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Home My WebLink AboutDEQ-CFW_00080013Chemours, XXXONv"I'l,"I'll December 2, 2016 Ms. Julie Woosley, Chief Hazardous Waste Section Division of Waste Management NC Department of Environmental Quality 1646 Mail Service Center Raleigh, NC 27699-1646 Re: Corrective Measures Study Work Plan Chemours Fayetteville Works Fayetteville, North Carolina EPA ID No. NCD 047 368 642 Dear Ms. Woosley: Enclosed please find one (1) paper copy and one (1) electronic copy of the Corrective Measures Study Work Plan for the above -referenced Site. The work plan was prepared in accordance with the requirements of the Site's North Carolina Hazardous Waste Management Permit. Chemours looks forward to continuing on with the Corrective Measures Study portion of the corrective action process. If you have any questions or need additional information please feel free to contact me at 704-560-6435. Sincerely, Kevin Garon Project Director Chemours Corporate Remediation Group cc: Michael Johnson — Chemours Fayetteville Works File Enclosures DEQ-CFW-00080013 CORRECTIVE MEASURES STUDY WORK PLAN RCRA PERMIT NO. NCD047368642-R2-M3 Prepared for: The Chemours Company HighwayCorporate Remediation Group 22828 NC Fayetteville, NC • •. • • -•i- # I' • 1 M gi I i 1' • _ ��. ''\ �' •ACC DEQ-CFW 00080014 This page intentionally left blank OEQ-CFVV_00080015 CORRECTIVE MEASURES STUDY WORK PLAN 1.0 INTRODUCTION ................................................................................................... 1 1.1 Site Background .................................................................................................. 1 1.1.1 Plant Site Operations ................................................................................. 2 1.1.2 Regulatory History ..................................................................................... 3 1.2 Corrective Action ................................................................................................ 4 1.2.1 RF1 Approach ............................................................................................. 4 1.2.2 Corrective Measures Study Objective and Goals ......................................4 2.0 CURRENT SITE CONCEPTUAL MODEL ............................................................ 7 2.1 Physical Setting ................................................................................................... 7 2.1.1 Site Geology .............................................................................................. 7 2.1.2 Site Hydrogeology ..................................................................................... 8 2.2 Risk -Based Prioritization Process ..................................................................... 8 2.2.1 Summary of Risk Screening Evaluation Results ........................................9 2.2.2 Summary of Risk -Based Re -Prioritization Results ...................................10 2.3 Areas with Releases that Require Corrective Measures Study ....................11 2.3.1 SWMLI 6 NafionO Common Sump ...........................................................11 2.3.2 SWM U 7 P PA Area .................................................................................. 11 2.3.3 AOC Site -Wide Groundwater ................................................................... 12 2.4 Data Gaps and Additional Investigation ..........................................................12 2.4.1 Site -Specific Arsenic Background Level Determination ...........................12 2.4.2 Additional Groundwater Investigation ......................................................13 3.0 CORRECTIVE MEASURE STUDY ..................................................................... 15 3.1 CMS Purpose and Objectives ........................................................................... 15 3.2 Identification of Media Cleanup Standards and Objectives ..........................15 3.3 Corrective Measures Evaluation and Alternatives Selection Process ......... 15 4.0 CMS REPORTING AND SCHEDULE ................................................................. 19 4.1 CMS Report ........................................................................................................ 19 4.2 CMS Schedule ................................................................................................... 19 5.0 PROJECT MANAGEMENT PLAN ...................................................................... 21 DEQ-CFW-00080016 CORRECTIVE MEASURES STUDY WORK PLAN Site Location Map Site Layout Map Monitoring Well and Piezometer Location Map Perched Zone Potentiornetric Surface Map Regional Aquifer Potentiometric Surface Map SWM U / AOC Location Map DEQ-CFW-00080017 CORRECTIVE MEASURES STUDY WORK PLAN cal Acronym Definition / Description AOC Area of concern APFO Ammonium Perfluorooctanoate bgs Below ground surface Chemours The Chemours Company FC, LLC CMS Corrective Measures Study COC Constituent of concern DuPont E. I. du Pont de Nemours and Company ECs Engineering Controls HH&E Human health and the environment HSWA Hazardous and Solid Waste Amendments IMAC Interim maximum allowable concentrations ICs Institutional Controls tag/L Microgram(s) per liter MNA Monitored natural attenuation MSL Mean sea level NC2L(s) North Carolina 2L Standards NCDENR North Carolina Department of Environment and Natural Resources NCDEQ North Carolina Department of Environmental Quality NFA No Further Assessment/Action O&M Operations and maintenance OWPHA (USEPA) Office of Water Public Health Advisory PAH Polynuclear aromatic hydrocarbon PCE Tetrachloroethene PFOA Perfluorooctanoic acid PPA Polymer processing aid RCRA Resource Conservation and Recovery Act RFI RCRA Facility Investigation RSL Regional screening level SCM Site conceptual model Site Fayetteville Works Facility SVOC Semi -volatile organic compound SWMU Solid waste management unit TCE Trichloroethylene USEPA U. S. Environmental Protection Agency VOC Volatile organic compound WWTP Wastewater treatment plant DEQ-CFW 00080018 CORRECTIVE MEASURES STUDY WORK PLAN This •.•- intentionally leftblank DEQ-CFW 00080019 CORRECTIVE MEASURES STUDY WORK PLAN EXECUTIVE SUMMARY CorrectiveThis -s Study Workprepared • • Company (Chemours)for -tteville Works facility near• • in BladenCounty,• Carolina (the Site). The work plan outlines a process to determine if remedial actions are required at the Site and, if so, to identify the optimal remedialto meet the Site goals site-wideand objectives. This work plan focuses on the units that were identified during the Site's Resource Conservation and Recovery Act Facility Investigation as requiring a corrective measures study. These include Solid Waste Management Unit (SWMU) 6, SWMU 7, and the groundwater area of • l Institutional# •ls, engineering controls,and/or ! • -•'. natural attenuationbeen selected as presumptive remedies forthe Site based on i' -•model, ' of the constituents of concern (COCs), and the lack of significant off -site impacts. These remedies (or combination of have been proven effective at similar sites,and alternative remedial technologies to address Site COCsbe significantly more expensive providing additional benefit.order to select frompresumptive remedies• • • • -' the remedies will be evaluated based on technical, environmental, human health, institutional, s cost concerns. As part of the CMS, media cleanup standards will be developed based on the current and future land use scenarios.• use of property is expected t remain industrial.However, as no site use restrictions are currently in place, a future residential scenario will also be considered as a potential - use. Since some constituents in both groundwater anr soil cleanupnaturally occurring, site -specific background levels may also be used as alternative media levels. In addition,- t • to evaluate the applicability of - -House referredBill 639 (dated April 14, 2015 as amended by House Bill 765 dated October 22, 2015; hereafter to as the Risk Bill) remediationAs • er the allowance of iecific, risk -based groundwater cleanu• standards subsequently be established for monitoring purposes (i.e., off -site migration), and land use restrictions will be considered to prevent future use of the site groundwater as potable water and eliminate potential for exposure by future residential users. DEQ-CFW 00080020 i IL/TVA CORRECTIVE MEASURES STUDY WORK PLAN -------------------------------------------------------------------------------------------------------------------------------------------------------- •.•- intentionally leftblank DEQ-CFW 00080021 CORRECTIVE MEASURES STUDY WORK PLAN 1011111100051114yffel 7 me unelfloIrs uunipaiTT r=,=7(r_;nen1o1.rs) for ine rdJULLUTAIle TTUIM5 INDIIIJ MUM*. near Duart Township in Bladen County, North Carolina (the Site). The Site was owned by E. 1. du Pont de Nemours and Company (DuPont) until July 2015. A Resource Conservation and Recovery Act (RCRA) Facility Investigation (RFI) was conducted at the Site in three phases from 2001 to 2014, and a site conceptual model (SCM) was developed from the data compiled. The SCM was used to identify units of the Site as either no further action required (NFA) or as requiring a corrective measures study. The units requiring a CIVIS are Solid Waste Management Unit (SWMU) 6, SWMU 7, and the groundwater area of concern (AOC GW). The RFI results were presented in the Final RCRA Facility Investigation Report (Parsons 2014), which recommended conducting a CMS. In a letter dated September 6, 2016, the North Carolina Department of Environmental Quality (NCDEQ; formerly North Carolina Department of Environment and Natural Resources [NCDENR]) requested that a CIVIS work plan be submitted for the Site. 1.. 117:1, . � ; "#T XM_V__Tr_T I F -79 - ME 1r•�; :!1 illivill the units that were identified during the RFI as requiring a corrective measures study and, if so, to identify the optimal remedial alternatives for use at the Site. This work plar. describes the current conditions of the Site, reviews the SCM, and outlines the applicable remedial technologies. This work plan is organized into six sections, including this Introduction, which presents site historical information and goals and objectives of the CMS. Section 2.0 presents the current SCM, including information about the physical setting and the risk -based prioritization process that was used to evaluate the Site. Section 3.0 discusses the proposed CIVIS approach to meet the stated objectives including collection of additional data to close remaining data gaps. Section 4.0 presents information about the CIVIS Report and a schedule for the CIVIS activities. Section 5.0 presents the Project Management Plan, which defines the responsibilities of the project personnel. Section 6.0 lists the references cited in this work plan. The Fayetteville Works facility is located near Duart Township in Bladen County, North Carolina. The Site is located 15 miles southeast of the City of Fayetteville on NC Highway 87, south of the Bladen-Cumberland county line. Its geographic location is 34050'30" north latitude, 78050'00" west longitude. The Site contains 2,177 acres of relatively flat undeveloped open land and woodland bounded on the east by the Cape Fear River, on the west by NC Highway 87, and on the north and south by farmland (Figure 1). DuPont purchased the site property in parcels from several families in 1970. The Site's first manufacturing area was constructed in the early 1970s. Currently, the Site manufactures plastic sheeting, fluorochemicals, and intermediates for plastics manufacturing. A former manufacturing area, which was sold in 1992, produced nylon strapping and elastomeric tape (Figure 2). DEQ-CFW-00080022 '40 • CORRECTIVE MEASURES STUDY WORK PLAN units. The polyvinyl fluoride (PVF) resin manufacturing unit remained with the DuPont Company. In addition to the manufacturing operations,• operates r natural • -r boilers • a wastewater• . for - treatment of process . • sanitary wastewaters from • and DuPont. Hazardous generated from the Chemours'• processes and laboratories are currently hazardousmanaged at the permitted Hazardous Waste Container Storage Area, in four permitted -tanks, andat the •0ignitable wasteaccumulation area prior o being shipped offsite for treatment, disposal, or recycling. Area Description Main Manufacturing Areas Chemours Manufactures Nafion° fluoropolymer membrane for electronic cells and Fluoromonomers various fluorochemicals used for Nafion® membrane, Teflon° and Nafion° fluoropolymer, Viton° elastomers, and other fluorinated products. Membrane Chemours Manufactures a fluorochemical that is used as a processing aid for off - Polymer site fluoropolymer manufacturing. This area formerly manufactured Processing Aid ammonium perfluorooctanoate (APFO). (Note: The last date of APFO (PPA) production at the Site was April 28, 2013. Although APFO was manufactured in this area, it was never used in any of the other manufacturing facilities at the Site.) Kuraray Manufactures Butacite° polyvinyl butyral sheeting and polyvinyl butyral Butacite° resin for automotive and architectural safety glass. Kuraray Manufactures SentryGlas® structural interlayer for automotive and SentryGlas° architectural safety glass (previous location of now defunct Dymetrol° nylon strapping). DuPont Manufactures polyvinyl fluoride (PVF) resin used to produce Tedlar° Company film. PVF Former Manufacturing Area Polymer Manufactured Teflon® fluorinated ethylene propylene (FEP) for electrical Manufacturing wiring insulation and other applications. (Note: this Teflon° unit did not Development use APFO in its process.) Since the PMDF unit was permanently shut Facility (PMDF) down in June 2009, it no longer manufactures DuPont Teflon°. DEQ-CFW 00080023 CORRECTIVE MEASURES STUDY WORK PLAN 1011111100051114yffel' Area Description Support Areas Power Generates steam via natural gas and fuel oil -fired boilers for the facility's manufacturing areas as well as comfort heating for employees. Produces process water and demineralized water from raw river water. Wastewater The WWTP treats process wastewater and sanitary wastewater prior to Treatment Plant discharge to the Cape Fear River. The Fayetteville Works facility received its initial RCRA Permit (NCD047368642) to operate a hazardous waste container storage area and tanks in February 1983, under DuPont ownership. DuPont submitted an amended Part A application in 1991 to document upgrades to its fluorocarbonand tank system. The RCRA Part B permit applicationsubmitted in August 1993 identifiedr of 1 gallons of container storage capacity at the container storage area. Stored waste included characteristic wastes (DO01, D002, D003, D007, D009, and D029) and listed wastes (F002, F003,. • 11 Since 99 .•- of •. • been • • -r at the Site under NCDENR •' oversight t• meet the conditions of the permit.•reports listedOletailing these investigations have been submitted. The previous investigations are below r • with the dates of • -r report submittals: In addition, the Site voluntarily agreed to the NCDENR request to investigate potential APFO releases as part the ongoing - findings of • ! investigation activities (conducted during the Phase were included in Appendix i of - -•• 1 a DEQ-CFW 00080024 CORRECTIVE MEASURES STUDY WORK PLAN Corrective action refers to all activities related to the investigation, characterization, and Cleanup of ' of •• or r•, waste constituentsof concern (COCs) from SWIVIUs and/or AOCs at the Site. Chemours has established several #verall goals for• •Works goals are listed below: Ensure the protection of i the environment1 4through t1Z development and use of an SCM based on a thorough understanding of site COCs, release pathways, and exposure potential; I Cost-effectively manage/minimize long-term liabilities associated with potential contaminant releases using a risk -based prioritization process; •r •• • • -•, . • -• • Coordinate RCRA •rrective action activities with other business Site to minimize disruption to plant operations, maximize benefits and synergiegi with other, overlapping environmental initiatives, and ensure field efforts are cot4ticte4 it a safe ,fir efficietittuwiter. The site RFI was conducted to gather sufficient information to make remedial decisions in support of overall corrective• goals. • accomplish• data were collected to determine the nature and extent of releases of hazardous wastes and/or hazardous COCs from regulated units, SWIVI Us, and other potential AOCs at the Site. Necessary data were also gathered to support environmental indicator determinations and development of this CIVIS work plan. In addition, risk management was integrated into the investigationevaluation toolto prioritize - units forfurther investigation and remediation. Establishing priorities using risked -based criteria and an SCM enabled the RFI to focus on • or posed the potential for adverse effects on HH&E. Each investigation phase of the RFI built upon the previous investigation phase to fill data gaps within the SCM. Data gaps identified in the SCM were then used to generate the goals and objectives • the next phase of investigation. The results of -• ♦. '• evaluation were presented in the Final RCRA Facility Investigation Report (Parsons 2014).The report identified three site units (SWMU • SWIVIU 7 and AOC GVV) as requiring a corrective measures study and recommended conducting . The objective of the CIVIS is to determine the appropriate corrective measuresto meet the following goals: Control releases fromimpacted media(soil• groundwater)to reduce o to the extent practical, further• ..• of . • •' constituents may pose an unacceptable risk to HH&E. DEQ-CFW 00080025 CORRECTIVE MEASURES STUDY WORK PLAN 1011111100051114yffel' Institutional• rengineering • • and monitored natural attenuation (MNA) have been selected as presumptive remedies for the Site based on the site conceptual model, nature of the constituents of concern (COCs), and the lack of significant off -site impacts. These remedies (or a combination of them) have proven effective at similar sites and alternative remedial technologies to address site COCs will be significantly more expensive while providing little additional benefit. In order to select from presumptive remedies• • • • -•f), the remedies will be evaluated based on technical, environmental, human health, institutional, and cost coitcents. As part of the CMS, media cleanup standards will be developed based on the current and future •' use scenarios.- land use of property is expected to remain industrial;however,• site use restrictionsplace, a future residenWi constituentsscenario will also be considered as a potential future use. Because there are both groundwater . • soil that are naturally occurring,site-specific background levels may also be used as alternative media cleanup levels. In addition, - rurs intends to evaluate the completionof remediation activities at the Site under the State's House Bill 639 (An Act to Expand the Use of Risk -Based Remediation to Accelerate the Cleanup of • -• dated April 14, 2015 Eliminatingamended by House Bill 765 (An Act To Provide Further Regulatory Relief To The Citizens Of North Carolina By Providing For Various Administrative Reforms, By Certain UnnecessaryOr Outdated - • Regulations t Modernizing Or Simplifying Cumbersome Or Outdated Regulations, And By Making Various Other Statutory Changes) dated October 22, 2015 (hereafter referred to as the Risk Bill). The Risk Bill allows NCDEQ "to approve the remediation of contaminated sites based on site -specific remediation standards in circumstances where site -specific remediation standards - adequate • protect public health, safety, and welfare and the environment and are consistent with protection of current and anticipated future use of groundwater and surface water affected or potentially affected by the contamination." Under the Risk Bill, site -specific, risk -based groundwater cleanup standards may subsequently be established for monitoring purposes (i.e., off -site migration) and land use restrictions will be considered to prevent future use of the site groundwater as potable and eliminate potential for!• by residential • 0i f •• of - Risk Bill statesi person who proposes t• conduct remediation pursuant to this Part shall submit a remedial investigation report to the Department prior to submitting a remedial• •. Y Facility Investigation-•r -v. 1) (Parsons• -• the elements required by Risk Bill for -•• and thus fulfills this requirement.• 1' 1 . • of Risk Bill states that i person • proposes • conduct remediationpursuant to this Part shall develop and submit a proposed - -• .I action plan to the Department." The r r-r by r plan is intended to fulfill this requirement. a DEQ-CFW 00080026 CORRECTIVE MEASURES STUDY WORK PLAN -------------------------------------------------------------------------------------------------------------------------------------------------------- page intentionally- blank DEQ-CFW 00080027 CORRECTIVE MEASURES STUDY WORK PLAN Chemours usesdevelop a representationof the chemical. • physical characteristics of the Site in order to focus investigation• • remedial decision making. The SCM also assists in the identification of data gaps to be addressed. An initial SCM for the Site was developed to determine the potential foror AOC to impact HH&E.used to identify existing data gaps prior to (Parsonsthe Phase III RFI -• following the Phase III r the findingsare summarized below.A detailed description of ba. found in the Final RFI report. 1 north.The region surrounding the facility is generally level to gently sloping. However, surfacit topography steepens when approaching the Cape Fear River and its tributaries. The facility topography is relatively flat within the developed portion of the Site, and then elevation decreases toward the Cape Fear River to the east and Willis Creek to the po .•hic relief fromplant to the river is approximately 51 feet and approximately 40 feet from the plant to Willis Creek. The .•- Fear River is located along the eastern property boundary of the plant, tributaryapproximately 1,850 feet from the eastern portion of the manufacturing area. Willis Creek, a of .•- Fear River is located in the northernportion of approximately 000 feet fromthe manufacturing (Figure i drainage channel leading to the Cape Fear River is located just south of the plant area and is used as the outfall areacovered by .DPermit Number10Portions of the Georgia Branch, another tributary to the Cape Fear River, flow along the southern boundary of the Site approximately • of •(Figure plant facilities are located on plateau •• • elevation of f feet above sea level (MSL). The plant is situated approximately 70 feet .•• 01 and f year Cape Fear River floodplains and at least 1,000 feet from the 1 00-year floodplain's nearest .•• • • •- -r•- • -• •-•• • • .•- r• -• • Paleozoic. Metamorphic and igneous r dthese deposits • • - r- r•• r:. --r • - r • r. r- • r -r r -• r • • -r • - - r • • •r r- • a a DEQ-CFW 00080028 CORRECTIVE MEASURES STUDY WORK PLAN Phasethe III RFI. Wherepresent, - clay lensencountered approximately bgs and is typicallyto 18 feet• • surface is approximately 145 f-- above MSL throughout the manufacturing area.•r of gently slopesfrom to west. Theredoes notappear to be . potential • . preferred • . • pathway throughfor any water perched on • separate saturated zones are present underr area: variably saturated perched water zone present on top of the clay lens and a deeper regional water -table aquifer - unconfined aquifer) encountered elevation between approximately 90 and 110 feet MSL. The variably saturated perched water zone present on top of caused by infiltration of •North/South Sediment Basins and percolation of local precipitation. The regional aquifer water originates from•• .• of The perched zone water is generally thickest beneath the basins,perched water extending eastward to the bluff and westward to the edge of - lens. Investigation results indicated that perched water is notpresenton •• of the clay lens northof 'Is' Street (other than in the immediate vicinity of - f The southern extent of the perched water is estimated (perched water in the areadoes not• -• Perched water flowradial • the settling b • - Perched zone water seepage has been observed along erosional channels on the bluff adjacent to the Cape Fear River, but not in areas away from the channels, suggesting that local vegetation is using perched zone water that migrates to the bluff. The Phase III RFI results indicated that perched water is likely migrating beyond the -••- of in the western portion of - between -- and 51h Street- the southern end of the PPA Manufacturing Area and the Contractors Gate). a •• -• • • • r • •-mop.]- • -• • - •lff;101412• • ••� ' • North of the manufacturing area, the regional aquifer hydraulic head contours indicate flow is toward Willis Creek. Topographically,• of about 50 feet MSL. The hydraulic heads gauged in wells SMW-10 through -12, installed near the creek, indicate the regional aquifer groundwater is lower than Willis Creek at locations SMW1 0 and SMW1 2. Willis Creek is therefore not a receptorof -•• aquifer groundwater. A man-made pond west of the Site provides the majority of observed baseflow DEQ-CFW 00080029 CORRECTIVE MEASURES STUDY WORK PLAN • - r �r .i .� • r-' - r • r - - • .r-' - conceptsand decision -making to prioritize efforts in order to achieve the objective of protecting more efficiently. • • • M. lam • r • • - - • r ► •• to potential - or - industrial or r rn workers who would be in contact with these media. For future hypothetical residential receptors, three polynuclear benzo(a)pyrene) and one metal (thallium) exceeded residential PSRGs at one location each 'A1. 1 ' and PAH detections only • exceeded- residential PSRG and the thallium detection is within an order of magnitude of •-Therefore, posed to future hypothetical residents-• • r based on - exposure time by •• -tical residents to these isolated detections. concernThus, site -wide groundwater (AOC GVV) was determined to be the primary medium of - ♦ by - - -• COCs that could result in potentially • exposure to future receptors but only under unlikely future land use scenarios. These unlikely future receptors and pathways of •ncern would be •n-site industrial workersand hypotheticalhypothetical residents who would use site groundwater as a potable water source, and future •- who may be exposed to mercury and trichloroethylene ••• due to volatilization fromgroundwater if a hr - would be constructed near areas with detections of these compounds in groundwater. The primary COCs in groundwater (i" groundwater w• be used for • r are metals as shown table• • ......................................................................................................................................................................................................................................................................... ........................................................................................................................................................................................................................................................................ ......................................................................................................................................................................................................................................................................... ........................................................................................................................................................................................................................................................................ ......................................................................................................................................................................................................................................................................... ::::::::::::.::::::: .::::::::::. :::::::::::::::::::::::::::::::: : .... :::: 4.t)t....................................... ............................ .................................................. ................................................................................................................................................. .......................................................................................................................................................... .............. ................................................................................................................................................. IaIII] S 1Sl'J . 1,2-Dichloroethane Bis(2-ethylhexyl)phthalate Antimony Methylene Chloride Perfluorooctanoic acid (PFOA) Arsenic PCE Chromium TICE Cobalt Vinyl Chloride Copper Fluoride Iron Lead Manganese Mercury Nickel Nitrate Selenium Thallium Vanadium Zinc DEQ-CFW 00080030 CORRECTIVE MEASURES STUDY WORK PLAN pathways. ■ No COCs were identified in the site soils for current or future industrial workers or utility/excavation/construction workers. 1• • • - - r. - • -r • •r - !i:1111 III- • •. • • • Will -•'• No COCs were identified drainages or groundwater or - water migrating to the Cape Fear Supplemental sampling activities confirmed that suspected additional releases at the Site • • not create any unacceptableto Z' Site-widegroundwater (Af determined to be the primary mediumof hypotheticalconcern affected by site -related COCs that could present a potential for significant exposure for future on -site receptors. However, this is only possible ir the unlikely scenarios of installation of a drinking water well on -site or future •eof •I LqE 5- -r • • - •r.:•- • r • • r - - I•-- r. - r - - • • •• r Exposure by - hypothetical residents to isolated PAHs and thallium in site soils at two locations via direct contact with the soils would be minimal, thus, no COCs were identified in site soils for future residential users. The risk -based determination process did n•I identify any significantrr to COCs in affected media forAs such, the Site continuesto remain protective of The results of • and current phase investigation- - used to make a final decision about potential exposureand to make an overall determination f• ' - location of each unit is presented on •: • . The units were separated into one of the two following categories based on of the determination r • 1. Corrective Measuresr d FA Based on of determination, - units wereplaced r the categories listed in the table below. i NIE DEQ-CFW 00080031 CORRECTIVE MEASURES STUDY WORK PLAN Measures NeededCorrective Study ar :. : =13TA IVA Ia SWMIJ a ------------------------------------------------------------ •* � a� a.�, � a • SWMU • is a system of •e••u i and aboveground sewer pipes,manholes, •. sumps that convey process wastewater from the main plant areas to the site's WWT system. Plant personnel and site sewer maps indicate that the pipes are constructed reinforced concrete, vitrified clay or steel. The common sump is part of the process sewer system located Monitoring • a i during the Phase III RFI as part of comprehensive site -wide round of groundwater sampling in order to determine current decision - making efforts.• •water samples were collected from 11 new and existing site monitoring - area during the Phase III RFI. Only • organic compounds chloride, 1,2-dichloroethane,• •- ' and I• • were detected above screening criteria.• •. f; (chromium, fluoride, iron, manganese• detected in this area above their NorthCarolina groundwater quality standards. - 1.� 1 - 1 • - r - -r DEQ-CFW 00080032 CORRECTIVE MEASURES STUDY WORK PLAN All remaining site -wide groundwater sampling results were evaluated holistically as part of AOC GW to evaluate the impacts to groundwater and surface water from a site -wide perspective. Although release to groundwater evaluatedaspart of holistic approach allowed determinations to be made with respect to current site conditions at perimeter boundaries and potential exposure points and for site -wide remediation decision making. This holistic view takes into consideration historical analytical data, the SCM, and an evaluation of the potential impact on receptors. Numerous groundwater m• • • wells and piezometers have been -s at the Site V.uring historical investigationefforts.• on -site do-r supply wellshave been used throughout the Site's• to provide potable, process, and domestic water supplies •needs.- two rn-site water wellshave been disconnected fr• drinking water system but •I been • -• During the RFI, groundwater samples• -• and analyzedfor •Cs, SVOCs, and metals, as well as methanol, glycols (selected• • only), gas -phase hydrocarbons,., • 1 monitored attenuationnatural 1 and water quality parameters Site -wide groundwater (1 wasdetermined to be the primary mediumof • affected by - r COCs that could result in potentially • exposure r future receptors but only •- r use scenarios.primary COCs that were identified groundwater (if groundwater wereto be used for r • listed in Section 2.2.1. In addition, metals from the Butaciteo Common Sump release • • • - • • • - •- •r• • - site-specificBecause background concentrations for• • determined !.uring the RFI, regionalbackground r - • •- -• through review were used for the risk screening evaluation presented in the in the Final RFI ReportP. • f 4• in Section.b The comparison P.gainst the regional- • -• that the detected arsenic concentrations 2re within natural background for the area. Thus, it was determined that the soil pathways for current and future on -site industrial workers, on -site utility/construction/excavation • • •n-site trespassers are incompletebecause 211 detected COPCs in site soils are either within natural background ranges or below 1 ■r DEQ-CFW 00080033 CORRECTIVE MEASURES STUDY WORK PLAN .•r .• - r1010 10191•' 9 * s 5 M. M • • • • ',- • • r r • • •IRWIN . - - •- •. • • • levels. As requested and to confirm the risk determination, site -specific background soil samples will be evaluated as part of the CMS. In 2015, six •' borings were advanced in the wooded area r - of the manufacturing area order to collect background • I samples to meet other #bjectives. Two samples were collected from each boring (one from surface to 1 foot .. r another fromto six feet•• The samples were submitted for.rr • 2nali,isms of arsenic. Durmnjy, the CIVIS these new anal tical data will be -r to calculate background r - • of - for - f to 1 footr• 2nd subsurface (4 to 6 feet bgs) soil. The concentrations will be calculated using the USEPA ProUCL software. If the analysis determinesr -- • six samples are required, additional soilborings will be collected in another•- - ••-a of In 005surface water samples•' - -• from the Cape Fear River during an investigation conducted by • •. Results of 105 sampling event • • an increase in concentrations of • ••, rs, including perfluoropentanoic acid (C5), from a spot on the river just north of the Site to a spot on the river adjacent to the Site's river water intake. The i ll suggested that these compounds• r potentially be present in groundwater that may have been traveling beneath Willis Creek from the Site r discharging • the Cape Fear River or • discharging • Willis "reekr the River. Therefore, - r •- • of the'activities, the NCIDEQ requested supplemental groundwater sampling to confirm that the concentrations that were detected in the river were not indicative of - - - from - Site via groundwater discharge Although these compoundsnot - to be of ••I groundwater sampling was conducted in 2015 to gather additional data from a selection of monitoring wells near Willis Creek and the Cape Fear River. The results of these sampling activities confirmed that the concentrations detected in the River near the river water intake were not a result of • one •le collected from monitoring well LTW-05 several thousand feet south of the river water intake had a detection of r further investigate this analytical result, an additional groundwater sample will be collected from this well and will be submitted for laboratory analysis of C5 in accordance with the procedures presented in the Supplemental Sampling Work Plan Technical Memorandum (P• 0 DEQ-CFW 00080034 Lml .. 4 l •l M q a MTV I 1J'rO CORRECTIVE MEASURES STUDY WORK PLAN This page intentionally left blank DEQ-CFW 00080035 CORRECTIVE MEASURES STUDY WORK PLAN purpose of the CMS is 1• determine the appropriate • - measures to me the following goals: ■ Protect HH&E Control the sourcesof - - - • as to reduce or - to extent the practicable, further releasesof . ••us COCs that may pose a threatto human health r the environment ■ Determine media cleanup standards ■ Evaluate the presumptive remedial technologies for effectiveness in containing or treating COCs ■ Evaluate the presumptive remedial technologies for effectiveness in construction and implementation ■ Recommend corrective measures (if required) • W • 'i ' i' I i • • • �` • scenariosMedia cleanup standards will be developed based on the current and future land use described in Section• use of property is expected to industrial.remain • - - no site use restrictions are currently in place, residential scenario will also be considered as a potential future use. Thus, remedial #bJectives and cleanup levels used in the CMS forgroundwater anr perched water will= be based on North Carolina drinking water standards. Media cleanup standards for groundwater will als• be developed for future hypotheticalr- •• -r to r TICE in indoorfrom r • from groundwater. •r r l occur residentialP. future r - were constructed near areas of groundwater that have been impacted by • TICE. Vapor• guidance issued by •Carolina CleanupDivision of Waste Management in October 2016 will be used to develop the media standards. site -specific background levels may also be used as alternative media cleanup levels. In addition, •- risk -based groundwater cleanu• standards may subsequentlybe established rr monitoring purposes (i- • - r • r the Risk Bill. Land use restrictionsbe considered to prevent future use of the site groundwater as potable water • to eliminate the potential forexposure by - residential • r f' • • • • •. -• DEQ-CFW 00080036 �. c l CORRECTIVE MEASURES STUDY WORK PLAN have been proven effective '.Alternative remedial technologiesto address Site COCs will likely be significantly more expensive while providing little additional benefit. order to select fromthe presumptive - -r - •r a combination ther-• presumptive -r • the no further actionbe evaluated based on the criteria listed in the Site's RCRA permit: technical aspects (performance, reliability, implementability, and safety), adverse environmental effects, mitigation of short- and long-term human health impacts, institutional concerns, and cost. Additional site .• - - - - . • - • - .•►I . • . - - •- • • Technical • ^. ^ it ' - •'.. . '.• '. - '. •'. . • • : • • • : The implementability and safety of the remedy will also be _• Both takes to implement the corrective measure and the time it takes to see beneficial results will • - considered !n. This evaluation will include threats to the safety of nearby• - and environments - • - to workers during implementation. Environ entallHu an Health actually addressed by each alternative. The environmentalfor alternative will, at a minimum, evaluate the .• • Adverseon environmentally sensitiveand -• . r- •I s• • • s -• • • DEQ-CFW 00080037 CORRECTIVE MEASURES STUDY WORK PLAN Institutional The selected remedies will be evaluated based on the relevant institutional needs for each alternative. Specifically, the effects of federal, state and local environmental and public health standards, regulations, guidance, advisories, ordinances, or community relations on the design, operation, and timing of each alternative. Cost estimates will be prepared to identify the direct and indirect capital construction costs and long-term O&M and monitoring costs necessary to maintain the continued effectiveness of the selected remedies. Direct capital costs will include such items as materials, labor, equipment, land and site development expenses, and building and service costs. Indirect capital costs will include such items as engineering expenses, legal fees, license or permit fees, startup and shakedown costs, and contingency allowances. O&M costs will include such items as operating labor costs, maintenance materials, maintenance labor costs, sampling and laboratory fees, disposal and treatment costs, regular reporting costs, insurance, and contingency funds. To assess the impact of long-term O&M costs, the present worth of each alternative will be calculated. The present worth calculation relates the cumulative value of 30 years' worth of is to a single cost in current dollars added to the capital cost. The present worth of the various alternatives can then be directly compared to determine their relative cost it curre-it 4ollars. DEQ-CFW-00080038 Pik 1l : 1 CORRECTIVE MEASURES STUDY WORK PLAN This page intentionally left blank DEQ-CFW 00080039 CORRECTIVE MEASURES STUDY WORK PLAN After • • - r of • - measures evaluation,• prepare . • submit• NCDEQ . draft and final CMS reportfor • • • under approved CMS workplan. The draft CMS reportbe submitted to NCDEQ in accordance with the schedule provided • 4.2 of • plan. The final CMS report will be submitted to NCDEQ within 60 days of receipt of comments that NCDEQ may have on the draft -••t The report will containof • recommend preferred -. - proposed outline of -•r t is as f • ■ Corrective action objectives r • • -M 9 1507 a M • • ■ References data and cost estimates. The CMS Report will contain adequate information to support i 11 decision on • - • • remedy. 0 activitiesThe described in this workplan will commence upon receiptof i, 11 approval of the work plan. The following is a list of anticipated scheduled tasks and the time it will take to complete each one. be completed in sequentialorder as indicated in the following table. Activity Duration Anticipated Schedule Work Plan Submittal December 2016 Field Planning Two to four weeks Upon work plan approval Field Work (soil and groundwater One week sampling) Laboratory Analyses Approximately four weeks from field work completion Data Evaluation and Draft CMS Three months from receipt Within 6 to 8 months Report Preparation of laboratory results after work plan approval Final CMS Report submittal to Within 60 days of receipt NCDEQ of comments by NCDEQ on the Draft CMS Report DEQ-CFW 00080040 Lei A Bd 04:101 l MAN 191 ael■ CORRECTIVE MEASURES STUDY WORK PLAN This page intentionally left blank DEQ-CFW 00080041 CORRECTIVE MEASURES STUDY WORK PLAN A project team consisting of numerous qualified resources will complete the evaluation. The roles and responsibilities for project team members and the lines of communication for project are summarized below. The Chemours Project Director•• • •r the execution of project and final remedial action alternative selection, including corresponding and coordinating activities with NCDEQ. Manager The Parsons Project Manager will manage Parsons personnel involved in the project and will be responsible for Parsons' cost and schedule tracking. The Parsons Project r provide - of project deliverables an• ensure that all deliverables meet applicable reporting standards. The Parsons Project Hydrogeologist will coordinate directly with the Parsons Proje Manager and the Principal Engineer and serve as a technical resource for the evaluation. The Project Hydrogeologist will help the engineering team understand the geologic and hydrogeologic conditions and the constituent characteristics and distribution within aquifers mediathe • standards. The Parsons Project Peer Reviewer will communicate with the Parsons Project Manager and will have direct reporting access to the Chemours Project Director on technical and deliverable • '• matters. The Project Peer Reviewer is •! r - • •-• - - - r- - • • •- - • calculations. Responsibilities of position inclu•- communicating with all levels of delivery.program and project management to ensure that a quality product is produced for DEQ-CFW 00080042 ':r 1►� it ► -► CORRECTIVE MEASURES STUDY WORK PLAN This page intentionally left blank DEQ-CFW 00080043 CORRECTIVE MEASURES STUDY WORK PLAN 9MM99M I =11 a =11 2-4:231 DuPont CRG. December 1996. RCRA Facility Assessment Report DuPont CRG. May 1999a. RCRA Confirmatory Sampling Report DuPont CRG. June 1999b. RCRA Confirmatory Sampling (Supplemental) Report DuPont CRG. November 2001. Former Fire Training Area Investigation Report. DuPont CRG. April 2003. Phase I RFI Report DuPont CRG. January 2005. Supplemental Phase I RFI Report. DuPont CRG. June 2006. Phase 11 RFI Report. Leab, Robert J. 1990. Soil Survey of Bladen County. United States Department of Agriculture, Soil Conservation Service. Parsons. April 2011. Phase III RCRA Facility Investigation Work Plan (Rev. 1). Parsons. August 2014. Final RCRA Facility Investigation Report (Rev. 1). Parsons. May 19, 2015. Supplemental Sampling Work Plan Technical Memorandum. USEPA. 1994. RCRA Corrective Action Plan (Final). Office of Waste Programs Enforcement, Office of Solid Waste. OSWER Directive 9902.3-2A, May 1994. USEPA. 1996. Advanced Notice of Proposed Rulemaking for Corrective Action for Release from Solid Waste Management Units at Hazardous Waste Management Facilities. DEQ-CFW-00080044 CORRECTIVE MEASURES STUDY WORK PLAN This page intentionally left blank DEQ-CFW 00080045 DEQ-CFW 00080046 DEQ-CFW 00080047 Aerial Photograph provided by DuPont, taken 12/2005 f' 750 1,500 Site Layout Map DRAWN:C. Oneal DATE DUPONT NO 1/29/2014 PEWCorrective Measures Study Work Plan REVISION: FIGURE NO.: PARSONS NO.: i 4701 Hedgemore Dr. ChenlOUrS Fayetteville Works 1 2 445438.03001 Charlotte, NC zszos Fayetteville, North Carolina Name: Fay_Site_Layout DEQ-CFW 00080048 DEQ-CFW 00080049 DEQ-CFW 00080050 DEQ-CFW 00080051 DEQ-CFW 00080052