Beckman Instruments (Porterville Plant)

Investigation and Cleanup Activities

Initial Actions

Immediate Actions: In 1983, the pond liquids, liners, and surface soils were removed and disposed of in an EPA-approved facility. Beckman installed groundwater monitoring wells and provided alternate water supplies to about 300 residences affected by the contamination. Between 1983 and 1985, the company connected over 150 of the affected residences to the Porterville municipal water supply system. In 1985, Beckman installed a groundwater pump and treat system to stop the westward spread of contaminants in the upper aquifer and to begin cleaning the groundwater. These activities helped to slow, and eventually halt, the migration of the contaminant plume. In 1987, an eastern containment and reclamation well field was installed. Groundwater from this area is pumped to an on-site air stripping tower. The treated groundwater from both systems is used for local irrigation or is diverted to percolation basins east of the facility and near the Tule River. By January 1990, groundwater cleanup standards were achieved in the upper aquifer.

Cleanup Ongoing

Entire Site: In 1989, the EPA selected a remedy to clean up the soils and lower aquifer areas of the Beckman Instruments site by extracting the contaminated groundwater, treating the groundwater by air stripping to remove the contaminants, releasing the treated groundwater into the aquifer, and excavating the lead-contaminated soil and disposing of it in an EPA-approved facility. In 1990, Beckman, under EPA oversight, began designing the technical specifications for the cleanup. The design of the groundwater remedy was completed in 1992. To date, soil cleanup has been completed and all components for the groundwater cleanup have been constructed and are operating.

Cleanup Ongoing

The ROD selected remedy in the upper aquitard and lower aquifer was carried out from 1991 to 1999 when cleanup goals were reached in most of the upper aquitard and lower aquifer groundwater. Small, localized areas of the upper aquitard and lower aquifer remained above the cleanup goal for 1,1-dichloroethylene (1,1-DCE) of 6 micrograms/liter. A focused operation of pump and treat system in areas failed to show progress toward achieving the cleanup goal due to the inability to accelerate contaminant removal from the upper aquitard. Since 1999, groundwater concentrations of 1,1-DCE have generally remained stable or decreased. In September 2003, EPA conducted a Five-Year Review of the site remedy. EPA concluded that these small remaining areas cannot be cleaned up with the conventional pump and treat at a reasonable cost.

From August 1-30, 2005, EPA conducted a comment period to allow the public an opportunity to comment on the three alternatives considered to solve this issue: 1) no action, 2) resume pump and treat and 3) monitored natural attenuation (MNA), which was EPA's preferred alternative. EPA conducted a public meeting in Porterville on August 9, 2005. After considering comments received, EPA issued an amendment to the ROD in September 2005. The ROD amendment memorializes EPA's decision to change the remedy from pump and treat to MNA and provides EPA's response to public comments.

Under EPA oversight, Beckman installed four new monitoring wells in August 2006 and has begun monitoring to implement the MNA remedy. In September 2008, EPA conducted the third five-year review of the site and determined that the MNA remedy is protective of human health and the environment. Concentrations of 1,1-DCE in the groundwater continue to decline.

In 1987, the EPA and Beckman Instruments signed a Consent Order requiring the company to clean up the site. Beckman designed cleanup technologies and is currently conducting cleanup activities under a Unilateral Administrative Order.