Liquid Gold Oil Corp. ran a waste oil storage and transfer facility on an 18-acre leased site in Richmond, California. Operations continued until 1982 and left soils and groundwater contaminated with metals, petroleum hydrocarbons, lead, and polycyclic aromatic hydrocarbons (PAHs). PAHs are a group of chemicals that form when organic materials burn or break down. The site was added to the National Priorities List (NPL), the federal Superfund program's roster of priority cleanup sites, in 1983.
EPA selected a cleanup plan in June 1993. The plan covered the overall site as a single operable unit and used four main approaches: building an engineered cap over contaminated soil, consolidating waste on-site, disposing of some contaminated material off-site, and ongoing monitoring. Construction wrapped up in August 1995, and the site was deleted from the NPL in 1996, confirming that cleanup goals had been met. The California Department of Toxic Substances Control (DTSC) now oversees ongoing maintenance. Contaminated soils remain on-site under a vegetated cap. The property is fenced, and a deed restriction bars residential and certain other uses.
Before the cap was in place, people could have been exposed to health risks through accidental ingestion or direct contact with contaminated soils. Adjacent wetlands may also have been harmed. Those pathways are now controlled. Current assessments show no unacceptable human exposure routes exist, and contaminated groundwater migration is stabilized with no unacceptable discharge to nearby surface water. EPA continues monitoring to confirm contamination stays within the original area.
EPA conducts Five-Year Reviews to make sure the cleanup keeps protecting people and the environment over time. Reviews were completed in 2000, 2005, 2010, 2015, 2020, and most recently on September 5, 2025. That sixth review found the remedy is short-term protective. The next review is scheduled for 2030. Operation and maintenance activities are expected to continue through late 2027, when the site is projected to be ready for anticipated reuse.
Community members can read the latest Five-Year Review at EPA's Superfund Records Center, located at 75 Hawthorne Street, 3rd Floor, San Francisco, California 94105, phone 415-947-8717. Copies are also available at the Richmond Public Library, 325 Civic Center Plaza, Richmond, California 94804, phone 510-620-6561. Questions about site conditions can go to the DTSC project manager or to EPA's Community Involvement Coordinator.
