koppers co., inc. (oroville plant)


Since 1948 until March 15, 2001, the 205-acre Koppers Company, Inc. (Oroville Plant) site was used to conduct wood treating operations to prevent wood deterioration by insects or fungi. Koppers purchased the plant from the National Wood Treating Company in 1955 and closed the facility March 15, 2001. Chemical and waste water handling procedures and wood treatment and storage operations contaminated the soil and groundwater on and off site. Fires at the Koppers facility occurred in 1963 and 1987, causing increased contamination at the site. Groundwater, surface water, and soils on and off site were contaminated with pentachlorophenol (PCP) and other hazardous substances used in Koppers' wood treating activities. The contaminated groundwater is located beneath this site and off-property south of the Koppers site. In 1973, PCP was discovered in nearby residential wells that are used as a source of drinking water. In 1988, the Koppers Company, Inc. was bought by the parent company of Beazer East, Inc (BEI). BEI later sold the wood treating plants to Koppers Industries, Inc. (KII). After KII closed its wood treating operation in March 2001, KII resold the site back to BEI in November 2002. In November 2006, BEI sold all the 205 acre site exclusive of parcel #1 containing the site's contaminated soils consolidated into two RCRA landfills to Gold Line Express, Inc. of Woodland CA for development as an industrial park (see attached 49 lot parcel plan). BEI remains the recognized potentially responsible party provided the new owner complies with the insitutional controls contained in the deed restrictions. Approximately 10,650 people live within a three mile radius of the site. These people also depend on groundwater as their source of drinking water. The nearest downgradient private water supply well is just off-property to the south, and there are numerous private water supply wells within three miles of the site. Contamination of groundwater from site-related chemicals extends two miles to the south.

Hazardous Ranking Score

34 / 100

A score of 28.5 or higher qualifies a site for the Superfund National Priority List.

Regional Contact

Region 9
Phone: (415) 947-4251

Contact Region



Site Inspection
Preliminary Assessment
Final Listing On NPL

Contaminants & Health Effects

      Endocrine Disrupter
      Reproductive Toxin
      Persistent, bioaccumulative and toxic


        African American
        American Indian and Alaska Native
        Native Hawaiian


        People living
        within a 1 mile radius


        Average Income


        Occupied homes

        Potentially Responsible Parties

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