PFAS 101

Overview of CERCLA

The Department of Defense (DoD) conducts investigations and takes action under the federal cleanup law - the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980, also known as “Superfund” - at active military installations, Base Realignment and Closure (BRAC) locations, and National Guard facilities where there are known or suspected DoD PFAS releases. Following CERCLA, DoD fully investigates releases and determines the appropriate cleanup actions based on risk. These investigations include assessing potential off-installation migration and potential impacts of these releases.

The CERCLA Process

DoD’s plan for cleanup consists of following the CERCLA process to investigate releases, prioritize responses, and determine appropriate cleanup actions based on risk to human health and the environment. The process ensures that facilities take and document a consistent, systematic, and thorough approach to investigate and cleanup releases. As DoD moves through the CERCLA process, it works in collaboration with regulatory agencies, communities, and other stakeholders to ensure open and transparent information sharing. The Defense Environmental Restoration Program (10 U.S. Code §§ 2700-2711) provides authorities to DoD to perform and fund these actions and requires that they be carried out in accordance with CERCLA. The steps in the CERCLA process include the following:

At any point during the process above, DoD may identify a site where contaminants must be addressed quickly to prevent, minimize, or mitigate damage to public health or welfare or to the environment. These responses can include short-term actions called “removal” or “interim” actions. Typically, a removal action does not provide a final response action, and the site will continue through the CERCLA remedial process after completion of the removal action.

DoD tailors the actual sequence, timing, and scope of cleanup actions to site-specific conditions. Additionally, the Department prioritizes resources and addresses sites where risk to human health is the highest. CERCLA takes time and each site has different characteristics that affect the timeframe of the cleanup (e.g., type of soil, depth to groundwater, concentration of chemicals in the groundwater). The timeline may change as investigations are completed and more is known about the sites as it collects information on the nature and extent of the releases, emerging chemicals are discovered, or regulatory standards change.

Click Each Phase Title Below to Expand a Quick Summary of the CERCLA Process

A Preliminary Assessment (PA) includes a historical record search and interviews with DoD employees who have historical knowledge of the operations that may have contributed to a potential release. The information collected from the record search and the interviews helps DoD determine whether there is a potential historical release and if further investigation is warranted.

The Site Investigation (SI) includes a physical inspection of the site with a small sample of soil, sediment, surface water and groundwater testing to determine whether there is evidence of a release and if further investigation is warranted.

Typically, the information collected during the PA and SI phases is combined into a single document – DoD drafts the report, provides a copy to regulators for review, and makes the final report available to the public in the information repository located at or near the cleanup site.

Consistent with the CERCLA process, DoD uses EPA’s Regional Screening Levels (RSLs) in DoD environmental cleanup investigations. These screening levels are used during the preliminary assessment/site inspections (PA/SI) to determine if further investigation in the remedial investigation (RI) phase is warranted or if no further action is required. PFAS analytes with RSLs derived from final, peer reviewed toxicity values that DoD will use for CERCLA screening levels and risk assessments are updated regularly and can be found here.

For sites moving to the RI phase, DoD uses the data it gathered during the PA and SI to prioritize further action. DoD follows the federal cleanup law, which includes prioritizing sites for cleanup using a risk-based process – essentially, “worst first.” Therefore, DoD addresses sites that pose a greater potential risk to human health or the environment before it addresses sites posing a lesser risk.

The RI collects detailed information through field investigations. This investigation includes determining the nature and extent of the release to answer “how much”, “how far”, and “from where.” This phase also looks at all potential exposure pathways including air, soils, surface water, groundwater, plants, and animal life.

If the chemicals from a release at a site are below the unacceptable risk level, no further work is required. If testing results are found to be an unacceptable risk to human health and the environment based on EPA’s risk assessment policies, then DoD will conduct a Feasibility Study. A Feasibility Study (FS) evaluates the potential cleanup alternatives and selection of a proposed remedy based on the nature and extent of the release determined in the RI phase. These two phases are often combined into a single document. In addition, a Proposed Plan (PP) is developed as part of this phase to summarize the findings of the RI/FS, identify which of the potential cleanup alternatives is the selected remedy, and summarize any formal comments received from supporting agencies. After the completion of the PP, and the opportunity for public comment, DoD selects the remedy in the decision document (a Record of Decision [ROD]). In the decision document, DoD identifies the final selected cleanup remedy and the cleanup level it is working to achieve, and considers public comments and community concerns. DoD provides the decision document to regulators for review. For sites on EPA’s National Priorities List, DoD must obtain regulatory concurrence on the decision document.

During the Cleanup phase, DoD develops the remedial design (RD) plans and specifications of the selected cleanup remedy in the decision document, which regulators review, and then constructs or implements the selected cleanup remedy. DoD documents that it has constructed and installed the remedy and provides this documentation (remedial action – construction) to the regulators. The RD/RA-C process typically takes approximately two to four years to complete.

After constructing the remedy, DoD operates, maintains, and monitors the cleanup system and site until it achieves the cleanup level(s) in the decision document. The RA-O phase may also include implementation, management, and maintenance of land use controls (LUCs) and may take from 1 to 30 or more years to complete, or in some cases may continue in perpetuity. During this time, DoD optimizes the systems, ensures the systems are operating properly, performs sampling to monitor progress, and verifies that the sites are protective of human health and the environment. When the remedy has been constructed and is operating as planned to meet cleanup objectives, the site is said to have the Remedy In Place (RIP).

For sites where the cleanup objectives have been met, the site is deemed “response complete.” The Department measures cleanup progress against the Response Complete milestone, which occurs when cleanup activities are complete and DoD has documented this determination and sought regulatory agreement (although DoD or a subsequent landowner may continue to monitor the site).

Even after cleanup goals are met, some sites may not permit unrestricted land use; in those situations, monitoring may be required to determine and demonstrate the long-term protectiveness of the remedy. The Long Term Management (LTM) phase is required when the cleanup levels do not allow unrestricted use of the property. Actions during this phase may involve monitoring site conditions, implementing and managing Land Use Controls (LUCs), and performing five-year reviews. DoD closes out a site only when there is no future environmental liability at the site (i.e., when cleanup goals have been achieved that allow for unlimited use and unrestricted exposure). However, not all sites can achieve unlimited use and unrestricted exposure; some may remain in the LTM phase in perpetuity.