INTRODUCTIONThe Department of Toxic SubstancesControl (DTSC) has prepared this factsheet to provide information on siteassessment and clean-up activities ofthe former DuPont manufacturingplant in Oakley, California. Theboundaries of the DuPont Oakley siteare shown in Figure 1 below.

On March 28, 2002, the Cal-EPA SiteDesignation Committee (consisting ofsix members representing the StateWater Resources Control Board,Cal/EPA, DTSC, Department of Fishand Game, Air Resources Board, andOffice of Environmental HealthHazards Assessment) transferredoversight of DuPont Oakley to DTSCfor all investigation and remediationactivities. The transfer of oversight to

The energy challenge facing California is real. Every Californian needs to take immediate action to reduce energy consumption.For a list of simple ways you can reduce demands and cut your energy costs, see our Web site at www.dtsc.ca.gov.

E.I. DuPont de Nemours andCompany, Inc. EPA ID No. CAD 009151671

6000 Bridgehead Road, Oakley CA 94561

Informational Status Report t

Fact Sheet

October 2002

DTSC will help to consolidateregulatory oversight of the DuPontOakley site. DuPont had beenoperating under the oversight of theCentral Valley Regional WaterQuality Control Board prior to thetransfer.

DTSC is authorized by the U.S.Environmental Protection Agency(U.S. EPA) to implement ResourceConservation and Recovery Act(RCRA) corrective action programrequirements in the State ofCalifornia. DTSC also implementsstate laws and regulations. TheDuPont Oakley site had regulatedunits thus making the site subject toRCRA corrective action. As leadagency, DTSC will be implementingboth state and federal hazardous wastecontrol laws to protect human healthand the environment in carrying outsite characterization and clean-upactivities at DuPont.

FACT SHEET PURPOSEAND CONTENTSThe purpose of this fact sheet is toprovide information about the DuPontOakley site, site history, contaminantscurrently found in soil andgroundwater, regulatory information,public participation opportunities, andwhere to find more information. Acommunity survey is also included.We ask that you complete this surveyand return it to DTSC to assist infuture planning activities.

Figure 1

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SITE HISTORY ANDDESCRIPTIONThe DuPont Oakley site is located in ContraCosta County in the newly incorporatedcommunity of Oakley. The property islocated on Bridgehead Road, bordered to thenorth by the San Joaquin River, to the southby the railroad, to the east by Big BreakRoad, and to the west by Highway 160. Thesite is in the heart of the City of OakleyRedevelopment District, situated along theEast 18th Street/Main Street corridor. Thesite consists of approximately 365 acres ofwhich 184 acres are wetlands adjacent to theSan Joaquin River.

DuPont operated a manufacturing plant bythe name of DuPont Antioch Works on thesite from 1956 to 1997, and at the height ofits operations employed nearly 600 people.

The site was originally constructed as amanufacturing facility for the gasoline “anti-

knock” agent tetraethyl lead (TEL), and forthe manufacture of the refrigeration coolingcompounds chlorofluorocarbons (Freon).

Production of titanium dioxide, a whitepigment used in a variety of householdproducts and food, was added in 1963. Abyproduct of the titanium dioxidemanufacturing process was stabilized withconcrete and sold for use as a roadway sub-base material under the trade name Sierra-Crete®.

All production activities at DuPont Oakleyhave been discontinued. In response to thefederal phase out of TEL and Freon,DuPont discontinued operations andultimately closed the Oakley plant in 1998.Manufacturing facilities were demolished in1999. A small portion of the site is currentlyused by a DuPont joint venture for qualitycontrol testing of automotive finishes.

Figure 2

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CONTAMINATION INGROUNDWATER AND SOILDuring the 1980s, DuPont began toinvestigate groundwater at the Oakley site.These tests showed that groundwater undercertain areas of the site contained variousmetallic and organic contaminantsassociated with the historical manufacture ofFreon® (a refrigeration cooling compound),tetraethyl lead (a gasoline antiknock agent),and titanium dioxide (a white pigment).Three separate groundwater contaminationareas (plumes) have been identified (seeFigure 2). The chemicals that have beenfound in groundwater are shown in Table 1on this page.

In 1989, DuPont installed a groundwatertreatment system to remove contaminantsfrom the site’s groundwater. Since then,groundwater investigations at the site havebeen ongoing with over 130 monitoringwells installed and thousands of samplescollected. The groundwater treatmentsystem was stopped in 2000 when it wasdetermined that it was not meeting expectedperformance results. A more effectiveprocess, a Permeable Reactive Barrier(PRB) Wall, is currently being evaluated.

In 2000, DuPont installed a test PRB wall toaccelerate the treatment of groundwatercontaminants. The PRB is a porousunderground wall composed of iron filingsinstalled deep into the aquifer. The ironfilings in the wall react with and destroyorganic compounds in the water that passesthrough it. A 110-foot wide test PRB wasinstalled at a depth of 50 to 110 feet belowthe ground surface.

As part of future site activities, DTSC isworking with DuPont to develop plans todetermine the levels of groundwatercontamination, and to clean-up the

groundwater to levels which are protectiveof human health and the environment.

DuPont has also conducted a series ofinvestigations as to the nature and extent ofsoil contamination at the Oakley site. Aspart of future site activities, DTSC isworking with DuPont to develop plans tocomplete the investigation of site soilssuspected of being contaminated, and toremediate these contaminated areas, asnecessary.

The contaminants that have been found ingroundwater and site soils are shown inTable 1 below. Figure 2 on the previouspage shows the location of eachgroundwater plume.

Table 1 - Contaminants Identified inDuPont Oakley Site Soils andGroundwater

Contaminants Present Soil Groundwater1

Arsenic* ü Plume 1Carbon tetrachloride* ü Plume 1Chromium* ü NPcis-1,2-Dicholorethene NP Plume 3Dioxins* ü NPEthylene dibromide* ü Plumes 1 & 2Ethylene dichloride* ü Plumes 1 & 2Fluoride ü Plume 1Freons* ü Plume 1Lead* ü Plumes 1 & 2Hexachlorobenzene* ü NPPolychlorinated biphenyls* ü NPTetrachloroethylene ü Plume 3Tetraethyl lead ü Plumes 1 & 2trans-1,2-Dichloroethene NP Plume 3Trichloroethylene* ü Plume 3Vanadium ü NPVinyl chloride* NP Plume 3* Contaminant has been shown to cause cancer inlaboratory animals.1 The number(s) after the Plume refer to theassociated groundwater plume(s) where thecontaminant is present.NP Sampling has not verified the presence of thecontaminant in the soil or the associatedgroundwater plume(s).

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REGULATORY OVERVIEWRCRA, an amendment to the Solid WasteDisposal Act, was enacted in 1976 toaddress the management of solid andhazardous waste in the United States. WhenRCRA regulations were issued in 1980,DuPont identified a number ofHazardous Waste Management Units onsite. DuPont received interim authorizationin 1981. As amended, the RCRA statutemandates that EPA require the investigationand associated clean-up of all hazardousreleases at RCRA-regulated facilities. Thisprocess is known as “Corrective Action.”

DTSC is currently preparing a CorrectiveAction Consent Agreement for DuPont’sOakley site. The consent agreement willaddress the completion of site-wideinvestigation and remediation activitiesrequired to complete DuPont’s correctiveaction obligations, and to redevelop the site.

The following steps shown in Table 2 belowwill ensure the appropriate clean-updecisions for the DuPont Oakley site:

Table 2 – Components of CorrectiveAction

ACTIVITY STATUSInitial Site Assessment CompletedRCRA Facility Assessment (RFA) CompletedRCRA Facility Investigation (RFI)(For Groundwater)

SubstantiallyComplete/Ongoing

RCRA Facility Investigation (RFI)(For Surface Water and Sediments)

Ongoing/Future

RCRA Facility Investigation (RFI)(For Soil)

Ongoing/Future

Perform Interim ActionsIf necessary to protect human health and theenvironment

Ongoing/Future

Corrective Measures Study (CMS)Evaluation of Remedial Alternatives

Future

Public Comment FutureProposed RCRA Remedy Selection FutureCorrective Measures Implementation(CMI) Remedy Implementation

Future

Corrective Action Termination Future

SITE REDEVELOPMENTDuPont plans to retain ownership of themajority of its Oakley property and to leaseland for compatible future uses. DuPontplans to preserve the 184 acres of wetlandson their Oakley property in their naturalcondition.

PUBLIC PARTICIPATIONACTIVITIESA major portion of the RCRA program is theinvolvement of citizens, the regulatedcommunity, and stakeholders. The publicplays a key role by providing input andcomments during varying stages ofinvestigation, permit development, and siteclean-up activities. DTSC is currentlyreviewing DuPont’s previously preparedPublic Participation Program. The currentPublic Participation Program consists of:

§ Stakeholder interviews with a broadcross section of interested parties.

§ A community-wide informational publicmeeting and open house.

§ Informational presentations at cityagency and civic meetings.

§ A fact sheet and newsletter distributed tolocal interested parties and agencies.

§ A public repository for public review ofsite-related documents.

§ A regularly updated public Web site(www.oakley.dupont.com).

§ Media interviews and outreach.

§ A Community Advisory Group toreview ongoing activities and to serve asa liaison with the larger community.

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Upcoming Activities

Under DTSC oversight, DuPont willconduct various activities to facilitate publicparticipation. These will include:

Fact Sheets – DTSC is responsible for and willprepare regular updates about regulatoryefforts through a series of fact sheets, such asthis one. Fact sheets will be mailed toresidents near the site, placed in informationrepositories and other city/communitylocations, posted on the Web site, andforwarded to the media.

Newsletter – DuPont is responsible for andproduces periodic newsletters that providedetailed information about DuPont’s efforts toinvestigate, remediate, and redevelop theDuPont site. These newsletters are preparedand distributed by DuPont, and DTSC doesnot review or provide input during thepreparation of DuPont’s newsletter.

Community Advisory Group – DuPont hasestablished a Community Advisory Group(CAG), comprised of Oakley citizens livingand working near the DuPont site as well asindividuals representing local and regionalagencies. DuPont will continue to host theCAG, scheduling meetings approximatelyevery quarter at the DuPont Oakley facility.CAG meetings are open to the public.

Community Meetings – DTSC is responsiblefor and will hold public meetings at key stepsin the project to provide the public with anopportunity to learn more about the DuPontOakley site and planned activities and toprovide comments.

GLOSSARY OF TERMSAquifer: A water-bearing layer of rock or sediment thatis capable of yielding useable amounts of water. Drinkingwater and irrigation wells draw water from the underlyingaquifer.

Clean-up process: A comprehensive program for theclean-up (remediation ) of a contaminated site. Itinvolves investigation, analysis, development of a clean-upplan, and implementation of that plan.

Groundwater: Water beneath the earth's surface thatflows through soil and rock openings, aquifers, and oftenserves as a primary source of drinking water.

Plume: A body of contaminated groundwater flowingfrom a specific source. The movement of the groundwater isinfluenced by such factors as local groundwater flowpatterns, the character of the aquifer in which thegroundwater is contained, and the density of contaminants.

Remediation: Clean-up of a site to levels determined tobe health-protective for its intended use.

Resource Conservation and Recovery Act(RCRA): A 1976 amendment to the first federal solidwaste legislation, the Solid Waste Disposal Act of 1965.In RCRA, Congress established initial directives andguidelines for U.S. EPA to regulate and manage solidwaste, including hazardous waste. RCRA established aregulatory system to track hazardous substances from thetime of generation to final disposal. The law requires safeand secure procedures to be used in treating, transporting,storing, and disposing of hazardous wastes. RCRA wasdesigned to prevent new, uncontrolled hazardous waste sites.

Wetland: An area that is regularly saturated by surfaceor groundwater and, under normal circumstances, capable ofsupporting vegetation typically adapted for life in saturatedsoil conditions; they are critical to sustaining many species offish and wildlife, including native and migratory birds.They include swamps, marshes, and bogs and may be eithercoastal or inland. Coastal wetlands are brackish (have acertain mixture of salt).

ANUNCIO - Si prefiere hablar con alguien en espanol acerca de DuPont, favor de llamar a Jesus Cruz,Departamento de Control de Substancias Toxicas. El numero de telefono es (510) 540-3933.

FOR MORE INFORMATIONIf you would like more information about the Site, please call the DTSC Public Participation Specialist, Jesus Cruz at (510)540-3933. For media inquiries, please contact the DTSC Public Information Officer, Angela Blanchette at (510) 540-3732.

Information RepositoriesA repository of information has been established and is maintained for the public to access material about the DuPontOakley site, remediation activities, and site redevelopment. The information repository is located at the Oakley PublicLibrary, located at 1050 Neroly Road in Oakley, California. Phone: (925) 625-2400.

Public records related to the DuPont Oakley site are subject to disclosure under the California Public Record Act(Government Code Section 6250-6260) and available for public inspection during normal business hours. The FullAdministrative Record for the DuPont Oakley site is available at DTSC. For a nominal fee, requests for public records mayalso be made by telephone, letter, or fax. The Full Administrative Record is available at the DTSC File Room, Departmentof Toxic Substances Control, Berkeley Field Office, located at 700 Heinz Avenue, Suite 200, Berkeley, CA 94710-2721.Phone: (510) 540-3800 - Fax: (510) 540-3738.

Web sitesInformation can also be found on the DTSC and DuPont Web sites.DTSC: www.dtsc.ca.govDuPont: www.oakley.dupont.com

Notice to Hearing Impaired IndividualsTDD users can obtain additional information about the Site by using the California State Relay Service(1-888-877-5378) to reach the Public Participation Specialist at (510) 540-3933.

Jesus CruzDepartment of Toxic Substances Control700 Heinz AvenueBerkeley, California 94710-2721

Community Survey Enclosed. Please complete and return to DTSC. Thank you.

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