The Omega Chemical Corporation site sits in Whittier, California, where a refrigerant and solvent recycling operation ran from about 1976 to 1991. Spills and leaks left soil and groundwater contaminated with chlorinated solvents. The site was added to the National Priorities List in January 1999, and cleanup has been underway in phases since 1995. Today, active treatment systems are running, but construction is not yet complete across the entire site.
Seventeen contaminants of concern have been identified. Soil in the Phase 1 area contains compounds including tetrachloroethene, trichloroethene, 1,1,1-trichloroethane, 1,1-dichloroethene, and 1,2-dichloroethane. Groundwater contamination is more widespread and includes those same substances plus 1,4-dioxane, carbon tetrachloride, chloroform, chromium(VI), and several other chlorinated compounds. Contaminated groundwater extends roughly three miles from the former facility to Telegraph Road in Santa Fe Springs.
About 170 potentially responsible parties have participated in cleanup alongside EPA. Three treatment systems are currently operating. A groundwater extraction system has treated more than 42 million gallons of contaminated water and removed roughly 969 pounds of contaminants. A soil vapor extraction system has pulled more than 9,600 pounds of contaminants from the ground and continues to prevent them from entering buildings at unsafe levels. An indoor air system has removed more than 2,250 pounds of contaminants. Together the three systems have removed more than 12,800 pounds of contamination. For the downgradient groundwater area, 66 responsible parties agreed in March 2017 to spend an estimated 70 million dollars on a regional pump-and-treat system, with remedial action estimated to begin between July and September 2027.
Human exposure is currently under control, meaning no unacceptable pathways exist for people to contact contamination. However, groundwater migration is not yet under control, and contaminated water is still spreading. The most recent five-year review was completed in September 2022. Seven businesses now operate on the site, employing 23 people and generating about $2.98 million in annual sales. The site has not yet been deleted from the National Priorities List.
Community members with questions can contact the Community Involvement Coordinator or the Remedial Project Manager.
