Overview of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Process

The objectives of the CERCLA process are to evaluate the nature and extent of contamination at a site and to identify, develop, and implement appropriate remedial actions (RAs) in order to protect human health and the environment. The page describes the mejor elements of the CERCLA process.

The CERCLA process begins site studies with a Preliminary Assessment/Site Investigation (PA/SI) to distinguish between sites that pose little or no threat to human health or the environment and sites that may pose a threat and require further investigation. This stage involves a review of historical documents and a visual site inspection. If the PA results in a recommendation for further investigation, a Site Investigation (SI) is performed. During the SI media samples (such as water and soil) are collected to confirm or deny the presence of potentially hazardous substances.

Based on the results of the PA/SI, a Remedial Investigation (RI) may be needed at a site. An RI is designed to learn more about the site contamination and determine if any known contamination is leaving (i.e., migrating from) the site. During this phase, samples are usually collected from the soil, groundwater, surface water (such as creeks or lakes), soils and sediments. The resulting data provides information about the extent of possible contamination and rate of migration, if applicable.

A Feasibility Study (FS) may be conducted concurrently with the RI. The data collected in the RI influence the development of remedial (i.e. cleanup) alternatives able to meet the environmental standards, considering factors such as the degree of contamination and potential human health and environmental risks. A variety of remedial methods are considered, including the “No Action” alternative. Next, a Proposed Plan (PP) is presented, outlining several feasible or likely alternatives and recommending the preferred remedial method.

The public has an opportunity to comment on the PP during an announced formal public comment period. Site information is compiled in an Administrative Record and placed in the general IRP Information Repositories established at local libraries for public review. The public comments are reviewed and the responses are recorded in a document called a Responsiveness Summary. At the end of the public comment period an appropriate remedial alternative is chosen to protect human health and the environment. The Record of Decision (ROD) document is issued that explains the selected remedial action and includes the Responsiveness Summary.

The final stage in the process is the Remedial Decision/Remedial Action (RD/RA).  The RD phase is where the technical specifications for cleanup remedies and technologies are designed. The RA is the actual construction or implementation phase of the cleanup process.