The Corrective Action Process being followed at the Pacific Gas and Electric Company (PG&E) Topock Compressor Station (Station) and project Site (Site) was established by the Resource Conservation and Recovery Act (RCRA) of 1980 and the Hazardous and Solid Waste Amendments of 1984, collectively known as RCRA. This act regulates generators of hazardous waste and hazardous waste treatment, storage, and disposal facilities. The Corrective Action Process requires the cleanup of contamination at RCRA-governed facilities. Facilities that treat or store hazardous substances as a part of normal operations, and where a hazardous substance has been released into the environment as a result of past or present facility operations, fall under the regulation of RCRA. To ensure cleanup remedies are appropriate for a particular site, the Corrective Action Process includes steps to evaluate the nature and extent of the hazardous substance release and to identify, develop, and implement appropriate corrective measures to protect public health and the environment.

Under the RCRA Corrective Action Process, the California Department of Toxic Substances Control (DTSC) must: (1) determine the extent of the contamination, (2) determine what should be done to clean it up, and (3) take steps to clean it up.

Cleanup activity at the Site is also must follow the process set forward by the Comprehensive Environmental, Response, Compensation and Liability Act (CERCLA), also known as the Superfund Law. CERCLA was created to fund cleanup of hazardous sites. The Corrective Action Process under CERCLA includes steps similar to the RCRA process described above.

Corrective Action Steps and "Milestones"
The Corrective Action Process can be broken down into steps, also known as "milestones," through which a project progresses toward a final cleanup action or remedy. Please see the RCRA Corrective Action Steps and Milestones figure to the right. Corrective action steps may include:

• Preliminary review (PR) of pertinent existing information.
• Visual site inspection (VSI) to verify preliminary information about the site and develop sampling strategy if needed.
• Sampling visit (SV) to gather limited field data, if necessary.
• RCRA Facility Assessment (RFA) to document areas that may be contaminated and to identify constituents of concern. The RFA was submitted to the DTSC in August 1987. The RFA is available on the RFA page of the Document Library.
• RCRA Facility Investigation (RFI) /Remedial Investigation (RI) to determine the nature and extent of contamination. Visit the RCRA Facility Investigation page to obtain more information about the Draft RFI Report and the RFI/RI page of the Document Library to view available documents.
• Human and Ecological Risk Assessments to evaluate potential risks to humans, plant and animal species.
• Corrective Measures Study/Feasibility Study (CMS/FS) to develop and evaluate alternatives that can be used to address the contamination. Visit the CMS/FS page to learn more about the CMS/FS process.
• Statement of Basis that describes the basis for DTSC’s proposed remedy and cleanup standards.
• California Environmental Quality Act (CEQA) documentation evaluates potential impacts of the proposed cleanup action.
• Final Remedy Selection, in which DTSC considers public comment and selects a final cleanup strategy.
• Corrective Measures Implementation of the selected remedy.
• Corrective Action Certification, in which the action is deemed complete.

Another step in the Corrective Action Process, Interim Measures (IM), can be implemented at any point in the process (usually prior to selection of a final remedy) if immediate action is deemed necessary to control or eliminate a release or potential release at or from a facility.

These steps typically occur, to one degree or another, during most cleanups. No one approach to implementing these cleanup steps is likely to be appropriate for all corrective action sites. Therefore, a successful corrective action program must be procedurally flexible. In addition, these steps are not ends in themselves. The focus is on the results of the cleanup rather than a mechanistic cleanup process.

Corrective action activities are being conducted at PG&E’s Topock Compressor Station under a voluntary agreement between PG&E and DTSC. This agreement is known as the Corrective Action Consent Agreement (CACA) and was finalized by PG&E and DTSC on February 26, 1996. PG&E is subject to the RCRA Corrective Action Process because past Station operations resulted in hexavalent chromium contamination in groundwater, called a plume, which extends from underneath the Station to underlie neighboring federal lands. PG&E is following the RCRA Corrective Action investigation and cleanup process described above. To learn about current corrective action activities being conducted at the Site, please visit the RCRA Facility Investigation or the Interim Measures pages on the website.