The Beckman Instruments plant sat on 12 acres in Porterville, California and ran from 1967 until it closed in 2017. It made electronic equipment assemblies and printed circuit boards using electroplating and degreasing processes. Those operations left lead in the soil and volatile organic compounds (VOCs) in the groundwater. The main VOC was 1,1-dichloroethene, which spread beyond the plant boundaries. Other contaminants of concern include 1,1,1-trichloroethane, 1,1,2-trichloro-1,2,2-trifluoroethane, 1,1-dichloroethane, and trichloroethene. All of these were found in both soil and groundwater except trichloroethene, which appeared in groundwater only.
The site was added to the National Priorities List (NPL) in June 1986. The NPL is the EPA's list of the most serious uncontrolled or abandoned hazardous waste sites in the country. A remedial investigation began in February 1987. The first cleanup remedy, selected in September 1989, used air stripping and pump-and-treat technology to pull contaminated groundwater out of the ground and clean it. In September 2005, the EPA updated the remedy to monitored natural attenuation, monitoring, and institutional controls. That final remedial action ran from January 2006 to March 2007. Long-term response actions continued until March 2022.
All contaminated soil has been removed. Groundwater now meets all state and federal drinking water standards. Human exposure is under control, with no unacceptable exposure pathways identified. Groundwater migration is also under control, with contamination stabilized and no unacceptable discharge to surface water. The EPA will continue monitoring to confirm the affected groundwater stays within the original area of contamination. Five-year reviews were conducted throughout the process, with the most recent completed in August 2018. The site achieved sitewide ready for anticipated reuse status in June 2006, and the EPA deleted it from the NPL on March 22, 2022.
Community members who want more information can contact the EPA's Community Involvement Coordinator. Public documents about the site, including two Records of Decision, five-year review reports, and groundwater and soil deletion records, are available through the EPA's site document collections.
