• 2013-2017:
    • A draft memorandum titled Ambient Study of Dioxins and Furans at the Pacfic Gas and Electric Company Topock Compressor Station, Needles, California was submitted on July 20, 2017 for comment. DTSC, FMIT, and the Hualapai Tribe submitted comments. DOI considered all comments and directed PG&E to revise the memorandum, which was re-submitted to DOI on October 13, 2017. DOI approved the revised memorandum on November 16, 2017.
    • Soil sampling and related Soil Investigation field work were completed between December 2015 and March 2016. That work fulfilled requirements of the Topock Soil Facility Investigation/Remedial Investigation (RFI/RI) Work Plan and Data Gap Work Plans #1 and #2. The Data Gaps Work Plan #1  was submitted January 13, 2016 and approved by DTSC on February 2, 2016. The Data Gaps Work Plan #2  was submitted February 12, 2016 and approved by DTSC on March 1, 2016. The DGWP #3  was submitted September 21, 2016 and approved by DTSC on November 10, 2016. DOI conditionally approved DGWP #3 on November 9, 2016. Soil sampling and related Soil Investigation field work was completed between December 2015 and March 2016, January through March 2017, and the latter part of April 2017.
    • A Final Decommissioning Plan for Topock Compressor Station Well Number 4 (TCS-4)  was submitted on December 7, 2015. DTSC provided concurrence on December 15, 2015 . PG&E completed the decommissioning of well TCS-4 in March 2016 and submitted the TCS-4 Well Decommissioning Report on June 7, 2016.
    • The California Department of Toxic Substances Control (DTSC) invited the public to review and comment on the Draft Subsequent Environmental Impact Report (Draft SEIR) for the Pacific Gas & Electric Topock Compressor Station Final Groundwater Remediation Project. The Notice of Availability can be viewed here and the Notice of Completion can be viewed here.
    • The Draft SEIR evaluates potential environmental impacts resulting from design details of the selected groundwater remedy. You can view the guide to the Draft SEIR and associated documents here. DTSC was accepting comments during a 47-day public comment period on the Draft SEIR from January 12, 2017 to February 27, 2017. The comment period has ended; all comments were considered and responded to in the Final SEIR.
    • Public meetings to learn more about the environmental issues addressed in the Draft SEIR were held in Needles, CA on January 31, 2017, and Golden Shores, AZ on February 1, 2017. An ad and flyer announcing the public meetings were posted.
    • PG&E submitted the Final (100%) Basis of Design Report and the Final Construction/Remedial Action Work Plan to DTSC and DOI on November 18, 2015.
    • DTSC filed a determination and certified the Final Soil EIR on August 24, 2015 along with the approval of the Final Soil RFI/RI Work Plan. DOI also approved the Soil RFI/RI Work Plan on August 24, 2015. PG&E began the soil field investigation on October 29, 2015 and completed it in April 2017.
    • The Risk Assessment Work Plan Addendum II, which contains updated information relevant to the evaluation of soil contamination, was approved on August 31, 2015 (clarified on September 15, 2015) by DTSC and on September 8, 2015 by DOI.
    • DTSC determined that the preparation of a Subsequent EIR was required to evaluate potential environmental impacts resulting from design details of the selected groundwater remedy (in situ Treatment with Freshwater Flushing) that were added or modified since the approval of the conceptual Groundwater Remediation Project in the 2011 Final Groundwater Remedy EIR and the 2013 Addendum to the EIR. In May 2015, DTSC issued a formal Notice of Preparation to prepare a Subsequent EIR for the groundwater remedy, and held a series of EIR scoping meetings on May 19 and 20, 2015. The public comment period began on May 5 and ended on June 4, 2015. All comments received were incorporated into the draft Subsequent EIR for the groundwater remedy for additional public review and comment.
    • A Final Soil RFI/RI Volume I Addendum that updated Site information was submitted on April 28, 2014. DTSC and DOI accepted the Addendum on June 4 and July 8, 2014, respectively.
    • PG&E and the DOI executed a Remedial Design/Remedial Action Consent Decree under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) in 2012, which was lodged with the U.S. District Court for the Central District of California in January 2013, and became effective upon approval by the court in November 2013.
    • DTSC filed a determination and certified an Addendum to the Groundwater EIR on September 4, 2013 along with the approval of the Final Implementation Plan for Evaluation of Alternative Freshwater Sources in the Topock Remediation Project Area. DOI also approved the Final Implementation Plan. Field work began on October 2, 2013. A summary report was included as an appendix in the Pre-Final 90% design.
  • 2010-2012:
    • Field activities were performed from December 2009 through December 2010 in compliance with the Time-Critical Removal ActionA time sensitive action to stabilize and mitigate the threat of release of contaminated material. It is not intended to substitute for any remedial activities or be the final remedy. (TCRA) Work Plan. During this time, approximately 11,800 tons of waste material was removed from the Area of Concern (AOC) 4 Debris Ravine. On March 15, 2011, Pacific Gas and Electric Company (PG&E) completed the Implementation Report for the TCRA at AOC 4.
    • The U.S. Department of the Interior's (DOI’s)The United States department charged with conservation and development of natural resources. The U.S. Department of the Interior uses sound science to manage and sustain America’s lands, water, wildlife, and energy resources, honors our nation’s responsibilities to tribal nations, and advocates for America’s island communities. Record of Decision and the Department of Toxic Substance Control's (DTSC’s)The department within the California Environmental Protection Agency in charge of the regulation of hazardous waste from generation to final disposal. DTSC oversees the investigation and cleanup of hazardous waste sites. Notice of Remedy Selection were completed in December 2010 and January 2011, respectively.
    • DTSC certified the Final Environmental Impact Report (EIR) for the proposed groundwater remedy decision on January 31, 2011.
    • The Corrective Measures Implementation/Remedial Design Work Plan was completed in November 2011 and approved by DOI.
  • 2005-2009:
    • In 2005, PG&E entered into a voluntary Consent Agreement with the DOI to perform corrective actions and response actions as a result of Site contamination.
    • DTSC and DOI approved the Corrective Measures Study/Feasibility Study Work Plan in June 2008.
    • In compliance with the Corrective Action Consent Agreement (CACA)A voluntary agreement between a lead agency and responsible party in which the company commits to investigate the nature and extent of contamination at and surrounding a site governed by Resource Conservation and Recovery Act (RCRA), and to take corrective action. and the DOI Consent AgreementA legally binding contract between a lead agency and responsible party that serves to resolve an environmental violation through an administrative settlement agreement rather than through a court action., data collected during environmental investigations are summarized in a three-volume Final Resource Conservation and Recovery Act (RCRA)A 1976 amendment to the first federal solid waste legislation, the Solid Waste Disposal Act of 1965. In RCRA, Congress established initial directives and guidelines for U.S. EPA to regulate and manage solid waste, including hazardous waste. RCRA established a regulatory system to track hazardous substances from the time of generation to final disposal. The law requires safe and secure procedures to be used in treating, transporting, storing and disposing of hazardous wastes. RCRA was designed to prevent new, uncontrolled hazardous waste sites. Facility Investigation/Remedial Investigation (RFI/RI)An investigation that occurs in the corrective action process following a Facility Assessment under RCRA and/or a Site Inspection under CERCLA. It is an in-depth study designed to gather data needed to determine the nature and extent of contamination at a site. Report. The RFI/RI Volume 1 - Site Background and History was completed in August 2007, and an addendum was submitted in 2013. The RFI/RI Volume 2 - Hydrogeologic Characterization and Results of Groundwater and Surface Water Investigation was completed in February 2009. An addendum to the RFI/RI Volume 2 Report was completed in June 2009. Both were approved by DTSC and DOI.
    • DTSC and DOI approved the Risk Assessment Work Plan in February 2009, and provided concurrence on the Groundwater Risk Assessment report in December 2009.
    • The Final Groundwater Corrective Measures Study/Feasibility Study Report for Solid Waste Management Unit (SWMU) 1/ AOC 1 and AOC 10 Chromium in Groundwater was completed in 2009. DTSC and DOI approved the report on December 18, 2014 and December 17, 2014, respectively.
    • On June 24, 2009, DOI directed PG&E to implement a TCRA through the issuance of the AOC 4 Debris Ravine TCRA Memorandum. Work planning and consultation for the removal activities immediately ensued, and DOI approved PG&E’s Work Plan on December 15, 2009.

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