Welcome to the Topock Remediation Project (Project) website. This website is dedicated to communicating information regarding the history and status of an environmental investigation and cleanup project at the Pacific Gas and Electric Company (PG&E) Topock Compressor Station (Station) and adjacent land, collectively known as the Topock Project Site (Site) in San Bernardino County, California. The PG&E Topock environmental investigation and remediation activities have been underway at the Site since 1997 as a result of historical releases of hexavalent chromium discharges from its cooling tower wastewater impacting soil and groundwater.

The Station is located in eastern San Bernardino County, about 12 miles southeast of the city of Needles, California, south of Interstate 40, and one-half mile west of the Colorado River. The Station is surrounded by land owned by PG&E, the Fort Mojave Indian Tribe, BNSF Railroad, and the federal government, including the Havasu National Wildlife Refuge (HNWR) managed by the U.S. Fish and Wildlife Service (USFWS), and lands owned and/or managed by the U.S. Bureau of Reclamation (BOR) and the Bureau of Land Management (BLM) (see the Site location map).  

GROUNDWATER: Protection of groundwater Water beneath the Earth’s surface that flows through soil and rock openings (aquifers).and surface waterWater collecting on the ground or in a stream, river, lake, wetland, or ocean. resources, including the Colorado River, as well as lands surrounding the Station, is one of the project’s highest priorities. In 1996, PG&E entered into an agreement with the California Department of Toxic Substances Control (DTSC), a department of the California Environmental Protection Agency, to conduct environmental investigations to identify and clean up past environmental contamination. In 2005, PG&E signed a similar agreement with the United States Department of the Interior (DOI).  In 2004, DTSC directed PG&E to take immediate, stopgap actions, known as Interim MeasuresCleanup actions taken to protect public health and the environment while long-term solutions are being developed., to ensure that the chromium plumeA body of contaminated groundwater. The movement of a groundwater plume can be influenced by such factors as local groundwater flow patterns, the character of the aquifer in which the groundwater is contained, and the density of contaminants. beneath the Site flows away from the Colorado River while additional investigation and final cleanup options were evaluated. After consideration of inputs received from federal, state, local, and tribal governments as well as community members, a Final Remedy approach for the groundwater contamination was selected and a Final Environmental Impact Report (EIR) was certified by DTSC in January 2011 based on an environmental study of the Site. DOI, as a co-regulatory agency overseeing the Site, also adopted a Groundwater Record of Decision in December 2010, and selected the same remedy for the groundwater cleanup.

After groundwater Water beneath the Earth’s surface that flows through soil and rock openings (aquifers).remedy selection, DTSC worked with PG&E, Federal Agencies, interested Tribes, and other key project stakeholders in the design of the DTSC and DOI worked with PG&E, Federal agencies (BLM, BOR, USFWS), the HNWR, State agencies (California Regional Water Quality Control Board, Arizona Department of Environmental Quality), interested Tribes, and other key project stakeholders in the design of the remedy. Because of the specificity of the design details and additional knowledge of the anticipated site impacts, DTSC prepared a Subsequent EIR (SEIR) for the groundwater remedy. The Final SEIR was certified in April 2018. DTSC and DOI subsequently also approved the final Groundwater Remedy Design in April 2018.

Phase 1 of remedy construction began on October 2, 2018. Phase 1 construction includes the National Trail Highway (NTH) In-situ Reactive Zone (IRZ) with 42 remediation wells (for groundwater injection and/or extraction) and a robust network of 74 monitoring wells (for measuring water levels and quality), as well as a network of over 74,000 linear feet of water conveyance piping and 41,000 feet of electrical conduits that connect the remediation wells to the power supply system, the carbon amendment building, and the Remedy-Produced Water Conditioning (RPWC) system.

Phase 1 systems and components were integrated and tested. On December 22, 2021, PG&E initiated injection of ethanol into the groundwater at select NTH IRZ wells.

Concurrently with the start of the remedy, DTSC and DOI terminated the Interim Measure No. 3 (IM-3) treatment system on December 21, 2021. PG&E prepared the IM-3 treatment system for lay-up mode pending future approval for decommissioning after DTSC and DOI determine the remedy to be operating as intended. The preparation for lay-up was completed on March 21, 2022. PG&E notified the agencies that IM-3 is in lay-up mode on March 22, 2022. When the IM-3 system is in a lay-up condition, the system will be left in a safe, secure, and preserved state. On March 22, 2022, PG&E notified the agencies that the IM-3 treatment system is officially in lay-up mode.

Phase 2 remedy construction commenced on March 2, 2022 and includes additional wells (located in Bat Cave Wash/East Ravine/ the Station, on the Transwestern Bench, and along historic route 66), and pipelines connecting the additional wells as well as a pipeline connecting the previously installed Riverbank (RB) wells. For the current schedule of construction activities click here.

SOIL:  Historical Compressor Station operations have resulted in soil contamination inside and outside the Station boundaries. Soil investigation activities and an assessment of potential risk to human health and the environment have been conducted. A draft summary report of the Soil Investigations and recommendations was submitted in May 2021 for agencies’ review. Revision of the report based on the comments received is underway, and a final report is anticipated in early 2023. The information in the report will assist decision-making regarding the need for soil remediation.

Areas where contamination either has impacted or may potentially impact federal lands were identified through the soil investigation and the Human Health and Ecological Risk Assessment. As a result, DOI contemplated a potential removal action for the protection of the Havasu National Wildlife Refuge. On October 30, 2018, DOI directed PG&E to prepare a Draft Engineering Evaluation/ Cost Analysis (EE/CA). The purpose of an EE/CA is to evaluate the need for a non-time critical removal action (NTCRA) on federal lands or at locations where contamination has the potential to migrate to federal land. The public comment period for the EE/CA occurred from June 3, 2020 to August 5, 2020. DOI responded to comments received on April 23, 2021 and directed PG&E to revise the draft EE/CA. The final EE/CA can be found here. DOI prepared and approved a decision document, called an Action Memorandum, for the NTCRA, on October 12, 2021. The Action Memorandum, along with a Responsiveness Summary and the Final EE/CA can be found here

In the Action Memorandum, DOI directed PG&E to prepare a work plan to conduct the NTCRA. A draft plan was submitted in October 2021 for DOI’s review. DOI solicited comments on the draft work plan from DTSC, Tribes, and stakeholders. Comments meetings were held in April and May 2022 to discuss the responses. A final Soil NTCRA Work plan was submitted on June 17, 2022. The final work plan can be found here. The Response to Comments Table can be downloaded here. DOI approved the final Soil NTCRA work plan on June 27, 2022.

PG&E commenced the EE/CA soil removal action on July 25, 2022.

This website provides an overview of current Site activities and other Site-related information. Information on this website includes:

  • PG&E Topock Compressor Station Site location and history
  • Investigation and cleanup activities: past, present, and future
  • Groundwater remedy construction activities
  • Public involvement information
  • Cleanup-related technical reports and work plans