What's New

Soil Risk Assessment and RFI/RI Report Completed

The human health and ecological risk assessment (HHERA) for soil began on June 20, 2017 upon completion of the soil investigation field work. The HHERA assessed potential human health and ecological risks based on soil sampling data. This information will assist risk management decisions on the need for soil remediation, if any. The Soil HHERA report was submitted to agencies on October 18, 2019, and an errata was submitted on February 19, 2020. The Soil Risk Assessment Report plus errata were approved on May 29, 2020. The report can be downloaded here.

Findings and conclusions of the soil investigation field work and the conclusions from the Risk Assessment are presented in the Soil Resource Conservation and Recovery Act (RCRA) Facility Investigation/Remedial Investigation (RFI/RI) Report (also called the RFI/RI Volume 3 Report). PG&E submitted a revised Soil RFI/RI Volume 3 report on May 31, 2021 for review and comment. Comments were received and meetings were held to resolve responses to comments. A final RFI/RI Volume 3 Report based on resolution of comments received was completed and submitted to DTSC and DOI on October 2, 2023. DTSC accepted the final report on June 10, 2024. DOI provided concurrence with DTSC’s acceptance on June 25, 2024. The final RFI/RI Volume 3 Report can be downloaded here.

Phase 2 of Construction of the Final Groundwater Remedy Continues and the Remedy is Operating

Click here for the current construction activities. 

Implementation of the Final Groundwater Remedy will adhere to the Final Groundwater Design. The conditional approvals of the final design can be viewed here. The Final Groundwater Remedy Design document can be downloaded here.

Phase 1 of remedy construction, which began on October 2, 2018, is now complete. It includes the National Trails Highway (NTH) In-situ Reactive Zone (IRZ) with 42 remediation wells (for 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 68,000 linear feet of water conveyance piping and 46,000 feet of electrical conduits that connect the remediation wells to the power supply system, the carbon amendment building, and the produced water conditioning system.

All systems and components were integrated and tested. On December 22, 2021, PG&E turned on the NTH IRZ remedy treatment system. Water level and groundwater chemistry are closely monitored and adjusted to ensure the best possible treatment conditions. PG&E and the regulatory agencies will continue to monitor and adjust the operation of the NTH IRZ.

In parallel, PG&E commenced Phase 2 of construction in March 2022, as shown in the summary schedule which can be downloaded here.

First Five-Year Review of Groundwater Remedy Completed

Under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), the U.S. Department of the Interior (DOI), in cooperation with the California Department of Toxic Substances Control (DTSC), has completed the Five-Year Review process that reviewed the groundwater remedy implemented at the Topock Compressor Station in San Bernardino County, California.

The selected remedy for groundwater includes the use of in-situ treatment with fresh water flushing for groundwater contamination associated with Solid Waste Management Unit (SWMU) 1/Area of Concern (AOC) 1 and AOC 10.

The purpose of the Five-Year Review is to ensure that the implemented remedy functions as intended and is protective of human health and the environment. Five-Year Reviews will continue for the life of the site until hazardous substances, pollutants, or contaminants no longer remain on site at levels that do not allow for unlimited use and unrestricted exposure.

The Public Notice of Completion can be found here.

The First Five-Year Review on the Groundwater Remedy can be found here.

Termination of Interim Measure (IM) No. 3

PG&E turned off the IM extraction wells on December 21, 2021, concurrently with the start of the groundwater remedy injection. The IM-3 treatment system has been placed in lay-up mode since March 22, 2022. When the IM-3 treatment system is in a lay-up condition, the system is cleaned and kept in a safe, secure, and preserved state and will not operate again until agency approval for decommissioning and removal of the system is provided.

Consultative Workgroup (CWG) Meeting

The Consultative Workgroup (CWG) is a specific group of key governmental agencies, stakeholders and Tribes established in 2000 to facilitate participation in the Site investigation and remediation process. In 2023, CWG meetings were held on May 9 and December 5, 2023.

Technical Workgroup (TWG) Meeting

The Technical Workgroup (TWG) was established as a subgroup of the Consultative Workgroup (CWG) for technical experts to deliberate on various scientific aspects of the Project and remediation issues as needed. In 2023, TWG meetings were held in person on May 9, July 11, August 8, and December 5, 2023, and a virtual meeting was held on September 7, 2023.

Clearinghouse Task Force (CTF) Meeting

The CTF is a small group of representatives from State and Federal agencies, key stakeholders, and Tribes. The focus of the CTF is to strategize and develop processes and tools to improve communications and enhance stakeholder understanding of Project and regulatory information. CTF meetings generally occur as needed throughout the year.

DTSC March 2023 Fact Sheet Available

DTSC provides periodic updates on the progress of the site investigation and cleanup efforts in periodic Community Updates/ Fact Sheets. The DTSC March 2023 Fact Sheet - Community Update for the PG&E Topock Compressor Station is available for viewing here.

Soil Non-Time Critical Removal Action (NTCRA) Completed

On October 30, 2018, U.S. Department of the Interior (DOI) directed PG&E to prepare a Draft 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 in soil has the potential to migrate to federal land. A fact sheet on the EE/CA can be found here. The public comment period for the EE/CA occurred from June 3, 2020 to August 5, 2020. In parallel, consultation with nine Native American Indian Tribes (Tribes) occurred through August 21, 2020. DOI issued responses to comments on April 23, 2021 and directed PG&E to finalize the EE/CA. The final EE/CA can be found here. 

On October 12, 2021, DOI selected a removal action of excavation of contaminated soil and debris at target action areas within the Topock Site. The removal action consists of mechanical separation/size separation of rocks, debris, and soil; and disposal of the contaminated soil and debris in approved and permitted landfills. DOI’s decision is documented in an Action Memorandum, which can be downloaded here. Subsequently, on October 29, 2021, PG&E submitted a draft Soil NTCRA work plan to present details about PG&E’s plan to perform the removal action. The work plan was sent to the Consultative Working Group (CWG) for review and comment. In parallel, BLM consulted with the Tribes on the draft work plan. Comments were received in December 2021. DOI issued responses to comments in March 2022, and directed PG&E to finalize the Soil NTCRA Work Plan in May 2022. The final Soil NTCRA Work Plan can be found here. The Response to Comments Table can be downloaded here. DOI approved the Soil NTCRA Work Plan on June 27, 2022.

PG&E commenced the NTCRA soil removal action on July 25, 2022. Work was completed in February 2024 and approximately 34,706 cubic yards of contaminated soil/debris was removed.