The Louisiana-Pacific Corp. site in Oroville, California includes a 100-acre wood-processing plant and a 115-acre landfill located about half a mile apart. Georgia-Pacific Corporation built and ran the plant starting in 1969. Louisiana-Pacific took over in 1973 and operated both facilities. Before 1980, wastewater from the plant's glue kitchen was discharged into an unlined pond. Workers also applied fungicide spray to treat timber seasonally until 1988. EPA added the site to the National Priorities List (NPL) in 1986 after an initial assessment in 1981.
Contamination affected groundwater across the entire site. EPA identified ten contaminants of concern, including pentachlorophenol (PCP), formaldehyde, arsenic, lead, manganese, barium, zinc, silver, boron oxide, and 2-propan-2-yloxypropane. In 1973, state officials found high levels of PCP in nearby residential wells. By 1983, the groundwater plume had spread 1.5 miles to the south.
Cleanup involved federal, state, and responsible party actions. An interim remedy selected in 1990 included a perimeter fence, deed restrictions against residential use, soil sampling, and groundwater monitoring for formaldehyde and arsenic. A combined investigation ran from March 1987 through September 1990. Remedial work began in December 1992. After further soil and groundwater investigations were completed by 1995, EPA determined no further cleanup was needed. A Record of Decision Amendment issued in August 1995 changed the selected remedy to No Further Action. Deed restrictions and well permit requirements were then removed, and monitoring was discontinued. Construction was finished by October 1995.
EPA deleted the site from the NPL in November 1996, confirming cleanup goals had been met. Human exposure is currently under control across the entire site, with no unacceptable exposure pathways identified. All required land-use controls are in place, and the site is considered ready for anticipated reuse. An industrial park now operates on the property. As of December 2024, eleven on-site businesses employ 62 people and generate about $8.4 million in annual sales.
Community members with questions can contact the EPA's Community Involvement Coordinator or Remedial Project Manager.
