Nearly eight decades after per- and polyfluoroalkyl substances (PFAS) first appeared in industrial and consumer products, the U.S. Environmental Protection Agency (EPA) published a PFAS Strategic Roadmap. The roadmap describes the Agency’s plan to expand its investment in research and innovation, limit further PFAS release into the environment, and accelerate cleanup of PFAS-impacted sites. In April 2024, the EPA designated perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or Superfund). With this designation, a site could be included on the National Priorities List (NPL) for PFAS alone, and PFAS could be investigated at existing Superfund sites, including sites in the five-year review (FYR) process.
Addressing contamination at Superfund sites is a complex multi-phase process, which begins with NPL placement and is generally followed by remedial investigation, feasibility study, remedial design, and action. Then, under the best circumstances, sites can be deleted from the NPL. More often, hazardous substances remain at the site after cleanup and limit future potential use. In this case, the site remedy is reviewed every five years under the FYR process. Since FYRs occur post-remedy and can continue for decades, they are subject to changing regulations, such as the listing of new contaminants as CERCLA hazardous substances.
Records available via EPA’s PFAS Analytic Tool reveal that PFAS have been detected at Superfund sites in the FYR process since at least 2003. This first reported PFAS detection occurred at a Minnesota Superfund site that historically received waste from a PFAS manufacturing facility. Until 2016, few sites in the FYR process reported new PFAS detections. Then, from 2016 through 2019, the number of sites with new PFAS detections increased; a likely result of the publication of Lifetime Health Advisories for PFOA and PFOS. We anticipate a similar spike in PFAS detections at Superfund sites in the FYR since PFOA and PFOS are designated as hazardous substances, though it is not yet evident in data available in the PFAS Analytic Tool. Nonetheless, trends regarding PFAS at Superfund sites in the FYR process can be gleaned from this tool.
At the close of 2024, PFAS detections had been reported at nearly 450 Superfund sites, with almost 70 percent of those detections occurring at private sites and the remaining detections at federal sites. The majority of these first-time detections occurred at sites in the FYR process. Furthermore, PFAS were first detected at sites that were new to the FYR process as well as at sites that had been in the FYR process for as long as seven review cycles (i.e., thirty-five years). At these sites, a responsible party may have mistakenly believed that the investigation and feasibility stages of the Superfund process were behind them, and correspondingly so was a period of unexpected and large expense.
The most common operations involving PFAS at FYR sites were waste disposal in landfills and aqueous film-forming foam storage/use, followed by a variety of manufacturing processes, including metal plating, and chemicals storage. As expected, PFAS detections were most often reported in groundwater.
Of the hundreds of Superfund sites with PFAS first detected during the FYR process, only a handful have seen PFAS formally added as a contaminant of concern (COC). Nevertheless, remediation specifically targeting PFAS is ongoing in at least eight of the sites in the FYR process. At some of these sites, the existing treatment systems intended to remediate other COCs were adequately addressing PFAS or required only minor adjustments to address PFAS. Other sites have had to install treatment systems (e.g., granular activated carbon (GAC), ion exchange systems, and point of entry (POET) systems at residences) to address impacts to municipal or private drinking water supplies.
If the approach taken by the outgoing administration continues, then we expect that more Superfund sites in the FYR process will measure and detect PFAS in the near-term due to the April 2024 designation of PFOA and PFOS as hazardous substances. Moreover, this increase may be sustained by the inclusion of additional PFAS as hazardous substances. Such a designation would follow the January 3, 2025, final rule that added nine PFAS to the Toxic Release Inventory (TRI) program bringing the total count of PFAS in the TRI program to 205. Responsible parties may consider expanding the suite of PFAS measured at a site to avoid future testing and potential remediation against the possibility of creating unnecessary liability. Significant uncertainty remains as the new administration may push to overturn the designation of PFOA and PFOS as hazardous substances or decline to enforce policy.
