| 6000 BRIDGEHEAD RD |
| OAKLEY, CA 945612940 |
| CONTRA COSTA COUNTY |
| SITE TYPE: CORRECTIVE ACTION |
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| PROJECT MANAGER: |
| PETER RUTTAN |
| SUPERVISOR: |
| RIZGAR GHAZI |
| OFFICE: |
| SACRAMENTO |
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Site Information
CLEANUP STATUS
ACTIVE AS OF 1/1/2008
| SITE TYPE: CORRECTIVE ACTION |
| NATIONAL PRIORITIES LIST: NO |
| ACRES: 378 ACRES |
| APN: NONE SPECIFIED |
| CLEANUP OVERSIGHT AGENCIES: |
| DTSC - SITE CLEANUP PROGRAM |
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| ASSOCIATED GEOTRACKER PROJECTS |
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| ENVIROSTOR ID: |
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80001610 |
| SITE CODE: |
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200165 |
| SPECIAL PROGRAM: |
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| FUNDING: |
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| ASSEMBLY DISTRICT: |
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15 |
| SENATE DISTRICT: |
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07 |
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| PAST USE(S) THAT CAUSED CONTAMINATION |
| HAZARDOUS WASTE TREATMENT, MANUFACTURING - CHEMICALS |
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| POTENTIAL MEDIA AFFECTED |
| OTHER GROUNDWATER AFFECTED (USES OTHER THAN DRINKING WATER), SEDIMENTS, SOIL, SOIL VAPOR |
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Site History
STATUS:
The overall RCRA Facility Investigation (RFI) process at the site has been separated into discrete RFI activities pertaining to Soil, Groundwater, Sediment, and Surface Water. The results of a Phase 1 Soil RFI were submitted to DTSC in March, 2006. Included in the submittal of the Phase 1 Soil RFI data was the proposed scope of work for Phase 2 Soil Sampling. DTSC and DuPont agreed to a modified approach, with portions of the site with identified soil remediation needs moving directly into corrective action. The Phase 2 Soil Sampling Workplan has been revised accordingly; sampling activities are scheduled to begin in late 2007. A small-scale exploratory soil sampling program was complete in October 2007; the laboratory results of the sampling are expected in November 2007.
Contaminants in groundwater have been categorized into three regions identified as Plumes 1, 2 and 3. A Phase 1 Groundwater RFI Report completed in September 2006 and under review, presents a summary of various geologic and hydrogeologic field activities conducted in the area of Plume 1 (predominantly the west and central portions of this plume). A Phase 2 Groundwater RFI report will address groundwater-related site investigation efforts conducted from April 2004 through December 2005, for which the predominant area of focus was the eastern portion of Plume 1, Plume 2, and the overlap area shared between Plumes 2 and 3. Finally, the Phase 3 Groundwater RFI will address any remaining groundwater issues under investigation after the Phase 2 Groundwater RFI is issued.
SITE HISTORY:
E.I. du Pont de Nemours and Company (DuPont) operated a chemical manufacturing facility at 6000 Bridgehead Road, Antioch, California that was referred to as the Antioch Plant. Operations at the Antioch Plant began in 1956. Production of fuel-additive anti-knock compounds (AKCs) and chlorofluorocarbons (CFCs) began in 1956, while titanium dioxide (TiO 2) production was added in 1963. Production of all three product lines has been eliminated, beginning with AKC manufacturing in 1981, CFC manufacturing in 1996, and TiO2 manufacturing in July 1998, followed by a general shutdown of all TiO 2 and CFC blending operations on March 31, 1999. The facility is now referred to as the DuPont Oakley Site and is undergoing investigation and remediation activity under the Resource Conservation and Recovery Act (RCRA), with the eventual goal of redeveloping the site as a business park, including commercial office and retail uses. The site has been designated as a “Jobs Opportunity Zone” as part of a smart growth initiative passed by the California State Legislature. The property had been subdivided into four areas and a separate wetlands area for evaluation of soil, soil gas, and sediment contamination. The Western and Eastern Development Areas consist of relatively uncontaminated areas of the site such as current and former vineyards, the administrative building, parking lots, etc. DTSC released the Western Development Area and Eastern Development Area from further regulatory oversight on May 1, 2006. Target cleanup levels for the remainder of the site Northern and Southern Development Areas and the wetlands will be risk-based remediation goals suitable for commercial/industrial/retail use. The Northern Development Area consists of the former CFC Manufacturing Area, the former AKC Blending Area, and closed surface impoundments. The Southern Development Area consists of the area just north of a plant rail spur extending south through the AKC Manufacturing Area, the TiO2 Manufacturing Area, and the Manufacturing Support Area to the main rail line along the southern property boundary.
RCRA Facility Investigations (RFI) have included the collection of more than 1,200 soil samples and the monitoring of nearly 200 groundwater wells at the site. Constituents of concern (COCs) in soils include primarily: arsenic, lead, organolead, and Tetrachloroethene (PCE). COCs detected in groundwater at concentrations exceeding applicable state or federal water quality objectives include primarily: arsenic; lead; organolead; carbon tetrachloride (CT) and daughter products; Tetrachloroethene (TCE) and daughter products; 1,2 dichloroethane (1,2-DCA); 1,2-dibromoethane (1,2-DBA); trichlorofluoromethane (Freon 11); and 1,1,2-trichlorotrifluoroethane (Freon 113). Regular groundwater monitoring and performance monitoring of a subsurface permeable reactive barrier, installed in 2005, continue at the site. Groundwater constituents have been detected at locations on the neighboring Lauritzen Yacht Harbor property. DuPont continues to collect wet and dry season surface water samples from the San Joaquin River, Lauritzen Yacht Harbor, and Little Break. DuPont has also collected sediment samples from the San Joaquin River and the Central Slough and Channel.
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