DOI OEPC - PG&E Topock Site

The PG&E Topock Compressor Station is in San Bernadino County, California, at the foot of the Chemehuevi Mountains.  It is approximately 15 miles southeast of the city of Needles, CA, and is located approximately 1,500 feet from the Colorado River and California/Arizona state border.

The surrounding area includes land owned or managed by the US Fish and Wildlife Service (USFWS), the US Bureau of Reclamation (BOR), the Bureau of Land Management (BLM), the Fort Mojave Indian Tribe, and the Metropolitan Water District of Southern California.  The site is within a larger area identified by Native American Tribes as an area of traditional and cultural importance.

Pacific Gas & Electric Company (PG&E) operates Topock Compressor Station to maintain pressure within the pipeline transporting natural gas to central and northern California.  Cooling towers are used to lower the temperature of the pressurized natural gas before it continues through the pipeline.

"The main health problems seen in animals following ingestion of chromium(VI) compounds are irritation and ulcers in the stomach and small intestine and anemia... The Department of Health and Human Services (DHHS), the International Agency for Research on Cancer (IARC), and the EPA have determined that chromium(VI) compounds are known human carcinogens." CDC Agency for Toxic Substances and Disease Registry

From 1951 to 1985, PG&E treated the water in the cooling towers with toxic hexavalent chromium to prevent corrosion.  In 1964, they began treating the water to remove hexavalent chromium before discharging it, and in 1985 they switched to a phosphate-based solution.

Groundwater investigations began in 1997 and documented a large plume of hexavalent chromium [Cr(VI)] extending towards the Colorado River.

The cleanup became a concern to the Department of the Interior (DOI) because hazardous substances impacted Department-managed lands.  Department properties include lands owned or managed by the BOR, the BLM, and the USFWS Havasu National Wildlife Refuge.

To begin and manage the cleanup, DOI tapped into the Central Hazardous Materials Fund (CHF).  

CHF funds are Congressionally appropriated funds, provided to the Department of the Interior and managed by the Office of Environmental Policy and Compliance (OEPC), for the cleanup of environmental contamination on public lands pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).  

Nine federally recognized Native American Tribes have ancestral ties to the Topock area.  Property exists in the Topock project area that has traditional religious and cultural significance, including the Topock Maze, which is listed on the National Register of Historic Places. 

Representatives from Tribes with ancestral ties to the Topock area were consulted throughout the process. 

Historic waste management practices by PG&E resulted in the potential for soil contamination in the area around the Compressor Station.  Soil sampling investigations and cleanup activities began in 1996. 

In 2010, DOI directed PG&E to conduct a soil removal action to address contaminated soil and debris in a ravine south of the Compressor Station. 

In 2021, DOI directed PG&E to conduct a more extensive soil removal action to address contamination on or adjacent to Federal property.  This action should be completed by 2023. 

Groundwater remediation efforts in the Topock area prevent hexavalent chromium from contaminating the Colorado River, which serves as a water resource for much of the American Southwest. 

Soil excavation efforts have removed heavy metal and organic contamination from the Havasu National Wildlife Refuge as well as places of cultural significance to Native American peoples. 

Phase 2 of the groundwater cleanup project will continue until approximately 2026.  The groundwater in-situ treatment will continue for approximately 30 years.  The final decisions regarding soil cleanup are anticipated after 2025.