collect and to perform the analyses to provide this information. 5.1 Physical Site Characteristics The original ash pond at the RBSS consisted of a single -cell basin commissioned in 1957 and was expanded in 1979. The single basin was divided by constructing a divider dike to form two separate cells in 1986. The Primary Cell is impounded by an earthen embankment dike, referred to as Dam #1 (Primary), located on the west side of the Primary Cell. The Secondary Cell is impounded by an earthen embankment dike, referred to as Dam #2 (Secondary), located along the northeast side of the Secondary Cell. The toe areas for both dikes are in close proximity to Mountain Island Lake. Topography at the RBSS site ranges from an approximate high elevation of 786 feet near the south edge of the property near Horseshoe Bend Beach Road to an approximate low elevation of 646 feet at the interface with Mountain Island Lake on the northern extent of the site. Topography generally slopes from a south to north direction with an elevation loss of approximately 140 feet over an approximate distance of 3,500 feet. Surface water drainage generally follows site topography and flows from the south to the north across the site except 10 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan _ Riverbend Steam Station Ash Basin 5.0 INITIAL CONCEPTUAL SITE MODEL where natural drainage patterns have been modified by the ash basin or other construction. Unnamed drainage features are located on the eastern and northwestern portions of the site and generally flow north to Mountain Island Lake. The approximate maximum pond elevation of the Primary Cell is 724 feet. The Secondary Cell has an approximate maximum pond elevation of 714 feet. The full pond elevation of Mountain Island Lake is approximately 646.8 feet. In addition to the ash basin, an unlined dry ash storage area is located topographically upgradient and adjacent to the southeast side of the Primary Cell. A cinder storage area is located immediately west/southwest of the Primary Cell and northwest of the dry ash storage area. The Primary Cell, Secondary Cell, dry ash storage area, and cinder storage area are shown on Figures 2 and 3. 5.1.1 ASH BASIN Coal ash residue from the coal combustion process was disposed in the RBSS ash basin from approximately 1957 until the last coal-fired generating units were retired in April 2013. The construction sequence of the ash basin was described in Section 2.0. Fly ash precipitated from flue gas and bottom ash collected in the bottom of the boilers were sluiced to the ash basin using conveyance water withdrawn from Mountain Island Lake. The discharge flow from the Primary Cell enters the Secondary Cell via a concrete discharge tower located in the northern portion of the cell near the divider dike. Flow is discharged from the Secondary Cell to Mountain Island Lake through a concrete discharge tower located in the southeast portion of the Secondary Cell. The concrete discharge tower drains through a 30- inch-diameter corrugated metal pipe into a concrete -lined channel that discharges to Mountain Island Lake. The approximate maximum pond elevation of the Primary Cell is 724 feet. The Secondary Cell has an approximate maximum pond elevation of 714 feet. The full pond elevation of Mountain Island Lake near the site is approximately 646.8 feet. The ash basin pond elevations are controlled by the use of concrete stop logs in the two discharge towers. The area contained within the waste boundary for the Primary Cell encompasses approximately 41 acres. The Secondary Cell encompasses approximately 28 acres. For purposes of delineating the waste boundary, the Primary Cell, Secondary Cell, Ash Storage Area, and Cinder Storage Area are considered a single waste disposal area, encompassing approximately 134.7 acres. The ash basin waste boundary is shown on Figures 2 and 3. During operation of the coal-fired units, the ash basin received variable inflows from the ash removal system and other permitted discharges. Currently, the ash basin receives variable inflows from the station yard drain sump and stormwater flows. Currently, Duke Energy is evaluating alternatives from removing these flows from the ash basin in order to allow total decommissioning of the ash basin. Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 5.0 INITIAL CONCEPTUAL SITE MODEL 5.1.2 ASH STORAGE AREA An unlined dry ash storage area is located topographically upgradient and adjacent to the southeast side of the Primary Cell. The footprint is approximately 29 acres and is estimated to contain approximately 1.5 million tons of CCR material. The ash storage area was constructed during two ash basin clean -out projects: one which occurred around 2000-2001 and the more recent which occurred from late 2006 to early 2008. The clean -out projects were performed to provide additional capacity in the ash basins for future sluiced ash. The storage area currently has a 1.5 to 2 foot soil cover and vegetation that has been maintained following the last deposition in this area. For the purpose of water management, the stormwater runoff from the ash storage area is routed to the ash basin system. Per Duke Energy's November 13, 2014 proposed Coal Ash Excavation Plan for the Riverbend Steam Station, Phase I of the Excavation Plan will include the excavation and removal of approximately 1.0 million tons of CCR material from the storage area. Subsequent phase(s) of excavation will remove the remaining ash in this area of the site. Ash removed from the site will be transported by the contractor to properly permitted facilities. The ash placement location will be properly managed and maintained to ensure environmental compliance with all applicable rules and regulations. 5.1.3 CINDER STORAGE AREA The cinder storage area is located topographically upgradient and immediately west/southwest of the Primary Cell, and northwest of the dry ash storage. The footprint is approximately 13 acres and is located in a triangular area northeast of the coal pile and northwest of the rail spur. Following initial station operation and prior to initial ash basin operation in 1957, bottom ash (cinders), generated as part of the coal combustion process, were deposited in a primarily dry condition in the cinder storage area and other areas near the cinder storage area and coal pile. This area was utilized for storage of ash material at the station prior to the installation of precipitators and a wet sluicing system. The cinder storage area contains predominantly dry cinders and is currently covered with dense vegetation. The storage area is estimated to contain approximately 300,000 tons of CCR material. Per Duke Energy's November 13, 2014 proposed Coal Ash Excavation Plan for the Riverbend Steam Station, the CCR material contained within the cinder storage area will be removed. 5.2 Source Characteristics The ash in the ash basin consists of fly ash and bottom ash produced from the combustion of coal. The physical and chemical properties of coal ash are determined by reactions that occur during the combustion of the coal and subsequent cooling of the flue gas. In general, coal is dried, pulverized, and conveyed to the burner area of a boiler for combustion. Material that forms larger particles of ash and falls to the bottom of the boiler is referred to as bottom ash. Smaller particles of ash, fly ash, are carried upward in the flue gas and are captured by an air pollution control device. Approximately 70 percent to 80 percent of the ash produced during coal combustion is fly ash (EPRI 1993). Typically 65 percent to 90 percent of fly ash has particle sizes that are less than 0.010 millimeter (mm). Bottom ash particle diameters can vary from approximately 38 mm to 0.05 mm. 12 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 5.0 INITIAL CONCEPTUAL SITE MODEL The chemical composition of coal ash is determined based on many factors including the source of the coal, the type of boiler where the combustion occurs (the thermodynamics of the boiler), and air pollution control technologies employed. The major elemental composition of fly ash (approximately 90 percent by weight) is composed of mineral oxides of silicon, aluminum, iron, and calcium. Minor constituents such as magnesium, potassium, titanium, and sulfur comprise approximately 8 percent of the mineral component, while trace constituents such as arsenic, cadmium, lead, mercury, and selenium make up less than approximately 1 percent of the total composition (EPRI 2009). Other trace constituents in coal ash (fly ash and bottom ash) consist of antimony, barium, beryllium, boron, chromium, copper, lead, mercury, molybdenum, nickel, selenium, strontium, thallium, uranium, vanadium, and zinc (EPRI 2009). In addition to these constituents, coal ash leachate contains chloride, fluoride, sulfate, and sulfide. In the U.S Environmental Protection Agency's (EPA's) Proposed Rules Disposal of Coal Combustion Residuals From Electric Utilities Federal Register / Vol. 75, No. 118 / Monday, June 21, 2010, 35206, EPA proposed that the following constituents be used as indicators of groundwater contamination in the detection monitoring program for coal combustion residual landfills and surface impoundments: boron, chloride, conductivity, fluoride, pH, sulfate, sulfide, and total dissolved solids (TDS). In selecting the constituents for detection monitoring, EPA selected those that are present in coal combustion residuals that would move rapidly through the subsurface, thereby, providing an early indication that contaminants were migrating from the landfill or ash basin. In the 1998 "Report to Congress Wastes from the Combustion of Fossil Fuels" (USEPA 1998), EPA presented waste characterization data for CCP wastes in impoundments and in landfills. The constituents listed were: arsenic, barium, beryllium, boron, cadmium, chromium, cobalt, copper, lead, manganese, nickel, selenium, silver, thallium, strontium, vanadium, and zinc. In this report, the EPA reviewed radionuclide concentrations in coal and ash and ultimately, eliminated radionuclides from further consideration due to the low risks associated with the radionuclides. The geochemical factors controlling the reactions associated with leaching of ash and the movement and transport of the constituents leached from ash is complicated. The mechanisms that affect movement and transport vary by constituent, but, in general, are mineral equilibrium, solubility, and adsorption onto inorganic soil particles. Due to the complexity associated with understanding or identifying the specific mechanism controlling these processes, HDR believes that the effect of these processes are best considered by determination of site -specific soil - water distribution coefficient, Kd, values as described in Section 7.7. The oxidation -reductions and precipitation -dissolution reactions that occur in a complex environment, such as an ash basin, are poorly understood. In addition to the variability that might be seen in the mineralogical composition of the ash, based on different coal types, different age of ash in the basin, etc., it would be anticipated that the chemical environment of the ash basin would vary over time and over distance and depth, increasing the difficulty of making specific predictions related to concentrations of specific constituents. HDR does not believe that conditions in the site groundwater will be likely to produce methane; therefore methane was not included in the sample parameters. 13 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 5.0 INITIAL CONCEPTUAL SITE MODEL Duke Energy has performed limited leaching analysis on fly ash and bottom ash. Available data is presented in Table 3. Due to the complex nature of the geochemical environment and processes in the ash basin, HDR believes that the most useful representation of the potential impacts to groundwater will be obtained from the sampling and analyses of ash in the basin and from pore water and groundwater samples proposed in Section 7.0 of this work plan. Understanding the factors controlling the mobility, retention, and transport of the constituents that may leach from ash are also complicated by the complex nature of the geochemical environment of the ash basin combined with the complex geochemical processes occurring in the soils beneath the ash basin along the groundwater flow paths. Mobility, retention, and transport of the constituents can vary by each individual constituent. As these processes are complex and are highly dependent on the mineral composition of the soils, it will not be possible to determine with absolute clarity the specific mechanism that controls the mobility and retention of the constituents; however, the effect of these processes will be represented by the determination of the site -specific soil -water distribution coefficient, Kd, values as described in Section 7.7. As described in that section, samples will be collected to develop Kd terms for the various materials encountered at the site. These Kd terms are then to be used as part of the groundwater modeling, if required to predict concentrations of constituents at the compliance boundary. The site residual soils were formed by in -place weathering of metamorphosed quartz diorite and tonalite. The tonalite unit is described as gray, usually medium- to coarse -grained, generally foliated rock composed dominantly of plagioclase, quartz biotite, hornblende, and epidote. Iron (Fe) and manganese (Mn), present in groundwater at a number of the on -site monitoring wells, are constituents of the bedrock, primarily in ferro-magnesium minerals. Manganese substitutes for iron and magnesium in a number of minerals and is enriched in mafic and ultramafic lithologies relative to felsic lithologies (1,000 parts per million [ppm] in basalt and 400 ppm in granite; Krauskopf 1972). In the Piedmont, manganese oxides occur as thin coatings along bedrock fractures and as thin -coatings along relict discontinuities in saprolite. Manganese ranges from 20 to 3,000 ppm in residual soils (Krauskopf 1972). In a study in Orange County, North Carolina, Cunningham and Daniel (2001) reported manganese in 94% and iron in 80% of the drinking water wells tested. Iron exceeded North Carolina drinking water standards in 6% of the wells and for manganese in 24% of the wells (Cunningham and Daniel 2001). In more recent study, Gillispie (2014) found that approximately 50% of wells in North Carolina have manganese concentrations exceeding the state standard of 0.05 mg/L (Gillispie 2014). The manganese detected in water wells at ten NC Division of Water Resources groundwater research stations studied by Gillispie (2014) is naturally derived and concentrations are spatially variable ranging from less than 0.01 to greater than 2 mg/L. 5.3 Hydrogeologic Site Characteristics Based on lithological data included in soil boring and monitoring well installation logs provided by Duke Energy (ARCADIS G&M of North Carolina, Inc., 2007 and MACTEC, 2011), subsurface stratigraphy consists of the following material types: fill, ash, residual soil, saprolite, alluvium, 14 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan _ Riverbend Steam Station Ash Basin 5.0 INITIAL CONCEPTUAL SITE MODEL partially weathered rock (PWR), and bedrock. In general, residual soil, saprolite, and PWR were encountered on most areas of the site. Alluvium was encountered in borings advanced along the northeastern extent of the Secondary Cell, within close proximity to Mountain Island Lake. Bedrock was encountered sporadically across the site ranging in depth from 34 feet on the northern extent of the site to greater than 200 feet on the southern extent of the site near Horseshoe Bend Beach Road. Cross -sections depicting the hydrostratigraphic units were developed for the preliminary ash basin assessment. The site plan and cross -sections are shown in Appendix C. The general stratigraphic units, in sequence from the ground surface down to boring termination, are defined as follows: • Fill — Fill material generally consisted of re -worked silts and clays that were borrowed from one area of the site and re -distributed to other areas. Fill was used in the construction of dikes and presumably as cover for the ash storage area. • Ash — Although previous exploration activities, for which Duke Energy provided boring logs, did not evaluate ash management areas of the site, ash is expected to be present within the ash basins and ash and cinder storage areas. • Alluvium — Alluvium is unconsolidated soil and sediment that has been eroded and redeposited by streams and rivers. Alluvium may consist of a variety of materials ranging from silts and clays to sands and gravels. Alluvium was encountered in three boring locations at the base of the northern embankment of the Secondary Cell, proximal to Mountain Island Lake. Alluvium in these borings was described as yellowish -red to reddish -yellow silty clay to clayey sand with well-rounded quartz pebbles. • Residual Soil — The soil that develops by in -place weathering and consists of white, orange, tan, brown, gray, or black sandy clay to clayey sand. This unit was encountered in various thicknesses across the site. The residual soil horizon grades into saprolite at depth. • Saprolite — Saprolite develops by the in -place weathering of igneous and metamorphic rocks. Saprolite is characterized by the preservation of structures that were present in the unweathered parent bedrock. • Partially Weathered Rock (PWR) — PWR occurs between the saprolite and bedrock and contains saprolite and rock remnants. The unit is described as white to brownish yellow to greenish gray with quartz and potassium feldspar fragments. • Bedrock — Bedrock was encountered in three deep borings completed around the northern extent of the Secondary Cell and the western extent of the Primary Cell. Depth to top of bedrock ranged from 34 feet to 51 feet below ground surface (bgs). Bedrock was described as granite, quartzite and gneiss. Hydraulic conductivity in these hydrostratigraphic units can vary, but is generally thought to fall within the ranges provided in below where Kh refers to hydraulic conductivity in the horizontal direction and Kv refers to hydraulic conductivity in the vertical direction: Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin 5.0 INITIAL CONCEPTUAL SITE MODEL HYDRAULIC CONDUCTIVITIES Hydrostratigraphic Unit Range of k Values (cm/sec) Fill (Kh)2 1.0E-06 to 1.0E-04 Ash (Kh)1,s Alluvium (Kh)1,3 Residual Soil/Saprolite (Kh)l 3 Partially Weathered / Fractured Rock — TZ (Kh)13 Bedrock (Kh)1,3 1.0E-06 to 1.0E-04 Ash (Kv)4 2.8E-05 to 1.2E-04 Alluvium (Kh)1,3 Residual Soil/Saprolite (Kh)l 3 Partially Weathered / Fractured Rock — TZ (Kh)13 Bedrock (Kh)1,3 ■ 1.3E-06 to 2.7E-03 9.7E-07 to 1.8E-02 1.9E-06 to 3.3E-02 1.8E-07 to 9.9E-03 Notes: 1. Data from in -situ permeability tests at ash basins located within the Carolina Piedmont. 2. Estimates for "F" (fill) based on data that indicates the "k" for fill is about an order of magnitude lower than the in -situ material used for the fill (after compaction). 3. Hydraulic Conductivity Database — HDR (unpublished data). 4. Hydraulic Conductivity data from site -specific laboratory testing of Shelby tube samples from BSS (HDR, 2014C) 5. Data from in -situ permeability tests at ash basins located within the Carolina Piedmont. As the site is located in the Piedmont, it is anticipated that the groundwater flow will be primarily in the saprolite and the transition zone material with flow also occurring in the fractured or weathered zones in bedrock. The sampling and testing proposed in Section 7 will provide additional information on the transport characteristics of the materials at the site. Groundwater flow and transport at the RBSS site are assumed to follow the local slope aquifer system, as described by LeGrand (2004). Under natural conditions the general direction of groundwater flow can be approximated from the surface topography. A topographic divide is located approximately along Horseshoe Bend Beach Road to the south of the ash basin. This topographic divide likely also functions as a groundwater divide. Mountain Island Lake is located to the north of the ash basin. The predominant direction of groundwater flow from the ash basin is likely in a northerly direction, generally towards Mountain Island Lake. Groundwater recharge in the Piedmont is derived entirely from infiltration of local precipitation. Groundwater recharge occurs in areas of higher topography (i.e., hilltops) and groundwater discharge occurs in lowland areas bordering surface water bodies, marshes, and floodplains (LeGrand 2004). At the RBSS site, groundwater recharge is expected to occur on the southern portion of the site where topography is higher. Groundwater is expected to discharge into tributary drainage features or into Mountain Island Lake. Following completion of the groundwater assessment work, a site conceptual model will be developed, as described in Section 7.5. 16 Notes: 1. Data from in -situ permeability tests at ash basins located within the Carolina Piedmont. 2. Estimates for "F" (fill) based on data that indicates the "k" for fill is about an order of magnitude lower than the in -situ material used for the fill (after compaction). 3. Hydraulic Conductivity Database — HDR (unpublished data). 4. Hydraulic Conductivity data from site -specific laboratory testing of Shelby tube samples from BSS (HDR, 2014C) 5. Data from in -situ permeability tests at ash basins located within the Carolina Piedmont. As the site is located in the Piedmont, it is anticipated that the groundwater flow will be primarily in the saprolite and the transition zone material with flow also occurring in the fractured or weathered zones in bedrock. The sampling and testing proposed in Section 7 will provide additional information on the transport characteristics of the materials at the site. Groundwater flow and transport at the RBSS site are assumed to follow the local slope aquifer system, as described by LeGrand (2004). Under natural conditions the general direction of groundwater flow can be approximated from the surface topography. A topographic divide is located approximately along Horseshoe Bend Beach Road to the south of the ash basin. This topographic divide likely also functions as a groundwater divide. Mountain Island Lake is located to the north of the ash basin. The predominant direction of groundwater flow from the ash basin is likely in a northerly direction, generally towards Mountain Island Lake. Groundwater recharge in the Piedmont is derived entirely from infiltration of local precipitation. Groundwater recharge occurs in areas of higher topography (i.e., hilltops) and groundwater discharge occurs in lowland areas bordering surface water bodies, marshes, and floodplains (LeGrand 2004). At the RBSS site, groundwater recharge is expected to occur on the southern portion of the site where topography is higher. Groundwater is expected to discharge into tributary drainage features or into Mountain Island Lake. Following completion of the groundwater assessment work, a site conceptual model will be developed, as described in Section 7.5. 16 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan _ Riverbend Steam Station Ash Basin 6.0 COMPLIANCE GROUNDWATER MONITORING 6.0 Compliance Groundwater Monitoring As described in Section 2.3, groundwater monitoring is required as a condition of the NPDES permit. From December 2010 through October 2014, the compliance groundwater monitoring wells at the RBSS site have been sampled a total of 13 times. During this period, these monitoring wells were sampled in: • December 2010 • February 2011 • June 2011 • October 2011 • February 2012 • June 2012 • October 2012 • February 2013 • June 2013 • October 2013 • February 2014 • June 2014 • October 2014 Note that compliance monitoring wells MW-11 DR, MW-11 SR, and MW-15 were first sampled in February 2011. With the exception of iron, manganese, antimony, and pH, the results for all monitored parameters and constituents were less than the 2L Standards. Table 2 lists the range of exceedances for iron, manganese, antimony, and pH for the period of December 2010 through October 2014. HDR previously completed an initial groundwater assessment of the 2L Standard exceedances in the compliance monitoring wells at RBSS through the February 2013 sampling event (HDR, 2013). The results and recommendations from this assessment report will be used during the groundwater assessment required by the NORR. All available groundwater quality data for compliance and voluntary monitoring wells (as mentioned above and shown on Figure 2) are summarized on Table 4. Ash quality data are provided in Table 5. Surface water quality data are provided in Table 6. Seep analytical results are provided in Table 7. Compliance groundwater monitoring will continue as scheduled in accordance with the requirements of the NPDES permit. Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN 7.0 Assessment Work Plan Solid and aqueous media sampling will be performed to provide information pertaining to the horizontal and vertical extent of potential soil and groundwater contamination and to determine physical properties of the ash and soil. Based on readily available site background information, and dependent upon accessibility, HDR anticipates collecting the following samples as part of the subsurface exploration plan: • Ash and soil samples from borings within and beneath the ash basin and ash storage area, • Soil samples from borings located outside the ash basin and ash storage area boundaries, • Groundwater samples from proposed monitoring wells, • Groundwater samples from the existing compliance and voluntary monitoring wells, • Surface water samples from water bodies located within the ash basin waste boundary, • Surface water and sediment samples from surface water locations potentially impacted by the ash basin due to their proximity to or downgradient locations from the basin, • Seep samples from locations identified as part of Duke Energy's NPDES permit renewal application (from April 2014), and • Groundwater samples from the existing onsite water supply wells. In addition, hydrogeologic evaluation testing will be conducted during and following monitoring well installation activities, as described in Section 7.1.6. Historical groundwater quality data from compliance monitoring wells and voluntary monitoring wells will be used to supplement data obtained from this assessment work. A summary of the proposed exploration plan, including estimated sample quantities and estimated depths of soil borings and monitoring wells is presented in Table 8. The proposed sampling locations are shown on Figure 3. Groundwater samples collected from compliance monitoring wells MW-8S, MW-81, and MW-8D are located at or close to the Duke Energy property line and have shown exceedances of the 2L Standards. These exceedances have primarily consisted of iron and/or manganese. Upon approval of the work plan, HDR proposes to perform an evaluation of these exceedances with respect to turbidity and to naturally occurring background conditions. If that evaluation finds the exceedances are caused by turbidity, the well(s) will be redeveloped and replaced, if required, as described in Section 7.2.1. If that evaluation finds that the exceedances are not caused by turbidity or naturally occurring conditions, then additional monitoring wells (GWA-20 through GWA-23) will be installed to delineate the extent of the exceedances. One of the proposed potential locations would not be located on Duke Energy property and would require permission from the adjacent property owners. The proposed potential locations of these wells are shown on Figure 3. The installation depths of the well screens will be determined based on site conditions and the depth of the compliance wells with the exceedance. 18 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN If it is determined that additional investigations are required during the review of existing data or data developed from this assessment, Duke Energy will notify the NCDENR regional office prior to initiating additional sampling or investigations. 7.1 Subsurface Exploration Characterization of subsurface materials will be conducted through the completion of soil borings and borings performed for installation of monitoring wells as shown on Figure 3. Installation details for soil borings and monitoring wells, as well as estimated sample quantities and depths, are described below and presented in Table 8. For nested monitoring wells, the deep monitoring well boring will be utilized for characterization of subsurface materials and a sample collected for laboratory analysis. Shallow, deep, and bedrock monitoring well borings will be logged in the field as described below. At the conclusion of well installation activities, well construction details — including casing depth; total well depth; and well screen length, slot size, and placement within specific hydrostratigraphic units — will be presented in tabular form for inclusion into the final CSA Report. Well completion records will be submitted to NCDENR within 30 days of completion. Duke Energy acknowledges that subsurface geophysics may be useful for evaluation of subsurface conditions in areas that have not been significantly reworked by construction or ash management activities, but less useful in basins and fills. Subsequent to evaluation of field data obtained during the proposed investigation activities, Duke Energy will evaluate the need for and potential usefulness of subsurface geophysics in select areas of the site. If it is determined that subsurface investigation is warranted, Duke Energy and HDR will notify the NCDENR regional office prior to initiating additional investigations. 7.1.1 Ash and Soil Borings Characterization of ash and underlying soil will be accomplished through the completion and sampling of borings advanced at eight locations within the Primary Cell, on the Primary and Secondary Cell dams, and on and adjacent to the intermediate dike (designated as AB-1 through AB-8), at three locations within the Ash Storage Area located immediately south/southwest of the Primary Cell (designated as AS-1 through AS-3), and at two locations within the Cinder Storage Area located west of the Primary Cell and northwest of the Ash Storage Area (designated as C-1 and C-2). In addition, 13 soil borings (designated as GWA-1 through GWA-10 and BG-1 through BG-3) will be completed outside of ash management areas to provide additional soil quality data. Soil borings will be completed at GWA-20 through GWA- 23, if these borings are determined to be necessary based on the evaluation described in Section 7.0. Field data collected during boring advancement will be used to evaluate: • Presence or absence of ash, • Areal extent and depth/thickness of ash, and 19 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN • Groundwater flow and transport characteristics, if groundwater is encountered. Borings will be advanced using hollow stem auger or roller cone drilling techniques to facilitate collection of downhole data. Standard Penetration Testing (SPT) (ASTM D 1586) and split - spoon sampling will be performed at 5-foot increments using an 18-inch split -spoon sampler. Note that continuous coring will be performed from auger refusal to a depth of at least 50 feet into competent bedrock for deep bedrock monitoring well borings (designated as BR soil boring/groundwater monitoring well locations on Figure 3). Borings will be logged and ash/soil samples will be photographed, described, and visually classified in the field for origin, consistency/relative density, color, and soil type in accordance with the Unified Soil Classification System (ASTM D2487/D2488). BORINGS WITHIN ASH BASIN, ASH STORAGE, AND CINDER STORAGE AREAS In areas where ash is known or suspected to be present (i.e., AB-, AS-, and C-borings), solid phase samples will be collected for laboratory analysis from the following intervals in each boring: • Shallow Ash — approximately 3feet bgs to 5 feet bgs • Deeper Ash — approximately 2 feet above the ash/soil interface • Upper Soil — approximately 2 feet below the ash/soil interface • Deeper Soil — approximately 8 feet to 10 feet below the ash/soil interface If ash is observed to be greater than 30 feet thick, a third ash sample will be collected from the approximate mid -point depth between the shallow and deeper samples. The ash samples will be used to evaluate geochemical variations in ash located in the ash basin and ash storage area. The remaining soil samples will be used to delineate the vertical extent of potential soil impacts beneath the ash basin and ash storage area. Ash and soil samples will be analyzed for total inorganic compounds, as presented in Table 9. Select ash samples will be analyzed for leachable inorganic compounds using the Synthetic Precipitation Leaching Procedure (SPLP) to evaluate the potential for leaching of constituents from ash into underlying soil. The ash SPLP analytical results will be compared to Class GA Standards as found in 15A NCAC 02L .0202 Groundwater Quality Standards, last amended on April 1, 2013 (2L Standards). Bathymetric surveys performed within the ponded areas of the Primary and Secondary Cells indicate that ash exists beneath most if not all of the ponded areas at varying depths. Due to safety concerns, borings will not be completed where ponded water is present within the ash basin. Safety concerns may also prevent access to proposed boing location on ash areas where saturated ash presents stability issues. If this occurs, ash samples collected from other safely accessible areas within the Primary Cell and on the dikes will be utilized to characterize the ash within the basin. Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN BORINGS OUTSIDE ASH BASIN, ASH STORAGE, AND CINDER STORAGE AREAS Borings located outside of the ash basin, ash storage, and ash cinder storage areas are designated as GWA- and BG- borings. The GWA soil samples will be used to provide additional characterization of soil conditions outside the ash basin and ash storage. Solid phase samples will be collected for laboratory analysis from the following intervals in each boring: • Approximately 2 feet to 3 feet above the water table, • Approximately 2 feet to 3 feet below the water table, • Within the saturated upper transition zone material (if not already included in the two sample intervals above), and • From a primary, open, and stained fracture within fresh bedrock if existent (bedrock core locations only). The laboratory analyses performed on these samples will depend on the nature and quantity of material collected. One or more of the above listed sampling intervals may be combined if field conditions indicate they are in close proximity to each other (i.e., one sample will be obtained that will be applicable to more than one interval). The boring locations designated as BG- borings will be used to evaluate site -specific background soil quality. Solid phase samples will be collected for laboratory analysis from the following intervals in each boring: • At approximately 10-foot intervals until reaching the water table (i.e., 0-2 feet, 10 feet to 12 feet, 20 feet to 22 feet, and so forth), • Approximately 2 feet to 3 feet above the water table, • Approximately 2 feet to 3 feet below the water table, • Within the saturated upper transition zone material (if not already included in the sample intervals above, and • From a primary, open, stained fracture within fresh bedrock if existent (bedrock core locations only). The laboratory analyses performed on these samples will depend on the nature and quantity of material collected. One or more of the above listed sampling intervals may be combined if field conditions indicate they are in close proximity to each other (i.e.one sample will be obtained that will be applicable to more than one interval). INDEX PROPERTY SAMPLING AND ANALYSES In addition, physical properties of ash and soil will be tested in the laboratory to provide data for use in groundwater modeling. Split -spoon samples will be collected at selected locations, with the minimum number of samples collected from the material types as follows: 21 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN • Fill — 5 samples • Ash — 5 samples • Alluvium — 5 samples • Soil/Saprolite — 5 samples • Soil/Saprolite (immediately above refusal) — 5 samples Select split -spoon samples will be tested for: • Natural Moisture Content Determination, in accordance with ASTM D-2216 • Grain size with hydrometer determination, in accordance with ASTM Standard D-422 The select split -spoon samples are anticipated to be collected from the following boring locations: • Fill — AB-1 S/D, AB-2S/D, AB-3S/D, AB-4S/D, and AB-5S/D • Ash — AB-5S/D, AB-7S/D, AS-2S/D, AS-3S/D, and C-2S/D • Alluvium (if present) — GWA-1 S/D, GWA-2S/D/BR, GWA-3S/D, GWA-9S/D/BR, and GWA-10S/D • Soil/Saprolite (two locations each as stated above) — GWA-4S/D, GWA-5S/D, GWA- 6S/D, GWA-7S/D/BR, and GWA-8S/D The depth intervals of the select split -spoon samples will be determined in the field by the Lead Geologist/Engineer. In addition to split -spoon sampling, a minimum of five thin -walled undisturbed tubes ("Shelby" Tubes) in fill, ash, and soil/saprolite layers will be collected from the above -referenced boring locations. Sample depths will be determined in the field based on conditions encountered during borehole advancement. The Shelby Tubes will be transported to a soil testing laboratory and each tube will be tested for the following: • Natural Moisture Content Determination, in accordance with ASTM D-2216 • Grain size with hydrometer determination, in accordance with ASTM Standard D-422 • Hydraulic Conductivity Determination, in accordance with ASTM Standard D-5084 • Specific Gravity of Soils, in accordance with ASTM Standard D-854 The results of the laboratory soil and ash property determination will be used to determine additional soil properties such as porosity, transmissivity, and specific storativity. The results from these tests will be used in the groundwater fate and transport modeling. The specific borings where these samples are collected from will be determined based on field conditions, with consideration given to their location relative to use in the groundwater model. 7.1.2 Shallow Monitoring Wells and Observation Wells SHALLOW MONITORING WELLS IN REGOLITH Groundwater quality and flow characteristics within the regolith aquifer and ash will be evaluated through the installation, sampling, and testing of 19 shallow monitoring wells at the locations outside of the ash basin specified on Figure 3 with an "S" qualifier in the well name (e.g., AS- Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN 1 S). Shallow monitoring wells in regolith are defined as wells that are screened wholly within the regolith zone or ash and set to bracket the water table surface at the time of installation. Four additional shallow monitoring wells (GWA-20S through GWA-23S) will potentially be installed if they are determined to be necessary based on the evaluation described in Section 7.0. The two observation wells (013-1 and 013-2) will be installed across the water table and will be used for measuring water levels only (no water quality samples). The OB's will be installed between the ash basin and the current site background monitoring well pair MW-7SR/D. The purpose of these OB's is to characterize groundwater flow in the region between the ash basin and the background monitoring wells MW-7SR/D. In addition, monitoring well GWA-7S will be utilized as an observation well in conjunction with OB-1 and 013-2 in order to characterize groundwater flow. Note that monitoring well GWA-7S will be installed to replace the proposed observation well 013-3, which was included in Duke Energy's NPDES permit renewal application dated May 15, 2014 Shallow monitoring and observation wells will be installed using hollow stem auger or roller cone drilling techniques. At each monitoring well location, a shallow well will be constructed with a 2- inch-diameter schedule 40 PVC screen and casing. Each of these wells will have a 10-foot to 15-foot pre -packed well screen having manufactured 0.010-inch slots. In the event that the regolith zone is found to be relatively thick at a particular well location, and that more than one discreet flow zone is observed during drilling (e.g., presence of confining unit), a second shallow monitoring well will be installed to provide groundwater flow and quality data for upper and lower flow zones. In these instances, the wells will be designated as "S" and "SL" to differentiate between the upper and lower shallow wells located in the regolith zone. SHALLOW MONITORING WELLS IN DAMS Groundwater quality and flow characteristics of the phreatic surface within ash basin dams not founded on ash will be evaluated through the installation, sampling and testing of 5 shallow monitoring wells at the locations specified on Figure 3 with an "S" qualifier in the well name (e.g., AB-25S). Wells will be installed with 10-foot to15-foot screens with the well screen set to bracket the phreatic surface at the time of installation. Shallow monitoring wells will be installed using hollow stem auger or roller cone drilling techniques. At each monitoring well location, a shallow well will be constructed with a 2-inch- diameter schedule 40 PVC screen and casing. Each of these wells will have a 10-foot to 15- foot pre -packed well screen having manufactured 0.010-inch slots. SHALLOW MONITORING WELLS IN ASH BASIN POREWATER The water quality and flow characteristics within the ash basin porewater will be evaluated through the installation, sampling, and testing of 4 porewater wells at the locations specified on Figure 3. Wells designated as "S" will be installed with 10-foot to15-foot screens with the well screen set to bracket the water table surface at the time of installation. Wells designated as "SL" will be installed with the bottom of the well screen set above the ash-regolith interface and will be installed with 10-foot screens. Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN These wells will be installed using hollow stem auger or roller cone drilling techniques. The wells will be constructed with 2-inch-diameter, schedule 40 PVC screen and casing. These wells will be installed with pre -packed well screens having manufactured 0.010-inch slots. 7.1.3 Deep Monitoring Wells Groundwater quality and flow characteristics within the transition zone (if present) will be evaluated through the installation, sampling, and testing of 26 deep monitoring wells at the locations specified on Figure 3 with a "D" qualifier in the well name (e.g., AB-1 D). Deep monitoring wells are defined as wells that are screened within the partially weathered/fractured bedrock transition zone at the base of the regolith. Four additional deep monitoring wells (GWA-20D through GWA-23D) will potentially be installed if they are determined to be necessary based on the evaluation described in Section 7.0. Deep monitoring wells will be installed using hollow stem augers and rock coring drilling techniques. At each deep monitoring well location, a double -cased well will be constructed with a 6-inch-diameter PVC outer casing and a 2-inch-diameter PVC inner casing and well screen. The purpose of installing cased wells at the site is to prevent possible cross -contamination of flow zones within the shallow and deeper portions of the unconfined aquifer during well installation. Outer well casings (6-inch casing) will be advanced to auger refusal and set approximately 1 foot into PWR (if present). Note that location -specific subsurface geology will dictate actual casing depths on a per -well basis. The annulus between the borehole and casing will be grouted to the surface using the tremie grout method. After the grout has been allowed to cure for a period of 24 hours, the borehole will be extended via coring approximately 10 feet to 15 feet into transition zone rock using an HQ core barrel. A 2-inch-diameter well with a 5-foot pre -packed well screen will be set at least 2 feet below the bottom of the outer casing. If the PWR thickness is determined to be greater than 30 feet thick at a nested well location, additional wells in the transition zone will be considered based on site -specific conditions. Rock cores will be logged in accordance with the Field Guide for Rock Core Logging and Fracture Analysis by Midwest GeoSciences Group. Percent recovery and rock quality designation (RQD) will be calculated in the field. The cores will be photographed and retained. 7.1.4 Bedrock Monitoring Wells Groundwater quality and flow within fractured bedrock beneath the site will be evaluated through the installation, sampling, and testing of seven bedrock monitoring wells at the locations specified on Figure 3 with a "BR" qualifier in the name (e.g., GWA-713R). Bedrock monitoring wells are defined as wells that are screened across water -bearing fractures wholly within fresh, competent bedrock. Four additional bedrock wells (GWA-20BR through GWA-23BR) will potentially be installed if they are determined to be necessary based on the evaluation described in Section 7.0. At these locations, continuous coring will be performed from refusal to a depth of at least 50 feet into competent bedrock. Packer testing will be performed on select fractures observed in the rock cores. See Section 7.1.6 for details regarding packer test implementation. Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN Water source(s) to be used in rock coring and packer testing will be analyzed for all of the constituents in Table 10 before use. Rock cores will be logged in accordance with the Field Guide for Rock Core Logging and Fracture Analysis by Midwest GeoSciences Group. Percent recovery and RQD will be calculated in the field. The cores will be photographed and retained. At each of these locations, a double -cased well will be constructed with a 6-inch-diameter PVC outer casing and a 2-inch-diameter PVC inner casing and well screen. Outer well casings will be advanced through the transition zone and set approximately 1 foot into competent bedrock. The annulus between the borehole and casing will be grouted to the surface using the tremie grout method. After the grout has been allowed to cure for a period of 24 hours, the borehole will be extended via coring approximately 50 feet into competent bedrock using an HQ core barrel. A 2-inch-diameter well with a 5-foot pre -packed well screen will be set at depth across an interpreted water -bearing fracture or fracture zone, based on the results of packer testing. Note that location -specific subsurface geology will dictate actual casing depths and screen placement on a per -well basis. 7.1.5 Well Completion and Development WELL COMPLETION As described above, pre -packed screens will be installed around the monitoring well screens to reduce turbidity during sample collection. The pre -packed screens will consist of environmental - grade sand contained within a stainless steel wire mesh cylinder. The sand gradation in the pre -packed screen will be made in advance anticipating a wide range of site conditions; however, HDR believes that the sand will typically be 20/40 mesh silica sand. The Geologist/Engineer involved with the specific installation will evaluate field conditions and determine if changes are required. A minimum one to two -foot -thick bentonite pellet seal hydrated with potable water will be placed above the pre -packed screen. Cement grout will be placed in the annular space between the PVC casing and the borehole above the bentonite pellet seal and extending to the ground surface. Each well will be finished at the ground surface with a 2-foot-square concrete well pad and new four -inch or eight -inch steel above -grade lockable covers. Following completion, all wells will be locked with a keyed pad lock. WELL DEVELOPMENT All newly installed monitoring wells will be developed to create an effective filter pack around the well screen and to remove fine particles within the well from the formation near the borehole. Based on site -specific conditions per 15A NCAC 02C .0108(p), appropriate measures (e.g., agitation, surging, pumping, etc.) will be utilized to stress the formation around the screen and the filter pack so that mobile fines, silts, and clays are pulled into the well and removed. Water quality parameters (specific conductance, pH, temperature, oxidation-reduction potential (ORP), and turbidity) will be measured and recorded during development and should stabilize before development is considered complete. Development will continue until development water is visually clear (< 10 Nephelometric Turbidity Units (NTU) Turbidity) and sediment free as determined by the absence of settled solids. Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN If a well cannot be developed to produce low turbidity (< 10 NTU) groundwater samples, NCDENR will be notified and supplied with the well completion and development measures that have been employed to make a determination if the turbidity is an artifact of the geologic materials in which the well is screened. Following development, sounding the bottom of the well with a water level meter should indicate a "hard" (sediment -free) bottom. Development records will be prepared under the direction of the Project Scientist/Engineer and will include development method(s), water volume removed, and field measurements of temperature, pH, conductivity, and turbidity. 7.1.6 Hydrogeologic Evaluation Testing In order to better characterize hydrogeologic conditions at the site, falling and constant head tests, packers tests, and slug tests will be performed as described below. Data obtained from these tests will be used in groundwater modeling. In addition, historical soil boring data at the site will be utilized as appropriate to better characterize hydrogeologic conditions and will be used for groundwater modeling. All water meters, pressure gages, and pressure transducers will be calibrated per specifications for testing. FALLING/CONSTANT HEAD TESTS A minimum of five in -situ borehole horizontal permeability tests, either falling or constant head tests, will be performed just below refusal in the upper bedrock (transition zone if present). In each of the hydrostratigraphic units above refusal, ash, fill, alluvium, soil/saprolite, a minimum of ten falling or constant head tests (five for vertical permeability and five for horizontal permeability) will be performed. The tests will be at locations based on site -specific conditions at the time of assessment work. The U.S. Bureau of Reclamation (1995) test method and calculation procedures as described in Chapter 10 of their Ground Water Manual (2nd Edition) will be used. PACKER TESTS A minimum of five packer tests using a double packer system will be performed in deep well/transition zone borings at locations based on site -specific conditions, as well as a minimum of one packer test in each soil/rock core well boring, as described in Section 7.1.4 after completion of the holes. Packer tests will utilize a double packer system and the interval (5 feet or 10 feet based on field conditions) to be tested will be based on observation of the rock core and will be selected by the Lead Geologist/Engineer. The U.S. Bureau of Reclamation (1995) test method and calculation procedures as described in Chapter 10 of their Groundwater Manual (2nd Edition) will be used. SLUG TESTS Hydraulic conductivity (slug) tests will be completed in all installed monitoring wells under the direction of the Lead Geologist/Engineer. Slug tests will be performed to meet the requirements of the NCDENR Memorandum titled, "Performance and Analysis of Aquifer Slug Tests and Pumping Tests Policy," dated May 31, 2007. Water level change during the slug tests will be recorded by a data logger. The slug test will be performed for no less than ten minutes, or until such time as the water level in the test well recovers 95 percent of its original pre -test level, 26 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN whichever occurs first. Slug tests will be terminated after two hours even if the 95 percent pre test level is not achieved. Slug test field data will be analyzed using the Aqtesolv (or similar) software using the Bouwer and Rice method. 7.1.7 Compliance and Voluntary Monitoring Wells Groundwater samples will be collected from selected existing voluntary and/or compliance monitoring wells. Prior to collecting groundwater samples from the existing voluntary and/or compliance monitoring wells, the historical turbidity values at each of the wells will be evaluated For wells where turbidity levels have historically been greater than 10 NTUs, these wells will be re -developed as described in Section 7.1.5 prior to collecting groundwater samples. 7.1.8 Onsite Water Supply Wells Groundwater samples will be collected from the existing onsite water supply wells using the pumping system installed in the well. Water supply wells will be purged for a minimum of 15 minutes prior to collection of a groundwater sample. Water samples will be collected prior to any filtration system (if possible) at each water supply well. 7.2 Groundwater Sampling and Analysis Subsequent to monitoring well installation and development, each newly installed well will be sampled using low -flow sampling techniques in accordance with USEPA Region 1 Low Stress (low flow) Purging and Sampling Procedure for the Collection of Groundwater Samples from Monitoring Wells (revised January 19, 2010). The purposes of the proposed monitoring wells are as follows: • AB -series Wells —The AB -series well locations were selected to provide water quality data in and beneath the ash basin. • AS -series Wells — The AS -series well locations were selected to provide additional groundwater quality data to evaluate the vertical extent of impacted groundwater in the vicinity of the ash storage area and to evaluate the migration of potentially impacted groundwater from beneath the ash basin. • C-series Wells — The C-series well locations were selected to provide additional groundwater quality data to evaluate the vertical extent of impacted groundwater in the vicinity of the ash storage area and to evaluate the migration of potentially impacted groundwater from beneath the ash basin. • GWA-series Wells — The GWA-series well locations were selected to provide water quality data beyond the ash basin waste boundary for use in groundwater modeling (i.e., to evaluate the horizontal and vertical extent of potentially impacted groundwater outside the ash basin waste boundary). • OB-series Wells — The OB-series wells will be used for measuring water levels only (no water quality samples). The OB's will be installed between the ash basin and the current site background monitoring well pair MW-7SR/D. The purpose of these OB's is to characterize groundwater flow in the region between the ash basin and the background monitoring wells MW-7SR/D. In addition, monitoring well GWA-7S will be utilized as an Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN observation well in conjunction with OB-1 and OB-2 in order to characterize groundwater flow. BG-series Wells — The BG-series wells will be used to provide information on background water quality. The background well locations were selected to provide additional physical separation from possible influence of the ash basin on groundwater. These wells will also be useful in the statistical analysis to determine the site -specific background water quality concentrations (SSBCs). During low -flow purging and sampling, groundwater is pumped into a flow -through chamber at flow rates that minimize or stabilize water level drawdown within the well. Indicator parameters are measured over time (usually at 5-minute intervals). When parameters have stabilized within ±0.2 pH units and ±10 percent for temperature, conductivity, and dissolved oxygen (DO), and ±10 millivolts (mV) for oxidation-reduction potential (ORP) over three consecutive readings, representative groundwater has been achieved for sampling. Turbidity levels of 10 NTU or less will be targeted prior to sample collection. Purging will be discontinued and groundwater samples will be obtained if turbidity levels of 10 NTU or less are not obtained after 2 hours of continuous purging. Groundwater samples will be analyzed by a North Carolina certified laboratory for the constituents included in Table 10. Select constituents will be analyzed for total and dissolved concentrations. In 2014 the Electric Power Research Institute published the results of a critical review that presented the current state -of -knowledge concerning radioactive elements in CCPs and the potential radiological impacts associated with management and disposal. The review found: Despite the enrichment of radionuclides from coal to ash, this critical review did not locate any published studies that suggested typical CCPs posed any significant radiological risks above background in the disposal scenarios considered, and when used in concrete products. These conclusions are consistent with previous assessments. The USGS (1997) concluded that "Radioactive elements in coal and fly ash should not be sources of alarm. The vast majority of coal and the majority of fly ash are not significantly enriched in radioactive elements, or in associated radioactivity, compared to common soils or rocks. "A year later, the U.S. EPA (1998) concluded that the risks of exposure to radionuclide emissions from electric utilities are "substantially lower than the risks due to exposure to background radiation. " Duke Energy proposes to sample monitoring well MW-13 and the proposed background wells BG-1 S/D for total combined radium 266 and radium 228 (Ra226 and Ra228) and will consult with the DWR regional office to determine if additional wells are to be sampled. Groundwater sample results will be compared to Class GA Standards as found in 15A NCAC 02L .0202 Groundwater Quality Standards, last amended on April 1, 2013 (2L Standards). Redox conditions are not likely to be strong enough to produce methane at the site; therefore methane was not included in the constituent list (Table 10). 28 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN 7.2.1 Compliance and Voluntary Monitoring Wells Groundwater samples will be collected from selected existing voluntary and/or compliance monitoring wells. Prior to collecting groundwater samples from the existing voluntary and/or compliance monitoring wells, the historical turbidity values at each of the wells will be evaluated. For wells where turbidity levels have historically been greater than 10 NTUs, these wells will be re -developed, as described above, prior to collecting groundwater samples. If redevelopment does not result in reduced turbidity, the well(s) will be replaced. The DWR regional office will be contacted prior to replacing a compliance monitoring well. 7.2.2 Onsite Water Supply Wells Groundwater samples will be collected from the existing onsite water supply well using the pumping system installed in the well. Water supply wells will be purged for a minimum of 15 minutes prior to collection of a sample. Water samples will be collected prior to any filtration system. The groundwater samples collected from the onsite water supply well will be analyzed for the constituents included in Table 10. 7.2.3 Speciation of Select Inorganics In addition to total analytes, speciation of select inorganics will be conducted for select sample locations to characterize the aqueous chemistry and geochemistry in locations and depths of concern. Speciation of iron (Fe(II), Fe(III)) and manganese (Mn(II), Mn(IV)) will be conducted in pore water samples collected from upper and lower elevations of ash and the transition zone within the basin, from the ash and cinder storage areas, and in groundwater samples collected from wells outside of the ash management areas. Specifically, Duke Energy proposes to speciate iron and manganese in pore water samples collected from proposed wells AB- 5S/SL/D, AB-7S/SL/D, AS-2S/D, and C-2S/D, and in groundwater samples collected from compliance wells MW-7SR, MW-8S/I/D, MW-9, MW-10, MW-11 SR/DR, MW-13, MW-14, and MW-15. Laboratory analyses will be performed in accordance with the methods provided in Table 10. 7.3 Surface Water, Sediment, and Seep Sampling 7.3.1 Surface Water Samples WITHIN ASH BASIN Surface water samples will be collected from the Primary and Secondary Cells at the approximate open water locations shown on Figure 3 (SW-AB1 and SW-A132). At each location, two water samples will be collected — one sample close to the surface (i.e., 0 to 1 foot from surface) and one sample at a depth just above the ash surface (i.e., 1 foot to 2 feet above the ash to avoid suspending the ash within the sample). Prior to sampling, the depth to ash will be measured by slowly lowering a measuring stick or tape until the ash surface is encountered, being careful to avoid suspending the ash. The depth to ash will be noted, and a sample thief will be slowly lowered to the desired depth to collect the sample. The sample thief and sample will be retrieved and the sample will be transferred to the appropriate sample containers Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN provided by the laboratory. In areas where the water body is less than 5 feet deep, one water sample will be collected from the location at a depth just above the ash surface. Ash basin surface water samples will be analyzed for the same constituents as groundwater samples (Table 10). Select constituents will be analyzed for total and dissolved concentrations. 7.3.2 Sediment Samples Sediment samples will be collected from the bed of the seep sample locations as shown on Figure 3 (designated as S-1 through S-13). The S-13 location will be considered a background sediment sample. The sediment samples will be analyzed for total inorganics using the same constituents list proposed for the soil and ash samples (Table 9). Due to safety concerns, sediment samples will not be collected at this time where open water or ponded water is present within the ash basin. 7.3.3 Seep Samples Water samples will be collected from the seep sample locations shown on Figure 3. These seep sample locations (designated as S-1 through S-13) will be collected near the time of the monitoring well sampling to minimize concerns about potential temporal variability between surface water and groundwater and analyzed for laboratory analysis for the constituents listed in Table 10. Select constituents will be analyzed for total and dissolved concentrations. In March 2014, DENR conducted sampling of seeps and surface water locations at the site. HDR does not have the analytical results from this sampling event at this time; however, once data is received, HDR will review the data and determine if changes in the proposed seep or surface water locations is needed. Analytical results from the seep sampling will be reviewed to determine if similar speciation analyses as described in Section 7.2.3 are to be performed for selected seep locations. After analytical results for seep samples are reviewed, a determination will be made concerning collection of off -site seep samples. If it is determined that off site seep samples are to be collected, the DWR regional office will be contacted. 7.4 Field and Sampling Quality Assurance/Quality Control Procedures Documentation of field activities will be completed using a combination of logbooks, field data records (FDRs), sample tracking systems, and sample custody records. Site and field logbooks are completed to provide a general record of activities and events that occur during each field task. FDRs have been designated for each exploration and sample collection task, to provide a complete record of data obtained during the activity. Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN 7.4.1 Field Logbooks The field logbooks provide a daily handwritten account of field activities. Logbooks are hardcover books that are permanently bound. All entries are made in indelible ink, and corrections are made with a single line with the author initials and date. Each page of the logbook will be dated and initialed by the person completing the log. Partially completed pages will have a line drawn through the unused portion at the end of each day with the author's initials. The following information is generally entered into the field logbooks: • The date and time of each entry. The daily log generally begins with the Pre -Job Safety Brief; • A summary of important tasks or subtasks completed during the day; • A description of field tests completed in association with the daily task; • A description of samples collected including documentation of any quality control samples that were prepared (rinse blanks, duplicates, matrix spike, split samples, etc.); • Documentation of equipment maintenance and calibration activities; • Documentation of equipment decontamination activities; and • Descriptions of deviations from the work plan. 7.4.2 Field Data Records Sample FDRs contain sample collection and/or exploration details. A FDR is completed each time a field sample is collected. The goal of the FDR is to document exploration and sample collection methods, materials, dates and times, and sample locations and identifiers. Field measurements and observations associated with a given exploration or sample collection task are recorded on the FDRs. FDRs are maintained throughout the field program in files that become a permanent record of field program activities. 7.4.3 Sample Identification In order to ensure that each number for every field sample collected is unique, samples will be identified by the sample location and depth interval, if applicable (e.g., MW-11 S (5-6'). Samples will be numbered in accordance with the proposed sample IDS shown on Figure 3. 7.4.4 Field Equipment Calibration Field sampling equipment (e.g., water quality meter) will be properly maintained and calibrated prior to and during continued use to assure that measurements are accurate within the limitations of the equipment. Personnel will follow the manufacturers' instructions to determine if the instruments are functioning within their established operation ranges. The calibration data will be recorded on a FDR. To be acceptable, a field test must be bracketed between acceptable calibration results. • The first check may be an initial calibration, but the second check must be a continuing verification check. • Each field instrument must be calibrated prior to use. 31 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN • Verify the calibration at no more than 24-hour intervals during use and at the end of the use if the instrument will not be used the next day or time periods greater than 24 hours. • Initial calibration and verification checks must meet the acceptance criteria recommended by each instrument manufacturer. • If an initial calibration or verification check fails to meet the acceptance criteria, immediately recalibrate the instrument or remove it from service. • If a calibration check fails to meet the acceptance criteria and it is not possible to reanalyze the samples, the following actions must be taken: • Report results between the last acceptable calibration check and the failed calibration check as estimated (qualified with a "J"); • Include a narrative of the problem; and • Shorten the time period between verification checks or repair/replace the instrument. • If historically generated data demonstrate that a specific instrument remains stable for extended periods of time, the interval between initial calibration and calibration checks may be increased. • Acceptable field data must be bracketed by acceptable checks. Data that are not bracketed by acceptable checks must be qualified. • Base the selected time interval on the shortest interval that the instrument maintains stability. • If an extended time interval is used and the instrument consistently fails to meet the final calibration check, then the instrument may require maintenance to repair the problem or the time period is too long and must be shortened. • For continuous monitoring equipment, acceptable field data must be bracketed by acceptable checks or the data must be qualified. Sampling or field measurement instrument determined to be malfunctioning will be repaired or will be replaced with a new piece of equipment. 7.4.5 Sample Custody Requirements A program of sample custody will be followed during sample handling activities in both field and laboratory operations. This program is designed to assure that each sample is accounted for at all times. The appropriate sampling and laboratory personnel will complete sample MRS, chain -of -custody records, and laboratory receipt sheets. The primary objective of sample custody procedures is to obtain an accurate written record that can trace the handling of all samples during the sample collection process, through analysis, until final disposition. FIELD SAMPLE CUSTODY Sample custody for samples collected during each sampling event will be maintained by the personnel collecting the samples. Each sampler is responsible for documenting each sample transfer, maintaining sample custody until the samples are shipped off -site, and sample shipment. The sample custody protocol followed by the sampling personnel involves: 32 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN • Documenting procedures and amounts of reagents or supplies (e.g., filters) which become an integral part of the sample from sample preparation and preservation; • Recording sample locations, sample bottle identification, and specific sample acquisition measures on appropriate forms; • Using sample labels to document all information necessary for effective sample tracking; and, • Completing sample FDR forms to establish sample custody in the field before sample shipment. Prepared labels are normally developed for each sample prior to sample collection. At a minimum, each label will contain: • Sample location and depth (if applicable); • Date and time collected; • Sampler identification; and, • Analyses requested and applicable preservative. A manually -prepared chain -of -custody record will be initiated at the time of sample collection. The chain -of -custody record documents: • Sample handling procedures including sample location, sample number, and number of containers corresponding to each sample number; • The requested analysis and applicable preservative; • The dates and times of sample collection; • The names of the sampler(s) and the person shipping the samples (if applicable); • The date and time that samples were delivered for shipping (if applicable); • Shipping information (e.g., FedEx Air Bill); and, • The names of those responsible for receiving the samples at the laboratory. Chain -of -custody records will be prepared by the individual field samplers. SAMPLE CONTAINER PACKING Sample containers will be packed in plastic coolers for shipment or pick up by the laboratory. Bottles will be packed tightly to reduce movement of bottles during transport. Ice will be placed in the cooler along with the chain -of -custody record in a separate, resealable, air tight, plastic bag. A temperature blank provided by the laboratory will also be placed in each cooler prior to shipment if required for the type of samples collected and analyses requested. 7.4.6 Quality Assurance and Quality Control Samples The following Quality Assurance/Quality Control samples will be collected during the proposed field activities: • Equipment rinse blanks (one per day); • Field Duplicates (one per 20 samples per sample medium) Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN Equipment rinse blanks will be collected from non -dedicated equipment used between wells and from drilling equipment between soil samples. The field equipment is cleaned following documented cleaning procedures. An aliquot of the final control rinse water is passed over the cleaned equipment directly into a sample container and submitted for analysis. The equipment rinse blanks enable evaluation of bias (systematic errors) that could occur due to decontamination. A field duplicate is a replicate sample prepared at the sampling locations from equal portions of all sample aliquots combined to make the sample. Both the field duplicate and the sample are collected at the same time, in the same container type, preserved in the same way, and analyzed by the same laboratory as a measure of sampling and analytical precision. Field QA/QC samples will be analyzed for the same constituents as proposed for the soil and groundwater samples, as identified on Tables 9 and 10, respectively. 7.4.7 Decontamination Procedures DECONTAMINATION PAD A decontamination pad will be constructed for field cleaning of drilling equipment. The decontamination pad will meet the following requirements: • The pad will be constructed in an area believed to be free of surface contamination. • The pad will be lined with a water -impermeable material with no seams within the pad. The material should be easily replaced (disposable) or repairable. • If possible, the pad will be constructed on a level, paved surface to facilitate the removal of decontamination water. This may be accomplished by either constructing the pad with one corner lower than the rest, or by creating a lined sump or pit in one corner. • Sawhorses or racks constructed to hold field equipment while being cleaned will be high enough above ground to prevent equipment from being contacted by splashback during decontamination. Decontamination water will be allowed to percolate into the ground adjacent to the decontamination pad. Containment and disposal of decontamination water is not required. At the completion of field activities, the decontamination pad will be removed and any sump or pit will be backfilled with appropriate material. DECONTAMINATION OF FIELD SAMPLING EQUIPMENT Field sampling equipment will be decontaminated between sample locations using potable water and phosphate -and -borax -free detergent solution and a brush, if necessary, to remove particulate matter and surface films. Equipment will then be rinsed thoroughly with tap water to remove detergent solution prior to use at the next sample location. DECONTAMINATION OF DRILLING EQUIPMENT Any downhole drilling equipment will be steam cleaned between boreholes. The following procedure will be used for field cleaning augers, drill stems, rods, tools, and associated downhole equipment. 34 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN • Hollow -stem augers, bits, drilling rods, split -spoon samplers and other downhole equipment will be placed on racks or sawhorses at least two feet above the floor of the temporary decontamination pad. Soil, mud, and other material will be removed by hand, brushes, and potable water. The equipment will be steam cleaned using a high pressure, high temperature steam cleaner. • Downhole equipment will be rinsed thoroughly with potable water after steam cleaning. The clean equipment will then be removed from the decontamination pad and either placed on the drill rig, if mobilizing immediately to the next boring, or placed on and covered with clean, unused plastic sheeting if not used immediately. 7.5 Site Hydrogeologic Conceptual Model The data obtained during the proposed assessment will be supplemented by available reports and data on site geotechnical, geologic, and hydrologic conditions to develop a site hydrogeologic conceptual model (SCM). The scope of these efforts will depend upon site conditions and existing geologic information for the site. The SCM is a conceptual interpretation of the processes and characteristics of a site with respect to the groundwater flow and other hydrologic processes at the site and will be a refinement of the ICSM described in Section 5.0. The NCDENR document, "Hydrogeologic Investigation and Reporting Policy Memorandum," dated May 31, 2007, will be used as general guidance. In general, components of the SCM will consist of developing and describing the following aspects of the site: geologic/soil framework, hydrologic framework, and the hydraulic properties of site materials. More specifically, the SCM will describe how these aspects of the site affect the groundwater flow at the site. In addition to these site aspects, the SCM will: • Describe the site and regional geology, • Present longitudinal and transverse cross -sections showing the hydrostratigraphic layers, • Develop the hydrostratigraphic layer properties required for the groundwater model, • Present a groundwater contour map showing the potentiometric surface of the shallow aquifer, and • Present information on horizontal and vertical groundwater gradients. The SCM will serve as the basis for developing understanding the hydrogeologic characteristics of the site and for developing a groundwater flow and transport model. The historic site groundwater elevations and ash basin water elevations will be used to develop a historic estimated seasonal high groundwater contour map for the site. A fracture trace analysis will be performed for the site, as well as onsite/near-site geologic mapping, to better understand site geology and to confirm and support the SCM. 35 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN 7.6 Site -Specific Background Concentrations Statistical analysis will be performed using methods outlined in the Resource Conservation and Recovery Act (RCRA) Unified Guidance (USEPA, 2009, EPA 530/R-09-007) to develop SSBCs. The SSBCs will be determined to assess whether or not exceedances can be attributed to naturally occurring background concentrations or attributed to potential contamination. Specifically, the relationship between exceedances and turbidity will be explored to determine whether or not there is a possible correlation due to naturally occurring conditions and/or well construction. Alternative background boring locations will be proposed to NCDENR if the background wells shown on Figure 3 are found to not represent background conditions. 7.7 Groundwater Fate and Transport Model A three-dimensional groundwater fate and transport model will be developed for the ash basin site. The objective of the model process will be to: • Predict concentrations of the Constituents of Potential Concern (COPC) at the facility's compliance boundary or other locations of interest over time, • Estimate the groundwater flow and loading to surface water discharge areas, and • Support the development of the CSA report and the corrective action plan, if required. The model and model report will be developed in general accordance with the guidelines found in the memorandum Groundwater Modeling Policy, NCDENR DWQ, May 31, 2007 (DENR modeling guidelines). The groundwater model will be developed from the SCM, from existing wells and boring information provided by Duke Energy, and from information developed from the site investigation. The model will also be supplemented with additional information developed by HDR from other Piedmont sites, as applicable. The SCM is a conceptual interpretation of the processes and characteristics of a site with respect to the groundwater flow and other hydrologic processes at the site. Development of the SCM is discussed in Section 7.5. Although the site is anticipated in general to conform to the LeGrand conceptual groundwater model, due to the configuration of the ash basin, the additional possible sources (structural fill and ash landfills), and the boundary conditions present at the site, HDR believes that a three- dimensional groundwater model would be more appropriate than performing two-dimensional modeling. The modeling process, the development of the model hydrostratigraphic layers, the model extent (or domain), and the proposed model boundary conditions are presented below. 7.7.1 MODFLOW/MT3DMS Model The groundwater modeling will be performed under the direction of Dr. William Langley, P.E., Department of Civil and Environmental Engineering, University of North Carolina Charlotte (UNCC). Groundwater flow and constituent fate and transport will be modeled using Visual MODFLOW 2011.1 (flow engine USGS MODFLOW 2005 from SWS) and MT3DMS. 36 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN Duke Energy, HDR, and UNCC considered the appropriateness of using MODFLOW and MT3DMS as compared to the use of MODFLOW coupled with a geochemical reaction code such as PHREEQC. The decision to use MODFLOW and MT3DMS was based on the intensive data requirements of PHREEQC, the complexity of developing an appropriate geochemical model given the heterogeneous nature of Piedmont geology, and the general acceptance of MODLFOW and MT3DMS. However, batch PHREEQC simulations may be used to estimate sensitivity of the proposed sorption constants used with MODFLOW/MT3DMS, as described below, if geochemistry varies significantly across the site. Additional factors that were considered in the decision to use MT3DMS as compared to a reaction based code utilizing geochemical modeling were as follows: 1. Modeling the complete geochemical fate and transport of trace, minor, or major constituents would require simultaneous modeling of the following in addition to groundwater flow: • All major, minor, and trace constituents (in their respective species forms) in aqueous, equilibrium (solid), and complexed phases • Solution pH, oxidation/reduction potential, alkalinity, dissolved oxygen, and temperature Reactions including oxidation/reduction, complexation, precipitation/dissolution, and ion exchange 2. Transient versus steady-state reaction kinetics may need to be considered. In general, equilibrium phases for trace constituents cannot be identified by mineralogical analysis. In this case, speciation geochemical modeling is required to identify postulated solid phases by their respective saturation indices. 3. If geochemical conditions across the site are not widely variable, an approach that considers each modeled COPC as a single species in the dissolved and complexed, or sorbed, phases is justified. The ratio of these two phases is prescribed by the sorption coefficient Kd which has dimensions of volume (L3) per unit mass (M). The variation in geochemical conditions can be considered, if needed, by examining pH, oxidation/reduction potential, alkalinity, and dissolved oxygen, perhaps combined with geochemical modeling, to justify the Kd approach utilized by MT3DMS. Geochemical modeling using PHREEQC (Parkhurst et al. 2013) running in the batch mode can be used to indicate the extent to which a COPC is subject to solubility constraints, a variable Kd, or other processes. The groundwater model will be developed in general accordance with the guidelines found in the Groundwater Modeling Policy, NCDENR DWQ, May 31, 2007 and based on discussions previously conducted concerning groundwater modeling between Duke Energy, HDR, UNCC, and NCDENR. 37 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN 7.7.2 Development of Kd Terms It is critical to determine the ability of the site soils to attenuate, adsorb, or through other processes, reduce the concentrations of COPCs that may impact groundwater. To determine the capacity of the site soils to attenuate a COPC, the site specific Kd terms will be developed by UNCC utilizing soil samples collected during the site investigation. These Kd terms quantify the equilibrium relationship between chemical constituents in the dissolved and sorbed phases. For soils at the site, sorption is most likely the reversible, exchange -site type, associated with hydrous oxides of iron on weathered soil surfaces (NCDENR DWQ 2012). Experiments to quantify sorption can be conducted using batch or column procedures (Daniels and Das 2014). A batch sorption procedure generally consists of combining soil samples and solutions across a range of soil -to -solution ratios, followed by shaking until chemical equilibrium is achieved. Initia and final concentrations of chemicals in the solution determine the adsorbed amount of chemical, and provide data for developing plots of sorbed versus dissolved chemical and the resultant Kd term. If the plot, or isotherm, is linear, the single -valued Kd is considered linear as well. Depending on the chemical constituent and soil characteristics, non -linear isotherms may also result (EPRI 2004). The column sorption procedure consists of passing a solution of known chemical concentration through a cylindrical column packed with the soil sample. Batch and column methods for estimating sorption were considered in development of the Kd terms. UNCC recommends an adaption of the column method (Daniels and Das, 2014) to develop Kd estimates that are more conservative and representative of in -situ conditions, especially with regards to soil- to -liquid ratios. Soil samples with measured dry density and maximum particle size will be placed in lab -scale columns configured to operate in the up -flow mode. A solution with measured COPC concentrations will be pumped through each column as effluent samples are collected at regular intervals over time. When constituent breakthroughs are verified, a "clean" solution (no COPCs) will be pumped through the columns and effluent samples will be collected as well. Samples will be analyzed by inductively coupled plasma -mass spectroscopy (ICP-MS) and ion chromatography (IC) in the Civil & Environmental Engineering laboratories at the EPIC Building, UNC Charlotte. COPCs measured in the column effluent as a function of cumulative pore volumes displaced will be analyzed using CXTFIT (Tang et al. 2010) to select the appropriate adsorption model and associated parameters of the partition coefficient Kd, either linear, Freundlich, or Langmuir. This allows use of a nonlinear partition coefficient in the event that the linear partition coefficient is not suitable for the modeled input concentration range. It is noted that some COPCs may have indeterminate Kd values by the column method due to solubility constraints and background conditions. In this case, batch sorption tests will be conducted in accordance with U.S. Environmental Protection Agency (EPA) Technical Resource Document EPA/530/SW-87/006-F, Batch -type Procedures for Estimating Soil Adsorption of Chemicals. COPC-specific solutions will be used to prepare a range of soil- to -solution ratios. After mixing, supernatant samples will be drawn and analyzed as described above. Plots of 38 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN sorbed versus dissolved COPC mass will be used to develop Kd terms. Batch tests will be performed in triplicate. When applied in the fate and transport modeling performed by MT31DMS, the Kds will determine the extent to which COPC transport in groundwater flow is attenuated by sorption. In effect, simulated COPC concentrations will be reduced, as will their rate of movement in advection in groundwater. Eight (8) soil core samples will be selected from representative material at the site for column tests to be performed in triplicate. Additionally, batch Kd tests, if performed, will be executed in triplicate. These Kd terms will apply to the selected soil core samples and background geochemistry of the test solution, including pH and oxidation-reduction potential. In order to make these results transferable to other soils and geochemical conditions at the site, UNCC recommends that the core samples with derived Kds and 20 to 25 additional core samples be analyzed for hydrous ferrous oxides (HFO) content, which is considered to the primary determinant of COPC sorption capacity of soils at the site. In the groundwater modeling study, the correlation between derived Kds and HFO content can be used to estimate Kd at other site locations where HFO and background water geochemistry, especially pH and oxidation-reduction potential, are known. If significant differences in water geochemistry are observed, batch geochemical modeling can be used to refine the Kd estimate, as described in section 7.1.1. UNCC recommends that core samples for Kd and HFO tests be taken from locations that are in the path of groundwater flowing from the ash impoundments. Determination of which COPCs will have Kd terms developed will be determined after review of the analyses on the site ash and review of the site groundwater analyses results. The COPCs selected will be considered simultaneously in each test. Competitive sorption is taken into account implicitly in the lab -measured sorption terms as COPCs are combined into a single test solution. Significant competition sorption is not anticipated given that COPCs in groundwater, where present, will be at trace levels. 7.7.3 MODFLOW/MT3DMS Modeling Process The MODFLOW groundwater model will be developed using the hydrostratigraphic layer geometry and properties of the site as described in this section. After the geometry and properties of the model layers are input, the model will be calibrated to existing water levels observed in the monitoring wells and ash basin. Infiltration into the areas outside of the ash basin will be estimated based on available information. Infiltration within the basin will be estimated based on available water balance information and pond elevation data provided by Duke Energy. The MT31VIS portion of the model will utilize the Kd terms and the input concentrations of constituents found in the ash. The leaching characteristics of ash are complex and expected to vary with time and as changes occur in the geochemical environment of the ash basin. Due to factors such as quantity of a particular constituent found in ash, mineral complex, solubility, and 39 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN geochemical conditions, the rate of leaching and leached concentrations of constituents will vary with time and respect to each other. The experience that UNCC brings to this process through their years of working with leaching and characterization of ash, particularly with Duke Energy ash, will be of particular value. Since the ash within the basin has been placed over a number of years, the analytical results from an ash sample collected during the groundwater assessment is unlikely to represent the current concentrations that are present in the hydrologic pathway between the ash basin and a particular groundwater monitoring well or other downgradient location. As a result of these factors and due to the time period involved in groundwater flow, • Concentrations may vary spatially over time, and • Peak concentrations may not yet have arrived at compliance wells. The selection of the initial concentrations and the predictions of the concentrations for constituents with respect to time will be developed with consideration of the following: • Site specific analytical results from leach tests (SPLP) and from total digestion of ash samples taken at varying locations and depths within the ash basin and ash storage areas (if present). Note that the total digestion concentrations, if used, would be considered an upper bound to concentrations and that the actual concentrations would be lower than the results from the total digestion. • Analytical results from appropriate groundwater monitoring wells or surface water sample locations outside of the ash basin. • Analytical results from monitoring wells installed in the ash basin pore water (screened in ash). • Published or other data on sequential leaching tests performed on similar ash. The information above will be used with constituent concentrations measured at the compliance boundary to calibrate the fate and transport model and to develop a representation of the concentration with respect to time for a particular constituent. The starting time of the model will correspond to the date that the ash basin was placed in service. The resulting model, which will be consistent with the calibration targets mentioned above, can then be used to predict concentrations over space and time. The model calibration process will consist of varying hydraulic conductivity and retardation within and between hydrostratigraphic units in a manner that is consistent with measured values of hydraulic conductivity, sorption terms, groundwater levels, and COPC concentrations. A sensitivity analysis will be performed for the fate and transport analyses. The model report will contain the information required by Section II of the NCDENR modeling guidelines, as applicable. Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN 7.7.4 Hydrostratigraphic Layer Development The three-dimensional configuration of the groundwater model hydrostratigraphic layers for a site will be developed using the Initial Site Conceptual Model (Section 5.0) and from pre-existing data and data obtained during the site investigation process. The thickness and extent for the various layers will be represented by a three-dimensional surface model for each hydrostratigraphic layer. For most sites the hydrostratigraphic layers will include ash, fills (both for dikes/dam and/or ash landfills/structural fills), soil/saprolite, transition zone (where present), and bedrock (Section 5.3). The boring data from the site investigation and from existing boring data, as available and provided by Duke Energy, will be entered into the RockWorks16TM program. This program, along with site -specific and regional knowledge of Piedmont hydrogeology, will be used to interpret and develop the layer thickness and extent across areas of the site where boring data is not available. The material layers will be categorized based on physical and material properties such as standard penetration blow count for soil/saprolite, and percent recovery and RQD for the transition zone and bedrock. The material properties required for the model such as total porosity, effective porosity, and specific storage for ash, fill, alluvium, and soil/saprolite will be developed from laboratory testing (grain size analysis as described in Section 7.1.1) and published data. Hydraulic conductivity (horizontal and vertical) of all layers will be developed utilizing existing site data, in -situ permeability testing (falling head, constant head, and packer testing where appropriate), slug tests in completed monitoring wells, laboratory testing of undisturbed samples (ash, fill, soil/saprolite), and from an extensive database of Piedmont soil and rock properties developed by HDR (Sections 7.1.1 and 7.1.6). The effective porosity (primarily fracture porosity) and specific storage of the transition zone and bedrock will be estimated from published data. 7.7.5 Domain of Conceptual Groundwater Flow Model The RBSS Ash Basin model domain encompasses that area where groundwater flow will be simulated to estimate the impacts of coal ash stored at the site. By necessity, the conceptual model domain extends beyond the ash storage area limits to physical or artificial hydraulic boundaries such that groundwater flow through the area is accurately simulated. Physical hydraulic boundary types may include specified head, head dependent flux, no -flow, and recharge at ground or water surface. Artificial boundaries, which are developed based on information from the site investigation, may include the specified head and no -flow types. The RBSS model domain is bounded approximately by the southern shore of Mountain Island Lake to the west, north, and east, the unnamed tributary to east between Mountain Island Lake and Horseshoe Bend Beach Road, Horseshoe Bend Beach Road to the south, and the unnamed drainage feature between Mountain Island Lake and Horseshoe Bend Beach Road to the west. The lower limit of the model domain coincides with the maximum depth of water yielding fractures in bedrock. The upper limit coincides with the upper surface of soil, fill, ash, landfilled 41 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN materials, or ash basin water surface, where present. The basis for selecting these boundaries is described in the following section. 7.7.6 Boundary Conditions for Conceptual Groundwater Flow Model The southern shore of Mountain Island Lake to the west, north, and east is considered to be a specified head type where the head is the average annual lake stage for steady-state simulations, or the stage observed simultaneously with groundwater level measurements at the site. Mountain Island Lake is considered to be the ultimate discharge boundary for all groundwater flowing through the model domain. The unnamed tributary to east between the Mountain Island Lake and Horseshoe Bend Beach Road is considered to be a specified head type. Horseshoe Bend Beach Road to the south is considered to be the no -flow type. The unnamed drainage feature between Mountain Island Lake and Horseshoe Bend Beach Road to the west is considered to be the no -flow type. The upper boundary across the site is the recharge type, where recharge is dependent on regional precipitation estimates and land cover type, either soil, fill, ash, or landfilled materials. Given that the hydrostratigraphic zones across the site are hydraulically connected, these boundaries are considered to be applicable to both local (shallow) and regional (deep) groundwater flow. If site conditions are encountered that warrant changes to the proposed extent of model, NCDENR will be notified. 7.7.7 Groundwater Impacts to Surface Water If the groundwater modeling predicts exceedances of the 2L Standards at or beyond the compliance boundary where the plume containing the exceedances would intercept surface waters, the groundwater model results will be coupled with modeling of surface waters to predict contaminant concentrations in the surface waters. This work would be performed by HDR in conjunction with UNCC. Model output from the fate and transport modeling (i.e. groundwater volume flux and concentrations of constituents with exceedances of the 2L Standards) will be used as input for surface water modeling in the adjacent water bodies (i.e., streams or reservoirs). The level of surface water modeling will be determined based on the potential for water quality impacts in the adjacent water body. That is, if the available mixing and dilution of the groundwater plume in the water body is sufficient that surface water quality standards are expected to be attained within a short distance a simple modeling approach will be used. If potential water quality impacts are expected to be such that the simple model approach is not sufficient, or if the water body type requires a more complex analysis, then a more detailed modeling approach will be used. A brief description of the simple and detailed modeling approaches is presented below. • Simple Modeling Approach — This approach will include the effects of upstream flow on dilution of the groundwater plume within allowable mixing zone limitations along with analytical solutions to the lateral spreading and mixing of the groundwater plume in the adjacent water body. This approach will be similar to that presented in EPA's Technical Support Document for Water Quality based Toxics Control (EPA/505/2-90-001) for Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 7.0 ASSESSMENT WORK PLAN ambient induced mixing that considers lateral dispersion coefficient, upstream flow and shear velocity. The results from this analysis will provide information constituent concentration as a function of the spatial distance from the groundwater input to the adjacent water body. Detailed Modeling Approach — This approach will involve the use of a water quality model that is capable of representing a multi -dimensional analysis of groundwater plume mixing and dilution in the adjacent water body. This method involves segmenting the water body into model segments (lateral, longitudinal and/or vertical) for calculating the resulting constituent concentrations spatially in the water body either in a steady-state or time -variable mode. The potential water quality models that could be used for this approach include: QUAL2K; CE-QUAL-W2; EFDC/WASP; ECOMSED/RCA; or other applicable models. With either modeling approach, the model output from the groundwater model will be coupled with the surface water model to determine the resulting constituent concentrations in the adjacent water body spatially from the point of input. These surface water modeling results can be used for comparison to applicable surface water quality standards to determine compliance. The development of the model inputs would require additional data for flow and chemical characterization of the surface water that would potentially be impacted. The specific type of data required (i.e., flow, chemical characterization, etc.) and the locations where this data would be collected would depend on the surface water body and the modeling approach selected. If modeling groundwater impacts to surface water is required, HDR and Duke Energy will consult with the DWR regional office to present those specific data requirements and modeling approach. 43 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 8.0 RISK ASSESSMENT 8.0 Risk Assessment To support the groundwater assessment and inform corrective action decisions, potential risks to human health and the environment will be assessed in accordance with applicable federal and state guidance. Initially, screening level human health and ecological risk assessments will be conducted that include development of conceptual site models (CSM) to serve as the foundation for evaluating potential risks to human and ecological receptors at the site. Consistent with standard risk assessment practices, separate CSMs will be developed for the human health and ecological risk evaluations. The purpose of the CSM is to identify potentially complete exposure pathways to environmental media associated with the site and to specify the types of exposure scenarios relevant to include in the risk analysis. The first step in constructing a CSM is to characterize the site and surrounding area. Source areas and potential transport mechanisms are then identified, followed by determination of potential receptors and routes of exposure. Potential exposure pathways are determined to be complete when they contain the following aspects: 1) a constituent source, 2) a mechanism of constituent release and transport from the source area to an environmental medium, 3) a feasible route of potential exposure at the point of contact (e.g., ingestion, dermal contact, and inhalation). Completed exposure pathways identified in the CSM are then evaluated in the risk assessment. Incomplete pathways are characterized by some gaps in the links between site sources and exposure. Based on this lack of potential exposure, incomplete pathways are not included in the estimation or characterization of potential risks, since no exposure can occur via these pathways. Preliminary constituents of potential concern (COPCs) for inclusion in the screening level risk assessments will be identified based on the preliminary evaluations performed at the site in conjunction with recommendations from NCDENR regarding coal ash constituents. Both screening level risk assessments will compare maximum constituent concentrations to appropriate risk -based screening values as a preliminary step in evaluating potential for risks to receptors. Based on results of the screening level risk assessments, a refinement of COPCs will be conducted and more definitive risk characterization will be performed as part of the corrective action process if needed. 8.1 Human Health Risk Assessment As noted above, the initial human health risk assessment (HHRA) will include the preparation of a CSM, illustrating potential exposure pathways from the source area to possible receptors. The information gathered in the CSM will be used in conjunction with analytical data collected as part of the Comprehensive Site Assessment (CSA). Although groundwater appears to be the primary exposure pathway for human receptors, a screening level evaluation will be performed to determine if other potential exposure routes exist. The HHRA for the site will include an initial comparison of constituent concentrations in various media to risk -based screening levels. The data will be screened against the following criteria: 44 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan _ Riverbend Steam Station Ash Basin 8.0 RISK ASSESSMENT • Soil analytical results will be compared to USEPA residential and industrial soil Regional Screening Levels (RSLs) (USEPA, November 2014 or latest update). • Groundwater results will be compared to USEPA tap water RSLs (USEPA, October 2014) and NCDENR Title 15A, Subchapter 2L Standards (NCDENR, 2006) • Surface water analytical results will be compared to USEPA national recommended water quality criteria and North Carolina surface water standards (USEPA, 2006; NCDENR, 2007). • The surface water classification as it pertains to drinking water supply, aquatic life, high/exceptional quality designations and other requirements for other activities (e.g., landfill permits, NPDES wastewater discharges) shall be noted. • Sediment results will be compared to USEPA residential soil RSLs (USEPA, November 2014 or latest update). • The soil, sediment, and groundwater data will also be compared to available background soil and groundwater data from previous monitoring and investigations. The results of this comparison will be presented in a table, along with recommendations for further evaluation. 8.1.1 Site -Specific Risk -Based Remediation Standards If deemed necessary, based on the results of the initial comparison to standards, Site -and media -specific risk -based remediation standards will be calculated in accordance with the Eligibility Requirements and Procedures for Risk -Based Remediation of Industrial Sites Pursuant to N.C.G.S. 130A-310.65 to 310.77, North Carolina Department of Environment and Natural Resources, Division of Waste Management, 29 July 2011. These calculations will include an evaluation of the following, based on site -specific activities and conditions: • Remediation methods and technologies resulting in emissions of air pollutants are to comply with applicable air quality standards adopted by the Environmental Management Commission (Commission). • Site -specific remediation standards for surface waters are to be the water quality standards adopted by the Commission. • The current and probable future use of groundwater shall be identified and protected. Site -specific sources of contaminants and potential receptors are to be identified, protected, controlled, or eliminated whether on or off the site of the contaminant source. • Natural environmental conditions affecting the fate and transport of contaminants (e.g., natural attenuation) shall be determined by appropriate scientific methods. • Permits for facilities subject to the programs or requirements of G.S. 130A-310.67(a) shall include conditions to avoid exceedances of applicable groundwater standards pursuant to Article 21 of Chapter 143 of the General Statutes; permitted facilities shall be designed to avoid exceedances of the North Carolina groundwater or surface water standards. Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 8.0 RISK ASSESSMENT • Soil shall be remediated to levels that no longer constitute a continuing source of groundwater contamination in excess of the site -specific groundwater remediation standards approved for the site. • The potential for human inhalation of contaminants from the outdoor air and other site - specific indoor air exposure pathways shall be considered during remediation, if applicable. • The site -specific remediation standard shall protect against human exposure to contamination through the consumption of contaminated fish or wildlife and through the ingestion of contaminants in surface water or groundwater supplies. • For known or suspected carcinogens, site -specific remediation standards shall be established at levels not to exceed an excess lifetime cancer risk of one in a million. The site -specific remediation standard may depart from this level based on the criteria set out in 40 Code of Federal Regulations § 300.430(e)(9) (July 1, 2003). The cumulative excess lifetime cancer risk to an exposed individual shall not be greater than one in 10,000 based on the sum of carcinogenic risk posed by each contaminant present. • For systemic toxicants (non -carcinogens), site -specific remediation standards shall be set at levels to which the human population, including sensitive subgroups, may be exposed without any adverse health effect during a lifetime or part of a lifetime. Site - specific remediation standards for systemic toxicants shall incorporate an adequate margin of safety and shall take into account cases where two or more systemic toxicants affect the same organ or organ system. • A comparison will also be made between the concentrations detected in ground water and the constituent specific primary drinking water standards, as well as the concentrations in impacted vs. background levels to determine if there are other considerations that will need to be addressed in risk management decision making. The site -specific remediation standards for each medium shall be adequate to avoid foreseeable adverse effects to other media or the environment that are inconsistent with the state's risk -based approach. 8.2 Ecological Risk Assessment The screening level ecological risk assessment (SLERA) for the site will begin with a description of the ecological setting and development of the ecological CSM specific to the ecological communities and receptors that may potentially be at risk. This scope is equivalent to Step 1: preliminary problem formulation and ecological effects evaluation (USEPA, 1998). The screening level evaluation will include compilation of a list of potential ecological receptors (e.g., plants, benthic invertebrates, fish, birds, etc.). Additionally, an evaluation of sensitive ecological populations will be performed. Preliminary information on listed rare animal species at or near the site will be compiled from the North Carolina Natural Heritage Program database and U.S. Fish and Wildlife Service (USFWS) county list to evaluate the potential for presence of rare or endangered animal and plant species. Rare natural communities will also be evaluated and identified if near the site. 46 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 8.0 RISK ASSESSMENT Appropriate state and federal natural resource trustees and their representatives (e.g., USFWS) will be contacted to determine the potential presence (or lack thereof) of sensitive species or their critical habitat at the time the screening is performed. If it is determined a sensitive species or critical habitat is present or potentially present, a survey of the appropriate area will be conducted. If it is found that sensitive species are utilizing the site, or may in the future, a finding concerning the likelihood of effects due to site -related contaminants or activities should be developed and presented to the trustee agency. The preliminary ecological risk screening will also include, as the basis for the CSM, a description of the known fate and transport mechanisms for site -related constituents and potentially complete pathways from assumed source to receptor. An ecological checklist will be completed for the site as required by the Guidelines for Performing Screening Level Ecological Risk Assessment within North Carolina (NCDENR, 2003). Following completion of Step 1, the screening level exposure estimate and risk calculations (Step 2), will be performed in accordance with the Guidelines for Performing Screening Level Ecological Risk Assessment within North Carolina (NCDENR, 2003). Step 2 estimates the level of a constituent a plant or animal is exposed to at the site and compares the maximum constituent concentrations to Ecological Screening Values (ESVs). Maximum detected concentrations or the maximum detection limit for non -detected constituents of potential concern (those metals or other chemicals present in site media that may result in risk to ecological receptors) will be compared to applicable ecological screening values intended to be protective of ecological receptors (including those sensitive species and communities noted above, where available) to derive a hazard quotient (HQ). An HQ greater than 1 indicates potential ecological impacts cannot be ruled out. ESVs will be taken from the following and other appropriate sources: • USEPA Ecological Soil Screening Levels • USEPA Region 4 Recommended Ecological Screening Values • USEPA National Recommended Water Quality Criteria and North Carolina Standards The state's SLERA guidance (NCDENR, 2003) requires that constituents be identified as a Step 2 COPC as follows: • Category 1 - Contaminants with a maximum detection exceeding the ESV • Category 2 - Undetected contaminants with a laboratory sample quantitation limit exceeding the ESV • Category 3 - Detected contaminants with no ESV • Category 4 - Undetected contaminants with no ESV Exceedances of the ESVs indicate the potential need for further evaluation of ecological risks at the site. The frequency, magnitude, pattern, and basis of any exceedances should also be considered. 47 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 8.0 RISK ASSESSMENT The process ultimately identifies a Scientific -Management Decision Point (SMDP) to determine if ecological threats are absent and no further assessment is needed; if further assessment should be performed to determine whether risks exist; or if there is the possibility of adverse ecological effects, and therefore, a determination made on whether a more detailed ecological risk and/or habitat assessment is needed, and if so, the scope of the assessment(s). 48 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 9.0 CSA REPORT 9.0 CSA Report The CSA report will be developed in the format required by the NORR, which include the following components: • Executive Summary • Site History and Source Characterization • Receptor Information • Regional Geology and Hydrogeology • Site Geology and Hydrogeology • Soil Sampling Results • Groundwater Sampling Results • Hydrogeological Investigation • Groundwater Modeling results • Risk Assessment • Discussion • Conclusions and Recommendations • Figures • Tables • Appendices The CSA report will provide the results of one iterative assessment phase. No off -site assessment or access agreements are anticipated to be utilized during this task, other than for the possible additional off -site wells discussed in Section 6.0. The CSA will be prepared to include the items contained in the Guidelines For Comprehensive Site Assessment (guidelines), included as attachment to the NORR, as applicable. HDR will provide the applicable figures, tables, and appendices as listed in the guidelines. As part of CSA deliverables, the following tables, graphs, and maps will be provided, at a minimum: • Box (whisker) plots for locations sampled on four or more events showing the quartiles of the data along with minimum and maximum. Plots will be aligned with multiple locations on one chart. Similar charts will be provided for each COC, • Stacked time -series plots will be provided for each COC. Multiple wells/locations will be stacked using the same x-axis to discern seasonal trends. Turbidity, dissolved oxygen, ORP, or other constituents will be shown on the plots where appropriate to demonstrate influence. • Piper and/or stiff diagrams showing selected monitoring wells and surface water locations as separate symbols. • Correlation charts where applicable. • Orthophoto potentiometric maps for shallow, deep, and bedrock wells. 49 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan �� Riverbend Steam Station Ash Basin 9.0 CSA REPORT • Orthophoto potentiometric difference maps showing the difference in vertical heads between selected flow zones. • Orthophoto iso-concentration maps for selected COCs and flow zones. • Orthophoto map showing the relationship between groundwater and surface water samples for selected COCs. • Geologic cross -sections. • Photographs of select split spoon samples and cores at each boring location. • Others as appropriate Recommendations will be provided in the CSA report for a sampling plan to be performed after completion this groundwater assessment. The sampling plan will describe the recommended sampling frequency, constituent and parameter list, and proposed sampling locations, including monitoring wells, seeps, and surface waters as required. 50 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin 10.0 PROPOSED SCHEDULE 10.0 Proposed Schedule Duke Energy will submit the CSA Report within 180 days of NCDENR approval of this work plan. The anticipated schedule for implementation of field work, evaluation of data, and preparation of the work plan is presented below. Work Plan Schedule Activity Start Date Duration to Complete Field Exploration Program 10 days following Work Plan approval 75 days Receive Laboratory Data 14 days following end of Exploration Program 15 days Evaluate Lab/Field Data, Develop SCM 5 days following receipt of Lab Data 30 days Prepare and Submit CSA 10 days following Work Plan approval 170 days In addition, the following permits and approvals from NCDENR will be required to commence field work: If site land disturbance, equal to or greater than 1 acre, is required for access and clearing associated with drilling work, an erosion and sedimentation control permit must be approved by the NCDENR Division of Energy, Mineral and Land Resources, Land Quality Section. Installation of monitoring wells and/or soil borings on the dams and/or dikes at the ash basin site must be approved by the NCDENR Division of Energy, Mineral and Land Resources, Dam Safety Section prior to drilling. Information on the location and well construction details will be submitted as the locations are finalized. Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Riverbend Steam Station Ash Basin 11.0 REFERENCES 11.0 References 1. ARCADIS G&M of North Carolina, Inc., 2007. Ash Basin Drilling Services for: Riverbend Steam Station, Mount Holly, North Carolina. 2. Cunningham, W. L. and Daniels, C. C, III, 2001. Investigation of ground -water availability and quality in Orange County, North Carolina: U. S. Geological Survey, Water -Resources Investigations Report 00-4286, 59 p. 3. Daniel, C.C., III, and Sharpless, N.B., 1983, Ground -water supply potential and procedures for well -site selection upper Cape Fear basin, Cape Fear basin study, 1981- 1983: North Carolina Department of Natural Resources and Community Development and U.S. Water Resources Council in cooperation with the U.S. Geological Survey, 73 p. 4. Daniels, John L. and Das, Gautam P. 2014. Practical Leachability and Sorption Considerations for Ash Management, Geo-Congress 2014 Technical Papers: Geo- characterization and Modeling for Sustainability. Wentworth Institute of Technology, Boston, MA. 5. EPRI, 1993. Electric Power Research Institute, Physical and Hydraulic Properties of Fly Ash and Other By -Products from Coal Combustion, EPRI TR-101999. February 1993. 6. EPRI, 2004. Electric Power Research Institute, "Chemical Attenuation Coefficients for Arsenic Species Using Soil Samples Collected from Selected Power Plant Sites: Laboratory Studies", Product ID: 1005505, December 2004. 7. EPRI, 2009. Electric Power Research Institute, Technical Update - Coal Combustion Products - Environmental Issues - Coal Ash: Characteristics, Management and Environmental Issues, EPRI 1019022. September 2009. 8. EPRI, 2014. Electric Power Research Institute, Assessment of Radioactive Elements in Coal Combustion Products, 2014 Technical Report 3002003774, Final Report August 2014. 9. Fenneman, Nevin Melancthon, 1938. "Physiography of eastern United States." McGraw- Hill. 1938. 10. Freeze, R. A., J. A. and Cherry, Ground Water, Englewood Cliffs, NJ, Prentice -Hall, 1979. 11. Gillispie, EC., Austin, R., Abraham, J., Wang, S., Bolich, R., Bradley, P., Amoozegar, A., Duckworth, O., Hesterberg, D., and Polizzotto, ML. Sources and variability of manganese in well water of the North Carolina Piedmont. Water Resources Research Institute of the University of North Carolina System Annual 2014 Conference, Raleigh, NC, March 2014. Poster Presentation. 12. Harned, D. A. and Daniel, C. C., III, 1992, The transition zone between bedrock and regolith: Conduit for contamination?, p. 336-348, in Daniel, C. C., III, White, R. K., and Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan ��� Riverbend Steam Station Ash Basin 11.0 REFERENCES Stone, P. A., eds., Groundwater in the Piedmont: Proceedings of a Conference on Ground Water in the Piedmont of the Eastern United States, October 16-18, 1989, Clemson University, 693p. 13. HDR, 2013. "Groundwater Assessment, Duke Energy Carolinas, LLC, Riverbend Steam Station Ash Basin, NPDES Permit NC0004961." 14. HDR, 2014A. `Riverbend Steam Station Ash Basin Drinking Water Supply Well and Receptor Survey, NPDES Permit NC0004961." 15. HDR, 2014B. "Riverbend Steam Station Ash Basin Supplement to Drinking Water Supply Well and Receptor Survey." 16. Heath, R.C., 1980, Basic elements of groundwater hydrology with reference to conditions in North Carolina: U.S. Geo-logical Survey Open -File Report 80-44, 86 p. 17. Heath, R.C. 1984, "Ground -water regions of the United States." U.S. Geological Survey Water -Supply Paper 2242, 78 p. 18. Krauskopf, K.B., 1972. Geochemistry of micronutrients: in Micronutrients in Agriculture, J.J. Mortvedt, F.R. Cox, L.M. Shuman, and R.M. Walsh, eds., Soil Science Society of America, Madison, Wisconsin, p. 7-36. 19. LeGrand, H.E. 1988. Region 21, Piedmont and Blue Ridge. In Hydrogeology, The Geology of North America, vol. 0-2, ed. W.B. Back, J.S. Rosenshein, and P.R. Seaber, 201-207. Geological Society of America. Boulder CO: Geological Society of America. 20. LeGrand, H.E. 1989. A conceptual model of ground water settings in the Piedmont region. In Ground Water in the Piedmont , ed. C.C. Daniel III, R.K. White, and P.A. Stone, 693. Proceedings of a Conference on Ground Water in the Piedmont of the Eastern United States, Clemson University, Clemson, South Carolina. Charlotte, NC: U.S. Geological Survey. 21. LeGrand, Harry E., 2004. "A Master Conceptual Model for Hydrogeological Site Characterization in the Piedmont and Mountain Region of North Carolina, A Guidance Manual," North Carolina Department of Environment and Natural Resources Division of Water Quality, Groundwater Section. 22. MACTEC, 2011. Amended Ash Basin Monitoring Well Installation Report, Riverbend Steam Station, MACTEC Project No. 6228-10-5284. 23. NCDENR, 2003. Division of Waste Management - Guidelines for Performing Screening Level Ecological Risk Assessments within North Carolina. 24. NCDENR Memorandum "Performance and Analysis of Aquifer Slug Tests and Pumping Tests Policy," May 31, 2007. 25. NCDENR document, "Hydrogeologic Investigation and Reporting Policy Memorandum," dated May 31, 2007. 53 Duke Energy Carolinas, LLC I Proposed Groundwater Assessment Work Plan Piverbend Steam Station Ash Basin 11.0 REFERENCES 26. NCDENR DWQ NCDENR Division of Water Quality, "Evaluating Metals in Groundwater at DWQ Permitted Facilities: A Technical Assistance Document for DWQ Staff", July 2013. 27. Parkhurst, D.L., and Appelo, C.A.J., 2013, Description of input and examples for PHREEQC version 3—A computer program for speciation, batch -reaction, one- dimensional transport, and inverse geochemical calculations: U.S. Geological Survey Techniques and Methods, book 6, chap. A43, 497 p. 28. Tang, G., Mayes, M. A., Parker, J. C., & Jardine, P. M. (2010). CXTFIT/Excel—A modular adaptable code for parameter estimation, sensitivity analysis and uncertainty analysis for laboratory or field tracer experiments. Computers & Geosciences, 36(9), 1200-1209. 29. USEPA, 1987. Batch -type procedures for estimating soil adsorption of chemicals Technical Resource Document 530/SW-87/006-F. 30. USEPA, 1997. Ecological Risk Assessment Guidance for Superfund: Process for Designing and Conducting Ecological Risk Assessments 31. USEPA, 2001. Region 4 Ecological Risk Assessment Bulletins —Supplement to RAGS. 32. USEPA, 1998. Guidelines for Ecological Risk Assessment. 33. US FWS, 2009. Range -wide Indiana Bat Protection and Enhancement Plan Guidelines, at http:Hwww.fws.qov/fran kfort/pdf/inbatpepguideIines.pdf. 34. US Geological Survey Geological Survey, Akio Ogata and R.B. Banks Professional Paper 411-A "A Solution of Differential Equation of Longitudinal Dispersion in Porous Media", 1961 35. US Geological Survey (USGS). 1997. Radioactive elements in coal and fly ash: abundance, forms, and environmental significance. U.S. Geological Survey Fact Sheet FS-163-97. 36. USEPA, 1998. Study of Hazardous Air Pollutant Emissions from Electric Utility Steam Generating Units —Final Report to Congress. Volume 1. Office of Air Quality, Planning and Standards. Research Triangle Park, NC 27711, EPA-453/R-98-004a. 37. USEPA, 1998. Report to Congress Wastes from the Combustion of Fossil Fuels, Volume 2 Methods, Findings, and Recommendations lip CiiZfF`f�7t yr ell ,.� 1 . , , '�,` �f --� _ ..` Cry S , ��� �,'� -` �•,� X N E 0,0 r 4 r ASH BASIN /jr Powerpla - • Uu Fay e�+JIa , O RIVERBEND STEAM STATION 10 iNC 16 : _. l 111 ��,, Rozzelle Bridge \ 48 NOTES: ti r 6 I. SOURCES: USGS TOPOGRAPHIC MAP - MT. ISLAND LAKE, CREATED 1993. USGS TOPOGRAPHIC MAP - LAKE NORMAN �l s„ SOUTH, CREATED 1993. SCALE (FEET) 1000 0 1000 2000 SITE LOCATION MAP DUKE ENERGY CAROLINAS, LLC RIVERBEND STEAM STATION NPDES PERMIT NO. NC0004961 GASTON COUNTY, NORTH CAROLINA DATE DEC. 30, 2014 FIGURE M W-3S ' MW-3D MW-4S ,„ „ ', ..�.. �G x Ao �F x;- =s�tiM M W-11SR t �Qys�=O t MW-11DR �� OG�gTq AFR yFRGY O✓�t ✓3✓/i Q �'MW-SD AT MW-2S V JZ QUO MW-2D,, �O wa• ASH BASIN `°, _ Q M W-5S CT��Y�/F'�P Y O d� � � $ SECC+NDAWCELL MW-6S -6D MW ,R -10, 1 " MW-14t , Yi �.NMI�. ASH BASIN ,� � x PRIMARYCELL t , * uP * v -: r���'� a� ♦� r F' �$° A m g' `w t � k 'x % R "`� .rt „i Tom`' Y '�• ys - R fiR ° � `� '// ;.. »a" ti.. � . - , '.v z,.. •, v,t�'rw:r ^r .. ::. x i .�^,`, �i"r sa€: e,:�"�: d r» ,a t�. �;l s T"..... �,;�•�. �. � iK .��-v.�. 'n �,,,+>;, '«r�.,.', �< , „ ,1� -',.�•.; as ,, a ,..�,. , ♦ '-: ,...,... ...�' ... :`fir az .i<.,,•a. g x , tz. ,,�..� Ilu+,r,i � '', -' �.::�. .,.. 7 .., ,. :..:; .. ,.:: . .,w.,... 'iw ....,. �., ..,: _ w.r r„ �. e•m. h� a k ,w, • w,. S .� ° �° atiG t t `•_�`.. �,.,R .. ,d ^'-'s :_ .. . ` ... - P 6". , _: 9,., p . _;,. .° .:,. ..� :: a >,„�kf , x m-,•«rtv..� k ` :i: TW� � � 3 . tla. .:. , .n�-fir'" '. K aA R"w f, ,4...h•; ,., fx. `.r i` /!�' - _ ''• ' .r'` .r .,,� ^ T «;:. .n , r t y # �. ..i►f 3 :� a ' e r:; .n,s, t a Z. �h. �� � ��"�:� „s , a: ° a :i� Ap wy , eo.. w i ° � Er '� ' z.. �/; -A-. '... w ,@:•� •�- > g ��y } . ; : _ � 3�«' a° ��"-�} `, R.�z�� ti,`. k. �... P � '.. i. %. � P• \' ..;g.a £C� � ..,.�yC. ?5 ,xv,+"- ,lye `�'3�• NOTES: 1. PARCEL DATA FOR THE SITE WAS OBTAINED FROM DUKE ENERGY REAL ESTATE AND IS APPROXIMATE. 2. ASH STORAGE BOUNDARY AND CINDER STORAGE BOUNDARY ARE APPROXIMATE. 3. AS -BUILT MONITORING WELL LOCATIONS PROVIDED BY DUKE ENERGY. 4. SHALLOW MONITORING WELLS (S) - WELL SCREEN INSTALLED ACROSS THE SURFICIAL WATER TABLE. S. DEEP MONITORING WELLS (D) - WELL SCREEN INSTALLED IN THE TRANSITION ZONE BETWEEN COMPETENT BEDROCK AND THE REGOLITH. 6. TOPOGRAPHY DATA FOR THE SITE WAS OBTAINED FROM NC DOT GEOGRAPHIC INFORMATION SYSTEM (GIS) WEB SITE. 7. ORTHOPHOTOGRAPHY WAS OBTAINED FROM WSP (DATED APRIL 2014). 8. THE COMPLIANCE BOUNDARY IS ESTABLISHED ACCORDING TO THE DEFINITION FOUND IN 15A NCAC 02L .0107 (a). g 4� t �F pt i4 e SCALE (FEET) 400' 0 400' 600, P, = 600' SITE LAYOUT MAP DUKE ENERGY CAROLINAS, LLC RIVERBEND STEAM STATION NPDES PERMIT NO. NC0004961 GASTON COUNTY, NORTH CAROLINA LEGEND: DUKE ENERGY PROPERTY BOUNDARY ASH BASIN COMPLIANCE BOUNDARY ASH BASIN COMPLIANCE BOUNDARY COINCIDENT WITH DUKE ENERGY PROPERTY BOUNDARY ASH BASIN WASTE BOUNDARY ASH OR CINDER STORAGE AREA BOUNDARY STREAM TOPOGRAPHIC CONTOUR (4 FOOT) EXISTING ASH BASIN COMPLIANCE GROUNDWATER MONITORING WELL LOCATION EXISTING ASH BASIN VOLUNTARY GROUNDWATER MONITORING WELL LOCATION EXISTING WATER SUPPLY WELL DATE DEC. 30, 2M 4 FIGURE 2 Table 1. Groundwater Monitoring Requirements Well Nomenclature Constituents and Parameters Frequency Antimony Chromium Nickel Thallium Monitoring Wells: MW-7SR1 Arsenic Copper Nitrate Water Level MW-71), MW-8S, MW-81, MW-8D, *MW-10, Barium Iron pH Zinc March, July, MW-81),'MW-9, Boron Lead Selenium November MW-11SR, MW-11DR, "MW-13, Cadmium Manganese Sulfate MW-14, MW-15 Chloride Mercury TDS Note: Monitoring wells marked with * are located inside of the compliance boundary. Tables - Page 1 TABLE 2 - EXCEEDANCES OF 2L STANDARDS DECEMBER 2010 — OCTOBER 2014 Parameter Units 2L Standard Iron 300 Manganese pH Antimony Ng/L SU pg/L 50 6.5 - 8.5 1 ** Well ID Range of Exceedances MW-7SR 445 — 790 67 — 413 5.0 — 5.4 No Exceedances MW-71) No Exceedances No Exceedances 5.5 — 5.8 1.04 MW-8S No Exceedances 64 — 144 4.3 — 5.2 No Exceedances MW-81 436 — 2,460 52 — 290 5.7 — 6.4 No Exceedances MW-81) 777 — 4,160 82 — 671 6.3— 6.5 No Exceedances MW-9* 341 — 1,950 62 — 147 5.8 — 6.4 No Exceedances MW-10* 310 — 1,420 67 — 355 4.8 — 5.4 No Exceedances MW-11SR 486 59 - 384 5.6 — 6.1 No Exceedances MW-11 DR No Exceedances 51 — 168 5.6 - 5.8 No Exceedances MW-13* 7,690— 37,700 8,070 — 11,200 5.8 — 6.4 No Exceedances MW-14 371 — 935 55 — 353 No Exceedances No Exceedances MW-15 399 - 465 52 — 86 5.1 — 5.3 No Exceedances Notes: Monitoring wells marked with * are located inside of the compliance boundary. ** Antimony concentration is an Interim Maximum Allowable Concentration (IMAC). Tables - Page 2 Table 3 - SPLP Leaching Analytical Results Analytical Parameter pH Aluminum Antimony Arsenic Barium Beryllium Boron Cadmium Calcium Chloride Chromium Cobalt Copper Fluoride Iron Lead Units Su mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L 15A NCAC 02L .0202(g) Groundwater Quality Standard 6.5 - 8.5 NE 0.001* 0.01 0.7 0.004* 0.7 0.002 NE 250 0.01 0.001* 1 2 0.3 0.015 Analytical Method 200.8 200.8 200.7 200.7 200.8 200.7 200.7 200.8 200.7 200.7 200.8 Site Name Protocol Sample Collection Date Ponded TCLP 1/1/1997 7.5 N/A N/A 0.098 1.3 N/A N/A <0.01 N/A N/A <0.02 N/A N/A N/A N/A <0.09 Ponded TCLP 1/1/1999 0 N/A N/A <0.1 0.96 N/A N/A <0.03 N/A N/A <0.04 N/A N/A N/A N/A <0.09 Ponded TCLP 1/1/2000 6.5 N/A N/A 0.14 2.5 N/A N/A <0.03 N/A N/A <0.04 N/A N/A N/A N/A <0.09 Ponded SPLP 1/1/2003 5.97 N/A N/A 0.054 0.1 N/A 0.178 <0.001 12.172 <1 0.001 N/A <0.002 <1 <0.01 <0.002 Ponded SPLP 12/12/2006 7.56 N/A 0.008 0.21 0.089 N/A 0.26 <0.069 11 0.42 0.004 N/A <0.014 0.26 N/A <0.34 Reuse Comp TCLP 10/14/2010 6.5 N/A N/A <0.1 0.679 N/A N/A <0.01 N/A N/A <0.05 N/A N/A N/A N/A <0.05 Tables - Page 3 Table 3 - SPLP Leaching Analytical Results Analytical Parameter Magnesium Manganese Mercury Molybdenum Nickel Nitrate as N Phosphorus Potassium Selenium Silver Sodium Strontium Sulfate Thallium Zinc Units mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L 15A NCAC 02L .0202(g) Groundwater Quality Standard NE 0.05 0.001 NE 0.1 10 NE NE 0.02 20 NE NE 250 0.0002* 1 Analytical Method 200.7 200.8 245.1 200.8 200.7 200.7 200.8 200.7 200.8 200.7 Site Name Protocol Sample Collection Date Ponded TCLP 1/1/1997 N/A N/A <0.01 N/A N/A N/A N/A N/A <0.06 0.1 N/A N/A N/A N/A N/A Ponded TCLP 1/1/1999 N/A N/A <0.01 N/A N/A N/A N/A N/A <0.13 <0.005 N/A N/A N/A N/A N/A Ponded TCLP 1/1/2000 N/A N/A <0.01 N/A N/A N/A N/A N/A <0.13 <0.005 N/A N/A N/A N/A N/A Ponded SPLP 1/1/2003 1.414 0.001 <0.001 N/A <0.002 <1 0.188 2.6 <0.004 <0.0005 N/A N/A 35.92 N/A 0.009 Ponded SPLP 12/12/2006 2 <0.0069 <0.014 N/A 0.001 0.71 0.74 0.7 0.015 <0.34 N/A N/A 16 N/A 0.007 Reuse Comp TCLP 10/14/2010 N/A N/A <0.01 N/A N/A N/A N/A N/A <0.1 <0.05 N/A N/A N/A N/A N/A Tables - Page 4 Table 3 - SPLP Leaching Analytical Results Notes: 1. TDS = Total dissolved solids SPLP = Synthetic Precipitation Leaching Procedure TCLP = Toxicity Characteristic Leaching Procedure 2. Units: mg/L = milligrams per liter pg/L = micrograms per liter 3. " IMAC (interim maximum allowable concentration) 4. Highlighted values indicate values that exceed the 15A NCAC 2L Standard 5. Analytical results with "<" preceding the result indicates that the parameter was not detected at a concentration which attains or exceeds the laboratory reporting limit Tables - Page 5 Table 4 - Groundwater Analytical Results Well Name MW-10 MW-10 MW-10 MW-10 MW-10 MW-10 MW-10 MW-10 MW-10 MW-10 MW-10 MW-10 MW-11 DR MW-11 DR MW-11 DR MW-11DR MW-11 DR MW-11 DR MW-11 DR MW-11 DR MW-11 DR MW-11DR MW-11 DR MW-11SR MW-11 SR MW-11 SR MW-11 SR MW-11SR MW-11 SR MW-11SR MW-11 SR MW-11 SR MW-11 SR MW-11SR MW-12 MW-12 MW-13 MW-13 MW-13 MW-13 MW-13 MW-13 MW-13 MW-13 MW-13 MW-13 MW-13 MW-13 MW-14 MW-14 MW-14 MW-14 MW-14 MW-14 MW-14 MW-14 MW-14 MW-14 MW-14 Analytical Parameter Depth to Temp. DO Water Units Feet C mg/L 15A NCAC 02L .0202(g) Groundwater Quality Standard NE NE NE Analytical Method Well Type Hydrostratigraph! c Unit Sample Collection Date C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C Cond. pH ORP pmhos/cm SU my NE 6.5-8.5 NE Field Measurements Turbidity Alkalinity NTU mg/L CaCO3 mg/L HCO3 NE NE NE 2320134d N/A Total ompliance Residuum 12/6/2010 10.21 15.2 N/A 71.4 5.57 N/A 182 ompliance Residuum 2/1/2011 9.77 14.1 N/A 84.7 5.4 N/A 84.1 ompliance Residuum 6/7/2011 10.26 15.93 N/A 79.4 5.3 N/A 6.92 ompliance Residuum 10/3/2011 9.87 16.81 N/A 133.6 5.36 N/A 29.7 ompliance Residuum 2/6/2012 9.34 14.67 1.52 65 5.3 408 10.7 ompliance Residuum 6/4/2012 9.95 15.53 1.01 68 5.26 401 3.19 ompliance Residuum 10/3/2012 10.03 17.87 0.88 124 5.41 243 8.19 ompliance Residuum 2/4/2013 9.52 14.88 2.08 86 5.29 388 5.23 ompliance Residuum 6/4/2013 9.86 14.84 1.39 65 4.8 444 7.73 ompliance Residuum 10/15/2013 10.54 17.37 0.28 123 5.28 311 6.95 ompliance Residuum 2/3/2014 9.62 15.35 1.77 78 5.22 375 5.81 ompliance Residuum 6/2/2014 10.12 14.99 0.96 79 5.24 470 21.7 ompliance Bedrock 2/1/2011 24.56 16.71 N/A 153.9 5.83 N/A 2.6 ompliance Bedrock 6/6/2011 24.72 19.39 N/A 154.6 5.63 N/A 0.68 ompliance Bedrock 10/3/2011 24.71 17.14 N/A 155.4 5.55 N/A 3.4 ompliance Bedrock 2/6/2012 24.17 17.16 0.78 148 5.67 262 0.64 ompliance Bedrock 6/4/2012 24.58 17.78 0.72 153 5.66 239 0.18 ompliance Bedrock 10/3/2012 24.67 18.28 0.51 154 5.75 151 0.94 ompliance Bedrock 2/4/2013 24.22 17.31 0.95 153 5.67 232 1.24 ompliance Bedrock 6/3/2013 24.26 17.83 0.65 152 5.64 239 2.24 ompliance Bedrock 10/14/2013 25.46 18.11 0.79 151 5.76 198 2.24 ompliance Bedrock 2/3/2014 24.41 18.06 1.12 149 5.65 262 1.94 ompliance Bedrock 6/2/2014 24.69 17.85 0.95 149 5.71 431 1.55 ompliance Residuum 2/1/2011 24.7 16.56 N/A 167.7 6.07 N/A 11 ompliance Residuum 6/6/2011 24.87 19.7 N/A 162.7 5.79 N/A 3.44 ompliance Residuum 10/3/2011 24.86 17.06 N/A 161.8 5.59 N/A 6.13 ompliance Residuum 2/6/2012 24.3 17.19 0.43 153 5.72 96 2.72 ompliance Residuum 6/4/2012 24.73 17.66 0.53 156 5.72 122 2.35 ompliance Residuum 10/3/2012 24.83 18.27 0.45 158 5.78 82 1.37 ompliance Residuum 2/4/2013 24.35 17.44 0.53 156 5.72 118 2.05 ompliance Residuum 6/3/2013 24.43 18.05 0.59 155 5.67 171 3.53 ompliance Residuum 10/14/2013 25.59 18.13 0.6 152 5.77 155 5.07 ompliance Residuum 2/3/2014 24.54 17.83 0.65 150 5.68 138 2.55 ompliance Residuum 6/2/2014 24.84 19.01 0.75 151 5.73 242 3.34 ompliance Residuum 12/6/2010 11.37 15.84 N/A 144.6 5.89 N/A 11.5 ompliance Residuum 2/1/2011 11.15 15.88 N/A 141.9 5.89 N/A 11.7 ompliance Residuum 12/6/2010 10.42 16.42 N/A 198.2 6.27 N/A 5.26 ompliance Residuum 2/1/2011 10.11 14.75 N/A 296.9 6.35 N/A 3.26 ompliance Residuum 6/7/2011 10.77 16.48 N/A 203 6.22 N/A 6.4 ompliance Residuum 10/4/2011 10.36 17.55 N/A 213.6 6.29 N/A 7.67 ompliance Residuum 2/6/2012 9.67 15.15 0.56 205 5.99 138 3.14 ompliance Residuum 6/5/2012 10.34 16.01 0.06 202 6.18 139 3.15 ompliance Residuum 10/3/2012 10.23 18.46 0.59 218 6.28 100 2.4 ompliance Residuum 2/5/2013 9.91 15.36 0.19 212 6.13 178 3.75 ompliance Residuum 6/3/2013 9.58 15.83 0.11 185 5.97 234 9.32 ompliance Residuum 10/15/2013 10.93 17.79 0.83 145 5.8 273 18.8 ompliance Residuum 2/3/2014 9.88 15.86 0.22 313 5.97 99 18.3 ompliance Residuum 6/2/2014 10.47 14.65 0.2 215 6.17 153 4.67 ompliance Residuum 12/6/2010 7.42 15.13 N/A 175.3 6.86 N/A 25.6 ompliance Residuum 2/1/2011 7.19 14.23 N/A 194.1 6.95 N/A 14.4 ompliance Residuum 6/7/2011 7.79 17.22 N/A 215.8 6.79 N/A 6.09 ompliance Residuum 10/4/2011 7.47 17.18 N/A 196.1 6.8 N/A 12.9 ompliance Residuum 2/6/2012 6.81 15.12 0.98 203 6.81 225 4.31 ompliance Residuum 6/5/2012 7.63 15.69 0.42 199 6.71 262 1.85 ompliance Residuum 10/3/2012 7.42 17.94 0.52 197 6.73 209 2.04 ompliance Residuum 2/4/2013 7.05 15.34 1.85 214 6.79 230 3.92 ompliance Residuum 6/3/2013 7.73 16.07 0.52 205 6.85 310 3.24 ompliance Residuum 10/15/2013 8.28 17.68 0.33 202 6.63 319 5.48 ompliance Residuum 2/3/2014 7.07 14.64 0.79 214 6.74 349 8.64 Aluminum Antimony Arsenic Barium Beryllium mg/L C032 Ng/L pg/L pg/L pg/L pg/L NE NE 1* 10 700 4* N/A 0 200.8 200.8 200.7 N/A Total Dissolved Total Dissolved Total Dissolved Total Total N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ 6.8 N/A N/A N/ 5.2 N/A N/A N/ 6.8 N/A N/A N/ 5.3 N/A N/A N/ <5 N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ 14 N/A N/A N/ 14 N/A N/A N/ 14 N/A N/A N/ 14 N/A N/A N/ 12 N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ 15 N/A N/A N/ 14 N/A N/A N/ 15 N/A N/A N/ 14 N/A N/A N/ 13 N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ 81 N/A N/A N/ 69 N/A N/A N/ 51 N/A N/A N/ 67 N/A N/A N/ 40 N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ N/A N/A N/A N/ 56 N/A N/A N/ 66 N/A N/A N/ 66 N/A N/A N/ 67 N/A N/A N/ A N/A <1 N/A <1 N/A 71 A N/A <1 N/A <1 N/A 63 A N/A <1 N/A <1 N/A 41 A N/A <1 N/A <1 N/A 73 A N/A <1 N/A <1 N/A 44 A N/A <1 N/A <1 N/A 41 A N/A <1 N/A <1 N/A 76 A <1 <1 <1 <1 46 51 A N/A <1 N/A <1 N/A 42 A N/A <1 N/A <1 N/A 77 A <1 <1 <1 <1 48 49 A N/A <1 N/A <1 N/A 48 A N/A <1 N/A <1 N/A 75 A N/A <1 N/A <1 N/A 78 A N/A <1 N/A <1 N/A 79 A N/A <1 N/A <1 N/A 77 A N/A <1 N/A <1 N/A 78 A N/A <1 N/A <1 N/A 76 A <1 <1 <1 <1 76 75 A N/A <1 N/A <1 N/A 81 A N/A <1 N/A <1 N/A 72 A <1 <1 <1 <1 72 71 A N/A <1 N/A <1 N/A 69 A N/A <1 N/A <1 N/A 32 A N/A <1 N/A <1 N/A 31 A N/A <1 N/A <1 N/A 29 A N/A <1 N/A <1 N/A 26 A N/A <1 N/A <1 N/A 26 A N/A <1 N/A <1 N/A 25 A <1 <1 <1 <1 25 25 A N/A <1 N/A <1 N/A 26 A N/A <1 N/A <1 N/A 26 A <1 <1 <1 <1 24 25 A N/A <1 N/A <1 N/A 26 A N/A <1 N/A <1 N/A 41 A N/A <1 N/A <1 N/A 41 A N/A <1 N/A <1 N/A 260 A N/A <1 N/A <1 N/A 250 A N/A <1 N/A <1 N/A 232 A N/A <1 N/A <1 N/A 295 A N/A <1 N/A <1 N/A 203 A N/A <1 N/A <1 N/A 219 A N/A <1 N/A <1 N/A 305 A <1 <1 <1 <1 289 289 A N/A <1 N/A <1 N/A 264 A N/A <1 N/A <1 N/A 177 A <1 <1 <1 <1 321 319 A N/A <1 N/A <1 N/A 275 A N/A <1 N/A <1 N/A 10 A N/A <1 N/A <1 N/A 10 A N/A <1 N/A <1 N/A 10 A N/A <1 N/A <1 N/A 9 A N/A <1 N/A <1 N/A 15 A N/A <1 N/A <1 N/A 12 A N/A <1 N/A <1 N/A 11 A <1 <1 <1 <1 9 10 A N/A <1 N/A <1 N/A 11 A N/A <1 N/A <1 N/A 11 A <1 <1 <1 <1 10 12 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Tables - Page 6 Table 4 - Groundwater Analytical Results Parameter Analytical Depth to Tem DO Cond. y p' pH ORP Turbidity Alkalinity Aluminum Antimony Arsenic Barium Beryllium Water Units Feet C mg/L pmhos/cm SU my NTU mg/L CaCO3 mg/L HCO3 mg/L C032" pg/L pg/L pg/L pg/L pg/L 15A NCAC 02L .0202(g) Groundwater Quality Standard NE NE NE NE 6.5 - 8.5 NE NE NE NE NE NE 1* 10 700 4* Analytical Method Field Measurements 2320B4d N/A N/A 0 200.8 200.8 200.7 N/A Well Name Well Type Hydrostratigraph! c Unit Sample Collection Date Total Total Dissolved Total Dissolved Total Dissolved Total Total MW-14 Compliance Residuum 6/2/2014 7.78 14.83 0.49 199 6.73 298 8.21 44 N/A N/A N/A N/A <1 N/A <1 N/A 11 N/A MW-15 Compliance Residuum 2/23/2011 12.49 15.48 2.21 109.5 5.29 424 13.2 N/A N/A N/A N/A N/A <1 N/A <1 N/A 71 N/A MW-15 Compliance Residuum 6/6/2011 13.15 17.15 N/A 106.7 5.21 N/A 10.8 N/A N/A N/A N/A N/A <1 N/A <1 N/A 86 N/A MW-15 Compliance Residuum 10/3/2011 12.68 16.94 N/A 106.2 5.16 N/A 10.9 N/A N/A N/A N/A N/A <1 N/A <1 N/A 81 N/A MW-15 Compliance Residuum 2/6/2012 12.37 15.63 2.12 96 5.19 360 7.99 N/A N/A N/A N/A N/A <1 N/A <1 N/A 76 N/A MW-15 Compliance Residuum 6/5/2012 12.86 15.93 0.91 103 5.07 422 2.73 N/A N/A N/A N/A N/A <1 N/A <1 N/A 78 N/A MW-15 Compliance Residuum 10/3/2012 12.94 18.02 2.37 102 5.24 383 4.16 N/A N/A N/A N/A N/A <1 N/A <1 N/A 76 N/A MW-15 Compliance Residuum 2/4/2013 12.42 16.25 1.39 100 5.2 330 3.35 5.3 N/A N/A N/A <1 <1 <1 <1 74 75 N/A MW-15 Compliance Residuum 6/3/2013 12.88 16.11 0.67 102 5.1 418 1.5 4.6 N/A N/A N/A N/A <1 N/A <1 N/A 80 N/A MW-15 Compliance Residuum 10/14/2013 13.42 17.66 0.83 103 5.19 207 3.83 4.2 N/A N/A N/A N/A <1 N/A <1 N/A 80 N/A MW-15 Compliance Residuum 2/3/2014 12.56 16.89 1.69 99 5.06 386 2.15 3.5 N/A N/A N/A <1 <1 <1 <1 79 79 N/A MW-15 Compliance Residuum 6/2/2014 12.94 15.18 0.98 101 5.05 433 6.02 <5 N/A N/A N/A N/A <1 N/A <1 N/A 83 N/A MW-1D Voluntary Not Reported 12/16/2008 N/A 17.81 N/A 269 6.16 N/A 3.1 21 N/A N/A N/A N/A N/A N/A <2 N/A 33 N/A MW-1D Voluntary Not Reported 6/22/2009 N/A 19.51 N/A 275 5.93 N/A 2.25 19 N/A N/A N/A N/A N/A N/A <1 N/A 31 N/A MW-1D Voluntary Not Reported 12/14/2009 N/A 17.46 N/A 286 6.16 N/A 1.27 21 N/A N/A N/A N/A N/A N/A <1 N/A 32.9 N/A MW-1D Voluntary Not Reported 6/28/2010 1.97 19.98 N/A 279 5.89 N/A 1.31 20 N/A N/A N/A N/A N/A N/A <1 N/A 31.7 N/A MW-is Voluntary Not Reported 12/16/2008 N/A 18.3 N/A 172 6.88 N/A 49.3 28 N/A N/A N/A N/A N/A N/A <2 N/A 25 N/A MW-IS Voluntary Not Reported 6/22/2009 N/A 17.47 N/A 167 6.53 N/A 19.3 20 N/A N/A N/A N/A N/A N/A <1 N/A 20 N/A MW-1S Voluntary Not Reported 12/14/2009 N/A 18.14 N/A 173 6.99 N/A 9.59 27 N/A N/A N/A N/A N/A N/A <1 N/A 22.3 N/A MW-1S Voluntary Not Reported 6/28/2010 0.1 19.16 N/A 169 6.47 N/A 6.91 54 N/A N/A N/A N/A N/A N/A <1 N/A 21 N/A MW-is Voluntary Not Reported 12/6/2010 -0.98 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-1S Voluntary Not Reported 2/1/2011 0.05 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-is Voluntary Not Reported 6/7/2011 0.13 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-2D Voluntary Not Reported 12/16/2008 N/A 17.3 N/A 73 6.46 N/A 34.5 37 N/A N/A N/A N/A N/A N/A <2 N/A 29 N/A MW-2D Voluntary Not Reported 6/22/2009 N/A 18.21 N/A 90 6.48 N/A 24.2 38 N/A N/A N/A N/A N/A N/A <1 N/A 26 N/A MW-2D Voluntary Not Reported 12/14/2009 N/A 16.55 N/A 123 6.53 N/A 16.9 38 N/A N/A N/A N/A N/A N/A <1 N/A 25.7 N/A MW-2D Voluntary Not Reported 6/28/2010 19.49 18.91 N/A 95 6.42 N/A 2.24 41 N/A N/A N/A N/A N/A N/A <1 N/A 22.8 N/A MW-2S Voluntary Not Reported 12/16/2008 N/A 20.87 N/A 152.3 4.59 N/A 6.06 <5 N/A N/A N/A N/A N/A N/A <2 N/A 69 N/A MW-2S Voluntary Not Reported 6/22/2009 N/A 18.01 N/A 142 4.44 N/A 5.65 <5 N/A N/A N/A N/A N/A N/A <1 N/A 51 N/A MW-2S Voluntary Not Reported 12/14/2009 N/A 19.25 N/A 168 4.45 N/A 5.53 <5 N/A N/A N/A N/A N/A N/A <1 N/A 64.1 N/A MW-2S Voluntary Not Reported 6/28/2010 19.72 17.71 N/A 149 4.36 N/A 2.56 <5 N/A N/A N/A N/A N/A N/A <1 N/A 57.3 N/A MW-2S Voluntary Not Reported 12/6/2010 20.09 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-2S Voluntary Not Reported 2/1/2011 20.52 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-2S Voluntary Not Reported 6/7/2011 20.25 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-2S Voluntary Not Reported 10/3/2011 19.65 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-3D Voluntary Not Reported 12/16/2008 N/A 14.07 N/A 179.5 6.98 N/A 1.52 57 N/A N/A N/A N/A N/A N/A <2 N/A 8 N/A MW-3D Voluntary Not Reported 6/22/2009 N/A 14.6 N/A 185.3 6.73 N/A 0.22 55 N/A N/A N/A N/A N/A N/A <1 N/A 8 N/A MW-3D Voluntary Not Reported 12/14/2009 N/A 13.78 N/A 184.6 6.79 N/A 2.66 56 N/A N/A N/A N/A N/A N/A <1 N/A <5 N/A MW-3D Voluntary Not Reported 6/28/2010 0.96 15.79 N/A 186.5 6.84 N/A 5.15 53 N/A N/A N/A N/A N/A N/A <1 N/A 8.09 N/A MW-3S Voluntary Not Reported 12/16/2008 N/A 15.03 N/A 189.3 6.49 N/A 29.7 49 N/A N/A N/A N/A N/A N/A <2 N/A 42 N/A MW-3S Voluntary Not Reported 6/22/2009 N/A 15.13 N/A 196.6 6.31 N/A 13.2 52 N/A N/A N/A N/A N/A N/A <1 N/A 37 N/A MW-3S Voluntary Not Reported 12/14/2009 N/A 14.64 N/A 195.4 6.24 N/A 56.8 54 N/A N/A N/A N/A N/A N/A <1 N/A 42.3 N/A MW-3S Voluntary Not Reported 6/28/2010 9.69 17.51 N/A 191.3 6.26 N/A 21.3 50 N/A N/A N/A N/A N/A N/A <1 N/A 42.4 N/A MW-3S Voluntary Not Reported 12/6/2010 9.48 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-3S Voluntary Not Reported 2/1/2011 9.23 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-3S Voluntary Not Reported 6/7/2011 9.72 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-3S Voluntary Not Reported 10/4/2011 9.48 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-4D Voluntary Not Reported 12/16/2008 N/A 13.98 N/A 133.1 5.92 N/A 137 18 N/A N/A N/A N/A N/A N/A <2 N/A 91 N/A MW-4D Voluntary Not Reported 6/22/2009 N/A 14.45 N/A 138.4 5.86 N/A 60 17 N/A N/A N/A N/A N/A N/A <1 N/A 79 N/A MW-4D Voluntary Not Reported 12/14/2009 N/A 13.39 N/A 135.6 5.79 N/A 89.5 19 N/A N/A N/A N/A N/A N/A <1 N/A 82.5 N/A MW-4D Voluntary Not Reported 6/28/2010 20.35 15.48 N/A 136.1 5.86 N/A 86.1 17 N/A N/A N/A N/A N/A N/A <1 N/A 94.8 N/A MW-4D Voluntary Not Reported 2/5/2013 20.12 13.01 0.11 131 5.62 347 43.6 18 N/A N/A N/A <1 <1 <1 <1 60 74 N/A MW-4D Voluntary Not Reported 10/15/2013 20.88 13.99 12.54 136 5.97 379 12.9 20 N/A N/A N/A N/A <1 N/A <1 N/A 68 N/A MW-4D Voluntary Not Reported 2/4/2014 20.12 13.57 1.72 135 5.74 479 19.1 19 N/A N/A N/A <1 <1 <1 <1 65 72 N/A MW-4D Voluntary Not Reported 6/3/2014 20.47 14.1 1.31 135 5.57 399 47 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-4S Voluntary Not Reported 12/16/2008 N/A 14.61 N/A 116.3 5.49 N/A 135 10 N/A N/A N/A N/A N/A N/A <2 N/A 17 N/A MW-4S Voluntary Not Reported 6/22/2009 N/A 14.43 N/A 111.8 5.38 N/A 41.5 9.3 N/A N/A N/A N/A N/A N/A <1 N/A 16 N/A MW-4S Voluntary Not Reported 12/14/2009 N/A 13.74 N/A 112.3 5.35 N/A 119 11 N/A N/A N/A N/A N/A N/A <1 N/A 22 N/A MW-4S Voluntary Not Reported 6/28/2010 18.83 17.49 N/A 113.6 5.51 N/A 22 9.6 N/A N/A N/A N/A N/A N/A <1 N/A 21.7 N/A Tables - Page 7 Table 4 - Groundwater Analytical Results Parameter Analytical y Depth to Tem p' DO Cond. pH ORP Turbidity Alkalinity Aluminum Antimony Arsenic Barium Beryllium Water Units Feet C mg/L pmhos/cm SU my NTU mg/L CaCO3 mg/L HCO3 mg/L C032" pg/L pg/L pg/L pg/L pg/L 15A NCAC 02L .0202(g) Groundwater Quality Standard NE NE NE NE 6.5 - 8.5 NE NE NE NE NE NE 1* 10 700 4* Analytical Method 2320B4d N/A N/A 0 200.8 200.8 200.7 N/A Field Measurements Well Name Well Type Hydrostratigraph! c Unit Sample Collection Date Total Total Dissolved Total Dissolved Total Dissolved Total Total MW-4S Voluntary Not Reported 12/6/2010 19.08 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-4S Voluntary Not Reported 2/1/2011 18.84 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-4S Voluntary Not Reported 6/7/2011 19.08 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-4S Voluntary Not Reported 10/4/2011 18.87 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-4S Voluntary Not Reported 2/5/2013 18.37 11.13 7.86 160 5.35 365 0 14 N/A N/A N/A 1.65 <5 <1 <5 17 262 N/A MW-4S Voluntary Not Reported 10/15/2013 19.33 14.99 0.04 120 5.43 372 2.38 13 N/A N/A N/A N/A <1 N/A <1 N/A 28 N/A MW-4S Voluntary Not Reported 2/4/2014 18.56 12.59 0.2 116 5.44 371 5.03 12 N/A N/A N/A <1 <1 <1 <1 24 26 N/A MW-4S Voluntary Not Reported 6/3/2014 18.97 14.84 1.85 115 5.33 412 11.3 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-5D Voluntary Not Reported 12/16/2008 N/A 15.32 N/A 278.1 6.83 N/A 0.74 80 N/A N/A N/A N/A N/A N/A <2 N/A 37 N/A MW-5D Voluntary Not Reported 6/22/2009 N/A 16.19 N/A 281 6.81 N/A 0.31 77 N/A N/A N/A N/A N/A N/A <1 N/A 34 N/A MW-5 D Voluntary Not Reported 12/14/2009 N/A 14.94 N/A 277.8 6.7 N/A 3.57 81 N/A N/A N/A N/A N/A N/A <1 N/A 36 N/A MW-5 D Voluntary Not Reported 6/28/2010 1.36 16.87 N/A 279.6 6.78 N/A 6.38 76 N/A N/A N/A N/A N/A N/A <1 N/A 35 N/A MW-5D Voluntary Not Reported 2/4/2013 1.66 13.95 3.82 265 6.65 323 9 77 N/A N/A N/A <1 <1 <1 <1 33 34 N/A MW-51) Voluntary Not Reported 10/15/2013 2.02 16.69 15.28 267 6.75 177 3.85 75 N/A N/A N/A N/A <1 N/A <1 N/A 34 N/A MW-5D Voluntary Not Reported 2/4/2014 1.23 14.3 14.08 241 6.79 229 2.6 75 N/A N/A N/A <1 7.9 <1 <1 33 33 N/A MW-5 D Voluntary Not Reported 6/3/2014 1.54 15.82 0.4 263 6.49 242 8.92 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-5S Voluntary Not Reported 12/16/2008 N/A 15.71 N/A 56 5.4 N/A 17.3 6.7 N/A N/A N/A N/A N/A N/A <2 N/A 14 N/A MW-5S Voluntary Not Reported 6/22/2009 N/A 16.73 N/A 64.1 5.37 N/A 3.4 5.9 N/A N/A N/A N/A N/A N/A <1 N/A 13 N/A MW-5S Voluntary Not Reported 12/14/2009 N/A 15.36 N/A 62.5 5.15 N/A 8.31 5.9 N/A N/A N/A N/A N/A N/A <1 N/A 15.1 N/A MW-5S Voluntary Not Reported 6/28/2010 5.11 18.52 N/A 64.3 5.27 N/A 7.12 5.8 N/A N/A N/A N/A N/A N/A <1 N/A 15.1 N/A MW-5S Voluntary Not Reported 12/6/2010 4.82 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-5S Voluntary Not Reported 2/1/2011 4.64 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-5S Voluntary Not Reported 6/7/2011 5.39 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-5S Voluntary Not Reported 10/4/2011 4.91 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-5S Voluntary Not Reported 2/4/2013 4.59 12.58 0.6 72 5.06 384 8.94 6.6 N/A N/A N/A <1 <1 <1 <1 22 21 N/A MW-5S Voluntary Not Reported 10/15/2013 5.26 18.32 0.97 76 5.12 383 8.21 5 N/A N/A N/A N/A <1 N/A <1 N/A 24 N/A MW-5S Voluntary Not Reported 2/4/2014 4.59 11.98 0.4 75 5.03 330 9.65 4.2 N/A N/A N/A <1 <1 <1 <1 22 25 N/A MW-5S Voluntary Not Reported 6/3/2014 5.14 15.68 0.07 78 4.84 378 6.61 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-6 D Voluntary Not Reported 12/16/2008 N/A 15.63 N/A 162.7 6.48 N/A 2.67 36 N/A N/A N/A N/A N/A N/A <2 N/A 8 N/A MW-6 D Voluntary Not Reported 6/22/2009 N/A 16.97 N/A 170.7 6.58 N/A 1.21 35 N/A N/A N/A N/A N/A N/A <1 N/A 8 N/A MW-6D Voluntary Not Reported 12/14/2009 N/A 15.45 N/A 169.7 6.45 N/A 3.23 34 N/A N/A N/A N/A N/A N/A <1 N/A 8 N/A MW-61D Voluntary Not Reported 6/28/2010 -0.86 17.54 N/A 170.1 6.7 N/A 4.91 34 N/A N/A N/A N/A N/A N/A <1 N/A 7.6 N/A MW-6S Voluntary Not Reported 12/16/2008 N/A 15.67 N/A 141.7 6.31 N/A 168 23 N/A N/A N/A N/A N/A N/A <2 N/A 13 N/A MW-6S Voluntary Not Reported 6/22/2009 N/A 16.88 N/A 149.8 6.38 N/A 8.88 22 N/A N/A N/A N/A N/A N/A <1 N/A 9 N/A MW-6S Voluntary Not Reported 12/14/2009 N/A 15.78 N/A 149.7 6.28 N/A 19.8 23 N/A N/A N/A N/A N/A N/A <1 N/A 9.44 N/A MW-6S Voluntary Not Reported 6/28/2010 0.68 17.26 N/A 151.7 6.39 N/A 3.67 22 N/A N/A N/A N/A N/A N/A <1 N/A 8.8 N/A MW-6S Voluntary Not Reported 12/6/2010 0.85 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-6S Voluntary Not Reported 2/1/2011 0.82 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-6S Voluntary Not Reported 6/7/2011 0.8 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-6S Voluntary Not Reported 10/4/2011 0.73 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A MW-7 D Upgradient Not Reported 12/16/2008 N/A 15.6 N/A 38.3 5.92 N/A 1.22 17 N/A N/A N/A N/A N/A N/A <2 N/A 25 N/A MW-7D Upgradient Not Reported 6/22/2009 N/A 16.83 N/A 40 5.78 N/A 3.07 15 N/A N/A N/A N/A N/A N/A <1 N/A 24 N/A MW-7D Upgradient Not Reported 12/14/2009 N/A 15.01 N/A 35 5.85 N/A 1.13 17 N/A N/A N/A N/A N/A N/A <1 N/A 25 N/A MW-71D Upgradient Not Reported 6/28/2010 46.71 17.27 N/A 39 5.64 N/A 1.14 16 N/A N/A N/A N/A N/A N/A <1 N/A 25.1 N/A MW-7 D Upgradient Not Reported 12/6/2010 48.38 13.31 N/A 37 5.79 N/A 0.74 N/A N/A N/A N/A N/A <1 N/A <1 N/A 25 N/A MW-7 D Upgradient Not Reported 2/2/2011 48.58 15.7 N/A 32.9 5.61 N/A 8.82 N/A N/A N/A N/A N/A <1 N/A <1 N/A 25 N/A MW-7D Upgradient Not Reported 6/6/2011 49.18 17.15 N/A 33 5.79 N/A 0.59 N/A N/A N/A N/A N/A <1 N/A <1 N/A 26 N/A MW-71) Upgradient Not Reported 10/4/2011 50.24 15.45 N/A 38 5.8 N/A 0.44 N/A N/A N/A N/A N/A <1 N/A <1 N/A 26 N/A MW-7D Upgradient Not Reported 2/22/2012 49.41 15.47 8.31 36 5.56 403 1.48 N/A N/A N/A N/A N/A <1 N/A <1 N/A 26 N/A MW-7D Upgradient Not Reported 6/5/2012 49.9 15.88 3.73 36 5.68 359 1.2 N/A N/A N/A N/A N/A <1 N/A <1 N/A 26 N/A MW-7 D Upgradient Not Reported 10/3/2012 50.54 16.47 8.31 37 5.68 369 0.29 N/A N/A N/A N/A N/A <1 N/A <1 N/A 27 N/A MW-7D Upgradient Not Reported 2/4/2013 50.38 15.57 8.16 37 5.51 395 0.89 17 N/A N/A N/A <1 <1 <1 <1 26 27 N/A MW-7D Upgradient Not Reported 6/3/2013 49.61 15.93 7.92 37 5.5 372 0.42 15 N/A N/A N/A N/A <1 N/A <1 N/A 27 N/A MW-7D Upgradient Not Reported 10/14/2013 50.43 15.92 7.88 37 5.69 371 3 16 N/A N/A N/A N/A 1.04 N/A <1 N/A 27 N/A MW-7D Upgradient Not Reported 2/5/2014 50.33 15.43 8.09 37 5.62 401 2.05 16 N/A N/A N/A <1 <1 <1 <1 27 26 N/A MW-7D Upgradient Not Reported 6/2/2014 49.52 15.82 8.03 37 5.48 394 4.73 11 N/A N/A N/A N/A <1 N/A <1 N/A 27 N/A MW-7SR Upgradient Residuum 12/6/2010 49.29 13.21 N/A 29 5.48 N/A 2.76 N/A N/A N/A N/A N/A <1 N/A <1 N/A 29 N/A MW-7SR Upgradient Residuum 2/2/2011 49.52 15.36 N/A 23.4 5.33 N/A 2.84 N/A N/A N/A N/A N/A <1 N/A <1 N/A 20 N/A MW-7SR Upgradient Residuum 6/6/2011 50.12 16.69 N/A 24 5.34 N/A 6.25 N/A N/A N/A N/A N/A <1 N/A <1 N/A 21 N/A Tables - Page 8 Table 4 - Groundwater Analytical Results Parameter Analytical Depth to Tem DO Cond. y p' pH ORP Turbidity Alkalinity Aluminum Antimony Arsenic Barium Beryllium Water Units Feet C mg/L pmhos/cm SU my NTU mg/L CaCO3 mg/L HCO3 mg/L C032" pg/L pg/L pg/L pg/L pg/L 15A NCAC 02L .0202(g) Groundwater Quality Standard NE NE NE NE 6.5 - 8.5 NE NE NE NE NE NE 1* 10 700 4* Analytical Method Field Measurements 2320B4d N/A N/A 0 200.8 200.8 200.7 N/A Well Name Well Type Hydrostratigraph! c Unit Sample Collection Date Total Total Dissolved Total Dissolved Total Dissolved Total Total MW-7SR Upgradient Residuum 10/4/2011 51.24 15.31 N/A 28 5.37 N/A 4.39 N/A N/A N/A N/A N/A <1 N/A <1 N/A 18 N/A MW-7SR Upgradient Residuum 2/22/2012 50.39 15.32 6.69 21 5.13 374 1.8 N/A N/A N/A N/A N/A <1 N/A <1 N/A 16 N/A MW-7SR Upgradient Residuum 6/5/2012 50.88 16.01 3.86 22 5.19 349 0.8 N/A N/A N/A N/A N/A <1 N/A <1 N/A 15 N/A MW-7SR Upgradient Residuum 10/3/2012 51.55 16.78 5.8 22 5.24 382 1.28 N/A N/A N/A N/A N/A <1 N/A <1 N/A 15 N/A MW-7SR Upgradient Residuum 2/4/2013 51.44 15.17 5.69 20 5.12 368 1.34 7.2 N/A N/A N/A <1 <1 <1 <1 14 14 N/A MW-7SR Upgradient Residuum 6/3/2013 50.57 16.24 5.86 20 4.96 366 0.81 <0.1 N/A N/A N/A N/A <1 N/A <1 N/A 14 N/A MW-7SR Upgradient Residuum 10/14/2013 51.4 16.52 6.81 22 5.29 348 9.17 6.5 N/A N/A N/A N/A <1 N/A <1 N/A 14 N/A MW-7SR Upgradient Residuum 2/5/2014 51.33 14.55 7.1 19 5.06 403 3.02 7.7 N/A N/A N/A <1 <1 <1 <1 N/A 12 N/A MW-7SR Upgradient Residuum 6/2/2014 50.59 17.38 6.87 20 5.05 415 5.66 <5 N/A N/A N/A N/A <1 N/A <1 N/A 14 N/A MW-8D Compliance Transition (Saprolite) 12/6/2010 47.68 13.47 N/A 90 7.08 N/A 217 N/A N/A N/A N/A N/A <1 N/A <1 N/A 67 N/A MW-8D Compliance Transition (Saprolite) 2/1/2011 48.51 14.27 N/A 90 6.84 N/A 60 N/A N/A N/A N/A N/A <1 N/A <1 N/A 43 N/A MW-8D Compliance Transition (Saprolite) 6/7/2011 49 17.97 N/A 95 7 N/A 25 N/A N/A N/A N/A N/A <1 N/A <1 N/A 34 N/A MW-8D Compliance Transition (Saprolite) 10/3/2011 50.2 15.38 N/A 88 6.8 N/A 27.4 N/A N/A N/A N/A N/A <1 N/A <1 N/A 39 N/A MW-8D Compliance Transition (Saprolite) 2/6/2012 50.07 13.93 5.7 82 6.77 241 41.4 N/A N/A N/A N/A N/A <1 N/A <1 N/A 44 N/A MW-8D Compliance Transition (Saprolite) 6/4/2012 49.54 16.22 6.71 79 6.81 262 76 N/A N/A N/A N/A N/A <1 N/A <1 N/A 46 N/A MW-8D Compliance Transition (Saprolite) 10/3/2012 50.44 17.75 7.85 76 6.49 365 100 N/A N/A N/A N/A N/A <1 N/A <1 N/A 45 N/A MW-8D Compliance Transition (Saprolite) 2/4/2013 51.27 14.12 3.98 82 6.41 171 44 41 N/A N/A N/A <1 <1 <1 <1 18 36 N/A MW-8D Compliance Transition (Saprolite) 6/3/2013 49.34 16.54 4.14 81 6.27 167 36 38 N/A N/A N/A N/A <1 N/A <1 N/A 27 N/A MW-8D Compliance Transition (Saprolite) 10/14/2013 49.41 16.24 4.78 75 6.31 286 24.7 36 N/A N/A N/A N/A <1 N/A <1 N/A 23 N/A MW-8D Compliance Transition (Saprolite) 2/4/2014 49.58 13.38 6.62 75 6.38 345 110 36 N/A N/A N/A <1 <1 <1 <1 16 44 N/A MW-8D Compliance Transition (Saprolite) 6/2/2014 47.01 16.86 7.15 71 6.34 366 93.7 32 N/A N/A N/A N/A <1 N/A <1 N/A 31 N/A MW-81 Compliance Residuum 12/6/2010 45.28 13.47 N/A 87 6.82 N/A 32.2 N/A N/A N/A N/A N/A <1 N/A <1 N/A 53 N/A MW-81 Compliance Residuum 2/1/2011 46.18 14.27 N/A 74 6.4 N/A 20.4 N/A N/A N/A N/A N/A <1 N/A <1 N/A 48 N/A MW-81 Compliance Residuum 6/7/2011 46.6 17.44 N/A 61 6.33 N/A 17.7 N/A N/A N/A N/A N/A <1 N/A <1 N/A 41 N/A MW-81 Compliance Residuum 10/3/2011 47.89 15.56 N/A 57 6.4 N/A 37.2 N/A N/A N/A N/A N/A <1 N/A <1 N/A 44 N/A MW-81 Compliance Residuum 2/6/2012 47.8 14.51 9.14 54 6.4 350 32.2 N/A N/A N/A N/A N/A <1 N/A <1 N/A 40 N/A MW-81 Compliance Residuum 6/4/2012 47.03 16.47 9.37 52 6.38 333 38.7 N/A N/A N/A N/A N/A <1 N/A <1 N/A 38 N/A MW-81 Compliance Residuum 10/3/2012 48.15 16.82 8.57 49 6.09 440 23 N/A N/A N/A N/A N/A <1 N/A <1 N/A 37 N/A MW-81 Compliance Residuum 2/4/2013 49 14.83 9.88 48 6.05 384 19.8 24 N/A N/A N/A <1 <1 <1 <1 24 35 N/A MW-81 Compliance Residuum 6/3/2013 46.89 16.74 9.44 47 5.65 401 14.1 21 N/A N/A N/A N/A <1 N/A <1 N/A 30 N/A MW-81 Compliance Residuum 10/14/2013 46.87 16.36 9.92 47 6 387 9.87 22 N/A N/A N/A N/A <1 N/A <1 N/A 29 N/A MW-81 Compliance Residuum 2/4/2014 47.55 12.88 10.45 47 6.03 399 10.8 23 N/A N/A N/A <1 <1 <1 <1 26 29 N/A MW-81 Compliance Residuum 6/2/2014 44.23 17.77 9.97 46 5.98 385 18.2 19 N/A N/A N/A N/A <1 N/A <1 N/A 31 N/A MW-8S Compliance Residuum 12/6/2010 43.85 11.8 N/A 19 5.33 N/A 13.2 N/A N/A N/A N/A N/A <1 N/A <1 N/A 47 N/A MW-8S Compliance Residuum 2/1/2011 44.83 13.54 N/A 19 5.22 N/A 18 N/A N/A N/A N/A N/A <1 N/A <1 N/A 48 N/A MW-8S Compliance Residuum 6/7/2011 45.08 16.86 N/A 17 4.94 N/A 9.98 N/A N/A N/A N/A N/A <1 N/A <1 N/A 51 N/A MW-8S Compliance Residuum 10/3/2011 46.58 14.42 N/A 18 5.22 N/A 7.89 N/A N/A N/A N/A N/A <1 N/A <1 N/A 51 N/A MW-8S Compliance Residuum 2/6/2012 46.41 12.74 8.23 18 5.08 443 16 N/A N/A N/A N/A N/A <1 N/A <1 N/A 50 N/A MW-8S Compliance Residuum 6/4/2012 45.14 16.14 8.17 20 5.07 409 6.76 N/A N/A N/A N/A N/A <1 N/A <1 N/A 53 N/A MW-8S Compliance Residuum 10/3/2012 46.94 17.2 7.76 16 5.01 470 7.65 N/A N/A N/A N/A N/A <1 N/A <1 N/A 52 N/A MW-8S Compliance Residuum 2/4/2013 47.77 14.52 8.21 15 4.92 444 2.77 3.3 N/A N/A N/A <1 <1 <1 <1 51 51 N/A MW-8S Compliance Residuum 6/3/2013 45.13 16.21 7.84 19 4.34 463 4.18 <0.1 N/A N/A N/A N/A <1 N/A <1 N/A 55 N/A MW-8S Compliance Residuum 10/14/2013 45.31 15.92 7.6 19 4.71 452 6.12 1.8 N/A N/A N/A N/A <1 N/A <1 N/A 57 N/A MW-8S Compliance Residuum 2/4/2014 46.08 14.71 8.15 17 4.8 473 7.07 1.8 N/A N/A N/A <1 <1 <1 <1 56 56 N/A MW-8S Compliance Residuum 6/2/2014 41.71 16.32 7.55 20 4.78 442 9.46 <5 N/A N/A N/A N/A <1 N/A <1 N/A 58 N/A MW-9 Compliance Residuum 12/6/2010 3.86 14.51 N/A 134.1 6.14 N/A 139 N/A N/A N/A N/A N/A <1 N/A <1 N/A 89 N/A MW-9 Compliance Residuum 2/1/2011 3.67 14.67 N/A 133 6.13 N/A 29.5 N/A N/A N/A N/A N/A <1 N/A <1 N/A 61 N/A MW-9 Compliance Residuum 6/6/2011 3.85 17.1 N/A 133 6.4 N/A 21.2 N/A N/A N/A N/A N/A <1 N/A <1 N/A 60 N/A MW-9 Compliance Residuum 10/4/2011 3.88 15.68 N/A 142 6.23 N/A 12.6 N/A N/A N/A N/A N/A <1 N/A <1 N/A 58 N/A MW-9 Compliance Residuum 2/6/2012 3.09 14.65 2.88 148 6.29 368 49.7 N/A N/A N/A N/A N/A <1 N/A <1 N/A 71 N/A MW-9 Compliance Residuum 6/5/2012 3.56 16 3.8 152 6.03 332 14.3 N/A N/A N/A N/A N/A <1 N/A <1 N/A 62 N/A MW-9 Compliance Residuum 10/3/2012 3.74 17.01 3.21 157 6.1 296 14.4 N/A N/A N/A N/A N/A <1 N/A <1 N/A 65 N/A MW-9 Compliance Residuum 2/4/2013 3.43 14.3 3.69 162 5.99 382 37 42 N/A N/A N/A <1 <1 <1 <1 62 74 N/A MW-9 Compliance Residuum 6/4/2013 3.41 15.66 2.77 170 5.82 386 10.3 40 N/A N/A N/A N/A <1 N/A <1 N/A 70 N/A MW-9 Compliance Residuum 10/15/2013 4.06 15.86 2.76 167 6.01 303 5.82 41 N/A N/A N/A N/A <1 N/A <1 N/A 66 N/A MW-9 Compliance Residuum 2/5/2014 3.06 15.67 2.73 169 5.98 356 4.79 41 N/A N/A N/A <1 <1 <1 <1 67 69 N/A MW-9 Compliance Residuum 6/2/2014 3.32 15.57 2.77 167 6 414 4.28 39 N/A N/A N/A N/A <1 N/A <1 N/A 69 N/A Tables - Page 9 Table 4 - Groundwater Analytical Results Well Name MW-10 MW-10 MW-10 MW-10 MW-10 MW-10 MW-10 MW-10 MW-10 MW-10 MW-10 MW-10 MW-11 DR MW-11 DR MW-11 DR MW-11 DR MW-11 DR MW-11DR MW-11 DR MW-11 DR MW-11 DR MW-11 DR MW-11 DR MW-11 SR MW-11 SR MW-11 SR MW-11 SR MW-11 SR MW-11 SR MW-11 SR MW-11 SR MW-11 SR MW-11SR MW-11SR MW-12 MW-12 MW-13 MW-13 MW-13 MW-13 MW-13 MW-13 MW-13 MW-13 MW-13 MW-13 MW-13 MW-13 MW-14 MW-14 MW-14 MW-14 MW-14 MW-14 MW-14 MW-14 MW-14 MW-14 MW-14 Analytical Parameter Boron Cadmium Calcium Chloride Chromium Cobalt Copper Flouride Iron Lead Magnesium Units pg/L pg/L mg/L mg/L pg/L pg/L mg/L mg/L pg/L pg/L mg/L 15A NCAC 02L .0202(g) Groundwater Quality Standard 700 2 NE 250 10 1* 1 2 300 15 NE Analytical Method 200.7 200.8 200.7 300 200.7 200.8 200.7 200.7 200.8 200.7 Well Type Hydrostratigraphic Unit Sample Collection Date Dissolved Total Dissolved Total Dissolved Total Total Dissolved Total Dissolved Total Dissolved Total Total Dissolved Total Dissolved Total Dissolved Total C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C ompliance Residuum 12/6/2010 N/A 125 N/A <1 N/A N/A 7.2 ompliance Residuum 2/1/2011 N/A 194 N/A <1 N/A N/A 7 ompliance Residuum 6/7/2011 N/A 115 N/A <1 N/A N/A 6.9 ompliance Residuum 10/3/2011 N/A 370 N/A <1 N/A N/A 6 ompliance Residuum 2/6/2012 N/A 94 N/A <1 N/A N/A 7.6 ompliance Residuum 6/4/2012 N/A 123 N/A <1 N/A N/A 6.5 ompliance Residuum 10/3/2012 N/A 383 N/A <1 N/A N/A 5.8 ompliance Residuum 2/4/2013 147 178 <1 <1 3.8 4.32 6.8 ompliance Residuum 6/4/2013 N/A 96 N/A <1 N/A 2.92 7.2 ompliance Residuum 10/15/2013 N/A 353 N/A <1 N/A 6.86 6.3 ompliance Residuum 2/3/2014 150 145 <1 <1 3.69 3.78 7.2 ompliance Residuum 6/2/2014 N/A 127 N/A <1 N/A 3.65 6.7 ompliance Bedrock 2/1/2011 N/A 362 N/A <1 N/A N/A 7.2 ompliance Bedrock 6/6/2011 N/A 362 N/A <1 N/A N/A 7.2 ompliance Bedrock 10/3/2011 N/A 369 N/A <1 N/A N/A 7 ompliance Bedrock 2/6/2012 N/A 374 N/A <1 N/A N/A 6.7 ompliance Bedrock 6/4/2012 N/A 366 N/A <1 N/A N/A 6.7 ompliance Bedrock 10/3/2012 N/A 372 N/A <1 N/A N/A 6.4 ompliance Bedrock 2/4/2013 347 342 <1 <1 9.1 8.91 6.7 ompliance Bedrock 6/3/2013 N/A 413 N/A <1 N/A 10.1 6.8 ompliance Bedrock 10/14/2013 N/A 375 N/A <1 N/A 9.31 7 ompliance Bedrock 2/3/2014 371 367 <1 <1 9.23 9.4 6.8 ompliance Bedrock 6/2/2014 N/A 353 N/A <1 N/A 9.3 6.6 ompliance Residuum 2/1/2011 N/A 366 N/A <1 N/A N/A 7.2 ompliance Residuum 6/6/2011 N/A 365 N/A <1 N/A N/A 7.3 ompliance Residuum 10/3/2011 N/A 368 N/A <1 N/A N/A 7 ompliance Residuum 2/6/2012 N/A 371 N/A <1 N/A N/A 6.7 ompliance Residuum 6/4/2012 N/A 362 N/A <1 N/A N/A 6.6 ompliance Residuum 10/3/2012 N/A 368 N/A <1 N/A N/A 6.5 ompliance Residuum 2/4/2013 354 349 <1 <1 9.6 9.42 6.7 ompliance Residuum 6/3/2013 N/A 390 N/A <1 N/A 9.85 6.9 ompliance Residuum 10/14/2013 N/A 379 N/A <1 N/A 9.7 7.1 ompliance Residuum 2/3/2014 379 377 <1 <1 9.55 9.78 6.8 ompliance Residuum 6/2/2014 N/A 366 N/A <1 N/A 9.59 6.6 ompliance Residuum 12/6/2010 N/A 289 N/A <1 N/A N/A 6.1 ompliance Residuum 2/1/2011 N/A 289 N/A <1 N/A N/A 6.3 ompliance Residuum 12/6/2010 N/A 60 N/A <1 N/A N/A 4.6 ompliance Residuum 2/1/2011 N/A <50 N/A <1 N/A N/A 5 ompliance Residuum 6/7/2011 N/A 52 N/A <1 N/A N/A 5 ompliance Residuum 10/4/2011 N/A 62 N/A <1 N/A N/A 4.4 ompliance Residuum 2/6/2012 N/A 54 N/A <1 N/A N/A 7.1 ompliance Residuum 6/5/2012 N/A 61 N/A <1 N/A N/A 4.5 ompliance Residuum 10/3/2012 N/A 65 N/A <1 N/A N/A 3.6 ompliance Residuum 2/5/2013 <50 <50 <1 <1 10.2 10.3 5.1 ompliance Residuum 6/3/2013 N/A 64 N/A <1 N/A 11.2 4.2 ompliance Residuum 10/15/2013 N/A 50 N/A <1 N/A 10.3 4.7 ompliance Residuum 2/3/2014 <50 <50 <1 <1 16.8 17.3 11 ompliance Residuum 6/2/2014 N/A 61 N/A <1 N/A 10.5 3.7 ompliance Residuum 12/6/2010 N/A 143 N/A <1 N/A N/A 6.6 ompliance Residuum 2/1/2011 N/A 109 N/A <1 N/A N/A 6.9 ompliance Residuum 6/7/2011 N/A 104 N/A <1 N/A N/A 8.2 ompliance Residuum 10/4/2011 N/A 149 N/A <1 N/A N/A 7.6 ompliance Residuum 2/6/2012 N/A 96 N/A <1 N/A N/A 9.5 ompliance Residuum 6/5/2012 N/A 90 N/A <1 N/A N/A 9.6 ompliance Residuum 10/3/2012 N/A 124 N/A <1 N/A N/A 7.3 ompliance Residuum 2/4/2013 114 109 <1 <1 6.99 7.15 9.2 ompliance Residuum 6/3/2013 N/A <50 N/A <1 N/A 8.33 8.4 ompliance Residuum 10/15/2013 N/A <50 N/A <1 N/A 7.71 8 ompliance Residuum 2/3/2014 <50 <50 <1 <1 8.32 8.24 9.2 N/A N/A N/A N/A N/A N/A N/A <5 N/A N/A <5 N/A N/A N/A N/A N/A N/A N/A <5 N/A N/A <5 N/A N/A N/A N/A N/A N/A N/A <5 N/A N/A <5 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A <5 N/A N/A <5 N/A N/A N/A N/A N/A N/A N/A N/A <5 N/A N/A <5 <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A <0.005 <0.005 0.000 15 <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A <0.005 <0.005 0.000 <10 <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A <0.005 <0.005 0.000 <10 <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A <0.005 <0.005 0.000 <10 <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A <0.005 <0.005 0.000 14 <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A <0.005 <0.005 0.000 <10 <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A <0.005 <0.005 0.000 20900 <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A <0.005 <0.005 0.000 32500 <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A 6 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A <0.005 <0.005 0.000 <10 <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A N/A <0.005 0.000 N/A <5 N/A N/A <0.005 <0.005 0.000 13 1 6 5 2 9 21 3 1 3 710 N/A 2.59 N/A N/A Tables - Page 10 Table 4 - Groundwater Analytical Results Well Name MW-14 MW-15 MW-15 MW-15 MW-15 MW-15 MW-15 MW-15 MW-15 MW-15 MW-15 MW-15 MW-1 D MW-1 D MW-1 D MW-1 D MW-is MW-is MW-is MW-is MW-is MW-is MW-is MW-2D MW-2D MW-2D MW-2D MW-2S MW-2S MW-2S MW-2S MW-2S MW-2S MW-2S MW-2S MW-3D MW-3D MW-3D MW-3D MW-3S MW-3S MW-3S MW-3S MW-3S MW-3S MW-3S MW-3S MW-4D MW-4D MW-4D MW-4D MW-4D MW-4D MW-4D MW-4D MW-4S MW-4S MW-4S MW-4S 151 Well Type Compliance Compliance Compliance Compliance Compliance Compliance Compliance Compliance Compliance Compliance Compliance Compliance Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary NCAC 02L .0202(g) Grou Hydrostratigraphic Unit Residuum Residuum Residuum Residuum Residuum Residuum Residuum Residuum Residuum Residuum Residuum Residuum Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Analytical Parameter Boron Cadmium Calcium Chloride Chromium Cobalt Copper Flouride Iron Lead Magnesium Units pg/L pg/L mg/L mg/L pg/L pg/L mg/L mg/L pg/L pg/L mg/L ndwater Quality Standard 700 2 NE 250 10 1* 1 2 300 15 NE Analytical Method 200.7 200.8 200.7 300 200.7 200.8 200.7 200.7 200.8 200.7 Sample Collection Date Dissolved Total Dissolved Total Dissolved Total Total Dissolved Total Dissolved Total Dissolved Total Total Dissolved Total Dissolved Total Dissolved Total 6/2/2014 N/A <50 N/A <1 N/A 7.58 7.9 N/A <5 N/A N/A N/A <0.005 0.000 N/A 686 N/A <1 N/A 19.5 2/23/2011 N/A 284 N/A <1 N/A N/A 7.1 N/A 5 N/A N/A N/A <0.005 0.000 N/A 227 N/A <1 N/A N/A 6/6/2011 N/A 294 N/A <1 N/A N/A 6.4 N/A <5 N/A N/A N/A <0.005 0.000 N/A 274 N/A <1 N/A N/A 10/3/2011 N/A 314 N/A <1 N/A N/A 6.5 N/A <5 N/A N/A N/A <0.005 0.000 N/A 198 N/A <1 N/A N/A 2/6/2012 N/A 302 N/A <1 N/A N/A 6.7 N/A <5 N/A N/A N/A <0.005 0.000 N/A 399 N/A <1 N/A N/A 6/5/2012 N/A 290 N/A <1 N/A N/A 6.6 N/A <5 N/A N/A N/A <0.005 0.000 N/A 45 N/A <1 N/A N/A 10/3/2012 N/A 315 N/A <1 N/A N/A 6.5 N/A <5 N/A N/A N/A <0.005 0.000 N/A 55 N/A <1 N/A N/A 2/4/2013 285 288 <1 <1 3.32 3.32 6.4 <5 <5 N/A N/A <0.005 <0.005 0.000 <10 58 <1 <1 2.58 2.58 6/3/2013 N/A 305 N/A <1 N/A 3.62 6.7 N/A <5 N/A N/A N/A <0.005 0.000 N/A 74 N/A <1 N/A 2.8 10/14/2013 N/A 312 N/A <1 N/A 3.64 6.8 N/A <5 N/A N/A N/A <0.005 0.000 N/A 168 N/A <1 N/A 2.83 2/3/2014 300 294 <1 <1 3.36 3.36 7.1 <5 <5 N/A N/A <0.005 <0.005 0.000 40 75 <1 <1 2.7 2.76 6/2/2014 N/A 273 N/A <1 N/A 3.61 6.6 N/A 5 N/A N/A N/A <0.005 0.000 N/A 230 N/A <1 N/A 2.87 12/16/2008 N/A 552 N/A <0.5 N/A 26.5 6.7 N/A <1 N/A N/A N/A <0.002 0.110 N/A 88 N/A <2 N/A 8.21 6/22/2009 N/A 509 N/A <1 N/A 25.3 7.2 N/A <1 N/A N/A N/A <0.001 <0.1 N/A 42 N/A <1 N/A 8.05 12/14/2009 N/A 609 N/A <1 N/A 27.6 6.8 N/A <1 N/A N/A N/A <0.001 <0.1 N/A 28.2 N/A <1 N/A 8.75 6/28/2010 N/A 604 N/A <1 N/A 0 7.4 N/A <1 N/A N/A N/A <0.001 1.200 N/A <10 N/A <1 N/A 8.41 12/16/2008 N/A 176 N/A <0.5 N/A 2.47 8.3 N/A <1 N/A N/A N/A <0.002 0.100 N/A 33800 N/A <2 N/A 1.11 6/22/2009 N/A 164 N/A <1 N/A 2.22 11 N/A <1 N/A N/A N/A 0.002 0.390 N/A 29100 N/A <1 N/A 1.02 12/14/2009 N/A 228 N/A <1 N/A 2.31 9.6 N/A <1 N/A N/A N/A <0.001 <0.1 N/A 31200 N/A <1 N/A 1.04 6/28/2010 N/A 199 N/A <1 N/A 2.18 8.7 N/A <1 N/A N/A N/A <0.001 <0.1 N/A 30700 N/A <1 N/A 1.01 12/6/2010 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 2/1/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 6/7/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 12/16/2008 N/A <100 N/A <0.5 N/A 6.06 2.8 N/A 1.71 N/A N/A N/A <0.002 0.100 N/A 525 N/A <2 N/A 3.86 6/22/2009 N/A <100 N/A <1 N/A 6.43 4.2 N/A 1.68 N/A N/A N/A <0.001 <0.1 N/A 262 N/A <1 N/A 3.98 12/14/2009 N/A <50 N/A <1 N/A 6.48 3.6 N/A 1.5 N/A N/A N/A 0.002 <0.1 N/A 376 N/A <1 N/A 3.95 6/28/2010 N/A <50 N/A <1 N/A 6.89 5.9 N/A 1.4 N/A N/A N/A <0.001 1.100 N/A 44.5 N/A <1 N/A 3.96 12/16/2008 N/A 387 N/A <0.5 N/A 8.72 8 N/A <1 N/A N/A N/A 0.004 <0.1 N/A 21 N/A <2 N/A 1.92 6/22/2009 N/A 254 N/A <1 N/A 7.39 6.2 N/A <1 N/A N/A N/A 0.003 <0.1 N/A 26 N/A <1 N/A 1.62 12/14/2009 N/A 332 N/A <1 N/A 8.33 9.3 N/A <1 N/A N/A N/A 0.004 <0.1 N/A 16.4 N/A <1 N/A 1.8 6/28/2010 N/A 254 N/A <1 N/A 8.71 5.7 N/A <1 N/A N/A N/A 0.004 1.100 N/A 14.3 N/A <1 N/A 1.86 12/6/2010 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 2/1/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 6/7/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 10/3/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 12/16/2008 N/A 259 N/A <0.5 N/A 18.1 5.5 N/A 1.22 N/A N/A N/A <0.002 <0.1 N/A 68 N/A <2 N/A 9.11 6/22/2009 N/A 233 N/A <1 N/A 17.1 5.9 N/A 1.25 N/A N/A N/A <0.001 <0.1 N/A <10 N/A <1 N/A 8.72 12/14/2009 N/A 271 N/A <1 N/A 18.3 5.7 N/A 1.3 N/A N/A N/A <0.001 <0.1 N/A 11.2 N/A <1 N/A 9.27 6/28/2010 N/A 263 N/A <1 N/A 18.2 6.5 N/A 1.3 N/A N/A N/A 0.001 <0.1 N/A 29.4 N/A <1 N/A 9.13 12/16/2008 N/A 241 N/A <0.5 N/A 15.5 7.6 N/A <1 N/A N/A N/A <0.002 <0.1 N/A 3390 N/A <2 N/A 9.79 6/22/2009 N/A 234 N/A <1 N/A 14.3 6.1 N/A <1 N/A N/A N/A <0.001 <0.1 N/A 3760 N/A <1 N/A 9.41 12/14/2009 N/A 245 N/A <1 N/A 15.4 6.5 N/A <1 N/A N/A N/A <0.001 0.120 N/A 5710 N/A <1 N/A 10.1 6/28/2010 N/A 259 N/A <1 N/A 14.3 4.5 N/A <1 N/A N/A N/A <0.001 <0.1 N/A 4510 N/A <1 N/A 9.32 12/6/2010 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 2/1/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 6/7/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 10/4/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 12/16/2008 N/A 258 N/A <0.5 N/A 11.8 5.9 N/A 1.59 N/A N/A N/A <0.002 <0.1 N/A 2640 N/A <2 N/A 5.59 6/22/2009 N/A 230 N/A <1 N/A 10.7 7.1 N/A 1.52 N/A N/A N/A <0.001 0.110 N/A 2050 N/A <1 N/A 5.01 12/14/2009 N/A 268 N/A <1 N/A 11.3 6 N/A 1.4 N/A N/A N/A <0.001 <0.1 N/A 1970 N/A <1 N/A 5.06 6/28/2010 N/A 259 N/A <1 N/A 12.1 6.3 N/A 2.2 N/A N/A N/A 0.002 <0.1 N/A 2720 N/A <1 N/A 5.53 2/5/2013 253 251 <1 <1 10.3 10.6 5.7 <5 <5 N/A N/A <0.005 <0.005 0.000 66 1080 <1 <1 3.59 4.13 10/15/2013 N/A 270 N/A <1 N/A 11.2 6 N/A <5 N/A N/A N/A <0.005 0.000 N/A 786 N/A <1 N/A 4.18 2/4/2014 283 284 <1 <1 11.1 11.6 6 <5 <5 N/A N/A <0.005 <0.005 0.000 18 1250 <1 <1 3.72 4.33 6/3/2014 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 12/16/2008 N/A 304 N/A <0.5 N/A 4.65 6.3 N/A 2.43 N/A N/A N/A <0.002 <0.1 N/A 370 N/A <2 N/A 3.58 6/22/2009 N/A 287 N/A <1 N/A 5.7 8 N/A 3.08 N/A N/A N/A 0.001 0.200 N/A 287 N/A <1 N/A 4.39 12/14/2009 N/A 340 N/A <1 N/A 6.01 5.7 N/A 2.8 N/A N/A N/A <0.001 <0.1 N/A 654 N/A 1.2 N/A 4.55 6/28/2010 N/A 328 N/A <1 N/A 6.46 5.6 N/A 3.3 N/A N/A N/A <0.001 <0.1 N/A 221 N/A <1 N/A 4.81 Tables - Page 11 Table 4 - Groundwater Analytical Results Well Name MW-4S MW-4S MW-4S MW-4S MW-4S MW-4S MW-4S MW-4S MW-5D MW-5D MW-5D MW-5D MW-5D MW-5D MW-5D MW-5D MW-5S MW-5S MW-5S MW-5S MW-5S MW-5S MW-5S MW-5S MW-5S MW-5S MW-5S MW-5S MW-6D MW-6D MW-6D MW-6D MW-6S MW-6S MW-6S MW-6S MW-6S MW-6S MW-6S MW-6S MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7SR MW-7SR MW-7SR 151 Well Type Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient NCAC 02L .0202(g) Grou Hydrostratigraphic Unit Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Residuum Residuum Residuum Analytical Parameter Boron Cadmium Calcium Chloride Chromium Cobalt Copper Flouride Iron Lead Magnesium Units pg/L pg/L mg/L mg/L pg/L pg/L mg/L mg/L pg/L pg/L mg/L ndwater Quality Standard 700 2 NE 250 10 1* 1 2 300 15 NE Analytical Method 200.7 200.8 200.7 300 200.7 200.8 200.7 200.7 200.8 200.7 Sample Collection Date Dissolved Total Dissolved Total Dissolved Total Total Dissolved Total Dissolved Total Dissolved Total Total Dissolved Total Dissolved Total Dissolved Total 12/6/2010 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 2/1/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 6/7/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 10/4/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 2/5/2013 353 361 <1 <5 4.66 22.2 7.6 <5 18 N/A N/A <0.005 0.016 0.000 184 11200 <1 31.3 3.59 17.2 10/15/2013 N/A 337 N/A <1 N/A 6.94 6.6 N/A <5 N/A N/A N/A <0.005 0.000 N/A 50 N/A <1 N/A 5.52 2/4/2014 350 331 <1 <1 6.29 6.26 6.7 <5 <5 N/A N/A <0.005 <0.005 0.000 21 283 <1 <1 4.99 5.07 6/3/2014 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 12/16/2008 N/A 227 N/A <0.5 N/A 27.6 7.7 N/A 1.89 N/A N/A N/A <0.002 0.110 N/A 23 N/A <2 N/A 13.4 6/22/2009 N/A 213 N/A <1 N/A 25.8 7.9 N/A 2.05 N/A N/A N/A 0.009 <0.1 N/A <10 N/A <1 N/A 12.7 12/14/2009 N/A 258 N/A <1 N/A 26.8 7.8 N/A 2.1 N/A N/A N/A <0.001 0.110 N/A 12 N/A <1 N/A 13.4 6/28/2010 N/A 263 N/A <1 N/A 0 8.1 N/A 2.3 N/A N/A N/A 0.002 <0.1 N/A 11.5 N/A <1 N/A 12.9 2/4/2013 345 337 <1 <1 25.3 24.7 7.2 <5 <5 N/A N/A <0.005 <0.005 0.000 13 208 <1 <1 12.5 12.3 10/15/2013 N/A 357 N/A <1 N/A 25.9 7.4 N/A <5 N/A N/A N/A <0.005 0.000 N/A 129 N/A <1 N/A 12.3 2/4/2014 388 384 <1 <1 25.4 26 7.4 <5 <5 N/A N/A <0.005 <0.005 0.000 <10 41 <1 <1 12.4 12.8 6/3/2014 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 12/16/2008 N/A 172 N/A <0.5 N/A 0.425 9.5 N/A <1 N/A N/A N/A <0.002 <0.1 N/A 87 N/A <2 N/A 0.423 6/22/2009 N/A 149 N/A <1 N/A 0.381 9.4 N/A <1 N/A N/A N/A <0.001 <0.1 N/A 63 N/A <1 N/A 0.428 12/14/2009 N/A 159 N/A <1 N/A 0.446 9 N/A <1 N/A N/A N/A <0.001 <0.1 N/A 28.4 N/A <1 N/A 0.529 6/28/2010 N/A 138 N/A <1 N/A 0.466 8.1 N/A <1 N/A N/A N/A 0.001 <0.1 N/A 30.7 N/A <1 N/A 0.576 12/6/2010 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 2/1/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 6/7/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 10/4/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 2/4/2013 310 336 <1 <1 0.954 0.888 8.1 <5 <5 N/A N/A <0.005 <0.005 0.000 53 155 <1 <1 0.842 0.797 10/15/2013 N/A 421 N/A <1 N/A 0.832 8.6 N/A <5 N/A N/A N/A <0.005 0.000 N/A 371 N/A <1 N/A 0.763 2/4/2014 451 470 <1 <1 0.837 0.837 8.3 <5 <5 N/A N/A <0.005 <0.005 0.000 70 551 <1 <1 0.764 0.79 6/3/2014 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 12/16/2008 N/A 307 N/A <0.5 N/A 15 5.8 N/A <1 N/A N/A N/A <0.002 <0.1 N/A 75 N/A <2 N/A 7.05 6/22/2009 N/A 270 N/A <1 N/A 14 6 N/A <1 N/A N/A N/A 0.002 <0.1 N/A 39 N/A <1 N/A 6.61 12/14/2009 N/A 319 N/A <1 N/A 14.8 6.1 N/A <1 N/A N/A N/A <0.001 <0.1 N/A 70 N/A <1 N/A 7.02 6/28/2010 N/A 298 N/A <1 N/A 14.2 6.8 N/A <1 N/A N/A N/A 0.001 <0.1 N/A 53.4 N/A <1 N/A 6.66 12/16/2008 N/A 214 N/A <0.5 N/A 11.2 5.3 N/A 1.53 N/A N/A N/A <0.002 0.190 N/A 1230 N/A <2 N/A 6.73 6/22/2009 N/A 194 N/A <1 N/A 10.4 5.4 N/A 1.36 N/A N/A N/A <0.001 0.220 N/A 167 N/A <1 N/A 6.22 12/14/2009 N/A 236 N/A <1 N/A 10.8 5.3 N/A <1 N/A N/A N/A <0.001 0.210 N/A 328 N/A <1 N/A 6.46 6/28/2010 N/A 233 N/A <1 N/A 10.7 6.4 N/A <1 N/A N/A N/A <0.001 0.100 N/A 144 N/A <1 N/A 6.32 12/6/2010 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 2/1/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 6/7/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 10/4/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000 N/A N/A N/A N/A N/A N/A 12/16/2008 N/A <100 N/A <0.5 N/A 2.46 1.1 N/A <1 N/A N/A N/A <0.002 <0.1 N/A 11 N/A <2 N/A 0.938 6/22/2009 N/A <100 N/A <1 N/A 2.36 1.2 N/A <1 N/A N/A N/A <0.001 <0.1 N/A 10 N/A <1 N/A 0.894 12/14/2009 N/A <50 N/A <1 N/A 2.46 1.3 N/A <1 N/A N/A N/A <0.001 <0.1 N/A <10 N/A <1 N/A 0.914 6/28/2010 N/A <50 N/A <1 N/A 2.52 1.5 N/A <1 N/A N/A N/A 0.001 <0.1 N/A <10 N/A <1 N/A 0.937 12/6/2010 N/A <50 N/A <1 N/A N/A 1.2 N/A <5 N/A N/A N/A <0.005 0.000 N/A <10 N/A <1 N/A N/A 2/2/2011 N/A <50 N/A <1 N/A N/A 1.2 N/A <5 N/A N/A N/A <0.005 0.000 N/A <10 N/A <1 N/A N/A 6/6/2011 N/A <50 N/A <1 N/A N/A 1.2 N/A <5 N/A N/A N/A <0.005 0.000 N/A <10 N/A <1 N/A N/A 10/4/2011 N/A <50 N/A <1 N/A N/A 1 N/A <5 N/A N/A N/A <0.005 0.000 N/A <10 N/A <1 N/A N/A 2/22/2012 N/A <50 N/A <1 N/A N/A <1 N/A <5 N/A N/A N/A <0.005 0.000 N/A <10 N/A <1 N/A N/A 6/5/2012 N/A <50 N/A <1 N/A N/A 1.2 N/A <5 N/A N/A N/A <0.005 0.000 N/A <10 N/A <1 N/A N/A 10/3/2012 N/A <50 N/A <1 N/A N/A 1.2 N/A <5 N/A N/A N/A <0.005 0.000 N/A <10 N/A <1 N/A N/A 2/4/2013 <50 <50 <1 <1 2.46 2.43 1.1 <5 <5 N/A N/A <0.005 <0.005 0.000 <10 <10 <1 <1 0.903 0.898 6/3/2013 N/A <50 N/A <1 N/A 2.53 1.2 N/A <5 N/A N/A N/A <0.005 0.000 N/A <10 N/A <1 N/A 0.919 10/14/2013 N/A <50 N/A <1 N/A 2.49 1.1 N/A <5 N/A N/A N/A <0.005 0.000 N/A <10 N/A <1 N/A 0.923 2/5/2014 <50 <50 <1 <1 2.38 2.44 1.3 <5 <5 N/A N/A <0.005 <0.005 0.000 <10 <10 <1 <1 0.894 0.927 6/2/2014 N/A <50 N/A <1 N/A 2.51 1.2 N/A <5 N/A N/A N/A <0.005 0.000 N/A <10 N/A <1 N/A 0.906 12/6/2010 N/A <50 N/A <1 N/A N/A 2 N/A <5 N/A N/A N/A <0.005 0.000 N/A 125 N/A <1 N/A N/A 2/2/2011 N/A <50 N/A <1 N/A N/A 2 N/A <5 N/A N/A N/A <0.005 0.000 N/A 790 N/A <1 N/A N/A 6/6/2011 N/A <50 N/A <1 N/A N/A 2 N/A <5 N/A N/A N/A <0.005 0.000 N/A 495 N/A <1 N/A N/A Tables - Page 12 Table 4 - Groundwater Analytical Results Analytical Parameter Boron Cadmium Calcium Chloride Chromium Cobalt Copper Flouride Iron Lead Magnesium Units pg/L pg/L mg/L mg/L pg/L pg/L mg/L mg/L pg/L pg/L mg/L 15A NCAC 02L .0202(g) Groundwater Quality Standard 700 2 NE 250 10 1* 1 2 300 15 NE Analytical Method 200.7 200.8 200.7 300 200.7 200.8 200.7 200.7 200.8 200.7 Well Name Well Type Hydrostratigraphic Unit Sample Collection Date Dissolved Total Dissolved Total Dissolved Total Total Dissolved Total Dissolved Total Dissolved Total Total Dissolved Total Dissolved Total Dissolved Total MW-7SR Upgradient Residuum 10/4/2011 N/A <50 N/A <1 N/A N/A 1.9 N/A <5 N/A N/A N/A <0.005 0.000 N/A 532 N/A <1 N/A N/A MW-7SR Upgradient Residuum 2/22/2012 N/A <50 N/A <1 N/A N/A 2.1 N/A <5 N/A N/A N/A <0.005 0.000 N/A 285 N/A <1 N/A N/A MW-7SR Upgradient Residuum 6/5/2012 N/A <50 N/A <1 N/A N/A 1.9 N/A <5 N/A N/A N/A <0.005 0.000 N/A 520 N/A <1 N/A N/A MW-7SR Upgradient Residuum 10/3/2012 N/A <50 N/A <1 N/A N/A 1.8 N/A <5 N/A N/A N/A <0.005 0.000 N/A 221 N/A <1 N/A N/A MW-7SR Upgradient Residuum 2/4/2013 <50 <50 <1 <1 0.311 0.312 1.8 <5 <5 N/A N/A <0.005 <0.005 0.000 132 158 <1 <1 1.05 1.07 MW-7SR Upgradient Residuum 6/3/2013 N/A <50 N/A <1 N/A 0.291 1.9 N/A <5 N/A N/A N/A <0.005 0.000 N/A 155 N/A <1 N/A 1.02 MW-7SR Upgradient Residuum 10/14/2013 N/A <50 N/A <1 N/A 0.295 1.9 N/A <5 N/A N/A N/A <0.005 0.000 N/A 445 N/A <1 N/A 1.05 MW-7SR Upgradient Residuum 2/5/2014 <50 <50 <1 <1 0.261 0.25 2 <5 <5 N/A N/A <0.005 <0.005 0.000 119 166 <1 <1 0.99 0.959 MW-7SR Upgradient Residuum 6/2/2014 N/A <50 N/A <1 N/A 0.268 1.9 N/A <5 N/A N/A N/A <0.005 0.000 N/A 117 N/A <1 N/A 0.963 MW-8D Compliance Transition (Saprolite) 12/6/2010 N/A <50 N/A <1 N/A N/A 2.5 N/A <5 N/A N/A N/A <0.005 0.000 N/A 2640 N/A <1 N/A N/A MW-8D Compliance Transition (Saprolite) 2/1/2011 N/A <50 N/A <1 N/A N/A 2 N/A <5 N/A N/A N/A <0.005 0.000 N/A 1330 N/A <1 N/A N/A MW-8D Compliance Transition (Saprolite) 6/7/2011 N/A <50 N/A <1 N/A N/A 1.3 N/A <5 N/A N/A N/A <0.005 0.000 N/A 777 N/A <1 N/A N/A MW-8D Compliance Transition (Saprolite) 10/3/2011 N/A <50 N/A <1 N/A N/A 1.2 N/A <5 N/A N/A N/A <0.005 0.000 N/A 954 N/A <1 N/A N/A MW-8D Compliance Transition (Saprolite) 2/6/2012 N/A <50 N/A <1 N/A N/A 1.2 N/A <5 N/A N/A N/A <0.005 0.000 N/A 1480 N/A <1 N/A N/A MW-8D Compliance Transition (Saprolite) 6/4/2012 N/A <50 N/A <1 N/A N/A 1.3 N/A <5 N/A N/A N/A <0.005 0.000 N/A 1320 N/A <1 N/A N/A MW-8D Compliance Transition (Saprolite) 10/3/2012 N/A <50 N/A <1 N/A N/A 1.2 N/A 5 N/A N/A N/A <0.005 0.000 N/A 2050 N/A <1 N/A N/A MW-8D Compliance Transition (Saprolite) 2/4/2013 <50 <50 <1 <1 4.55 5.58 1.3 <5 <5 N/A N/A <0.005 <0.005 0.000 71 1720 <1 <1 0.822 1.34 MW-8D Compliance Transition (Saprolite) 6/3/2013 N/A <50 N/A <1 N/A 4.44 1.3 N/A <5 N/A N/A N/A <0.005 0.000 N/A 1680 N/A <1 N/A 1.05 MW-8D Compliance Transition (Saprolite) 10/14/2013 N/A <50 N/A <1 N/A 3.67 1.2 N/A <5 N/A N/A N/A <0.005 0.000 N/A 948 N/A <1 N/A 0.821 MW-8D Compliance Transition (Saprolite) 2/4/2014 <50 <50 <1 <1 3.79 5.38 1.3 <5 6 N/A N/A <0.005 <0.005 0.000 36 4160 <1 <1 0.696 1.75 MW-8D Compliance Transition (Saprolite) 6/2/2014 N/A <50 N/A <1 N/A 4.49 1.2 N/A <5 N/A N/A N/A <0.005 0.000 N/A 2410 N/A <1 N/A 1.24 MW-81 Compliance Residuum 12/6/2010 N/A <50 N/A <1 N/A N/A 1.4 N/A <5 N/A N/A N/A <0.005 0.000 N/A 787 N/A <1 N/A N/A MW-81 Compliance Residuum 2/1/2011 N/A <50 N/A <1 N/A N/A 1.2 N/A <5 N/A N/A N/A <0.005 0.000 N/A 643 N/A <1 N/A N/A MW-81 Compliance Residuum 6/7/2011 N/A <50 N/A <1 N/A N/A 1.2 N/A <5 N/A N/A N/A <0.005 0.000 N/A 812 N/A <1 N/A N/A MW-81 Compliance Residuum 10/3/2011 N/A <50 N/A <1 N/A N/A 1.1 N/A <5 N/A N/A N/A <0.005 0.000 N/A 942 N/A <1 N/A N/A MW-81 Compliance Residuum 2/6/2012 N/A <50 N/A <1 N/A N/A 1.1 N/A <5 N/A N/A N/A <0.005 0.000 N/A 976 N/A <1 N/A N/A MW-81 Compliance Residuum 6/4/2012 N/A <50 N/A <1 N/A N/A 1.2 N/A <5 N/A N/A N/A <0.005 0.000 N/A 853 N/A <1 N/A N/A MW-81 Compliance Residuum 10/3/2012 N/A <50 N/A <1 N/A N/A 1.1 N/A <5 N/A N/A N/A <0.005 0.000 N/A 618 N/A <1 N/A N/A MW-81 Compliance Residuum 2/4/2013 <50 <50 <1 <1 2.11 2.3 1.1 <5 <5 N/A N/A <0.005 <0.005 0.000 38 497 <1 <1 0.458 0.692 MW-81 Compliance Residuum 6/3/2013 N/A <50 N/A <1 N/A 2.23 1.1 N/A <5 N/A N/A N/A <0.005 0.000 N/A 593 N/A <1 N/A 0.62 MW-81 Compliance Residuum 10/14/2013 N/A <50 N/A <1 N/A 2.15 1.1 N/A <5 N/A N/A N/A <0.005 0.000 N/A 436 N/A <1 N/A 0.584 MW-81 Compliance Residuum 2/4/2014 <50 <50 <1 <1 2.08 2.11 1.2 <5 <5 N/A N/A <0.005 <0.005 0.000 44 618 <1 <1 0.472 0.639 MW-81 Compliance Residuum 6/2/2014 N/A <50 N/A <1 N/A 2.11 1.1 N/A <5 N/A N/A N/A <0.005 0.000 N/A 629 N/A <1 N/A 0.622 MW-8S Compliance Residuum 12/6/2010 N/A <50 N/A <1 N/A N/A 2 N/A <5 N/A N/A N/A <0.005 0.000 N/A 53 N/A <1 N/A N/A MW-8S Compliance Residuum 2/1/2011 N/A <50 N/A <1 N/A N/A 2.2 N/A <5 N/A N/A N/A <0.005 0.000 N/A 41 N/A <1 N/A N/A MW-8S Compliance Residuum 6/7/2011 N/A <50 N/A <1 N/A N/A 2.7 N/A <5 N/A N/A N/A <0.005 0.000 N/A 73 N/A <1 N/A N/A MW-8S Compliance Residuum 10/3/2011 N/A <50 N/A <1 N/A N/A 2.1 N/A <5 N/A N/A N/A <0.005 0.000 N/A 16 N/A <1 N/A N/A MW-8S Compliance Residuum 2/6/2012 N/A <50 N/A <1 N/A N/A 2.2 N/A <5 N/A N/A N/A <0.005 0.000 N/A 58 N/A <1 N/A N/A MW-8S Compliance Residuum 6/4/2012 N/A <50 N/A <1 N/A N/A 3 N/A <5 N/A N/A N/A <0.005 0.000 N/A 24 N/A <1 N/A N/A MW-8S Compliance Residuum 10/3/2012 N/A <50 N/A <1 N/A N/A 2.2 N/A <5 N/A N/A N/A <0.005 0.000 N/A 19 N/A <1 N/A N/A MW-8S Compliance Residuum 2/4/2013 <50 <50 <1 <1 0.334 0.318 2 <5 <5 N/A N/A <0.005 <0.005 0.000 <10 12 <1 <1 0.252 0.25 MW-8S Compliance Residuum 6/3/2013 N/A <50 N/A <1 N/A 0.352 2.7 N/A <5 N/A N/A N/A <0.005 0.000 N/A 71 N/A <1 N/A 0.276 MW-8S Compliance Residuum 10/14/2013 N/A <50 N/A <1 N/A 0.342 3 N/A <5 N/A N/A N/A <0.005 0.000 N/A 68 N/A <1 N/A 0.275 MW-8S Compliance Residuum 2/4/2014 <50 <50 <1 <1 0.29 0.287 2.5 <5 <5 N/A N/A <0.005 <0.005 0.000 <10 90 <1 <1 0.267 0.285 MW-8S Compliance Residuum 6/2/2014 N/A <50 N/A <1 N/A 0.4 3.3 N/A <5 N/A N/A N/A <0.005 0.000 N/A 23 N/A <1 N/A 0.283 MW-9 Compliance Residuum 12/6/2010 N/A <50 N/A <1 N/A N/A 2.3 N/A <5 N/A N/A N/A <0.005 0.000 N/A 2440 N/A 1.87 N/A N/A MW-9 Compliance Residuum 2/1/2011 N/A <50 N/A <1 N/A N/A 2.2 N/A <5 N/A N/A N/A <0.005 0.000 N/A 1110 N/A <1 N/A N/A MW-9 Compliance Residuum 6/6/2011 N/A <50 N/A <1 N/A N/A 2.3 N/A <5 N/A N/A N/A <0.005 0.000 N/A 1060 N/A <1 N/A N/A MW-9 Compliance Residuum 10/4/2011 N/A <50 N/A <1 N/A N/A 2.1 N/A <5 N/A N/A N/A <0.005 0.000 N/A 464 N/A <1 N/A N/A MW-9 Compliance Residuum 2/6/2012 N/A <50 N/A <1 N/A N/A 2.3 N/A <5 N/A N/A N/A <0.005 0.000 N/A 1870 N/A 1.23 N/A N/A MW-9 Compliance Residuum 6/5/2012 N/A <50 N/A <1 N/A N/A 2.4 N/A <5 N/A N/A N/A <0.005 0.000 N/A 381 N/A <1 N/A N/A MW-9 Compliance Residuum 10/3/2012 N/A <50 N/A <1 N/A N/A 2.2 N/A <5 N/A N/A N/A <0.005 0.000 N/A 569 N/A <1 N/A N/A MW-9 Compliance Residuum 2/4/2013 <50 <50 <1 <1 13.7 13.9 2.4 <5 <5 N/A N/A <0.005 <0.005 0.000 13 1950 <1 1.12 3.73 3.93 MW-9 Compliance Residuum 6/4/2013 N/A <50 N/A <1 N/A 14.7 2.5 N/A <5 N/A N/A N/A <0.005 0.000 N/A 1130 N/A <1 N/A 4.03 MW-9 Compliance Residuum 10/15/2013 N/A <50 N/A <1 N/A 14.6 2.5 N/A <5 N/A N/A N/A <0.005 0.000 N/A 341 N/A <1 N/A 3.99 MW-9 Compliance Residuum 2/5/2014 <50 <50 <1 <1 14.8 15.2 2.6 <5 <5 N/A N/A <0.005 <0.005 0.000 19 263 <1 <1 3.98 4.16 MW-9 Compliance Residuum 6/2/2014 N/A <50 N/A <1 N/A 15.2 2.5 N/A <5 N/A N/A N/A <0.005 0.000 N/A 272 N/A <1 N/A 4.14 Tables - Page 13 Table 4 - Groundwater Analytical Results Well Name MW-10 MW-10 MW-10 MW-10 MW-10 MW-10 MW-10 MW-10 MW-10 MW-10 MW-10 MW-10 MW-11 DR MW-11 DR MW-11 DR MW-11 DR MW-11 DR MW-11DR MW-11 DR MW-11 DR MW-11 DR MW-11 DR MW-11 DR MW-11 SR MW-11 SR MW-11 SR MW-11 SR MW-11 SR MW-11 SR MW-11 SR MW-11 SR MW-11 SR MW-11SR MW-11SR MW-12 MW-12 MW-13 MW-13 MW-13 MW-13 MW-13 MW-13 MW-13 MW-13 MW-13 MW-13 MW-13 MW-13 MW-14 MW-14 MW-14 MW-14 MW-14 MW-14 MW-14 MW-14 MW-14 MW-14 MW-14 Analytical Parameter Manganese Mercury Molybdenum Nickel Nitrate as N Potassium Selenium Sodium Strontium Sulfate TDS Thallium Units pg/L pg/L pg/L pg/L mg-N/L mg/L pg/L mg/L N/A mg/L mg/L pg/L 15A NCAC 02L .0202(g) Groundwater Quality Standard 50 1 NE 100 10 NE 20 NE NE 250 500 0.2* Analytical Method 200.8 245.1 200.8 200.7 300.0 200.7 200.8 200.7 N/A 300.0 2540C 200.8 Well Type Hydrostratigraphic Unit Sample Collection Date Dissolved Total Dissolved Total Dissolved Total Dissolved Total Total Dissolved Total Dissolved Total Dissolved Total Total Total Total Dissolved Total C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C ompliance Residuum 12/6/2010 N/A 198 N/A <0.05 N/A N/A N/A ompliance Residuum 2/1/2011 N/A 242 N/A <0.05 N/A N/A N/A ompliance Residuum 6/7/2011 N/A 72 N/A <0.05 N/A N/A N/A ompliance Residuum 10/3/2011 N/A 355 N/A <0.05 N/A N/A N/A ompliance Residuum 2/6/2012 N/A 67 N/A <0.05 N/A N/A N/A ompliance Residuum 6/4/2012 N/A 48 N/A <0.05 N/A N/A N/A ompliance Residuum 10/3/2012 N/A 232 N/A <0.05 N/A N/A N/A ompliance Residuum 2/4/2013 36 33 N/A <0.05 N/A N/A <5 ompliance Residuum 6/4/2013 N/A 21 N/A <0.05 N/A N/A N/A ompliance Residuum 10/15/2013 N/A 133 N/A <0.05 N/A N/A N/A ompliance Residuum 2/3/2014 15 19 N/A <0.05 N/A N/A <5 ompliance Residuum 6/2/2014 N/A 37 N/A <0.05 N/A N/A N/A ompliance Bedrock 2/1/2011 N/A 168 N/A <0.05 N/A N/A N/A ompliance Bedrock 6/6/2011 N/A 103 N/A <0.05 N/A N/A N/A ompliance Bedrock 10/3/2011 N/A 87 N/A <0.05 N/A N/A N/A ompliance Bedrock 2/6/2012 N/A 101 N/A <0.05 N/A N/A N/A ompliance Bedrock 6/4/2012 N/A 92 N/A <0.05 N/A N/A N/A ompliance Bedrock 10/3/2012 N/A 87 N/A <0.05 N/A N/A N/A ompliance Bedrock 2/4/2013 89 88 N/A <0.05 N/A N/A <5 ompliance Bedrock 6/3/2013 N/A 93 N/A <0.05 N/A N/A N/A ompliance Bedrock 10/14/2013 N/A 60 N/A <0.05 N/A N/A N/A ompliance Bedrock 2/3/2014 51 51 N/A <0.05 N/A N/A <5 ompliance Bedrock 6/2/2014 N/A 51 N/A <0.05 N/A N/A N/A ompliance Residuum 2/1/2011 N/A 384 N/A <0.05 N/A N/A N/A ompliance Residuum 6/6/2011 N/A 59 N/A <0.05 N/A N/A N/A ompliance Residuum 10/3/2011 N/A 30 N/A <0.05 N/A N/A N/A ompliance Residuum 2/6/2012 N/A 24 N/A <0.05 N/A N/A N/A ompliance Residuum 6/4/2012 N/A 17 N/A <0.05 N/A N/A N/A ompliance Residuum 10/3/2012 N/A 16 N/A <0.05 N/A N/A N/A ompliance Residuum 2/4/2013 12 12 N/A <0.05 N/A N/A <5 ompliance Residuum 6/3/2013 N/A 12 N/A <0.05 N/A N/A N/A ompliance Residuum 10/14/2013 N/A 14 N/A <0.05 N/A N/A N/A ompliance Residuum 2/3/2014 8 8 N/A <0.05 N/A N/A <5 ompliance Residuum 6/2/2014 N/A 9 N/A <0.05 N/A N/A N/A ompliance Residuum 12/6/2010 N/A 211 N/A <0.05 N/A N/A N/A ompliance Residuum 2/1/2011 N/A 144 N/A <0.05 N/A N/A N/A ompliance Residuum 12/6/2010 N/A 10900 N/A <0.05 N/A N/A N/A ompliance Residuum 2/1/2011 N/A 11200 N/A <0.05 N/A N/A N/A ompliance Residuum 6/7/2011 N/A 10400 N/A <0.05 N/A N/A N/A ompliance Residuum 10/4/2011 N/A 10000 N/A <0.05 N/A N/A N/A ompliance Residuum 2/6/2012 N/A 10300 N/A <0.05 N/A N/A N/A ompliance Residuum 6/5/2012 N/A 10300 N/A <0.05 N/A N/A N/A ompliance Residuum 10/3/2012 N/A 10300 N/A <0.05 N/A N/A N/A ompliance Residuum 2/5/2013 10400 10500 N/A <0.05 N/A N/A <5 ompliance Residuum 6/3/2013 N/A 10100 N/A <0.05 N/A N/A N/A ompliance Residuum 10/15/2013 N/A 8070 N/A <0.05 N/A N/A N/A ompliance Residuum 2/3/2014 10500 10300 N/A <0.05 N/A N/A 9 ompliance Residuum 6/2/2014 N/A 10000 N/A <0.05 N/A N/A N/A ompliance Residuum 12/6/2010 N/A 270 N/A <0.05 N/A N/A N/A ompliance Residuum 2/1/2011 N/A 55 N/A <0.05 N/A N/A N/A ompliance Residuum 6/7/2011 N/A 43 N/A <0.05 N/A N/A N/A ompliance Residuum 10/4/2011 N/A 193 N/A <0.05 N/A N/A N/A ompliance Residuum 2/6/2012 N/A 353 N/A <0.05 N/A N/A N/A ompliance Residuum 6/5/2012 N/A 56 N/A <0.05 N/A N/A N/A ompliance Residuum 10/3/2012 N/A 20 N/A <0.05 N/A N/A N/A ompliance Residuum 2/4/2013 <5 18 N/A <0.05 N/A N/A <5 ompliance Residuum 6/3/2013 N/A 63 N/A <0.05 N/A N/A N/A ompliance Residuum 10/15/2013 N/A 81 N/A <0.05 N/A N/A N/A ompliance Residuum 2/3/2014 <5 205 N/A <0.05 N/A N/A <5 <5 0.2 N/A N/A N/A <1 N/A N/A N/A 12 78 N/A <0.2 <5 <0.1 N/A N/A N/A <1 N/A N/A N/A 19 90 N/A <0.2 <5 0.04 N/A N/A N/A <1 N/A N/A N/A 12 74 N/A <0.2 <5 0.03 N/A N/A N/A <1 N/A N/A N/A 35 85 N/A <0.2 <5 0.04 N/A N/A N/A <1 N/A N/A N/A 11 62 N/A <0.2 <5 0.04 N/A N/A N/A <1 N/A N/A N/A 14 61 N/A <0.2 <5 <0.023 N/A N/A N/A <1 N/A N/A N/A 40 97 N/A <0.2 <5 0.05 0.353 0.401 <1 <1 5.95 6.28 N/A 21 73 <0.2 <0.2 <5 0.05 N/A 0.41 N/A <1 N/A 5.45 N/A 11 58 N/A <0.2 <5 0.03 N/A 0.506 N/A <1 N/A 8.06 N/A 38 95 N/A <0.2 <5 0.04 0.32 0.362 <1 <1 5.93 5.82 N/A 18 92 <0.2 <0.2 <5 0.04 N/A 0.452 N/A <1 N/A 5.32 N/A 16 72 N/A <0.2 <5 0.16 N/A N/A N/A <1 N/A N/A N/A 44 120 N/A <0.2 <5 0.21 N/A N/A N/A <1 N/A N/A N/A 45 120 N/A <0.2 <5 0.2 N/A N/A N/A <1 N/A N/A N/A 42 98 N/A <0.2 <5 0.17 N/A N/A N/A <1 N/A N/A N/A 45 110 N/A <0.2 <5 0.19 N/A N/A N/A <1 N/A N/A N/A 44 112 N/A <0.2 <5 0.18 N/A N/A N/A <1 N/A N/A N/A 42 100 N/A <0.2 <5 0.17 2.11 2.08 <1 <1 7.33 7.22 N/A 43 110 <0.2 <0.2 <5 0.18 N/A 2.3 N/A <1 N/A 7.91 N/A 44 120 N/A <0.2 <5 0.19 N/A 2.17 N/A <1 N/A 7.3 N/A 43 110 N/A <0.2 <5 0.18 2.17 2.15 <1 <1 7.35 7.25 N/A 40 150 <0.2 <0.2 <5 0.19 N/A 2.06 N/A <1 N/A 7.09 N/A 41 110 N/A <0.2 <5 0.13 N/A N/A N/A <1 N/A N/A N/A 45 130 N/A <0.2 <5 0.18 N/A N/A N/A <1 N/A N/A N/A 47 130 N/A <0.2 <5 0.18 N/A N/A N/A <1 N/A N/A N/A 45 100 N/A <0.2 <5 0.15 N/A N/A N/A <1 N/A N/A N/A 46 110 N/A <0.2 <5 0.16 N/A N/A N/A <1 N/A N/A N/A 45 113 N/A <0.2 <5 0.16 N/A N/A N/A <1 N/A N/A N/A 43 110 N/A <0.2 <5 0.16 1.64 1.62 <1 <1 8.16 8.03 N/A 44 110 <0.2 <0.2 <5 0.16 N/A 1.68 N/A <1 N/A 8.14 N/A 44 130 N/A <0.2 <5 0.17 N/A 1.69 N/A <1 N/A 7.94 N/A 43 110 N/A <0.2 <5 0.16 1.72 1.71 <1 <1 7.97 7.92 N/A 41 130 <0.2 <0.2 <5 0.17 N/A 1.66 N/A <1 N/A 7.7 N/A 41 110 N/A <0.2 <5 1 N/A N/A N/A <1 N/A N/A N/A 42 120 N/A <0.2 <5 0.24 N/A N/A N/A <1 N/A N/A N/A 42 140 N/A <0.2 <5 <0.1 N/A N/A N/A <1 N/A N/A N/A 17 120 N/A <0.2 <5 <0.1 N/A N/A N/A <1 N/A N/A N/A 17 110 N/A <0.2 <5 <0.023 N/A N/A N/A <1 N/A N/A N/A 16 120 N/A <0.2 <5 0.06 N/A N/A N/A <1 N/A N/A N/A 15 110 N/A <0.2 <5 0.16 N/A N/A N/A <1 N/A N/A N/A 17 120 N/A <0.2 <5 <0.023 N/A N/A N/A <1 N/A N/A N/A 15 111 N/A <0.2 <5 <0.023 N/A N/A N/A <1 N/A N/A N/A 14 110 N/A <0.2 <5 <0.023 0.458 0.458 <1 <1 3.07 3.08 N/A 14 130 <0.2 <0.2 <5 <0.023 N/A 0.579 N/A <1 N/A 3.59 N/A 16 110 N/A <0.2 <5 0.07 N/A 0.532 N/A <1 N/A 3.56 N/A 17 91 N/A <0.2 11 <0.023 1.72 1.82 <1 <1 6.93 7.07 N/A 29 240 <0.2 <0.2 <5 <0.023 N/A 0.425 N/A <1 N/A 3.45 N/A 15 130 N/A <0.2 6 0.35 N/A N/A N/A <1 N/A N/A N/A 32 140 N/A <0.2 <5 <0.1 N/A N/A N/A <1 N/A N/A N/A 30 140 N/A <0.2 <5 0.06 N/A N/A N/A <1 N/A N/A N/A 36 180 N/A <0.2 <5 0.09 N/A N/A N/A <1 N/A N/A N/A 29 120 N/A <0.2 9 0.06 N/A N/A N/A <1 N/A N/A N/A 35 150 N/A <0.2 <5 0.07 N/A N/A N/A <1 N/A N/A N/A 32 148 N/A <0.2 <5 0.08 N/A N/A N/A <1 N/A N/A N/A 31 150 N/A <0.2 <5 0.07 0.192 0.215 <1 <1 2.58 2.65 N/A 35 150 <0.2 <0.2 <5 <0.023 N/A 0.213 N/A <1 N/A 3.47 N/A 27 140 N/A <0.2 <5 <0.023 N/A 0.196 N/A <1 N/A 3.35 N/A 27 140 N/A <0.2 <5 <0.023 0.158 0.222 <1 <1 3.63 3.49 N/A 30 180 <0.2 <0.2 Tables - Page 14 Table 4 - Groundwater Analytical Results Well Name MW-14 MW-15 MW-15 MW-15 MW-15 MW-15 MW-15 MW-15 MW-15 MW-15 MW-15 MW-15 MW-1 D MW-1 D MW-1 D MW-1 D MW-is MW-is MW-1S MW-is MW-is MW-is MW-is MW-2D MW-2D MW-2D MW-2D MW-2S MW-2S MW-2S MW-2S MW-2S MW-2S MW-2S MW-2S MW-3D MW-3D MW-3D MW-3D MW-3S MW-3S MW-3S MW-3S MW-3S MW-3S MW-3S MW-3S MW-4D MW-4D MW-4D MW-4D MW-4D MW-4D MW-4D MW-4D MW-4S MW-4S MW-4S MW-4S 151 Well Type Compliance Compliance Compliance Compliance Compliance Compliance Compliance Compliance Compliance Compliance Compliance Compliance Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary NCAC 02L .0202(g) Grou Hydrostratigraphic Unit Residuum Residuum Residuum Residuum Residuum Residuum Residuum Residuum Residuum Residuum Residuum Residuum Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Analytical Parameter Manganese Mercury Molybdenum Nickel Nitrate as N Potassium Selenium Sodium Strontium Sulfate TDS Thallium Units pg/L pg/L pg/L pg/L mg-N/L mg/L pg/L mg/L N/A mg/L mg/L pg/L ndwater Quality Standard 50 1 NE 100 10 NE 20 NE NE 250 500 0.2* Analytical Method 200.8 245.1 200.8 200.7 300.0 200.7 200.8 200.7 N/A 300.0 2540C 200.8 Sample Collection Date Dissolved Total Dissolved Total Dissolved Total Dissolved Total Total Dissolved Total Dissolved Total Dissolved Total Total Total Total Dissolved Total 6/2/2014 N/A 185 N/A <0.05 N/A N/A N/A 6 <0.023 N/A 0.184 N/A <1 N/A 3.21 N/A 27 140 N/A <0.2 2/23/2011 N/A 55 N/A <0.05 N/A N/A N/A <5 0.23 N/A N/A N/A 1.98 N/A N/A N/A 29 84 N/A <0.2 6/6/2011 N/A 64 N/A <0.05 N/A N/A N/A <5 0.19 N/A N/A N/A 1.79 N/A N/A N/A 33 110 N/A <0.2 10/3/2011 N/A 81 N/A <0.05 N/A N/A N/A <5 0.18 N/A N/A N/A 1.97 N/A N/A N/A 28 75 N/A <0.2 2/6/2012 N/A 86 N/A <0.05 N/A N/A N/A <5 0.14 N/A N/A N/A 1.91 N/A N/A N/A 26 84 N/A <0.2 6/5/2012 N/A 52 N/A <0.05 N/A N/A N/A <5 0.15 N/A N/A N/A 2.03 N/A N/A N/A 30 77 N/A <0.2 10/3/2012 N/A 46 N/A <0.05 N/A N/A N/A <5 0.13 N/A N/A N/A 2.08 N/A N/A N/A 28 77 N/A <0.2 2/4/2013 49 49 N/A <0.05 N/A N/A <5 <5 0.11 1.22 1.22 1.91 1.93 9.4 9.41 N/A 27 81 <0.2 <0.2 6/3/2013 N/A 45 N/A <0.05 N/A N/A N/A <5 0.09 N/A 1.33 N/A 1.58 N/A 9.89 N/A 28 81 N/A <0.2 10/14/2013 N/A 58 N/A <0.05 N/A N/A N/A <5 0.11 N/A 1.31 N/A 1.83 N/A 9.46 N/A 29 81 N/A <0.2 2/3/2014 47 50 N/A <0.05 N/A N/A <5 <5 0.07 1.26 1.27 1.69 1.58 9.55 9.56 N/A 27 120 <0.2 <0.2 6/2/2014 N/A 41 N/A <0.05 N/A N/A N/A <5 0.05 N/A 1.27 N/A 1.7 N/A 9.26 N/A 28 83 N/A <0.2 12/16/2008 N/A 439 N/A <0.05 N/A N/A N/A 4.92 0.03 N/A 1.87 N/A <2 N/A 9.29 N/A 95 224 N/A N/A 6/22/2009 N/A 433 N/A <0.05 N/A N/A N/A 5.48 <0.02 N/A 1.72 N/A <1 N/A 8.73 N/A 110 302 N/A N/A 12/14/2009 N/A 476 N/A <0.05 N/A N/A N/A 5.4 <0.02 N/A 1.91 N/A <1 N/A 9.56 N/A 95 194 N/A N/A 6/28/2010 N/A 478 N/A <0.05 N/A N/A N/A 5.4 <0.2 N/A 1.91 N/A <1 N/A 9.29 N/A 110 218 N/A N/A 12/16/2008 N/A 3300 N/A <0.05 N/A N/A N/A <2 0.03 N/A 1.62 N/A <2 N/A 6.53 N/A 1.1 92 N/A N/A 6/22/2009 N/A 2950 N/A <0.05 N/A N/A N/A <1 0.02 N/A 1.38 N/A <1 N/A 5.97 N/A 2.1 156 N/A N/A 12/14/2009 N/A 3130 N/A <0.05 N/A N/A N/A <1 <0.02 N/A 1.58 N/A <1 N/A 6.65 N/A 3 <100 N/A N/A 6/28/2010 N/A 2880 N/A <0.05 N/A N/A N/A <1 <0.2 N/A 1.47 N/A <1 N/A 6.17 N/A <1 90 N/A N/A 12/6/2010 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2/1/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 6/7/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 12/16/2008 N/A 42 N/A <0.05 N/A N/A N/A <2 0.05 N/A 0.54 N/A <2 N/A 5.5 N/A 0.54 96 N/A N/A 6/22/2009 N/A 27 N/A <0.05 N/A N/A N/A 1.01 <0.02 N/A 0.52 N/A <1 N/A 5.6 N/A 0.33 130 N/A N/A 12/14/2009 N/A 27 N/A <0.05 N/A N/A N/A <1 <0.02 N/A 0.496 N/A <1 N/A 5.72 N/A 0.3 64 N/A N/A 6/28/2010 N/A 15 N/A <0.05 N/A N/A N/A <1 <0.2 N/A 0.548 N/A <1 N/A 5.84 N/A 28 101 N/A N/A 12/16/2008 N/A 258 N/A <0.05 N/A N/A N/A <2 0.16 N/A 6.07 N/A <2 N/A 7.94 N/A 45 98 N/A N/A 6/22/2009 N/A 208 N/A <0.05 N/A N/A N/A 1.72 0.09 N/A 4.49 N/A <1 N/A 7.46 N/A 51 216 N/A N/A 12/14/2009 N/A 218 N/A <0.05 N/A N/A N/A 1.7 0.07 N/A 5.67 N/A <1 N/A 8.03 N/A 42 64 N/A N/A 6/28/2010 N/A 225 N/A <0.05 N/A N/A N/A 1.8 <0.2 N/A 4.98 N/A <1 N/A 7.51 N/A 49 91 N/A N/A 12/6/2010 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2/1/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 6/7/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 10/3/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 12/16/2008 N/A <5 N/A <0.05 N/A N/A N/A <2 0.08 N/A 0.71 N/A <2 N/A 4.06 N/A 26 154 N/A N/A 6/22/2009 N/A <5 N/A <0.05 N/A N/A N/A <1 0.06 N/A 0.65 N/A <1 N/A 3.76 N/A 34 156 N/A N/A 12/14/2009 N/A <5 N/A <0.05 N/A N/A N/A <1 0.06 N/A 0.69 N/A <1 N/A 4.09 N/A 26 140 N/A N/A 6/28/2010 N/A <5 N/A <0.05 N/A N/A N/A <1 <0.2 N/A 0.726 N/A <1 N/A 4.04 N/A 34 149 N/A N/A 12/16/2008 N/A 991 N/A <0.05 N/A N/A N/A 2.15 0.04 N/A 0.66 N/A <2 N/A 5.26 N/A 33 128 N/A N/A 6/22/2009 N/A 1750 N/A <0.05 N/A N/A N/A 2.86 <0.02 N/A 0.43 N/A <1 N/A 4.86 N/A 37 144 N/A N/A 12/14/2009 N/A 1750 N/A <0.05 N/A N/A N/A 2 <0.02 N/A 0.475 N/A <1 N/A 5.1 N/A 31 132 N/A N/A 6/28/2010 N/A 1890 N/A <0.05 N/A N/A N/A 2.4 <0.2 N/A 0.419 N/A <1 N/A 4.61 N/A <10 143 N/A N/A 12/6/2010 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2/1/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 6/7/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 10/4/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 12/16/2008 N/A 74 N/A 0.074 N/A N/A N/A <2 0.06 N/A 0.75 N/A <2 N/A 8.76 N/A 33 134 N/A N/A 6/22/2009 N/A 60 N/A 0.052 N/A N/A N/A 2.04 0.06 N/A 0.63 N/A <1 N/A 8.05 N/A 40 112 N/A N/A 12/14/2009 N/A 59.7 N/A 0.074 N/A N/A N/A 1.8 0.03 N/A 0.62 N/A <1 N/A 8.72 N/A 33 116 N/A N/A 6/28/2010 N/A 64.9 N/A <0.05 N/A N/A N/A 2.8 <0.2 N/A 0.697 N/A <1 N/A 8.43 N/A 41 127 N/A N/A 2/5/2013 32 48 N/A <0.05 N/A N/A <5 <5 0.04 0.484 0.567 <1 <1 8.01 8 N/A 33 130 <0.2 <0.2 10/15/2013 N/A 34 N/A <0.05 N/A N/A N/A <5 0.04 N/A 0.562 N/A <1 N/A 8.16 N/A 35 120 N/A <0.2 2/4/2014 27 36 N/A 0.06 N/A N/A <5 <5 0.04 0.52 0.615 <1 <1 8.07 8.13 N/A 34 120 <0.2 <0.2 6/3/2014 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 12/16/2008 N/A 229 N/A <0.05 N/A N/A N/A <2 0.11 N/A 0.77 N/A <2 N/A 12.1 N/A 30 124 N/A N/A 6/22/2009 N/A 187 N/A <0.05 N/A N/A N/A 1.91 0.16 N/A 0.82 N/A <1 N/A 5.97 N/A 33 106 N/A N/A 12/14/2009 N/A 187 N/A <0.05 N/A N/A N/A 1.8 0.15 N/A 1.06 N/A <1 N/A 8.5 N/A 27 118 N/A N/A 6/28/2010 N/A 199 N/A <0.05 N/A N/A N/A 1.3 <0.2 N/A 0.785 N/A <1 N/A 5.55 N/A 34 100 N/A N/A Tables - Page 15 Table 4 - Groundwater Analytical Results Well Name MW-4S MW-4S MW-4S MW-4S MW-4S MW-4S MW-4S MW-4S MW-5D MW-5D MW-5D MW-5D MW-5D MW-5D MW-5D MW-5D MW-5S MW-5S MW-5S MW-5S MW-5S MW-5S MW-5S MW-5S MW-5S MW-5S MW-5S MW-5S MW-6D MW-6D MW-6D MW-6D MW-6S MW-6S MW-6S MW-6S MW-6S MW-6S MW-6S MW-6S MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7D MW-7SR MW-7SR MW-7SR 151 Well Type Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Voluntary Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient Upgradient NCAC 02L .0202(g) Grou Hydrostratigraphic Unit Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Not Reported Residuum Residuum Residuum Analytical Parameter Manganese Mercury Molybdenum Nickel Nitrate as N Potassium Selenium Sodium Strontium Sulfate TDS Thallium Units pg/L pg/L pg/L pg/L mg-N/L mg/L pg/L mg/L N/A mg/L mg/L pg/L ndwater Quality Standard 50 1 NE 100 10 NE 20 NE NE 250 500 0.2* Analytical Method 200.8 245.1 200.8 200.7 300.0 200.7 200.8 200.7 N/A 300.0 2540C 200.8 Sample Collection Date Dissolved Total Dissolved Total Dissolved Total Dissolved Total Total Dissolved Total Dissolved Total Dissolved Total Total Total Total Dissolved Total 12/6/2010 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2/1/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 6/7/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 10/4/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2/5/2013 375 1750 N/A <0.5 N/A N/A <5 16 0.08 1.16 3.34 <1 5.62 14.9 16.9 N/A 44 1100 <0.2 <1 10/15/2013 N/A 189 N/A <0.05 N/A N/A N/A <5 0.1 N/A 0.797 N/A <1 N/A 5.85 N/A 31 81 N/A <0.2 2/4/2014 219 212 N/A <0.05 N/A N/A <5 <5 0.13 0.797 0.792 <1 <1 7.04 6.61 N/A 30 100 <0.2 <0.2 6/3/2014 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 12/16/2008 N/A 49 N/A <0.05 N/A N/A N/A <2 0.15 N/A 1.24 N/A <2 N/A 8.19 N/A 50 224 N/A N/A 6/22/2009 N/A 30 N/A <0.05 N/A N/A N/A <1 0.16 N/A 1.09 N/A <1 N/A 7.68 N/A 61 186 N/A N/A 12/14/2009 N/A 26.9 N/A <0.05 N/A N/A N/A <1 0.14 N/A 1.12 N/A <1 N/A 8.15 N/A 51 196 N/A N/A 6/28/2010 N/A 17 N/A <0.05 N/A N/A N/A <1 <0.2 N/A 1.14 N/A <1 N/A 8.02 N/A 64 200 N/A N/A 2/4/2013 17 22 N/A <0.05 N/A N/A <5 <5 0.15 1.07 1.07 <1 <1 8.03 7.82 N/A 47 210 <0.2 <0.2 10/15/2013 N/A 20 N/A <0.05 N/A N/A N/A <5 0.12 N/A 1.1 N/A <1 N/A 8.17 N/A 50 220 N/A <0.2 2/4/2014 <5 <5 N/A <0.05 N/A N/A <5 <5 0.13 1.08 1.09 <1 <1 8.49 8.35 N/A 47 220 <0.2 <0.2 6/3/2014 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 12/16/2008 N/A 44 N/A 0.058 N/A N/A N/A <2 0.08 N/A <0.25 N/A <2 N/A 9.35 N/A 3.4 74 N/A N/A 6/22/2009 N/A 36 N/A 0.061 N/A N/A N/A <1 1.14 N/A <0.25 N/A <1 N/A 8.95 N/A 5.1 52 N/A N/A 12/14/2009 N/A 54 N/A 0.161 N/A N/A N/A <1 0.13 N/A <0.1 N/A <1 N/A 8.5 N/A 3.6 62 N/A N/A 6/28/2010 N/A 46.6 N/A 0.061 N/A N/A N/A <1 <0.2 N/A 0.147 N/A <1 N/A 8.1 N/A 31 48 N/A N/A 12/6/2010 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2/1/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 6/7/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 10/4/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2/4/2013 137 120 N/A 0.14 N/A N/A <5 <5 0.04 0.117 0.123 <1 <1 9.75 10.5 N/A 11 65 <0.2 <0.2 10/15/2013 N/A 50 N/A 0.58 N/A N/A N/A <5 0.03 N/A 0.196 N/A <1 N/A 12.1 N/A 13 80 N/A <0.2 2/4/2014 93 54 N/A 0.18 N/A N/A <5 <5 0.05 0.148 0.182 <1 <1 12.6 12.9 N/A 14 81 <0.2 <0.2 6/3/2014 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 12/16/2008 N/A 8 N/A <0.05 N/A N/A N/A <2 0.03 N/A 0.82 N/A <2 N/A 6.49 N/A 35 126 N/A N/A 6/22/2009 N/A 6 N/A <0.05 N/A N/A N/A <1 <0.02 N/A 0.78 N/A <1 N/A 6.03 N/A 44 134 N/A N/A 12/14/2009 N/A 7 N/A <0.05 N/A N/A N/A <1 <0.02 N/A 0.8 N/A <1 N/A 6.53 N/A 36 130 N/A N/A 6/28/2010 N/A 6.42 N/A <0.05 N/A N/A N/A <1 <0.2 N/A 0.833 N/A <1 N/A 6.32 N/A 38 113 N/A N/A 12/16/2008 N/A 93 N/A <0.05 N/A N/A N/A <2 0.03 N/A 0.37 N/A <2 N/A 6.73 N/A 36 114 N/A N/A 6/22/2009 N/A 53 N/A <0.05 N/A N/A N/A <1 <0.23 N/A 0.3 N/A <1 N/A 6.32 N/A 44 108 N/A N/A 12/14/2009 N/A 66.3 N/A <0.05 N/A N/A N/A <1 <0.02 N/A 0.34 N/A <1 N/A 6.91 N/A 37 116 N/A N/A 6/28/2010 N/A 57 N/A <0.05 N/A N/A N/A <1 <0.2 N/A 0.446 N/A <1 N/A 6.97 N/A 47 107 N/A N/A 12/6/2010 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2/1/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 6/7/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 10/4/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 12/16/2008 N/A 7 N/A <0.05 N/A N/A N/A <2 0.04 N/A 1.02 N/A <2 N/A 3.5 N/A 0.27 44 N/A N/A 6/22/2009 N/A <5 N/A <0.05 N/A N/A N/A <1 <0.02 N/A 0.9 N/A <1 N/A 3.31 N/A 0.31 54 N/A N/A 12/14/2009 N/A <5 N/A <0.05 N/A N/A N/A <1 <0.02 N/A 0.92 N/A <1 N/A 3.46 N/A 0.22 46 N/A N/A 6/28/2010 N/A <5 N/A <0.05 N/A N/A N/A <1 <0.2 N/A 0.945 N/A <1 N/A 3.52 N/A <1 63 N/A N/A 12/6/2010 N/A <5 N/A <0.05 N/A N/A N/A <5 <0.1 N/A N/A N/A <1 N/A N/A N/A 0.22 <50 N/A <0.2 2/2/2011 N/A <5 N/A <0.05 N/A N/A N/A <5 <0.1 N/A N/A N/A <1 N/A N/A N/A 0.21 <50 N/A <0.2 6/6/2011 N/A <5 N/A <0.05 N/A N/A N/A <5 <0.023 N/A N/A N/A <1 N/A N/A N/A 0.21 45 N/A <0.2 10/4/2011 N/A <5 N/A <0.05 N/A N/A N/A <5 <0.023 N/A N/A N/A <1 N/A N/A N/A 0.22 27 N/A <0.2 2/22/2012 N/A <5 N/A <0.05 N/A N/A N/A <5 <0.1 N/A N/A N/A <1 N/A N/A N/A <1 47 N/A <0.2 6/5/2012 N/A <5 N/A <0.05 N/A N/A N/A <5 <0.023 N/A N/A N/A <1 N/A N/A N/A 0.19 40 N/A <0.2 10/3/2012 N/A <5 N/A <0.05 N/A N/A N/A <5 <0.023 N/A N/A N/A <1 N/A N/A N/A 0.2 30 N/A <0.2 2/4/2013 <5 <5 N/A <0.05 N/A N/A <5 <5 <0.023 0.948 0.949 <1 <1 3.35 3.33 N/A 0.25 39 <0.2 <0.2 6/3/2013 N/A <5 N/A <0.05 N/A N/A N/A <5 <0.023 N/A 0.975 N/A <1 N/A 3.51 N/A 0.18 32 N/A <0.2 10/14/2013 N/A <5 N/A <0.05 N/A N/A N/A <5 <0.023 N/A 0.96 N/A <1 N/A 3.37 N/A 0.2 42 N/A <0.2 2/5/2014 <5 <5 N/A <0.05 N/A N/A <5 <5 <0.023 0.989 0.96 <1 <1 3.32 3.28 N/A 0.18 42 <0.2 <0.2 6/2/2014 N/A <5 N/A <0.05 N/A N/A N/A <5 <0.023 N/A 0.94 N/A <1 N/A 3.47 N/A 0.15 41 N/A <0.2 12/6/2010 N/A 256 N/A <0.05 N/A N/A N/A 7 <0.1 N/A N/A N/A <1 N/A N/A N/A 0.97 120 N/A <0.2 2/2/2011 N/A 413 N/A <0.05 N/A N/A N/A <5 <0.1 N/A N/A N/A <1 N/A N/A N/A 0.22 <50 N/A <0.2 6/6/2011 N/A 304 N/A <0.05 N/A N/A N/A <5 <0.023 N/A N/A N/A <1 N/A N/A N/A 0.17 22 N/A <0.2 Tables - Page 16 Table 4 - Groundwater Analytical Results Analytical Parameter Manganese Mercury Molybdenum Nickel Nitrate as N Potassium Selenium Sodium Strontium Sulfate TDS Thallium Units pg/L pg/L pg/L pg/L mg-N/L mg/L pg/L mg/L N/A mg/L mg/L pg/L 15A NCAC 02L .0202(g) Groundwater Quality Standard 50 1 NE 100 10 NE 20 NE NE 250 500 0.2* Analytical Method 200.8 245.1 200.8 200.7 300.0 200.7 200.8 200.7 N/A 300.0 2540C 200.8 Well Name Well Type Hydrostratigraphic Unit Sample Collection Date Dissolved Total Dissolved Total Dissolved Total Dissolved Total Total Dissolved Total Dissolved Total Dissolved Total Total Total Total Dissolved Total MW-7SR Upgradient Residuum 10/4/2011 N/A 167 N/A <0.05 N/A N/A N/A <5 <0.023 N/A N/A N/A <1 N/A N/A N/A 0.17 <10 N/A <0.2 MW-7SR Upgradient Residuum 2/22/2012 N/A 113 N/A <0.05 N/A N/A N/A <5 <0.1 N/A N/A N/A <1 N/A N/A N/A <1 24 N/A <0.2 MW-7SR Upgradient Residuum 6/5/2012 N/A 122 N/A <0.05 N/A N/A N/A <5 <0.023 N/A N/A N/A <1 N/A N/A N/A 0.13 32 N/A <0.2 MW-7SR Upgradient Residuum 10/3/2012 N/A 67 N/A <0.05 N/A N/A N/A <5 <0.023 N/A N/A N/A <1 N/A N/A N/A 0.19 10 N/A <0.2 MW-7SR Upgradient Residuum 2/4/2013 49 43 N/A <0.05 N/A N/A <5 <5 0.02 0.773 0.776 <1 <1 1.17 1.11 N/A 0.21 15 <0.2 <0.2 MW-7SR Upgradient Residuum 6/3/2013 N/A 38 N/A <0.05 N/A N/A N/A <5 <0.023 N/A 0.777 N/A <1 N/A 1.21 N/A 0.15 <25 N/A <0.2 MW-7SR Upgradient Residuum 10/14/2013 N/A 68 N/A <0.05 N/A N/A N/A <5 <0.023 N/A 0.799 N/A <1 N/A 1.05 N/A 0.16 <25 N/A <0.2 MW-7SR Upgradient Residuum 2/5/2014 41 40 N/A <0.05 N/A N/A <5 <5 0.02 0.756 0.737 <1 <1 1.19 1.12 N/A 0.16 <25 <0.2 <0.2 MW-7SR Upgradient Residuum 6/2/2014 N/A 33 N/A <0.05 N/A N/A N/A <5 <0.023 N/A 0.737 N/A <1 N/A 1.18 N/A 0.12 <25 N/A <0.2 MW-8D Compliance Transition (Saprolite) 12/6/2010 N/A 743 N/A <0.05 N/A N/A N/A <5 <0.1 N/A N/A N/A <1 N/A N/A N/A 0.7 140 N/A <0.2 MW-8D Compliance Transition (Saprolite) 2/1/2011 N/A 671 N/A <0.05 N/A N/A N/A <5 <0.1 N/A N/A N/A <1 N/A N/A N/A 0.74 130 N/A <0.2 MW-8D Compliance Transition (Saprolite) 6/7/2011 N/A 622 N/A <0.05 N/A N/A N/A <5 <0.023 N/A N/A N/A <1 N/A N/A N/A 0.71 120 N/A <0.2 MW-8D Compliance Transition (Saprolite) 10/3/2011 N/A 535 N/A <0.05 N/A N/A N/A <5 0.02 N/A N/A N/A <1 N/A N/A N/A 0.74 110 N/A <0.2 MW-8D Compliance Transition (Saprolite) 2/6/2012 N/A 452 N/A <0.05 N/A N/A N/A <5 <0.02 N/A N/A N/A <1 N/A N/A N/A 0.62 120 N/A <0.2 MW-8D Compliance Transition (Saprolite) 6/4/2012 N/A 174 N/A <0.05 N/A N/A N/A <5 0.02 N/A N/A N/A <1 N/A N/A N/A 0.76 122 N/A <0.2 MW-8D Compliance Transition (Saprolite) 10/3/2012 N/A 82 N/A <0.05 N/A N/A N/A <5 0.03 N/A N/A N/A <1 N/A N/A N/A 0.53 130 N/A <0.2 MW-8D Compliance Transition (Saprolite) 2/4/2013 19 143 N/A <0.05 N/A N/A <5 <5 0.05 1.02 1.14 <1 <1 12.3 13 N/A 1.3 150 <0.2 <0.2 MW-8D Compliance Transition (Saprolite) 6/3/2013 N/A 86 N/A <0.05 N/A N/A N/A <5 0.04 N/A 1.14 N/A <1 N/A 13.7 N/A 1.4 120 N/A <0.2 MW-8D Compliance Transition (Saprolite) 10/14/2013 N/A 34 N/A <0.05 N/A N/A N/A <5 0.04 N/A 1.06 N/A <1 N/A 13.1 N/A 1.1 120 N/A <0.2 MW-8D Compliance Transition (Saprolite) 2/4/2014 <5 118 N/A <0.05 N/A N/A <5 <5 0.04 1.01 1.45 <1 <1 12.1 12.7 N/A 0.97 140 <0.2 <0.2 MW-8D Compliance Transition (Saprolite) 6/2/2014 N/A 35 N/A <0.05 N/A N/A N/A <5 0.03 N/A 1.22 N/A <1 N/A 11.7 N/A 0.8 140 N/A <0.2 MW-81 Compliance Residuum 12/6/2010 N/A 538 N/A <0.05 N/A N/A N/A <5 <0.1 N/A N/A N/A <1 N/A N/A N/A 0.66 110 N/A <0.2 MW-81 Compliance Residuum 2/1/2011 N/A 290 N/A <0.05 N/A N/A N/A <5 <0.1 N/A N/A N/A <1 N/A N/A N/A 1.2 100 N/A <0.2 MW-81 Compliance Residuum 6/7/2011 N/A 43 N/A <0.05 N/A N/A N/A <5 <0.023 N/A N/A N/A <1 N/A N/A N/A 1.2 92 N/A <0.2 MW-81 Compliance Residuum 10/3/2011 N/A 52 N/A <0.05 N/A N/A N/A <5 <0.023 N/A N/A N/A <1 N/A N/A N/A 1.1 100 N/A <0.2 MW-81 Compliance Residuum 2/6/2012 N/A 32 N/A <0.05 N/A N/A N/A <5 <0.02 N/A N/A N/A <1 N/A N/A N/A 0.57 100 N/A <0.2 MW-81 Compliance Residuum 6/4/2012 N/A 39 N/A <0.05 N/A N/A N/A <5 <0.023 N/A N/A N/A <1 N/A N/A N/A 0.46 95 N/A <0.2 MW-81 Compliance Residuum 10/3/2012 N/A 23 N/A <0.05 N/A N/A N/A <5 <0.023 N/A N/A N/A <1 N/A N/A N/A 0.35 87 N/A <0.2 MW-81 Compliance Residuum 2/4/2013 <5 168 N/A <0.05 N/A N/A <5 <5 <0.023 0.904 0.979 <1 <1 7.27 7.42 N/A 0.27 91 <0.2 <0.2 MW-81 Compliance Residuum 6/3/2013 N/A 93 N/A <0.05 N/A N/A N/A <5 <0.023 N/A 0.978 N/A <1 N/A 7.4 N/A 0.25 78 N/A <0.2 MW-81 Compliance Residuum 10/14/2013 N/A 24 N/A <0.05 N/A N/A N/A <5 <0.023 N/A 0.965 N/A <1 N/A 7.48 N/A 0.26 79 N/A <0.2 MW-81 Compliance Residuum 2/4/2014 <5 15 N/A <0.05 N/A N/A <5 <5 <0.023 0.961 0.973 <1 <1 7.86 7.64 N/A 0.24 87 <0.2 <0.2 MW-81 Compliance Residuum 6/2/2014 N/A 47 N/A <0.05 N/A N/A N/A <5 <0.023 N/A 0.968 N/A <1 N/A 7.46 N/A 0.21 88 N/A <0.2 MW-8S Compliance Residuum 12/6/2010 N/A 123 N/A <0.05 N/A N/A N/A <5 <0.1 N/A N/A N/A <1 N/A N/A N/A 0.58 <50 N/A <0.2 MW-8S Compliance Residuum 2/1/2011 N/A 135 N/A <0.05 N/A N/A N/A <5 <0.1 N/A N/A N/A <1 N/A N/A N/A 0.39 <50 N/A <0.2 MW-8S Compliance Residuum 6/7/2011 N/A 144 N/A <0.05 N/A N/A N/A <5 <0.023 N/A N/A N/A <1 N/A N/A N/A 0.26 20 N/A <0.2 MW-8S Compliance Residuum 10/3/2011 N/A 135 N/A <0.05 N/A N/A N/A <5 <0.023 N/A N/A N/A <1 N/A N/A N/A 0.25 18 N/A <0.2 MW-8S Compliance Residuum 2/6/2012 N/A 133 N/A <0.05 N/A N/A N/A <5 <0.02 N/A N/A N/A <1 N/A N/A N/A 0.16 22 N/A <0.2 MW-8S Compliance Residuum 6/4/2012 N/A 126 N/A <0.05 N/A N/A N/A <5 <0.023 N/A N/A N/A <1 N/A N/A N/A 0.19 <25 N/A <0.2 MW-8S Compliance Residuum 10/3/2012 N/A 104 N/A <0.05 N/A N/A N/A <5 <0.023 N/A N/A N/A <1 N/A N/A N/A 0.18 11 N/A <0.2 MW-8S Compliance Residuum 2/4/2013 99 90 N/A <0.05 N/A N/A <5 <5 <0.023 0.625 0.648 <1 <1 1.19 1.18 N/A 0.17 12 <0.2 <0.2 MW-8S Compliance Residuum 6/3/2013 N/A 87 N/A <0.05 N/A N/A N/A <5 <0.023 N/A 0.615 N/A <1 N/A 1.59 N/A 0.15 <25 N/A <0.2 MW-8S Compliance Residuum 10/14/2013 N/A 78 N/A <0.05 N/A N/A N/A <5 <0.023 N/A 0.601 N/A <1 N/A 1.66 N/A 0.18 <25 N/A <0.2 MW-8S Compliance Residuum 2/4/2014 68 68 N/A <0.05 N/A N/A <5 <5 <0.023 0.626 0.662 <1 <1 1.43 1.43 N/A 0.15 <25 <0.2 <0.2 MW-8S Compliance Residuum 6/2/2014 N/A 77 N/A <0.05 N/A N/A N/A <5 <0.023 N/A 0.628 N/A <1 N/A 1.92 N/A 0.16 <25 N/A <0.2 MW-9 Compliance Residuum 12/6/2010 N/A 282 N/A <0.05 N/A N/A N/A <5 0.43 N/A N/A N/A <1 N/A N/A N/A 23 200 N/A <0.2 MW-9 Compliance Residuum 2/1/2011 N/A 147 N/A <0.05 N/A N/A N/A <5 0.1 N/A N/A N/A <1 N/A N/A N/A 22 140 N/A <0.2 MW-9 Compliance Residuum 6/6/2011 N/A 87 N/A <0.05 N/A N/A N/A <5 0.1 N/A N/A N/A <1 N/A N/A N/A 24 140 N/A <0.2 MW-9 Compliance Residuum 10/4/2011 N/A 62 N/A <0.05 N/A N/A N/A <5 0.09 N/A N/A N/A <1 N/A N/A N/A 23 120 N/A <0.2 MW-9 Compliance Residuum 2/6/2012 N/A 68 N/A <0.05 N/A N/A N/A <5 0.08 N/A N/A N/A <1 N/A N/A N/A 28 150 N/A <0.2 MW-9 Compliance Residuum 6/5/2012 N/A 25 N/A <0.05 N/A N/A N/A <5 0.08 N/A N/A N/A <1 N/A N/A N/A 29 127 N/A <0.2 MW-9 Compliance Residuum 10/3/2012 N/A 25 N/A <0.05 N/A N/A N/A <5 0.08 N/A N/A N/A <1 N/A N/A N/A 30 140 N/A <0.2 MW-9 Compliance Residuum 2/4/2013 5 49 N/A <0.05 N/A N/A <5 <5 0.08 1.13 1.26 <1 <1 11.8 11.8 N/A 32 170 <0.2 <0.2 MW-9 Compliance Residuum 6/4/2013 N/A 20 N/A <0.05 N/A N/A N/A <5 0.08 N/A 1.22 N/A <1 N/A 11.9 N/A 35 150 N/A <0.2 MW-9 Compliance Residuum 10/15/2013 N/A 10 N/A <0.05 N/A N/A N/A <5 0.1 N/A 1.17 N/A <1 N/A 12 N/A 35 140 N/A <0.2 MW-9 Compliance Residuum 2/5/2014 <5 7 N/A <0.05 N/A N/A <5 <5 0.09 1.19 1.21 <1 <1 12.3 12.3 N/A 36 150 <0.2 <0.2 MW-9 Compliance Residuum 6/2/2014 N/A 7 N/A <0.05 N/A N/A N/A <5 0.08 N/A 1.19 N/A <1 N/A 12.1 N/A 34 150 N/A <0.2 Tables - Page 17 Table 4 - Groundwater Analytical Results Analytical Parameter TOC TOX TSS Zinc Units mg/L pg/L NE mg/L NE mg/L 15A NCAC 02L .0202(g) Groundwater Quality Standard NE 1 Analytical Method 5310E 2450D Total N/A 200.7 Dissolved N/A Well Name Well Type Hydrostratigraphic Unit Sample Collection Date Total Total Total 0.009 MW-10 Compliance C MW-10 C N/A N/A <0.005 MW-10 C N/A N/A <0.005 MW-10 C N/A N/A <0.005 MW-10 C N/A N/A <0.005 MW-10 C N/A N/A <0.005 MW-10 C N/A N/A <0.005 MW-10 C N/A <0.005 <0.005 MW-10 C N/A N/A <0.005 MW-10 C N/A N/A <0.005 MW-10 C N/A <0.005 <0.005 MW-10 C N/A N/A 0.009 MW-11DR C N/A N/A <0.005 MW-11DR C N/A N/A 0.008 MW-11DR C N/A N/A 0.009 MW-11DR C N/A N/A 0.011 MW-11DR C N/A N/A 0.01 MW-11DR C N/A N/A 0.009 MW-11DR C N/A 0.009 0.009 MW-11DR C N/A N/A 0.01 MW-11DR C N/A N/A <0.005 MW-11DR C N/A 0.007 0.007 MW-11DR C N/A N/A 0.008 MW-11SR C N/A N/A <0.005 MW-11SR C N/A N/A <0.005 MW-11SR C N/A N/A <0.005 MW-11SR C N/A N/A <0.005 MW-11SR C N/A N/A <0.005 MW-11SR C N/A N/A <0.005 MW-11SR C N/A <0.005 <0.005 MW-11SR C N/A N/A <0.005 MW-11SR C N/A N/A <0.005 MW-11SR C N/A <0.005 <0.005 MW-11SR C N/A N/A <0.005 MW-12 C N/A N/A <0.005 MW-12 C N/A N/A <0.005 MW-13 C N/A N/A <0.005 MW-13 C N/A N/A <0.005 MW-13 C N/A N/A <0.005 MW-13 C N/A N/A <0.005 MW-13 C N/A N/A <0.005 MW-13 C N/A N/A <0.005 MW-13 C N/A N/A <0.005 MW-13 C N/A <0.005 <0.005 MW-13 C N/A N/A <0.005 MW-13 C N/A N/A <0.005 MW-13 C N/A <0.005 <0.005 MW-13 C N/A N/A <0.005 MW-14 C N/A N/A <0.005 MW-14 C N/A N/A <0.005 MW-14 C N/A N/A <0.005 MW-14 C N/A N/A <0.005 MW-14 C N/A N/A <0.005 MW-14 C N/A N/A <0.005 MW-14 C N/A N/A <0.005 MW-14 C N/A <0.005 <0.005 MW-14 C N/A N/A <0.005 MW-14 C N/A N/A <0.005 MW-14 C N/A <0.005 <0.005 Residuum 12/(i/2010 N/A N/A Tables -Page 18 Table 4 - Groundwater Analytical Results Analytical Parameter TOC TOX TSS Zinc Units mg/L pg/L mg/L mg/L 15A NCAC 02L .0202(g) Groundwater Quality Standard NE NE NE 1 Analytical Method 5310E 2450D 200.7 Well Name Well Type Hydrostratigraphic Unit Sample Collection Date Total Total Total Dissolved Total MW-14 Compliance Residuum 6/2/2014 N/A N/A N/A N/A <0.005 MW-15 Compliance Residuum 2/23/2011 N/A N/A N/A N/A 0.006 MW-15 Compliance Residuum 6/6/2011 N/A N/A N/A N/A <0.005 MW-15 Compliance Residuum 10/3/2011 N/A N/A N/A N/A <0.005 MW-15 Compliance Residuum 2/6/2012 N/A N/A N/A N/A 0.007 MW-15 Compliance Residuum 6/5/2012 N/A N/A N/A N/A <0.005 MW-15 Compliance Residuum 10/3/2012 N/A N/A N/A N/A 0.005 MW-15 Compliance Residuum 2/4/2013 N/A N/A N/A <0.005 0.006 MW-15 Compliance Residuum 6/3/2013 N/A N/A N/A N/A 0.005 MW-15 Compliance Residuum 10/14/2013 N/A N/A N/A N/A <0.005 MW-15 Compliance Residuum 2/3/2014 N/A N/A N/A <0.005 0.006 MW-15 Compliance Residuum 6/2/2014 N/A N/A N/A N/A 0.006 MW-1D Voluntary Not Reported 12/16/2008 0.118 40 N/A N/A 0.006 MW-1D Voluntary Not Reported 6/22/2009 0.143 130 N/A N/A 0.007 MW-1D Voluntary Not Reported 12/14/2009 0.1 <50 N/A N/A 0.009 MW-1D Voluntary Not Reported 6/28/2010 <0.1 <100 N/A N/A 0.01 MW-is Voluntary Not Reported 12/16/2008 0.28 80 N/A N/A 0.007 MW-is Voluntary Not Reported 6/22/2009 0.288 40 N/A N/A 0.007 MIS Voluntary Not Reported 12/14/2009 0.278 <50 N/A N/A <0.005 MW-is Voluntary Not Reported 6/28/2010 0.216 <100 N/A N/A <0.005 MW-is Voluntary Not Reported 12/6/2010 N/A N/A N/A N/A N/A MW-is Voluntary Not Reported 2/1/2011 N/A N/A N/A N/A N/A MW-is Voluntary Not Reported 6/7/2011 N/A N/A N/A N/A N/A MW-2D Voluntary Not Reported 12/16/2008 0.132 20 N/A N/A <0.005 MW-2D Voluntary Not Reported 6/22/2009 0.131 40 N/A N/A <0.005 MW-2D Voluntary Not Reported 12/14/2009 0.109 <50 N/A N/A 0.009 MW-2D Voluntary Not Reported 6/28/2010 <0.1 <100 N/A N/A <0.005 MW-2S Voluntary Not Reported 12/16/2008 0.151 40 N/A N/A 0.006 MW-2S Voluntary Not Reported 6/22/2009 0.138 30 N/A N/A <0.005 MW-2S Voluntary Not Reported 12/14/2009 0.108 <50 N/A N/A 0.007 MW-2S Voluntary Not Reported 6/28/2010 <0.1 <100 N/A N/A 0.006 MW-2S Voluntary Not Reported 12/6/2010 N/A N/A N/A N/A N/A MW-2S Voluntary Not Reported 2/1/2011 N/A N/A N/A N/A N/A MW-2S Voluntary Not Reported 6/7/2011 N/A N/A N/A N/A N/A MW-2S Voluntary Not Reported 10/3/2011 N/A N/A N/A N/A N/A MW-3D Voluntary Not Reported 12/16/2008 0.124 90 N/A N/A <0.005 MW-3D Voluntary Not Reported 6/22/2009 0.135 50 N/A N/A <0.005 MW-3D Voluntary Not Reported 12/14/2009 <0.1 <50 N/A N/A <0.005 MW-3D Voluntary Not Reported 6/28/2010 <0.1 <100 N/A N/A <0.005 MW-3S Voluntary Not Reported 12/16/2008 0.616 80 N/A N/A <0.005 MW-3S Voluntary Not Reported 6/22/2009 0.514 50 N/A N/A <0.005 MW-3S Voluntary Not Reported 12/14/2009 0.671 <50 N/A N/A <0.005 MW-3S Voluntary Not Reported 6/28/2010 0.448 <100 N/A N/A <0.005 MW-3S Voluntary Not Reported 12/6/2010 N/A N/A N/A N/A N/A MW-3S Voluntary Not Reported 2/1/2011 N/A N/A N/A N/A N/A MW-3S Voluntary Not Reported 6/7/2011 N/A N/A N/A N/A N/A MW-3S Voluntary Not Reported 10/4/2011 N/A N/A N/A N/A N/A MW-4D Voluntary Not Reported 12/16/2008 0.152 80 N/A N/A 0.009 MW-4D Voluntary Not Reported 6/22/2009 0.164 40 N/A N/A 0.009 MW-4D Voluntary Not Reported 12/14/2009 0.113 <50 N/A N/A 0.008 MW-4D Voluntary Not Reported 6/28/2010 <0.1 <100 N/A N/A 0.012 MW-4D Voluntary Not Reported 2/5/2013 N/A N/A N/A <0.005 0.006 MW-4D Voluntary Not Reported 10/15/2013 N/A N/A N/A N/A <0.005 MW-4D Voluntary Not Reported 2/4/2014 N/A N/A N/A <0.005 0.006 MW-4D Voluntary Not Reported 6/3/2014 N/A N/A N/A N/A N/A MW-4S Voluntary Not Reported 12/16/2008 2.44 50 N/A N/A 0.018 MW-4S Voluntary Not Reported 6/22/2009 0.641 30 N/A N/A 0.03 MW-4S Voluntary Not Reported 12/14/2009 0.794 <50 N/A N/A 0.059 MW-4S Voluntary Not Reported 6/28/2010 0.44 <100 N/A N/A 0.012 Tables - Page 19 Table 4 - Groundwater Analytical Results Analytical Parameter TOC TOX TSS Zinc Units mg/L pg/L mg/L mg/L 15A NCAC 02L .0202(g) Groundwater Quality Standard NE NE NE 1 Analytical Method 5310E Total 2450D Total 200.7 Well Name Well Type Hydrostratigraphic Unit Sample Collection Date Total Dissolved Total MW-4S Voluntary Not Reported 12/6/2010 N/A N/A N/A N/A N/A MW-4S Voluntary Not Reported 2/1/2011 N/A N/A N/A N/A N/A MW-4S Voluntary Not Reported 6/7/2011 N/A N/A N/A N/A N/A MW-4S Voluntary Not Reported 10/4/2011 N/A N/A N/A N/A N/A MW-4S Voluntary Not Reported 2/5/2013 N/A N/A N/A 0.036 0.281 MW-4S Voluntary Not Reported 10/15/2013 N/A N/A N/A N/A <0.005 MW-4S Voluntary Not Reported 2/4/2014 N/A N/A N/A 0.013 0.01 MW-4S Voluntary Not Reported 6/3/2014 N/A N/A N/A N/A N/A MW-5D Voluntary Not Reported 12/16/2008 0.197 <20 N/A N/A <0.005 MW-5D Voluntary Not Reported 6/22/2009 0.164 30 N/A N/A <0.005 MW-5D Voluntary Not Reported 12/14/2009 0.165 <50 N/A N/A <0.005 MW-5D Voluntary Not Reported 6/28/2010 0.116 <100 N/A N/A <0.005 MW-5D Voluntary Not Reported 2/4/2013 N/A N/A N/A <0.005 <0.005 MW-5D Voluntary Not Reported 10/15/2013 N/A N/A N/A N/A <0.005 MW-5D Voluntary Not Reported 2/4/2014 N/A N/A N/A <0.005 <0.005 MW-5D Voluntary Not Reported 6/3/2014 N/A N/A N/A N/A N/A MW-5S Voluntary Not Reported 12/16/2008 0.317 <20 N/A N/A <0.005 MW-5S Voluntary Not Reported 6/22/2009 0.224 50 N/A N/A <0.005 MW-5S Voluntary Not Reported 12/14/2009 0.201 <50 N/A N/A <0.005 MW-5S Voluntary Not Reported 6/28/2010 0.182 <100 N/A N/A <0.005 MW-5S Voluntary Not Reported 12/6/2010 N/A N/A N/A N/A N/A MW-5S Voluntary Not Reported 2/1/2011 N/A N/A N/A N/A N/A MW-5S Voluntary Not Reported 6/7/2011 N/A N/A N/A N/A N/A MW-5S Voluntary Not Reported 10/4/2011 N/A N/A N/A N/A N/A MW-5S Voluntary Not Reported 2/4/2013 N/A N/A N/A <0.005 <0.005 MW-5S Voluntary Not Reported 10/15/2013 N/A N/A N/A N/A <0.005 MW-5S Voluntary Not Reported 2/4/2014 N/A N/A N/A <0.005 <0.005 MW-5S Voluntary Not Reported 6/3/2014 N/A N/A N/A N/A N/A MW-6D Voluntary Not Reported 12/16/2008 0.124 20 N/A N/A <0.005 MW-6D Voluntary Not Reported 6/22/2009 0.129 40 N/A N/A <0.005 MW-6D Voluntary Not Reported 12/14/2009 <0.1 <50 N/A N/A <0.005 MW-6D Voluntary Not Reported 6/28/2010 <0.1 <100 N/A N/A <0.005 MW-6S Voluntary Not Reported 12/16/2008 0.128 20 N/A N/A <0.005 MW-6S Voluntary Not Reported 6/22/2009 0.148 30 N/A N/A <0.005 MW-6S Voluntary Not Reported 12/14/2009 0.102 <50 N/A N/A <0.005 MW-6S Voluntary Not Reported 6/28/2010 <0.1 <100 N/A N/A <0.005 MW-6S Voluntary Not Reported 12/6/2010 N/A N/A N/A N/A N/A MW-6S Voluntary Not Reported 2/1/2011 N/A N/A N/A N/A N/A MW-6S Voluntary Not Reported 6/7/2011 N/A N/A N/A N/A N/A MW-6S Voluntary Not Reported 10/4/2011 N/A N/A N/A N/A N/A MW-7D Upgradient Not Reported 12/16/2008 0.1 <20 N/A N/A 0.006 MW-7D Upgradient Not Reported 6/22/2009 0.134 <20 N/A N/A <0.005 MW-7D Upgradient Not Reported 12/14/2009 0.12 <50 N/A N/A 0.006 MW-7D Upgradient Not Reported 6/28/2010 <0.1 <100 N/A N/A 0.006 MW-7D Upgradient Not Reported 12/6/2010 N/A N/A N/A N/A 0.005 MW-7D Upgradient Not Reported 2/2/2011 N/A N/A N/A N/A <0.005 MW-7D Upgradient Not Reported 6/6/2011 N/A N/A N/A N/A <0.005 MW-7D Upgradient Not Reported 10/4/2011 N/A N/A N/A N/A <0.005 MW-7D Upgradient Not Reported 2/22/2012 N/A N/A N/A N/A <0.005 MW-7D Upgradient Not Reported 6/5/2012 N/A N/A N/A N/A <0.005 MW-7D Upgradient Not Reported 10/3/2012 N/A N/A N/A N/A <0.005 MW-7D Upgradient Not Reported 2/4/2013 N/A N/A N/A 0.006 0.005 MW-7D Upgradient Not Reported 6/3/2013 N/A N/A N/A N/A <0.005 MW-7D Upgradient Not Reported 10/14/2013 N/A N/A N/A N/A <0.005 MW-7D Upgradient Not Reported 2/5/2014 N/A N/A N/A <0.005 0.006 MW-7D Upgradient Not Reported 6/2/2014 N/A N/A N/A N/A 0.006 MW-7SR Upgradient Residuum 12/6/2010 N/A N/A N/A N/A 0.006 MW-7SR Upgradient Residuum 2/2/2011 N/A N/A N/A N/A <0.005 MW-7SR Upgradient Residuum 6/6/2011 N/A N/A N/A N/A <0.005 Tables - Page 20 Table 4 - Groundwater Analytical Results Analytical Parameter TOC TOX TSS Zinc Units mg/L pg/L mg/L mg/L 15A NCAC 02L .0202(g) Groundwater Quality Standard NE NE NE 2450D Total 1 200.7 Dissolved Analytical Method 5310E Well Name Well Type Hydrostratigraphic Unit Sample Collection Date Total Total Total MW-7SR Upgradient Residuum 10/4/2011 N/A N/A N/A N/A <0.005 MW-7SR Upgradient Residuum 2/22/2012 N/A N/A N/A N/A <0.005 MW-7SR Upgradient Residuum 6/5/2012 N/A N/A N/A N/A 0.005 MW-7SR Upgradient Residuum 10/3/2012 N/A N/A N/A N/A <0.005 MW-7SR Upgradient Residuum 2/4/2013 N/A N/A N/A <0.005 <0.005 MW-7SR Upgradient Residuum 6/3/2013 N/A N/A N/A N/A <0.005 MW-7SR Upgradient Residuum 10/14/2013 N/A N/A N/A N/A <0.005 MW-7SR Upgradient Residuum 2/5/2014 N/A N/A N/A <0.005 <0.005 MW-7SR Upgradient Residuum 6/2/2014 N/A N/A N/A N/A <0.005 MW-8D Compliance Transition (Saprolite) 12/6/2010 N/A N/A N/A N/A 0.012 MW-8D Compliance Transition (Saprolite) 2/1/2011 N/A N/A N/A N/A <0.005 MW-8D Compliance Transition (Saprolite) 6/7/2011 N/A N/A N/A N/A <0.005 MW-8D Compliance Transition (Saprolite) 10/3/2011 N/A N/A N/A N/A <0.005 MW-8D Compliance Transition (Saprolite) 2/6/2012 N/A N/A N/A N/A 0.007 MW-8D Compliance Transition (Saprolite) 6/4/2012 N/A N/A N/A N/A 0.007 MW-8D Compliance Transition (Saprolite) 10/3/2012 N/A N/A N/A N/A 0.009 MW-8D Compliance Transition (Saprolite) 2/4/2013 N/A N/A N/A <0.005 0.009 MW-8D Compliance Transition (Saprolite) 6/3/2013 N/A N/A N/A N/A 0.006 MW-8D Compliance Transition (Saprolite) 10/14/2013 N/A N/A N/A N/A <0.005 MW-8D Compliance Transition (Saprolite) 2/4/2014 N/A N/A N/A <0.005 0.014 MW-8D Compliance Transition (Saprolite) 6/2/2014 N/A N/A N/A N/A 0.01 MW-81 Compliance Residuum 12/6/2010 N/A N/A N/A N/A <0.005 MW-81 Compliance Residuum 2/1/2011 N/A N/A N/A N/A <0.005 MW-81 Compliance Residuum 6/7/2011 N/A N/A N/A N/A <0.005 MW-81 Compliance Residuum 10/3/2011 N/A N/A N/A N/A <0.005 MW-81 Compliance Residuum 2/6/2012 N/A N/A N/A N/A 0.006 MW-81 Compliance Residuum 6/4/2012 N/A N/A N/A N/A <0.005 MW-81 Compliance Residuum 10/3/2012 N/A N/A N/A N/A <0.005 MW-81 Compliance Residuum 2/4/2013 N/A N/A N/A <0.005 <0.005 MW-81 Compliance Residuum 6/3/2013 N/A N/A N/A N/A <0.005 MW-81 Compliance Residuum 10/14/2013 N/A N/A N/A N/A <0.005 MW-81 Compliance Residuum 2/4/2014 N/A N/A N/A <0.005 <0.005 MW-81 Compliance Residuum 6/2/2014 N/A N/A N/A N/A <0.005 MW-8S Compliance Residuum 12/6/2010 N/A N/A N/A N/A <0.005 MW-8S Compliance Residuum 2/1/2011 N/A N/A N/A N/A <0.005 MW-8S Compliance Residuum 6/7/2011 N/A N/A N/A N/A <0.005 MW-8S Compliance Residuum 10/3/2011 N/A N/A N/A N/A <0.005 MW-8S Compliance Residuum 2/6/2012 N/A N/A N/A N/A 0.005 MW-8S Compliance Residuum 6/4/2012 N/A N/A N/A N/A <0.005 MW-8S Compliance Residuum 10/3/2012 N/A N/A N/A N/A <0.005 MW-8S Compliance Residuum 2/4/2013 N/A N/A N/A <0.005 <0.005 MW-8S Compliance Residuum 6/3/2013 N/A N/A N/A N/A <0.005 MW-8S Compliance Residuum 10/14/2013 N/A N/A N/A N/A <0.005 MW-8S Compliance Residuum 2/4/2014 N/A N/A N/A <0.005 <0.005 MW-8S Compliance Residuum 6/2/2014 N/A N/A N/A N/A 0.007 MW-9 Compliance Residuum 12/6/2010 N/A N/A N/A N/A 0.01 MW-9 Compliance Residuum 2/1/2011 N/A N/A N/A N/A <0.005 MW-9 Compliance Residuum 6/6/2011 N/A N/A N/A N/A 0.006 MW-9 Compliance Residuum 10/4/2011 N/A N/A N/A N/A <0.005 MW-9 Compliance Residuum 2/6/2012 N/A N/A N/A N/A 0.009 MW-9 Compliance Residuum 6/5/2012 N/A N/A N/A N/A <0.005 MW-9 Compliance Residuum 10/3/2012 N/A N/A N/A N/A <0.005 MW-9 Compliance Residuum 2/4/2013 N/A N/A N/A <0.005 0.007 MW-9 Compliance Residuum 6/4/2013 N/A N/A N/A N/A <0.005 MW-9 Compliance Residuum 10/15/2013 N/A N/A N/A N/A <0.005 MW-9 Compliance Residuum 2/5/2014 N/A N/A N/A 0.013 <0.005 MW-9 Compliance Residuum 6/2/2014 N/A N/A N/A N/A <0.005 Tables - Page 21 Table 4 - Groundwater Analytical Results Notes: 1. Depth to Water measured from the top of well casing 2. Analytical parameter abbreviations: Temp. = Temperature DO = Dissolved oxygen Cond. = Specific conductivity ORP = Oxidation reduction potential TDS = Total dissolved solids TSS = Total suspended solids TOC = Total organic carbon TOX = Total organic halides 3. Units: °C = Degrees Celsius SU = Standard Units my = millivolts NTU = Nephelometric Turbidity Unit mg/L = milligrams per liter pg/L = micrograms per liter pmhos/cm = micromhos per centimeter CaCO3 = calcium carbonate HCO3 = bicarbonate C032- = carbonate 4. N/A = Not applicable 5. NE = Not established 6. ' Interim Maximum Allowable Concentration (IMAC) standards 7. Highlighted values indicate values that exceed the 15A NCAC 2L Standard 8. Analytical results with "<" preceding the result indicates that the parameter was not detected at a concentration which attains or exceeds the laboratory reporting limit. Tables - Page 22 Table 5 - Ash Analytical Results Analytical Parameter pH % Solids Aluminum Antimony Arsenic Barium Beryllium Boron Cadmium Calcium Chromium Cobalt Copper Iron Lead Magnesium Manganese Mercury Molybdenum Units Su % mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg Analytical Method Field Measurement 200.8 200.8 200.7 200.7 200.8 200.7 200.7 200.8 200.7 200.7 200.8 200.7 200.8 245.1 200.8 Site Name Sample Collection Date Comp_1 11/30/2006 7.65 N/A N/A 0.75 31 260 N/A 41 0.64 2100 13 N/A 54 N/A 12 710 58 0.036 N/A Comp_1 3/21/2007 7.05 N/A N/A 0.4 24 240 N/A <1.89105 0.44 1300 9.2 N/A 37 N/A 7.9 400 53 0.057 N/A Comp_2 11/30/2006 7.56 N/A N/A 1.2 48 400 N/A 51 0.75 3600 18 N/A 74 N/A 21 1100 59 0.043 N/A Com p_2 3/21/2007 7.01 N/A N/A 0.51 24 270 N/A 4.8 0.39 1400 10 N/A 39 N/A 9 660 62 0.063 N/A Ponded 1/1/1997 N/A N/A N/A N/A N/A N/A N/A N/A N/A 2630 N/A N/A 53 N/A N/A 700 67 N/A N/A Ponded 1/1/1999 N/A N/A N/A N/A N/A N/A N/A N/A N/A 1025.4 N/A N/A 24.1 20824 N/A 360.6 89.3 N/A N/A Ponded 1/1/2000 N/A N/A N/A N/A N/A N/A N/A N/A N/A 1643.6 N/A N/A 32.2 25650 N/A 435.4 130.9 N/A N/A Ponded 1/1/2003 N/A N/A N/A N/A N/A N/A N/A N/A N/A 1833.1 N/A N/A 43.3 N/A N/A 549.5 38.8 N/A N/A Ponded 12/12/2006 1 N/A I N/A I N/A 1 <0.81 1 30 1 260 1 N/A 1 26 1 0.19 1 2000 1 12 1 N/A 1 45 1 0.04 1 11 1 730 1 44 1 0.036 1 2.8 Tables - Page 23 Table 5 - Ash Analytical Results Analytical Parameter Nickel Phosphorus Potassium Selenium Silver Sodium Strontium Thallium Zinc Units mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg Analytical Method 200.7 200.7 200.8 200.7 200.8 200.7 Site Name Sample Collection Date Comp_1 11/30/2006 20 400 1500 N/A <1.1 270 N/A N/A 21 Comp_1 3/21/2007 15 320 830 3.7 <0.0256642 120 N/A N/A 13 Comp_2 11/30/2006 28 520 2500 N/A <1 400 N/A N/A 36 Comp_2 3/21/2007 15 400 1200 2.6 <0.0266274 140 N/A N/A 16 Ponded 1/1/1997 15 640 1070 N/A N/A 170 N/A N/A 20 Ponded 1/1/1999 11.3 <0.2 753 N/A N/A 130.5 N/A N/A 12.3 Ponded 1/1/2000 14.9 6.4 532.5 N/A N/A 96 N/A N/A 15.8 Ponded 1/1/2003 12 271.7 983 N/A N/A 203.5 N/A N/A 15.35 Ponded 12/12/2006 19 410 1500 2.2 <1 250 N/A N/A 19 Tables - Page 24 Table 5 - Ash Analytical Results Notes: 1. Units: SU = Standard Units mg/kg = milligrams per kilogram 2. N/A = Not applicable 3. NE = Not established Tables - Page 25 TABLE 6- SURFACE WATER ANALYTICAL RESULTS Analytical Parameter Depth to Water Temp. DO Cond. pH ORP Turbidity Alkalinity Aluminum Antimony Units Feet C mg/L pmhos/cm SU my NTU mg/L CaCO3 mg/L HCO3 mg/L C032" N/A pg/L 15A NCAC 02B .0200 Surface Water Quality Standard (WS Waters) NE NE NE NE 6.0 - 9.0 NE NE NE NE NE 87 5.6 Analytical Method 2320134d N/A N/A 0 200.8 Field Measurements Well Name Sample Collection Date Total Total Dissolved Total 277.5-0.3M 4/29/2014 N/A 17.96 N/A 57.9 7.19 N/A N/A N/A N/A N/A 237 N/A <1 277.E-0.3 m 2/25/2010 N/A 8.26 10.75 56 7.35 N/A 8.5 N/A N/A N/A N/A N/A N/A 277.E-0.3 m 8/4/2010 N/A 29.93 6.28 66 7.14 N/A 3.1 N/A N/A N/A N/A N/A N/A 277.E-0.3m 2/9/2011 N/A 8.24 10.61 66 7.19 N/A 3 15 N/A N/A N/A N/A N/A 277.E-0.3 m 8/3/2011 N/A 30.65 6.5 70 7.04 N/A 1.8 12 N/A N/A N/A N/A N/A 277.E-0.3 m 2/2/2012 N/A 10.87 9.91 68 6.94 N/A 3.9 14 N/A N/A N/A N/A N/A 277.E-0.3m 8/2/2012 N/A 29.97 5.76 68 6.91 N/A 2.1 15 N/A N/A N/A N/A N/A 277.E-0.3m 2/14/2013 N/A 9.95 10.13 65 6.87 N/A 4 15 N/A N/A N/A N/A N/A 278.0-0.3 m 2/25/2010 N/A 8.32 10.75 56 7.3 N/A N/A N/A N/A N/A N/A N/A N/A 278.0-0.3 m 8/4/2010 N/A 30.24 5.63 63 6.99 N/A N/A N/A N/A N/A N/A N/A N/A 278.0-0.3m 2/9/2011 N/A 8.38 10.53 66 7.24 N/A N/A N/A N/A N/A N/A N/A N/A 278.0-0.3 m 8/3/2011 N/A 30.28 5.69 69 6.93 N/A N/A N/A N/A N/A N/A N/A N/A 278.0-0.3m 8/30/2011 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 278.0-0.3m 2/2/2012 N/A 10.88 9.97 68 7.02 N/A 1.1 14 N/A N/A N/A N/A N/A 278.0-0.3m 8/2/2012 N/A 29.82 5.24 67 6.88 N/A 2 15 N/A N/A N/A N/A N/A 278.0-0.3m 2/14/2013 N/A 9.55 10.11 65 6.92 N/A 5.1 15 N/A N/A N/A N/A N/A 278.0-0.3m 4/29/2014 N/A 17.99 N/A 57.7 7.21 N/A N/A N/A N/A N/A 158 N/A <1 Tower-0.3m 2/5/2013 N/A 7.92 11.74 120 7 342 18.8 16 N/A N/A N/A 2.96 2.8 Tower-0.3m 6/3/2013 N/A 26.95 8.05 154 8.23 151 2.16 17 N/A N/A N/A N/A 4.31 Tower-0.3m 10/14/2013 N/A 22.08 7.42 161 7.2 300 4.74 19 N/A N/A N/A N/A 3.24 Tower-0.3m 2/4/2014 N/A 6.39 12.03 166 5.99 395 4.99 3.3 N/A N/A N/A 1.72 1.65 Tower-0.3m 4/29/2014 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 119 N/A 1.28 Tower-0.3m 6/2/2014 N/A 27.61 7.32 163 6.6 338 2.77 <5 N/A N/A N/A N/A 1.89 Tables - Page 26 TABLE 6- SURFACE WATER ANALYTICAL RESULTS Analytical Parameter Arsenic Barium Beryllium Boron Cadmium Calcium Chloride Chromium Cobalt Units pg/L pg/L pg/L pg/L pg/L mg/L mg/L pg/L pg/L 15A NCAC 02B .0200 Surface Water Quality Standard (WS Waters) 10 1000 6.5 NE 2 NE 230 50 3 Analytical Method 200.8 200.7 N/A 200.7 200.8 200.7 300 200.7 200.8 Well Name 277.5-0.3M 277.E-0.3m 277.E-0.3m 277.E-0.3m 277.E-0.3m 277.E-0.3m 277.E-0.3m 277.E-0.3m 278.0-0.3m 278.0-0.3m 278.0-0.3m 278.0-0.3m 278.0-0.3m 278.0-0.3m 278.0-0.3m 278.0-0.3m 278.0-0.3m Tower-0.3m Tower-0.3m Tower-0.3m Tower-0.3m Tower-0.3m Tower-0.3m Sample Collection Date Dissolved Total Dissolved Total Total Dissolved Total Dissolved Total Dissolved Total Total Dissolved Total Dissolved Total 4/29/2014 N/A <1 N/A 15 N/A N/A <50 N/A <1 N/A 4.09 5 N/A <1 N/A N/A 2/25/2010 N/A <1 15.2 N/A N/A N/A 38.7 N/A <1 3.77 N/A 6 N/A <1 N/A N/A 8/4/2010 N/A 1.1 17.2 N/A N/A N/A 50.6 N/A <1 4.47 N/A 7 N/A <1 N/A N/A 2/9/2011 N/A <1 13 N/A N/A 55 61.2 N/A <1 4.4 N/A 7.3 N/A <1 N/A N/A 8320 NA <1 18 NA NA NA 66.4 NA <1 4.75 N/A 7.4 N/A <1 N/A N/A 2/2/2012 N/A <1 14 N/A N/A N/A 66.2 N/A <1 4.28 N/A 7.5 N/A <1 N/A N/A 8/2/2012 N/A <1 14 N/A N/A N/A 56.9 N/A <1 4.17 N/A 6.8 N/A <1 N/A N/A 2/14/2013 N/A <1 15 N/A N/A 55 N/A N/A <1 4.32 N/A 6.7 N/A <1 N/A N/A 2/25/2010 N/A <1 N/A N/A N/A N/A 36.7 N/A N/A N/A N/A N/A N/A N/A N/A N/A 8/4/2010 N/A <1 N/A N/A N/A N/A 45.2 N/A N/A N/A N/A N/A N/A N/A N/A N/A 2/9/2011 N/A <1 N/A N/A N/A N/A 65.9 N/A N/A N/A N/A N/A N/A N/A N/A N/A 8/3/2011 N/A <1 N/A N/A N/A N/A 60.4 N/A <1 N/A N/A N/A N/A <1 N/A N/A 8/30/2011 N/A <1 N/A N/A N/A N/A N/A N/A <1 N/A N/A N/A N/A <1 N/A N/A 2/2/2012 N/A <1 14 N/A N/A N/A 63.4 N/A <1 4.29 N/A 7.6 N/A <1 N/A N/A 8/2/2012 N/A <1 14 N/A N/A N/A 54.6 N/A <1 4.13 N/A 6.8 N/A <1 N/A N/A 2/14/2013 N/A <1 15 N/A N/A 56 N/A N/A <1 4.39 N/A 6.8 N/A <1 N/A N/A 4/29/2014 N/A <1 N/A 14 N/A N/A <50 N/A <1 N/A 4.06 4.9 N/A <1 N/A N/A 2/5/2013 17.1 19.2 131 133 N/A 177 175 <1 <1 9.91 9.86 7 <5 <5 N/A N/A 6/3/2013 N/A 57.8 N/A 179 N/A N/A 357 N/A <1 N/A 14.8 6.9 N/A <5 N/A N/A 10/14/2013 N/A 68.2 N/A 176 N/A N/A 406 N/A <1 N/A 15 7 N/A <5 N/A N/A 2/4/2014 1.93 2.7 146 147 N/A 319 312 <1 <1 15.1 15.4 5.6 <5 <5 N/A N/A 4/29/2014 N/A 7.41 N/A 129 N/A N/A 294 N/A <1 N/A 15.3 5 N/A <1 N/A N/A 6/2/2014 N/A 9.85 N/A 127 N/A N/A 293 N/A <1 N/A 15.1 5.2 N/A <5 N/A N/A Tables - Page 27 TABLE 6- SURFACE WATER ANALYTICAL RESULTS Analytical Parameter Copper Fluoride Iron Lead Magnesium Manganese Mercury Molybdenum Units mg/L mg/L pg/L pg/L pg/L pg/L pg/L Ng/L 15A NCAC 02B .0200 Surface Water Quality Standard (WS Waters) 7 1.8 1000 25 NE 200 0.012 160 Analytical Method 200.7 200.7 200.8 200.7 200.8 245.1 200.8 Well Name Sample Collection Date Dissolved Total Total Dissolved Total Dissolved Total Dissolved Total Dissolved Total Dissolved Total Dissolved Total 277.5-0.3M 4/29/2014 N/A 0.002 <1 N/A 210 N/A <1 N/A 1.78 N/A 20 N/A <0.05 N/A <1 277.E-0.3m 2/25/2010 0.001 0.002 0.000 N/A 449 N/A <1 1.63 N/A N/A 18.5 N/A <0.05 N/A N/A 277.E-0.3m 8/4/2010 0.001 0.001 0.000 N/A 161 N/A <1 1.82 N/A N/A 32.8 N/A <0.05 N/A N/A 277.E-0.3m 2/9/2011 <0.001 0.001 0.000 N/A 133 N/A <1 1.85 N/A N/A 16.5 N/A <0.05 N/A N/A 277.E-0.3m 8/3/2011 0.001 0.001 0.000 N/A 75.7 N/A <1 2.17 N/A N/A 33.3 N/A <0.05 N/A N/A 277.E-0.3m 2/2/2012 <0.001 <0.001 0.000 N/A 135 N/A <1 2.05 N/A N/A 19.8 N/A <0.05 N/A N/A 277.E-0.3m 8/2/2012 <0.001 0.001 0.000 N/A 78.5 N/A <1 1.92 N/A N/A 40.7 N/A <0.05 N/A N/A 277.E-0.3m 2/14/2013 <0.001 0.001 0.000 N/A 231 N/A <1 1.96 N/A N/A 24.7 N/A <0.05 N/A N/A 278.0-0.3m 2/25/2010 N/A N/A 0.000 N/A 451 N/A N/A N/A N/A N/A 15.6 N/A N/A N/A N/A 278.0-0.3m 8/4/2010 N/A N/A 0.000 N/A 108 N/A N/A N/A N/A N/A 36.5 N/A N/A N/A N/A 278.0-0.3m 2/9/2011 N/A N/A 0.000 N/A 114 N/A N/A N/A N/A N/A 15.2 N/A N/A N/A N/A 278.0-0.3m 8/3/2011 N/A 0.001 0.000 N/A 76.7 N/A <1 N/A N/A N/A 41.2 N/A N/A N/A N/A 278.0-0.3m 8/30/2011 N/A 0.001 0.000 N/A 74.6 N/A <1 N/A N/A N/A 46.7 N/A <0.05 N/A N/A 278.0-0.3m 2/2/2012 <0.001 <0.001 0.000 N/A 89.6 N/A <1 2.06 N/A N/A 13.1 N/A <0.05 N/A N/A 278.0-0.3m 8/2/2012 <0.001 0.001 0.000 N/A 84.3 N/A <1 1.91 N/A N/A 48.1 N/A <0.05 N/A N/A 278.0-0.3m 2/14/2013 <0.001 0.001 0.000 N/A 240 N/A <1 1.97 N/A N/A 28 N/A <0.05 N/A N/A 278.0-0.3m 4/29/2014 N/A 0.002 <1 N/A 132 N/A <1 N/A 1.77 N/A 14 N/A <0.05 N/A <1 Tower-0.3m 2/5/2013 <0.005 <0.005 0.000 <10 59 <1 <1 2.51 2.51 12 17 N/A <0.05 N/A N/A Tower-0.3m 6/3/2013 N/A <0.005 0.000 N/A 32 N/A <1 N/A 3.01 N/A 15 N/A <0.05 N/A N/A Tower-0.3m 10/14/2013 N/A <0.005 0.000 N/A 44 N/A <1 N/A 3.2 N/A 32 N/A <0.05 N/A N/A Tower-0.3m 2/4/2014 <0.005 <0.005 0.000 <10 70 <1 <1 3.15 3.25 155 156 N/A <0.05 N/A N/A Tower-0.3m 4/29/2014 N/A 0.003 <1 N/A 51 N/A <1 N/A 3.13 N/A 123 N/A <0.05 N/A 22.7 Tower-0.3m 6/2/2014 N/A <0.005 0.000 N/A 23 N/A <1 N/A 3.03 N/A 39 N/A <0.05 N/A N/A Tables - Page 28 TABLE 6- SURFACE WATER ANALYTICAL RESULTS Analytical Parameter Nickel Nitrate as N Potassium Selenium Sodium Strontium Sulfate TDS Thallium TOC Units Ng/L mg -NIL mg/L Ng/L mg/L mg/L mg/L mg/L Ng/L mg/L 15A NCAC 02B .0200 Surface Water Quality Standard (WS Waters) 25 10 NE 5 NE 14 250 500 0.24 NE Analytical Method 200.7 300.0 200.7 200.8 200.7 N/A 300.0 2540C 200.8 5310B Well Name Sample Collection Date Dissolved Total Total Dissolved Total Dissolved Total Dissolved Total Total Total Total Dissolved Total Total 4/29/2014 N/A N/A N/A N/A 277.5-0.3M N/A <1 N/A <1 N/A N/A 3.9 39 N/A <0.2 N/A 277.E-0.3m 2/25/2010 N/A <1 N/A 1.67 N/A N/A <1 3.57 N/A N/A 4.5 24 N/A N/A N/A 277.E-0.3m 8/4/2010 N/A <1 N/A 1.73 N/A N/A <1 4.02 N/A N/A 4.7 <50 N/A N/A N/A 277.E-0.3m 2/9/2011 N/A <1 N/A 1.65 N/A N/A <1 4.06 N/A N/A 4.2 41 N/A N/A N/A 277.E-0.3m 8/3/2011 N/A <1 N/A 2.09 N/A N/A <1 5.25 N/A N/A 4.5 49 N/A N/A N/A 277.E-0.3m 2/2/2012 N/A <1 N/A 1.8 N/A N/A <1 4.7 N/A N/A 4.2 49 N/A N/A N/A 277.E-0.3m 8/2/2012 N/A <1 N/A 1.76 N/A N/A <1 4.45 N/A N/A 4.1 43 N/A N/A N/A 277.E-0.3m 2/14/2013 N/A <1 N/A 1.85 N/A N/A <1 4.47 N/A N/A 4 49 N/A N/A N/A 278.0-0.3m 2/25/2010 N/A N/A N/A N/A N/A N/A <1 N/A N/A N/A 41 N/A N/A N/A N/A 278.0-0.3m 8/4/2010 N/A N/A N/A N/A N/A N/A <1 N/A N/A N/A 4.1 N/A N/A N/A N/A 278.0-0.3m 2/9/2011 N/A N/A N/A N/A N/A N/A <1 N/A N/A N/A 4.2 N/A N/A N/A N/A 278.0-0.3m 8/3/2011 N/A <1 N/A N/A N/A N/A <1 N/A N/A N/A 4.4 N/A N/A N/A N/A 278.0-0.3m 8/30/2011 N/A N/A N/A N/A N/A N/A <1 N/A N/A N/A N/A 51 N/A N/A N/A , 278.0-0.3m 2/2/2012 N/A <1 N/A 1.81 N/A N/A <1 4.72 N/A N/A 4.3 52 N/A N/A N/A 278.0-0.3m 8/2/2012 N/A <1 N/A 1.75 N/A N/A <1 4.41 N/A N/A 4.1 42 N/A N/A N/A 278.0-0.3m 2/14/2013 N/A <1 N/A 1.86 N/A N/A <1 4.5 N/A N/A 4 51 N/A N/A N/A 278.0-0.3m 4/29/2014 N/A <1 N/A N/A N/A N/A <1 N/A N/A N/A 3.8 38 N/A <0.2 N/A Tower-0.3m 2/5/2013 6 6 <0.023 3.28 3.3 <1 <1 5.38 5.38 N/A 28 78 0.67 0.672 N/A Tower-0.3m 6/3/2013 N/A <5 <0.023 N/A 4.58 N/A <1 N/A 6.19 N/A 41 89 N/A 0.845 N/A Tower-0.3m 10/14/2013 N/A <5 <0.023 N/A 5 N/A 1.03 N/A 6.04 N/A 42 100 N/A 0.21 N/A Tower-0.3m 2/4/2014 24 24 0.07 5.03 5.03 <1 <1 5.45 5.38 N/A 59 110 0.76 0.75 N/A Tower-0.3m 4/29/2014 N/A 21 N/A N/A N/A N/A <1 N/A N/A N/A 55 95 N/A 0.917 N/A Tower-0.3m 6/2/2014 N/A 19 <0.023 N/A 4.52 N/A 1.05 N/A 4.85 N/A 56 97 N/A 0.876 N/A Tables - Page 29 TABLE 6- SURFACE WATER ANALYTICAL RESULTS Analytical Parameter TOX TSS Zinc Units pg/L mg/L mg/L 15A NCAC 02B .0200 Surface Water Quality Standard (WS Waters) NE NE 0.05 Analytical Method 2450D 200.7 Well Name Sample Collection Date Total N/A Total <5 Dissolved Total <0.00 4/29/2014 277.5-0.3M N/A 277.E-0.3m 2/25/2010 N/A N/A N/A 0.001� 277.E-0.3m 8/4/2010 N/A N/A N/A 0.004 277.E-0.3m 2/9/2011 N/A N/A N/A <0.00 277.E-0.3m 8/3/2011 N/A N/A N/A <0.00 277.E-0.3m 2/2/2012 N/A N/A N/A <0.00 277.E-0.3m 8/2/2012 N/A N/A N/A <0.00 277.E-0.3m 2/14/2013 N/A N/A N/A 0.M 278.0-0.3m 2/25/2010 N/A N/A N/A N/A 278.0-0.3m 8/4/2010 N/A N/A N/A N/A 278.0-0.3m 2/9/2011 N/A N/A N/A N/A 278.0-0.3m 8/3/2011 N/A N/A N/A <0.00 278.0-0.3m 8/30/2011 N/A N/A N/A <0.00 278.0-0.3m 2/2/2012 N/A N/A N/A <0.00 278.0-0.3m 8/2/2012 N/A N/A N/A <0.00 278.0-0.3m 2/14/2013 N/A N/A N/A 0.002 278.0-0.3m 4/29/2014 N/A <5 N/A <0.00 Tower-0.3m 2/5/2013 N/A N/A 0.01 0.011 Tower-0.3m 6/3/2013 N/A N/A N/A <0.00 Tower-0.3m 10/14/2013 N/A N/A N/A <0.00 Tower-0.3m 2/4/2014 N/A N/A 0.092 0.097 Tower-0.3m 4/29/2014 N/A <5 N/A 0.07 Tower-0.3m 6/2/2014 N/A N/A N/A 0.03E Tables - Page 30 Notes: 1. Analytical parameter abbreviations: Temp. = Temperature DO = Dissolved oxygen Cond. = Specific conductivity ORP = Oxidation reduction potential TDS = Total dissolved solids TSS = Total suspended solids TOC = Total organic carbon 2. Units: °C = Degrees Celsius SU = Standard Units my = millivolts NTU = Nephelometric Turbidity Unit mg/L = milligrams per liter pg/L = micrograms per liter pmhos/cm = micromhos per centimeter CaCO3 = calcium carbonate HCO3 = bicarbonate C032- = carbonate 3. N/A = Not applicable 4. NE = Not established 5. Highlighted values indicate values that exceed the 15A NCAC 2B Standard 6. Analytical results with "<" preceding the result indicates that the parameter was not detected at a concentration which attains or exceeds the laboratory reporting limit. Tables - Page 31 Table 7 - Seep Analytical Results Analytical Parameter Temp. Cond. pH Aluminum Antimony Arsenic Barium Beryllium Boron Cadmium Calcium COD Chloride Chromium Cobalt Copper Flow Fluoride Units C Nmhos/cm SU Ng/L pg/L Ng/L mg/L pg/L mg/L Ng/L mg/L mg/L mg/L Ng/L Ng/L mg/L MGD mg/L 15A NCAC 02B .0200 Surface Water Quality Standard NE NE 6.0 - 9.0 0.087 5.6 10 1 6.5 NE 2 NE NE 230 50 3 0.007 N/A 1.8 Analytical Method 200.7 200.8 200.8 200.7 N/A 200.7 200.8 200.7 HACH 8000 300 200.7 200.8 200.7 N/A 300.0 Site Name Sample Collection Date _ S-1 4/29/2014 15.81 207 5.9 0.115 <1 <1 0.05 N/A 0.089 <1 _ 14.2 N/A 4.6 <1 N/A <0.001 0.00056 <1 S-3 4/29/2014 16.75 150 5.57 0.065 <1 <1 0.091 N/A 0.349 <1 10.5 N/A 7.3 <1 N/A <0.001 0.00562 <1 S-4 4/29/2014 15.84 133 7.98 0.193 <1 <1 0.043 N/A 0.361 <1 6.83 N/A 6.6 <1 N/A <0.001 0.01754 <1 S-5 4/29/2014 16.49 134 6.29 0.394 <1 <1 0.059 N/A 0.443 <1 5.14 N/A 7 <1 N/A <0.001 0.00287 <1 S-6 4/29/2014 16.59 104 7.62 0.022 <1 <1 0.017 N/A 0.154 <1 2.94 N/A 6.3 <1 N/A <0.001 0.02085 <1 S-7 4/29/2014 15.71 70 6.62 0.159 <1 <1 0.024 N/A 0.082 <1 3.76 N/A 5.2 <1 N/A <0.001 0.0332 <1 S-8 4/29/2014 17.23 83 6.76 0.216 <1 <1 0.019 N/A <0.05 <1 7.49 N/A 2.7 <1 N/A <0.001 0.0245 <1 S-9 4/29/2014 16.01 126 6.38 0.366 <1 <1 0.043 N/A 0.388 <1 6.33 <20 6.7 <1 N/A <0.001 0.01206 <1 S-11 4/29/2014 15.56 95.2 5.9 0.047 <1 <1 0.027 N/A 0.259 <1 3.55 <20 5.9 <1 N/A <0.001 0.00835 <1 S-12 4/29/2014 17.53 129.3 6.02 0.029 <1 <1 0.098 N/A 0.242 <1 3.32 <20 7 <1 N/A 0.00158 0.00568 <1 277.5 4/29/2014 17.96 57.9 7.19 0.237 <1 <1 0.015 N/A <0.05 <1 4.09 <20 5 <1 N/A 0.00163 N/A <1 278 4/29/2014 17.99 57.7 7.21 0.158 <1 <1 0.014 N/A <0.05 <1 4.06 <20 4.9 <1 N/A 0.00168 N/A <1 Tables - Page 32 Table 7 - Seep Analytical Results Analytical Parameter Hardness Iron Lead Magnesium Manganese Mercury Molybdenum Nickel Nitrate as N Oil and Grease Potassium Selenium Sodium Strontium Sulfate TDS Thallium Units mg/L as CaCO3 pg/L pg/L mg/L mg/L pg/L pg/L pg/L mg-N/L mg/L mg/L pg/L mg/L N/A mg/L mg/L pg/L 15A NCAC 02B .0200 Surface Water Quality Standard 100 1000 25 NE 200 0.012 160 25 10 see note 3 NE 5 NE 14 250 500 0.24 Analytical Method 200.7 200.7 200.8 200.7 200.8 245.1 200.8 200.7 300.0 1664B 200.7 200.8 200.7 N/A 300.0 2540C 200.8 Site Name Sample Collection Date S-1 4/29/2014 58.8 6510 <1 5.68 1.03 <0.05 <1 <1 N/A N/A N/A <1 N/A N/A 63 140 <0.2 S-3 4/29/2014 40.6 140 <1 3.48 0.841 <0.05 <1 8.77 N/A N/A N/A <1 N/A N/A 49 90 <0.2 S-4 4/29/2014 41.9 539 <1 6.04 0.429 <0.05 <1 <1 N/A N/A N/A <1 N/A N/A 31 88 <0.2 S-5 4/29/2014 37.1 1030 <1 5.89 0.282 <0.05 <1 2.47 N/A N/A N/A <1 N/A N/A 38 86 <0.2 S-6 4/29/2014 31.5 293 <1 5.87 1 <0.05 <1 1 N/A N/A N/A <1 N/A N/A 20 66 <0.2 S-7 4/29/2014 26.1 880 <1 4.05 0.345 <0.05 <1 2.07 N/A N/A N/A <1 N/A N/A 3.1 51 <0.2 S-8 4/29/2014 29.3 2150 <1 2.58 0.028 <0.05 <1 <1 N/A N/A N/A <1 N/A N/A 1.5 81 <0.2 S-9 4/29/2014 39.6 720 <1 5.77 0.208 <0.05 <1 1.48 N/A <5 N/A <1 N/A N/A 30 84 <0.2 S-11 4/29/2014 21.4 472 <1 3.04 1.23 <0.05 <1 1.1 N/A <5 N/A <1 N/A N/A 26 56 <0.2 S-12 4/29/2014 33 374 <1 6 1.14 <0.05 <1 6.33 N/A <5 N/A <1 N/A N/A 41 78 <0.2 277.5 4/29/2014 17.5 210 <1 1.78 0.02 <0.05 <1 <1 N/A <5 N/A <1 N/A N/A 3.9 39 <0.2 278 4/29/2014 17.4 132 <1 1.77 0.014 <0.05 <1 <1 N/A <5 N/A <1 N/A N/A 3.8 38 <0.2 Tables - Page 33 Table 7 - Seep Analytical Results Analytical Parameter TOC TSS Zinc Units mg/L mg/L mg/L 15A NCAC 02B .0200 Surface Water Quality Standard NE NE 0.05 Analytical Method 5310B 2450D 200.7 Site Name Sample Collection Date S-1 4/29/2014 N/A 11 <0.005 S-3 4/29/2014 N/A <5 0.019 S-4 4/29/2014 N/A <5 <0.005 S-5 4/29/2014 N/A 9 <0.005 S-6 4/29/2014 N/A <5 <0.005 S-7 4/29/2014 N/A 7 <0.005 S-8 4/29/2014 N/A <5 <0.005 S-9 4/29/2014 N/A 11 <0.005 S-11 4/29/2014 N/A <5 <0.005 S-12 4/29/2014 N/A <5 0.018 277.5 4/29/2014 N/A <5 <0.005 278 4/29/2014 N/A <5 <0.005 Tables - Page 34 Table 7 - Seep Analytical Results Notes: 1. Analytical parameter abbreviations: Temp. = Temperature Cond. = Specific conductivity TDS = Total dissolved solids TSS = Total suspended solids 2. Units: °C = Degrees Celsius SU = Standard Units pmhos/cm = micromhos per centimeter mg/L = milligrams per liter pg/L = micrograms per liter CaCO3 = calcium carbonate 3. Take the lowest LC50 available for the particular type of OG you have (or similar OG) and multiply it by a safety factor of 0.01 to obtain the criteria 4. N/A = Not applicable 5. NE = Not established 6. Flow measurements and analytical samples were collected on April 29, 2014. 7. Flow was not exhibited at S-10 during the time of seep sampling 8. Highlighted values indicate values that exceed the 15A NCAC 2B Standard 9. Analytical results with "<" preceding the result indicates that the parameter was not detected at a concentration which attains or exceeds the laboratory reporting limit Tables - Page 35 TABLE 8 - ENVIRONMENTAL EXPLORATION AND SAMPLING PLAN RIVERBEND STEAM STATION Exploration Area Soil Borings Shallow Monitoring Wells Deep Monitoring Wells Bedroc Estimated Estimated Screen Estimated Estimated Screen Boring Us Quantity Boring Depth Well IDs Quantity Well Depth Length Well IDs Quantity Casing Well Length Well IDs Quantity (ft bgs) (ft bgs) (ft) Depth Depth (ft) (ft bgs) (ft bgs) AB-1 S through AB-1 AB-8S, AB- AB-1 D throu h AB - Ash Basin through 8 75 - 125 5SL and AB- 10 20-80 15 8D g 8 40-60 55-75 5 AB-3BR 1 AB-8 7SL Ash AS-1 AS-1 S through Storage/ through 5 80 - 100 AS-3S, C-1 S 5 30-80 15 AS-1 D through AS- 5 40-90 55-105 5 N/A N/A Cinder AS-3, C-1 and C-2S 3D, C-1 D and C-2D Storage and C-2 GWA-1 GWA-1S GWA-2BR, Beyond through GWA- GWA-1 D through GWA-4BR, Waste GWA-10, 12 50 — 80 10Sthrough OB-1 and 10 25-125 40-140 5 12 15-45 10-15 GWA-10D GWA-7BR 5 Boundary OB-1 and , OB-2 GWA-9BR, OB-2 MW-7BR BG-1, BG- BG-1 S, BG- BG-1 D, BG-2D, and Background 2, and BG- 3 30-100 2S, and BG- 3 20-60 10-15 BG-3D 3 30-125 40-140 5 BG-2BR 1 3 3S Potential GWA- Additional GWA-20 GWA-20S GWA-20D through 20BR, Beyond through 4 80-100 through GWA- 4 30-80 10-15 4 40-90 55-105 5 GWA-23D GWA- 4 Waste GWA-23 23S 23BR Boundary Notes: 1. Estimated boring and well depths based on data available at the time of work plan preparation and subject to change based on site -specific conditions in the field. 2. Laboratory analyses of soil, ash, groundwater, and surface water samples will be performed in accordance with the constituents and methods identified in Tables 9 and 10. 3. Additionally, soils will be tested in the laboratory to determine grain size (with hydrometer), specific gravity, and permeability. 4. During drilling operations, downhole testing will be conducted to determine in -situ soil properties such as horizontal and vertical hydraulic conductivity. 5. Actual number of field and laboratory tests will be determined in field by Field Engineer or Geologist. k Monitoring Wells Estimated Estimated Screen Casing Well Length Depth Depth (ft) (ft bgs) (ft bgs) 70-100 100-150 5 N/A N/A N/A 45-105 95-155 5 45-105 115-180 5 45-105 95-155 5 Water Supply Wells Surface Water/Sediment Well IDs Quantity Quantity of Quantity of Locations Samples 2 Surface N/A N/A Water 4 Locations N/A N/A N/A N/A Existing 13 Seeps Water 3 13 Supply 13 Wells Sediment N/A N/A N/A N/A N/A N/A N/A N/A Tables - Page 36 TABLE 9 — SOIL AND ASH PARAMETERS AND CONSTITUENT ANALYTICAL METHODS INORGANIC COMPOUNDS UNITS METHOD Antimony mg/kg EPA 6020A Arsenic mg/kg EPA 6020A Barium mg/kg EPA 6010C Boron mg/kg EPA 6010C Cadmium mg/kg EPA 6020A Chloride mg/kg EPA 9056A Chromium (Total) mg/kg EPA 6010C Copper mg/kg EPA 6010C Iron mg/kg EPA 6010C Lead mg/kg EPA 6020A Manganese mg/kg EPA 6010C Mercury mg/kg EPA Method 7470A/7471 B Nickel mg/kg EPA 6010C pH SU EPA 9045D Selenium mg/kg EPA 6020A Thallium (low level) (SPLP Extract only) mg/kg EPA 6020A Zinc mg/kg EPA 6010C Notes: 1. Soil samples to be analyzed for Total Inorganics using USEPA Methods 6010/6020 and pH using USEPA Method 9045, as noted above. 2. Ash samples to be analyzed for Total Inorganics using USEPA Methods 6010/6020 and pH using USEPA Method 9045; select ash samples will also be analyzed for leaching potential using SPLP Extraction Method 1312 in conjunction with USEPA Methods 6010/6020. SPLP results to be reported in units of mg/L for comparison to 2L Standards. Tables - Page 37 TABLE 10 - GROUNDWATER, SURFACE WATER, AND SEEP PARAMETERS AND CONSTITUENT ANALYTICAL METHODS PARAMETER FIELD PARAMETERS pH Specific Conductance Temperature Dissolved Oxygen Oxidation Reduction Potential NA NA NA NA RL UNITS Turbidity NA Ferrous Iron NA INORGANICS Aluminum 5 Antimony 1 Arsenic 1 Barium 5 Beryllium 1 Boron 50 Cadmium 1 Chromium 1 Cobalt 1 Copper 0.005 Iron 10 Lead 1 Manganese 5 Mercury (low level) 0.012 Molybdenum 5 Nickel 5 Selenium 1 Strontium 5 Thallium (low level) 0.2 Vanadium (low level) 0.3 Zinc 5 ANIONS/CATION S Alkalinity (as CaCO3) 20 Bicarbonate 20 Calcium 0.01 Carbonate 20 Chloride 0.1 Magnesium 0.005 Methane 0.1 Nitrate as Nitrogen 0.023 Potassium 0.1 Sodium 0.05 Sulfate 0.1 Sulfide (as 1-12S) 4 0.05 Total Dissolved Solids 25 Total Organic Carbon 0.1 Total Suspended Solids 2 ADDITIONAL GROUNDWATER CONSTITUENTS Iron Speciation (Fe(II), Fe(III) Vendor Specific Manganese Speciation (Mn(II), Mn(IV) I Vendor Specific SU mmho/cm °C mg/L mV NTU mg/L pg/L pg/L pg/L pg/L pg/L pg/L pg/L pg/L pg/L mg/L pg/L pg/L pg/L pg/L pg/L pg/L pg/L pg/L lag/L mg/L lag/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L mg-N/L mg/L mg/L mg/L mg/L mg/L mg/L mg/L pg/L lag/L I METHOD Field Water Quality Meter Field Water Quality Meter Field Water Quality Meter Field Water Quality Meter Field Water Quality Meter Field Water Quality Meter Field Test Kit EPA 200.7 or 6010C EPA 200.8 or 6020A EPA 200.8 or 6020A EPA 200.7 or 6010C EPA 200.8 or 6020A EPA 200.7 or 6010C EPA 200.8 or 6020A EPA 200.7 or 6010C EPA 200.8 or 6020A EPA 200.7 or 6010C EPA 200.7 or 6010C EPA 200.8 or 6020A EPA 200.7 or 6010C EPA 245.7 or 1631 EPA 200.7 or 6010C EPA 200.7 or 6010C EPA 200.8 or 6020A EPA 200.7 or 6010C EPA 200.8 or 6020A EPA 200.8 or 6020A EPA 200.7 or 6010C SM 2320B SM 2320 EPA 200.7 SM 2320 EPA 300.0 or 9056A EPA 200.7 RSK 175 EPA 300.0 or 9056A EPA 200.7 EPA 200.7 EPA 300.0 or 9056A SM450OS-D SM 2540C SM 5310 SM 2450D IC-ICP-CRC-MS IC-ICP-CRC-MS Notes: 1. Select constituents will be analyzed for total and dissolved concentrations. 2. RL is the laboratory analytical method reporting limit. 3. NA indicates not applicable. 4. Following wells to be sampled for Total Combined Radium: MW-13 and l3G-1S/D 5. Sulfide (as 1-12S) will be analyzed for groundwater samples only. 6. All EPA methods and RLs are at or below the respective 2L or 213 Standard for constituents with standards. Tables - Page 38 A:4i'A&A NCDENR North Carolina Department of Environment and Natural Resources Pat McCrory John E. Skvarla, III Governor Secretary August 13, 2014 CERTIFIED MAIL 7004 2510 0000 3651 1168 RETURN RECEIPT REQUESTED Paul Newton Duke Energy 526 South Church Street Charlotte, NC 28202 Subject: Notice of Regulatory Requirements Title 15A North Carolina Administrative Code (NCAC) 02L .0106 14 Coal Ash Facilities in North Carolina Dear Mr. Newton: Chapter 143, North Carolina General Statutes, authorizes and directs the Environmental Management Commission of the Department of Environment and Natural Resources to protect and preserve the water and air resources of the State. The Division of Water Resources (DWR) has the delegated authority to enforce adopted pollution control rules. Rule 15A NCAC 02L .0103(d) states that no person shall conduct or cause to be conducted any activity which causes the concentration of any substance to exceed that specified in 15A NCAC 02L .0202. As of the date of this letter, exceedances of the groundwater quality standards at 15A NCAC 02L .0200 Classifications and Water Quality Standards Applicable to the Groundwaters of North Carolina have been reported at each of the subject coal ash facilities owned and operated by Duke Energy (herein referred to as Duke). Groundwater Assessment Plans No later than September, 26 2014 Duke Energy shall submit to the Division of Water Resources plans establishing proposed site assessment activities and schedules for the implementation, completion, and submission of a comprehensive site assessment (CSA) report for each of the following facilities in accordance with 15A NCAC 02L .0106(g): Asheville Steam Electric Generating Plant Belews Creek Steam Station Buck Steam Station Cape Fear Steam Electric Generating Plant Cliffside Steam Station 1636 Mail Service Center, Raleigh, North Carolina 27699-1636 Phone: 919-807-64641 Internet: www.ncdenr.gov An Equal Opportunity 1 Affirmative Action Employer — Made in part by recycled paper A-1 Mr. Paul Newton August 12, 2014 Page 2 of 3 Dan River Combined Cycle Station H.F. Lee Steam Electric Plant Marshall Steam Station Mayo Steam Electric Generating Plant Plant Allen Steam Station Riverbend Steam Station Roxboro Steam Electric Generating Plant L.V. Sutton Electric Plant Weatherspoon Steam Electric Plant The site assessment plans shall include a description of the activities proposed to be completed by Duke that are necessary to meet the requirements of 15A NCAC 02L .0106(g) and to provide information concerning the following: (1) the source and cause of contamination; (2) any imminent hazards to public health and safety and actions taken to mitigate them in accordance to 15A NCAC 02L .0106(f); (3) all receptors- and significant exposure pathways; (4) the horizontal and vertical extent of soil and groundwater contamination and all significant factors affecting contaminant transport; and (5) geological and hydrogeological features influencing the movement, chemical, and physical character of the contaminants. For your convenience, we have attached guidelines detailing the information necessary for the preparation of a CSA report. The DWR will review the plans and provide Duke with review comments, either approving the plans or noting any deficiencies to be corrected, and a date by which a corrected plan is to be submitted for further review and comment or approval. For those facilities for which Duke has already submitted groundwater assessment plans, please update your submittals to ensure they meet the requirements stated in this letter and referenced attachments and submit them with the others. Receptor Survey No later than October 14'', 2104 as authorized pursuant to 15A NCAC 02L .0106(g), the DWR is requesting that Duke perform a receptor survey at each of the subject facilities and submitted to the DWR. The receptor survey is required by 15A NCAC 02L .0106(g) and shall include identification of all receptors within a radius of 2,640 feet (one-half mile) from the established compliance boundary identified in the respective National Pollutant Discharge Elimination System (NPDES) permits. Receptors shall include, but shall not be limited to, public and private water supply wells (including irrigation wells and unused or abandoned wells) and surface water features within one-half mile of the facility compliance boundary. For those facilities for which Duke has already submitted a receptor survey, please update your submittals to ensure they meet the requirements stated in this letter and referenced attachments and submit them with the others. If they do not meet these requirements, you must modify and resubmit the plans. A-2 Mr. Paul Newton August 12, 2014 Page 3 of 3 The results of the receptor survey shall be presented on a sufficiently scaled map. The map shall show the coal ash facility location, the facility property boundary, the waste and compliance boundaries, and all monitoring wells listed in the respective NPDES permits. Any identified water supply wells shall be located on the map and shall have the well owner's name and location address listed on a separate table that can be matched to its location on the map. Failure to comply with the State's rules in the manner and time specified may result in the assessment of civil penalties and/or the use of other enforcement mechanisms available to the State. We appreciate your attention and prompt response in this matter. If you have any questions, please feel free to contact S. Jay Zimmerman, Water Quality Regional Operations Section Chief, at (919) 807-6351. Sincerely, hn E. Skvarla, III Attachment enclosed cc: Thomas A. Reeder, Director, Division of Water Resources Regional Offices — WQROS File Copy A-3 August 12, 2014 GUIDELINES FOR COMPREHENSIVE SITE ASSESSMENT This document provides guidelines for those involved in the investigation of contaminated soil and/or groundwater, where the source of contamination is from: ■ Incidents caused by activities subject to permitting under G.S. 143-215.1 ■ Incidents caused by activities subject to permitting under G.S. 87-88 ■ Incidents arising from agricultural operations, including application of agricultural chemicals, but not including unlawful discharges, spills or disposal of such chemicals Comprehensive Site Assessment (CSA) NOTE: Regional Offices may request additional information in support of the CSA to aid in their review and will not approve the CSA if any of the elements specified below have not been included or have not been sufficiently addressed Minimum Elements of the Comprehensive Site Assessment Report: A. Title Page • Site name, location and Groundwater Incident number (if assigned) and Permit Number; • Date of report; • Responsible Party and/or permittee, including address and phone number; • Current property owner including address and phone number; • Consultanticontractor information including address and phone number; • Latitude and longitude of the facility; and • Seal and signature of certifying P.E. or P.G., as appropriate. B. Executive Summary The Executive Summary should provide a brief overview of the pertinent site information (i.e., provide sufficient information to acquaint the reader with the who, what, when, where, why and how for site activities to date). 1. Source information: Type of contaminants 2. Initial abatement/emergency response information. 1 A-4 August 12, 2014 3. Receptor information: • Water supply wells; • Public water supplies (wells, surface water intakes); • Surface water bodies; • Wellhead protection areas; • Deep aquifers in the Coastal Plain physiographic region; • Subsurface structures; and • Land use. 4. Sampling/investigation results: • Nature and extent of contamination; • Maximum contaminant concentrations; • Site hydrogeology. 5. Conclusions and recommendations. C. Table of Contents • First page number for each section listed. • List of figures (all referenced by number and placed in a single section following contents text). • List of tables (all referenced by number and placed in a single section following contents text). • List of appendices. D. Site History and Source Characterization • Provide a history of property ownership and use. Indicate dates of ownership, uses of the site, and potential sources of contaminants. • Discuss the source(s) of contamination, including primary and secondary sources. • For permitted activities, describe nature of activity, permitted waste, application of all instances of over-application/irrigation of wastes or water • Summarize assessment activities and corrective actions performed to date including emergency response, initial abatement, primary and secondary source removal. • Discuss geographical setting and present/future surrounding land uses. E. Receptor Information Provide a site map showing labeled well locations within a 2 A-5 August 12, 2014 minimum of 1500 feet of the known extent of contamination. Key to the table and maps described. NOTE: As the known extent of contamination changes, the receptor survey must be updated to reflect the change. This applies throughout the Receptor Information section. • In table format, list all water supply wells, public or private, including irrigation wells and unused wells, (omit those that have been properly abandoned in accordance with 15A NCAC 2C .0100) within a minimum of 1500 feet of the known extent of contamination. Note whether well users are also served by a municipal water supply. • For each well, include well number, well owner and user names, addresses and telephone numbers, use of the well, well depth, well casing depth, well screen interval, and distance from source of contamination; NOTE: It will often be necessary to conduct any or all of the following in order to ensure reliability in a water supply well survey. o Call the city/county water department to inquire about city water connections; o Visit door-to-door (make sure that you introduce yourself and state your purpose to residents prior to examining their property) to obtain accurate description of water usage, and if some residents are not at home, ask surrounding neighbors who are home about the water usage at those residences. Even if a public water line is available, some residents still use their well water and are not connected to the public water system; and o Search for water meters and well houses. • Site map showing location of subsurface structures (e.g., sewers, utility lines, conduits, basements, septic tanks, drain fields, etc.) within a minimum of 1,500 feet of the known extent of contamination; • Table of surrounding property owner addresses; • Discuss the availability of public water supplies within a minimum of 1,500 feet of the source area, including the distance and location to the nearest public water lines and the source(s) of the public water supply; 3 A-6 August 12, 2014 • Identify all surface water bodies (e.g., ditch, pond, stream, lake, river) within a minimum of 1,500 feet of the source of contamination; Determine the location of any designated wellhead protection areas as defined in 42 USC 300h-7(e) within a minimum of 1,500 feet of the source of contamination. Identify and discuss the location of the water supply well(s) for which the area was designated a wellhead protection area, and the extent of the protected area. Include information about the well owner, well -construction specifications (especially at screened intervals), pumping rate and pumping schedule. Information regarding designated wellhead protection areas may be obtained by contacting the Public Water Supply Section at (919) 707-9083; • Discuss the uses and activities (involving possible human exposure to contamination) that could occur at the site and adjacent properties. Examples of such activities and uses include but are not limited to use of a property for an office, manufacturing operation, residence, store, school, gardening or farming activities, recreational activities, or undeveloped land; • Determine whether the contaminated area is located in an area where there is recharge to an unconfined or semi -confined deeper aquifer that is being used or may be used as a source of drinking water. Based on a review of scientific literature on the regional hydrogeology and well construction records and lithological logs for deeper wells in the area, identify and describe the deep aquifers underlying the source of contamination. Include information on the depth of the deep aquifer in relation to the surficial saturated zone, the lithology and hydraulic conductivity of the strata between the surficial aquifer and the deeper aquifer, and the difference in groundwater head between the surficial aquifer and the deeper aquifer. Discuss the local and regional usage of the deep aquifer and the draw down from major pumping influences. Also, specify the distance from the source of contamination to major discharge areas such as streams and rivers. Cite all sources and references used for this discussion. NOTE: This requirement (last bullet) only pertains to A-7 August 12, 2014 contamination sources in the Coastal Plain physiographic region as designated on a map entitled "Geology of North Carolina" published by the Department in 1985. However, recharge/discharge, hydraulic conductivity, lithology, head difference, etc. is also important information at mountains and piedmont sites. F. Regional Geology and Hydrogeology Provide a brief description of the regional geology and hydrogeology. Cite all references. G. Site Geology and Hydrogeology • Describe the soil and geology encountered at the site. Use the information obtained during assessment activities (e.g., lithological descriptions made during drilling, probe surveys, etc.). This information should correspond to the geologic cross sections required in N. below; and • Based on the results of the groundwater investigation, describe the site hydrogeology, including a discussion of groundwater flow direction, hydraulic gradient, hydraulic conductivity and groundwater velocity. Discuss the effects of the geologic and hydrogeological characteristics on the migration, retardation, and attenuation of contaminants. H. Soil Sampling Results Using figures and tables to the extent possible, describe all soil sampling performed to date and provide the rationale for sample locations, number of samples collected, etc. Include the following information: • Location of soil samples; • Date of sampling; • Type of soil samples (from excavation, borehole, Geoprobe, etc.); • Soil sample collection procedures (split spoon, grab, hand auger, etc.) • Depth of soil samples below land surface; • Soil sample identification • Soil sample analyses; • Soil sample analytical results (list any contaminant detected above the method detection limit); and 5 A-8 August 12, 2014 • Identify any sample analytical results that exceed the applicable cleanup levels. NOTE: Information related to H. above should correspond to the sampling location and sampling results maps required in N. below. I . Groundwater Sampling Results Using figures and tables to the extent possible describe the groundwater sampling performed to date and provide the rationale for sample locations (based on source and contaminant type), number of samples collected, etc. Include the following information: • Location of groundwater samples and monitoring wells; • Date of sampling; • Groundwater sample collection procedures (bailer, pump, etc.); • Groundwater sample identification and whether samples were collected during initial abatement, CSA, etc.; • Groundwater sample analyses; • Groundwater sample analytical results (list any contaminant detected above the method detection limit; and • Identify all sample analytical results that exceed 15A NCAC 2L or interim standards. NOTE: Information related to I. above should correspond to the sampling location and sampling results maps required in N. below. J. Hydrogeological Investigation Describe the hydrogeological investigation performed including all methods, procedures and calculations used to characterize site hydrogeological conditions. The following information should be discussed and should correspond to the maps and figures required below: • Groundwater flow direction; • Hydraulic gradient (horizontal and vertical); • Hydraulic conductivity; • Groundwater velocity; Contaminant velocity; • Slug test results; * • Aquifer test results; • Plume's physical and chemical characterization; and • Fracture trace study if groundwater in bedrock is impacted. 6 A-9 August 12, 2014 * Check with the Regional Office prior to performing these tests and study to see if necessary for the site. K. Groundwater Modeling Results Groundwater modeling or predictive calculations may be necessary at some sites (source area proximate to surface water, source area located within wellhead protection area or source area overlying semi -confined or unconfined deeper Coastal Plain aquifer) to verify, based on site specific hydrogeological conditions, whether groundwater contamination poses a risk to receptors. For contamination shown to pose a risk to receptors, groundwater modeling may be necessary to determine an appropriate cleanup level for contaminated groundwater. Modeling should illustrate the input data used to complete the model and will generally be required for natural attenuation proposals (see Groundwater Modeling Policy at hftr)://Portal.ncdenr.org/web/wci/aps/���-qwpro/Soricy). NOTE: Input data for models should be derived from site specific information with limited assumptions or estimates. All assumptions and estimated values including biodegradation rates must be conservative (predict reasonable worst -case scenarios) and must be well documented. L. Discussion Nature and extent of contamination, including primary and secondary source areas, and impacted groundwater and surface water resources; • Maximum contaminant concentrations; • Contaminant migration and potentially affected receptors M. Conclusions and Recommendations If corrective action will be necessary, provide a preliminary evaluation of remediation alternatives appropriate for the site. Discuss the remediation alternatives likely to be selected. Note that for impacts to groundwater associated with permitted activities, corrective action pursuant to 15A NCAC 2L .0106(k), (1) and (m) is not applicable, unless provided for pursuant to 15A NCAC 2L .0106(c) and (e) or through a variance from the Environmental Management Commission (EMC). N. Figures ■ 71/2 minute USGS topographic quadrangle map showing an area A-10 August 12, 2014 within a minimum of a 1,500-foot radius of the source of contamination and depicting the site location, all water supply wells, public water supplies, surface water intakes, surface water bodies, designated well head protection areas, and areas of recharge to deeper aquifers in the Coastal Plain that are or may be used as a source for drinking water; Site map locating source areas, site boundaries, buildings, all water supply wells within a minimum of 1,500 feet, named roads/easements/right-of-ways, subsurface utilities, product or chemical storage areas, basements and adjacent properties, scale and north arrow; At least two geologic cross sections through the saturated and unsaturated zones intersecting at or near right angles through the contaminated area using a reasonable vertical exaggeration. Indicate monitoring well/sample boring/sample locations and analytical results for soil samples. Identify the depth to the water table. Provide a site plan showing the locations of the cross sections; Site map(s) showing the results of all soil sampling conducted. Indicate sampling identifications, sampling depths, locations and analytical results; ■ Site map(s) showing the results of all groundwater sampling conducted. Indicate sampling locations, monitoring well identifications, sample identifications, and analytical results; Separate groundwater contaminant iso-concentration contour maps showing total volatile organic compound concentrations, total semi -volatile organic compound concentrations and concentrations for the most extensive contaminant. Maps should depict the horizontal and vertical extent. Contour line for applicable 2L standard should be shown in bold; Site map(s) showing the elevation of groundwater in the monitoring wells and the direction of groundwater flow. Contour the groundwater elevations. Identify and locate the datum (arbitrary A-11 August 12, 2014 100', USGS, NGVD) or benchmark. Indicate the dates that water level measurements were made. There should be one map for each series of water level measurements obtained; ■ Groundwater contaminant iso-concentration contour cross-section; and ■ Site map(s) showing the monitoring wells. NOTE: If possible, use a single base map to prepare site maps using a map scale of 1 inch = 40 feet (or a smaller scale for large sites, if necessary). Maps and figures should include conventional symbols, notations, labeling, legends, scales, and north arrows and should conform to generally accepted practices of map presentation such as those enumerated in the US Geological Survey pamphlet, "Topographic Maps". O. Tables List all water supply wells, public or private, including irrigation wells and unused wells, (omit those that have been properly abandoned in accordance with 15A NCAC 2C .0100) within a minimum of 1500 feet of the known extent of contamination For each well, include the well number (may use the tax map number), well owner and user names, addresses and telephone numbers, use of the well, well depth, well casing depth, well screen interval and distance from the source of contamination; List the names and addresses of property owners and occupants within or contiguous to the area containing contamination and all property owners and occupants within or contiguous to the area where the contamination is expected to migrate; List the results for groundwater samples collected including sample location; date of sampling; sample collection procedures (bailer, pump, etc.); sample identifications; sample analyses; and sample analytical results (list any contaminant detected above the method detection limit in bold); and ■ List for each monitoring well, the monitoring well identification r_10M August 12, 2014 numbers, date water levels were obtained, elevations of the water levels, the land surface, top of the well casing, screened interval and bottom of the well. P Appendices • Boring logs and lithological descriptions; • Well construction records; • Standard procedures used at site for sampling, field equipment decontamination, field screening, etc.; • Laboratory reports and chain -of -custody documents; • Copies of any permits or certificates obtained, permit number, permitting agency, and • Modeling data and results; • Slug/pumping test data; and • Certification form for CSA 10 A-13 August 12, 2014 DIVISION OF WATER RESOURCES Certification for the Submittal of a Comprehensive Site Assessment Responsible Party and/or Permittee: Contact Person: Address: City: State: Zip Code: Site Name: Address: City: State: Zip Code: Groundwater Incident Number (applicable): I, , a Professional Engineer/Professional Geologist (circle one) for (firm or company of employment) do hereby certify that the information indicated below is enclosed as part of the required Comprehensive Site Assessment (CSA) and that to the best of my knowledge the data, assessments, conclusions, recommendations and other associated materials are correct, complete and accurate. (Each item must be initialed by the certifying licensed professional) 1. The source of the contamination has been identified. A list of all potential sources of the contamination are attached. 2. Imminent hazards to public health and safety have been identified. 3. Potential receptors and significant exposure pathways have been identified. 4. Geological and hydrogeological features influencing the movement of groundwater have been identified. The chemical and physical character of the contaminants have been identified. 5. The CSA sufficiently characterizes the cause, significance and extent of groundwater and soil contamination such that a Corrective Action Plan can be developed. If any of the above statements have been altered or items not initialed, provide a detailed explanation. Failure to initial any item or to provide written justification for the lack thereof will result in immediate return of the CSA to the responsible party. (Please Affix Seal and Signature) 11 A-14 Appendix B Review of Groundwater Assessment Work Plan Letter from S. Jay Zimmerman, Chief, Water Quality Regional Operations Section, NCDENR, To Harry Sideris, Duke Energy, dated November 4, 2014. 10 NCDENR North Carolina Department of Environment and Natural Resources Division of Water Resources Pat McCrory Governor November 4, 2014 Mr. Harry Sideris Senior Vice -President Environment, Health, and Safety Duke Energy 526 South Church Street Mail Code EC3XP Charlotte, NC 28202 RE: Duke Energy Carolinas, LLC Riverbend Steam Station NPDES Permit No. NCO004961 — Gaston County Review of Groundwater Assessment Work Plan Dear Mr. Sideris: John E. Skvarla, Ili Secretary On September 26, 2014, the Division of Water Resources (Division) received the Groundwater Assessment Work Plan (GAP) for the subject facility. The GAP was submitted in accordance with the August 13, 2014, Notice of Regulatory Requirements (NORR) and G.S. 130A- 309.209(a)(1). After careful review, the Division has determined that the GAP is deficient in detailing a strategy to achieve compliance with NCAC 15A 2L .0106(g), the NORR issued to Duke, and (or) applicable general statutes. The plan as submitted fails to provide an adequate level of detail regarding the planned assessment activities, which if left unchanged may lead to an inadequate assessment of environmental conditions at the site. To assist you in drafting a complete GAP, the Division offers you the following review comments which must be addressed and incorporated into a revised groundwater assessment work plan. This review document is separated into comments applicable to all previously submitted plans followed by comments applicable to the referenced facility General Comments Applicable to All Facilities The Site Conceptual Model (SCM) section of the work plans does not provide sufficient detail needed for the Division to adequately review the proposed data collection efforts. The SCM section should include an "initial conceptual model" as described in Groundwater Modeling Policy, May 31, 2007, page 6, paragraph 2, which states, "An initial conceptual model should be developed from available regional and local studies and information [existing site data], and initial site visits before significant site -specific 1636 Mail Service Center, Raleigh, North Carolina 27699-1636 Phone: 919-807-64641Internet: www.ncdenr.gov An Equal Opportunity 1 Affirmative Action Employer — Made in part by recycled paper B-1 Duke Energy Carolinas, LLC - Riverbend November 4, 2014 Page 2of11 data collection efforts are undertaken. This step is necessary to assure that adequate types and quantities of data are collected..." The initial conceptual model will be refined or modified later in the process as a result of data collection. The refined or modified model, the SCM, will then be used as the foundation upon which any numerical models are developed for the site. Importantly, the initial conceptual model should identify data gaps and provide the content and rationale for the types and amounts of data collection proposed in the work plans. Refer to the Modeling policy, the Hydrogeologic Investigation and Reporting Policy (May 31, 2007), and other pertinent references such as ASTM E16$9-95, for the elements expected in the initial conceptual model. Ensure also that the nature, sources, and sinks of site contaminants of concern, along with their mobility, retention, and transport characteristics are addressed. 2. The numerical modeling description presented in the GAP is inadequate. The draft GAP states that fate and transport modeling will be conducted using MODFLOW and MT313 or RT31), with very little supporting rationale or information identified to justify the use of the chosen model or approach. Explaining the rationale for the chosen model type and design (including the inputs that will be needed for the model) will help make site assessment data collection more efficient and may highlight deficiencies in the initial conceptual model. To provide context and rationale for the chosen model(s) and proposed data collection efforts, provide in the GAP, at a minimum, the following information: a) the purpose of any proposed numerical modeling, b) the question(s) the model will help answer, c) basic information about the model (type, boundaries, layers, whether/how site heterogeneities will be modeled, etc.), d) a description of the partition coefficient (KA how, where, and at what depths it will be derived, and how/whether it will adequately account for the dominant mechanisms of contaminant retention, c) whether stream flow measurements are needed for the model and, if so, when, where, and how those would be measured, f) model limitations, and g) specific data gaps (types, general locations and depths, etc) that must be filled in order to develop the model(s). Refer to Groundwater Modeling Policy, May 31, 2007 for the elements expected in any numerical model developed for the site. B-2 Duke Energy Carolinas, LLC - Riverbend November 4, 2014 Page 3 of 11 3. The proposed borings, core, and well installation work are inadequate to understand, characterize, and (or) model subsurface conditions at the sites. For piedmont and mountain sites, the GAP shall propose field work necessary to evaluate and document the following: a) presence/absence, b) areal extent and depth/thickness, c) flow and transport properties, and d) heterogeneity of the following groundwater flow zones: alluvial/fluvial, fill/residuum/saprolite, weathered rock (transition zone), and fresh, competent fractured bedrock. Specifically, continuous core shall be collected from land surface to a depth of at least 50 feet into fresh, competent bedrock at a sufficient number of locations inside and outside of ash basins to understand the flow system in areas proposed for modeling and (or) areas of contaminant concern. All cores shall be described/logged, photographed, and retained. Data previously obtained from existing voluntary and compliance well borings and wells shall also be used to understand and characterize the multipart flow system. Data collection should also be sufficient for the development of any proposed numerical models. Note: Drilling and coring methods shall be used to prevent potential cross contamination of flow zones, as stipulated in 15A NCAC 02C, and, where applicable, to maintain structural integrity of dam. 4. Rather than abandoning the cored locations, consideration should be given to converting borings to either a well nest/cluster or a piezometer nest/cluster. Nested/clustered wells shall be open to each of the dominant flow zones through the use of appropriately sized screens and discreet screened intervals and shall be installed to measure groundwater quality and properties that may affect contaminant mobility and transport. If the boring is not of sufficient diameter to install all of the necessary nested wells/piezometers, the remaining wells/piezometers should be installed in the immediate vicinity. In addition to the logging described in comment 3 above, each core location shall include the collection of a solid phase sample at the following intervals: a) immediately above the water table, b) immediately below the water table, c) within the saturated upper transition zone material (if not already included in a) or b) above), and d) from a primary, open, stained fracture within fresh bedrock, if these zones exist. B-3 Duke Energy Carolinas, LLC - Riverbend November 4, 2014 Page 4 of 11 The sample(s) shall be analyzed, at a minimum, for the following: type of material, formation from which it came, minerals present, chemical composition as oxides, hydrous Fe, Mn, and Al oxides content, organic carbon content, organic carbonate content, cation exchange capacity, anion exchange capacity, surface area, .moisture content, particle size analysis, Atterberg limits, specific gravity, porosity, permeability, and any other physical properties or analyses that may be required to estimate a batch partition coefficient Kd or otherwise serve as input to a chosen model. In addition, total analytes (see comment #12), SPLP analytes (see comment #12), and speciation of selected inorganics shall be conducted for selected sample locations in sufficient quantity and distribution to characterize the solid and aqueous chemistry and geochemistry in locations and depths of contaminant concern, and this work shall be clearly defined in the GAP. Inorganic speciation typically will include Fe and Mn, along with others that may shed light on contaminant toxicity, mobility, and (or) prevailing geochemical conditions. Sulfide and methane shall also be collected at selected locations to evaluate geochemical conditions. 'Water and bed sediment samples from seeps and streams shall be treated and analyzed in a manner consistent with the description above. If a given analysis is believed to be unnecessary at a given location or depth based on site conditions or assessment objectives, provide a detailed rationale for its omission for the Division's consideration. In general, the collection strategy for ash samples from cores inside of ash basins as described in the GAP appear to be adequate, along with the proposed total and SPLP analyses. The need for additional core locations, where applicable, is provided in the site -specific comment section below. Note that the chosen numerical model(s), extent of contamination, and size of site shall drive the number, distribution, and type of solid phase sample collection and analyses needed to understand the retention and mobility of constituents of concern. 5. Duke shall describe the batch partition coefficient Kd, the individual inorganics that will be tested, and whether multi -metals will be co -tested. Duke shall identify the approximate number, distribution, and depths/flow zones of solid phase samples used to derive the Kd(s) across the site. 6. The term "deep" as it relates to a well is subjective. For consistency and to avoid confusion as to whether a deep well is open to transition zone material or competent bedrock, please refer in all descriptions to each well as alluvial/fluvial, saprolite, transition zone, or bedrock. If one or more of these zones are relatively thick, contain more than one discreet flow zone, and should be thought of as "upper" and "lower", that qualifying designation is also appropriate (for example, upper transition zone and lower transition zone if the two intervals represent discreet flow intervals). 7. Surface water and bed sediment sampling are limited or are not proposed in the CAP, The Division expects base flow surface water and bed sediment sampling to be included in the site assessment and the GAP. These data will provide information on surface water B-4 Duke Energy Carolinas, LLC - Riverbend November 4, 2014 Page 5 of 11 quality and will be useful in efforts to understand the interaction of ground and surface water at the site. Sample locations and distribution shall be based on site specific considerations, but seepage areas, key tributaries, and ash ponds should be given special emphasis. Surface water data collected by the Division during the March 2014 sampling event, and existing ground and surface water data collected by Duke should be used in the. sample design and site assessment. 8. It is expected that Duke conduct assessment work, including borings, wells, and surface waterbed sediment sampling, offsite (outside of property boundaries) as needed for adherence to 15A NCAC 02L.0106 (g)(4) and (or) for the evaluation of background conditions. The plans as submitted do not adequately account for offsite assessment work or provide a justification that offsite work is not needed. Proposed offsite assessment locations should be described in the GAP. 9. It is expected that as data from wells, borings, and water samples are derived and evaluated, Duke will identify and sample additional locations as needed to complete the horizontal and vertical extent of impacts associated with coal ash to subsurface soils, saprolite, bedrock, and the ground and surface water resources. These activities and anticipated locations shall be proposed in the GAP and included in the assessment. 10. Please note that wells identified as "background" are subject to periodic review based on an increased understanding of site chemistry and hydrogeologic conditions. If a well currently identified or otherwise labeled as background does not, in fact, represent background conditions, it shall be excluded from further consideration as "background". The need for additional or replacement background wells shall be considered during site assessment and (or) as outlined in the site specific comment section below. However, in general, each facility must have a background well or wells screened or open to each of the dominant flow systems that occur at the site that are associated with groundwater contamination (e.g., alluvium, fluvial deposits, saprolite, transition zone, and (or) competent bedrock). Each of these wells must represent ambient background conditions unaffected by site or offsite activities. Offsite well placement will, in some cases, be expected depending on the position and proximity of waste, compliance, and property boundaries. At least four independent sampling events generally are needed for a well to be used in formal statistical testing. 11. Quality control samples shall be proposed in the GAP. These shall include but are not limited to, descriptions of field calibration procedures, collection of replicate measurements, use of field blanks, use of "blind" quality control samples, etc. B-5 Duke Energy Carolinas, LLC - Riverbend November 4, 2014 Page 6 of 11 12. The analyte list for supply well sampling, compliance well sampling, and site assessment sampling shall include, but is not limited to, the following: Al, Sb, As, Ba, B, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Pb, Mg, Mn, Mo, Hg, Na, Ni, Se, Sr, Tl, V, Zn, Cl, SO4, total dissolved solids (TDS), alkalinity, bicarbonate, carbonate, total suspended solids (TSS), turbidity, pH; temperature, specific conductance (SC), dissolved oxygen (DO), oxidation reduction potential (ORP), and water level (water level measurements in supply wells may be omitted if well head hardware prevents ready access). In addition, total combined radium (Ra- 226 + Ra-228) shall be measured on at least one occasion in selected compliance wells of highest concern at each facility. Note that .15A NCAC 02H 0804 requires certification for field parameters. The GAP shall include the sampling frequency for each sample type. Justification must be provided for Division consideration for any sample types/locations in which a sample frequency of one is proposed. 13. Duke shall list and provide a detailed description of each coal combustion residuals (CCR) waste storage or disposal area (unit) at each facility. This description shall state the following: a) known or approximate quantities of CCR waste stored in the unit(s); b) details of the operational history of the unit(s), including years of use, all known waste types, methods of emplacement, rationale for formal or informal closure, and methods of closure or abandonment; c) whether the unit is already included in the facility's current NPDES permit; d) whether the unit was permitted and managed by an agency other than the Division and pertinent details of that permit; e) whether there are additional permitted or unpermitted waste storage areas within CCR waste storage areas; f) the location and distribution of any coal ash used as structural fill or other construction (i.e. roadbeds, storage pads, berms, etc.) both on and offsite (proximal to the site); and g) whether the existing compliance boundary captures all the CCR waste storage areas or if revisions need to be made. Based on requirements specified in 15A NCAC 02L .0107 and a review of the information discussed in a) to g) above, the Division will determine whether additional units or areas need to be included in an existing or a new compliance boundary. 14. It is expected that the reporting limits associated with all analytical methods proposed in the GAP be EPA approved and be at or below the state groundwater standards at 15A NCAC 2L or surface water standards at 15A NCAC 2B. a-6 Duke Energy Carolinas, LLC - Riverbend November 4, 2014 Page 7 of 11 15. 15A NCAC 02C .0108(p) specifies that each non -water supply well be developed such that the level of turbidity or settleable solids does not preclude accurate chemical analyses of any fluid samples collected. The GAP shall acknowledge and state that well construction design will be based on site specific conditions and shall be actively modified in the field (alternate screen slot size, use of well sock, or others, for example) to accommodate the grain size of the formation, as -needed to minimize turbidity or address other unforeseen issues. Any deviations from originally proposed protocols shall be fully documented and provided to the Division. 16. The GAP shall state that well development and purging protocols will be based on site specific conditions and shall be actively modified in the field as needed to minimize turbidity or address other unforeseen issues. In all cases, well development and purging prior to sample collection shall be conducted to specific field standards which shall be clearly stated in the GAP. Deviations from this protocol or from other proposed development and purging protocols shall be fully documented and provided to the Division. If the Division concludes that turbidity is impacting analytical results for any reason, a replacement well will, in some cases, be required. 17. Duke shall contact adjacent property owners for site access as needed to complete the assessment activities. If Duke is unable to obtain access from an owner, Duke shall request liaison assistance from the Division in writing. This request shall include all contact information, details of all prior discussions regarding access to the property for purposes of conducting site assessment, and results of those discussions. Duke shall provide the Division a copy of any formal access agreements proposed for use. 18. The statewide 1:500,000 geologic map is not a substitute for local, larger scale geologic mapping and site scale geologic information where available. The GAP shall propose the use of fracture trace analysis (where applicable) and onsite/near-site geologic mapping to better understand site geology. The scope of these efforts shall depend upon site conditions and existing geologic information. 19. If proposed, please provide a detailed rationale for the use of Rotosonic or similar drill method and why it is appropriate for use in the site assessments. Please address any potential issues (such as the consolidation of aquifer material in the vicinity of the well screen) that could affect aquifer or groundwater analyses. 20. The purpose, methods, and numbers (including anticipated depths/flow zone(s) and, where known, locations) of packer testing shall be clearly detailed in the GAP. 21. The use of statistics to help establish background concentrations of specific parameters shall be based on site -specific data and shall follow the methods approved for use by the Division. In most cases, the methods outlined in RCRA Unified Guidance (U.S. EPA, 2009, EPA 530/R-09-007) are considered to be appropriate for use at these sites. Background wells deemed appropriate for use in statistical analyses must be approved by the Division. Final background determinations are made by the Division Director based on available data and information. B-7 Dube Energy Carolinas, LLC - Riverbend November 4, 2014 Page 8 of 11 22. As part of the GAP, provide an oversized summary table of all existing compliance and voluntary well data collected to date at the site. Please place all constituents, including DO, SC, ORP, and turbidity, as headings across the top of the table, and all wells and sample dates as rows along the left side of the table. Highlight in yellow those values that exceed a 2L standard. Please also include on this table any surface water, ash, and (or) ash leachate data relevant to the site. This table should -be included in the GAP and also made available in electronic (Excel or similar) format. 23. As part of future site assessment reporting deliverables, provide at a minimum the following tables, graphs, and maps: a) box (whisker) plots, for locations sampled on four or more events (show min, 25, 50, 75, max); align plots for multiple locations on one chart; construct a similar chart for each constituent of concern (COC), b) stacked time -series plots (for each COC, stack multiple wells/locations using same x-axis to discern seasonal trends; construct similar chart for each COC; consider also showing turbidity, DO, ORP, or other constituent on plot to demonstrate influence, c) piper and (or) stiff diagrams showing selected monitor wells, supply wells, surface water locations, ash leachate as separate symbols, d) correlation charts, where applicable, e) orthophoto potentiometric maps for "like" flow zones (maps for bedrock wells likely will be plotted on a different map than maps for transition zone wells), f) orthophoto potentiometric difference maps, showing the difference in vertical heads between selected flow zones, g) orthophoto iso-concentration maps for selected COCs and flow zones, h) orthophoto map showing relationship between ground and surface water samples for selected COC(s), i) geologic cross sections, j) photographed borings/core for each boring location, and k) others as appropriate. For summary statistics tables, avoid presenting "average" value(s) unless the constituent(s) at the location in question is (are) normally distributed, in which case a mean and standard deviation are acceptable. For non -normal data, use of the median value is more appropriate. In either case, use of the maximum value is often misleading if it is a formally -tested outlier or is associated with high turbidity; footnote maximum values as appropriate. 24. With respect to the use of the terms "may" versus "will", the GAP shall use the term "will" or clearly state, in detail, why the qualifying term "may" is used. In either case, the Division reserves the right to request at any time additional work needed to meet site assessment objectives. During the assessment, if Duke decides that additional work is B-8 Duke Energy Carolinas, LLC - Riverbend November 4, 2014 Page 9 of 11 needed at a facility, the Division shall be contacted immediately with a description of the proposed work and timeline. 25. Any assumptions or timelines stated in the GAP shall not be used as justification to circumvent the mandatory deadlines established by legislative order, Governor's Executive Action, or NORR. Additional_ Comments Specific to the Referenced Facility 26. GAP Figures 2 and 3 depict the facility's northern property boundary on the northern and southern shores of the Catawba River/Mountain Island Lake, however, the compliance boundary has been drawn on these figures as though the northern shore property boundary is the actual property boundary. Previous figures on file for this site illustrate the northern property boundary on the southern shore line (S&ME, NPDES Permit NCO004961 Waste, Review, and Compliance Boundary, Figure 1, 4/27/09) and the northern shore line (Figure 2 from the Groundwater Monitoring Program — Sampling, Analysis, and Reporting Plan by HDR Engineering, Inc., 5/14/14). The location of the true northern property boundary will have an impact on the location of the facility's permitted compliance boundary. If the southern shore line is the actual property boundary, then the compliance boundary should be adjusted. As related to "All Facilities" Comment 13, the GAP shall include an accurate depiction of the facility's property boundary and provide detailed notes where this depiction has changed from previously provided information and where any property boundary changes would impact or necessitate the relocation of the compliance boundary. Specifically for the Riverbend facility, the GAP should illustrate and explain whether the northern property boundary lies along the northern or southern shore of the Catawba River/Mountain Island Lake.. Does Duke Energy own the Catawba River/Mountain Island Lake and/or the riverbed and/or lakebed? 27. Although there are perimeter ash samples proposed around the Secondary Cell, there are no proposed locations from within the Secondary Cell. The GAP should include a discussion of whether ash is also present within the waters of the Secondary Cell. If ash is present with this cell, the GAP should include a proposal for characterization of the ash within this location or an explanation as to why ash samples are not needed or are unable to be obtained from this area. 28. The GAP proposed to collect solid phase "ash" samples from the 4-foot to 5-foot interval and at the 1-foot to 2-foot interval overlying the ash/native soil interface in the AB, AS, and C series borings within ash storage areas. For "ash" samples, at a minimum the GAP should also include samples and characterization of "ash' from middle range depths where ash thickness is expected to be greater than 30 feet. 29. The GAP proposed collecting native soil samples from immediately below the ash basins and storage areas in the AB, AS, and C series borings. Additional soil samples are also proposed from six "background" boring/monitoring well locations, however no details have been provided regarding from what depth intervals these soil samples will be B-9 Duke Energy Carolinas, LLC - Riverbend November 4, 2014 Page 10 of 11 collected. The GAP should address this deficiency. Additionally, the GAP does not propose plans to collect soil samples from the GWA series boring/monitoring well locations because they will be located outside the waste boundary. Inclusion of soil samples from the GWA series borings will provide additional characterization of soil solid phase conditions outside the waste storage area and should be detailed in the GAP. In addition to soil samples, the GAP should include a sufficient number of borings and cores to understand, characterize, and (or) model subsurface conditions (both solid phase and groundwater) at the site at all depths of interest. The current GAP lacks sufficient detail, proposes an insufficient number of soil samples and a complete lack of bedrock core samples for characterization of the site's subsurface conditions. Please refer to "All Facilities" comments 3 and 4. 30. Three "background" borings/monitoring wells (BG-555, BG-815, BG-85S) are proposed in the GAP to assist in characterizing the site and to further define exceedances of the iron and manganese 15A NCAC 2L (2L) standards detected in the MW-8SID well nest. The proposed borings are all shallow and within immediate proximity of the on -site ash storage area. These locations may provide some useful information for the assessment but are very unlikely to be representative of background conditions that are clearly outside the influence of the ash waste storage areas. Additionally, exceedances of the iron and manganese 2L standards detected in the MW-8SID nest have historically been progressively higher in concentration as depth increases. The MW-8SID nest is located on the facility's compliance boundary and property boundary. The GAP shall include sufficient borings/monitoring well nests to characterize all zones of interest and this shall include off -site borings where necessary to delineate exceedances of the 2L standards. Please refer to "All Facilities" continents 7, 8 and 9. Your assessment plan must be submitted to the DWR Mooresville Regional Office and Central Office for review within 30 days of the receipt of this letter. A revised plan must be submitted that fully incorporates the responses to the above comments rather than a letter response intended to supplement the previously submitted plans. Please note that failure to conduct a complete assessment pursuant to the above referenced rule and statute will be considered a violation, subject to potential enforcement actions by the Division. B-10 Duke Energy Carolinas, LLC - Riverbend November 4, 2014 Page 11 of 11 We appreciate your attention and prompt response in this matter. If you have questions, please do not hesitate to call Bruce Parris at 704-663-1699. Sincerely, S. J� Zi merman, P.G., Chief Water Quality Regional Operations Section Cc: WQROS — MRO WQROS — Central Office Don van der Vaart HDR (Attn: William Miller) 440 South Church Street, Suite 1000, Charlotte, NC 28202 B-11 Appendix C Site Plan with Cross -sections Riverbend Steam Station Ash Basin Duke Energy Carolinas, LLC Gaston County, NC, Figures 4.1-3, 4.1-4, and 4.1-5, May 31, 2013; Cross - sections A -A', B-B', C-C' Y CAN W-v J Y NOTES: 1. PARCEL DATA FOR THE SITE WAS OBTAINED FROM DUKE ENERGY REAL ESTATE AND IS APPROXIMATE. 2. ASH STORAGE BOUNDARY AND CINDER STORAGE BOUNDARY ARE APPROXIMATE. 3. AS -BUILT MONITORING WELL LOCATIONS PROVIDED BY DUKE ENERGY. SOIL BORING AND PIEZOMETER LOCATIONS FROM DUKE ENERGY DRAWINGS RB-3011 AND RB-3010A. 4. SHALLOW MONITORING WELLS (S) - WELL SCREEN INSTALLED ACROSS THE SURFICIAL WATER TABLE. 5. DEEP MONITORING WELLS (D) - WELL SCREEN INSTALLED IN THE TRANSITION ZONE BETWEEN COMPETENT BEDROCK AND THE REGOLITH. 6. TOPOGRAPHY DATA FOR THE SITE WAS OBTAINED FROM NC DOT GEOGRAPHIC INFORMATION SYSTEM (GIS) WEB SITE. 7. ORTHOPHOTOGRAPHY WAS OBTAINED FROM NC ONEMAP GIS WEB SITE (DATED 2009). 8. THE COMPLIANCE BOUNDARY IS ESTABLISHED ACCORDING TO THE DEFINITION FOUND IN 15A NCAC 02L.0107 (a). �I '" r " F� 51� f ut � L 6 ry t LEGEND: PROPERTY BOUNDARY COMPLIANCE BOUNDARY COMPLIANCE BOUNDARY COINCIDENT WITH DUKE ENERGY PROPERTY BOUNDARY WASTE BOUNDARY ASH OR CINDER STORAGE AREA TOPOGRAPHIC CONTOUR COMPLIANCE GROUNDWATER MONITORING WELL - VOLUNTARY GROUNDWATER MONITORING WELL ­UBEACHROADSOIL BORING 7 I PIEZOMETER SCALE (FEET) Q n r J00' 0 300 600' P = 600' HDR Engineering, Inc. n me�e.aun.x SITE PLAN WITH CROSS SECTIONS RIVERBEND STEAM STATION ASH BASIN DUKE ENERGY CAROLINAS, LLC GASTON COUNTY, NC DATE MAY 31, 20t FIGURE 4.1 -� L 740 720` 700 680 660 640 620 600 580 560 540L 0+00 N M Zk z1h N N N w w w a a a 1+00 2+00 3+00 4+00 5+00 6+00 7+00 8+00 9+00 10+00 11+00 12+00 13+00 14+00 15+00 16+00 17+00 18+00 SECTION A' -A' SCALE: 1 "=200' HDR Engineering, Inc. of the Carolinas GENERAL NOTES: 1. ALL WATER LEVEL AND SOIL BORING INFORMATION PROVIDED BY DUKE ENERGY, 2. GROUND SURFACE ELEVATION SOURCES: 1992 CONTOURS (RIVFLY2D.DWG) MOUNTAIN ISLAND BATHYMETRY (2005) PROJECTED FROM DUKE ENERGY DRAWINGS RB-3010A AND RB-3011A LEGE D F FILL (EMBANKMENTS) A SLUICED ASH (FROM 4841X001-TOPO.DWG FEB-MARCH 2O11) S M1/M2 - ALLUVIUM/SOIL/SAPROLITE; REC < 50% D BEDROCK; REC > 85% AND ROD > 50% - - WATER SURFACE 200 0 900 200 SCALE: 1 "=200' CROSS SECTION A' -A' RIVERBEND STEAM STATION ASH BASIN DUKE ENERGY CAROLINAS, LLC GASTON COUNTY, NC MAY 31, 2013 4.1-4 W S— Church Street Charlotte, NO U20 740 PRIMARY CELL 720— — — — — — — — — — — — — — — — — — — — — — GENERAL NOTES: 1, ALL WATER LEVEL AND SOIL BORING INFORMATION PROVIDED BY DUKE ENERGY, 2. GROUND SURFACE ELEVATION SOURCES: 1992 CONTOURS (RIVFLY2D.DWG) MOUNTAIN ISLAND BATHYMETRY (2005) PROJECTED FROM DUKE ENERGY DRAWINGS RB-3010A AND RB-3011A rn v 1334.45 GROUND SURFACE BENEATH MOUNTAIN ISLAND LAKE 680 660 MOUNTAIN ISLAND LAKE 640 620 600 580 D 560 540 0+00 1+00 2+00 3+00 4+00 5+00 6+00 7+00 8+00 9+00 10+00 11+00 12+00 13+00 SECTION B'-B' SCALE: 1"=100' A 0 0 M d \ \ (n r��r� rr� „� fn r��r� „r M TOP OF "S" LAYER COINCIDENT WITH 1992 CONTOURS 0+00 1+00 2+00 3+00 4+00 5+00 6+00 7+00 8+00 9+00 10+00 11+00 SECTION C'-C' SCALE: 1 "=100' HDR Engineering, Inc. of the Carolinas 1,22 LEGE D F FILL (EMBANKMENTS) A SLUICED ASH (FROM 4841X001-TOPO.DWG FEB-MARCH 2O11) S M1/M2 - ALLUVIUM/SOIL/SAPROLITE; REC < 50% D BEDROCK; REC > 85% AND ROD > 50% — — WATER SURFACE 100 0 100 200 SCALE: 1 "=100' CROSS SECTION B'-B' AND C'-C' RIVERBEND STEAM STATION ASH BASIN DUKE ENERGY CAROLINAS, LLC GASTON COUNTY, NC MAY 31, 2013 4.1-5 U S— Church Street Charlotte, NO 2-