Addressing PFOA and PFOS in the CERCLA Program

Much has been written about the potential implications of the Environmental Protection Agency’s (EPA) recent designation of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS)—including their salts and structural isomers—as hazardous substances pursuant to section 102(a) of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). The April 2024 regulation, which amends Table 302.4 of 40 CFR part 302 (List of Hazardous Substances and Reportable Quantities), will have impacts on a wide range of CERCLA-related actions, including: real estate transactions; addressing Reportable Quantity releases under CERCLA Section 103(a) and Emergency Planning and Community Right-to-Know Act (EPCRA) Section 304; private party litigation; newly identified Potentially Responsible Parties (PRPs) and the need to address newly identified sites where PFOA/PFOS (and other PFAS) were used/disposed; CERCLA sites where PFOA/PFOS have not been previously investigated; and sites where Record of Decision (ROD) actions have been completed, but CERCLA obligations are still active. 

This article focuses on the CERCLA actions that should be anticipated by PRPs at new and existing CERCLA sites due to the recently issued PFAS hazardous substances regulation. It is important to note that EPA has been continually updating regulations, guidance, and policy related to PFAS, so the potential actions discussed below may be superseded by future EPA actions.   

Newly Identified Sites

For the purpose of this article, newly identified sites are those that have not been previously assessed under the CERCLA program. This may include sites where a release was reported under CERCLA Section 103(a), or sites identified by other entities like citizens and other state or federal environmental programs. We expect EPA to follow the process below in assessing newly identified sites. 

EPA will likely use its existing/formal Pre-CERCLA Screening process to determine if a site qualifies for further action under the CERCLA program. It is also assumed EPA will use its

PFAS Enforcement Discretion and Settlement Policy Under CERCLA (April 2024) in making determinations regarding CERCLA applicability. If it is determined that PFOA or PFOS require further assessment, EPA will likely follow its pre-remedial process of conducting a Preliminary Assessment (PA) and, if necessary, a Site Inspection (SI) or Supplemental/Expanded SI followed by a Hazard Ranking System (HRS) score. Thousands of sites across the United States underwent these PA/SIs and HRS scoring over the last 40-plus years, driven by releases of other hazardous substances. Based on these pre-remedial assessments, a site may be proposed for the National Priorities List (NPL), assigned as a Superfund Alternative Approach (SAA) site, or designated as a No Further Remedial Action Planned (NFRAP). Sites may also be referred to EPA’s Emergency Response and Removal Program for more immediate actions.

Non-NPL CERCLA Sites

Even if it is not a NPL or SAA site, a site with PFOA or PFOS considerations may already be on EPA’s Active or Archived CERCLA list. The Proposed Rule (87 FR 54415, September 2022) indicates that 53,400 sites have been assessed under the pre-remedial program (only about 3 percent of which are NPL sites). According to EPA’s Superfund Site Information page, these sites fall into various CERCLA categories including, but not limited to, active and inactive removal sites, sites deferred to RCRA and (mostly) NFRAP remedial sites. To address PFOA or PFOS issues at these Active or Archived sites, EPA will likely follow the PA/SI/HRS process described above or perform a pre-remedial “Site Reassessment,” which can be conducted on Active or Archived CERCLA sites.

Key Items for New and Existing Sites Undergoing Pre-Remedial Assessments

If you are potentially responsible for PFOA and/or PFOS releases at a newly identified site or at an Active or Archived CERCLA site, the following key items need to be considered:

• EPA, or a designated state or other federal agency, will conduct the pre-remedial assessments and inspections, as required by CERCLA.
• The primary objective of EPA’s pre-remedial program is to evaluate HRS scores to determine if a site qualifies for the NPL. Sampling and analysis are biased toward supporting the HRS scoring, not determining the nature and extent of contamination.
• NFRAP sites are entered into EPA’s Active and Archived Site databases under CERCLA but may still end up being investigated/remediated under state, tribal, or municipal programs or other federal programs.
• EPA will consider and assess all potential sources of PFOA and PFOS, including precursor PFAS that may be transformed into PFOA and PFOS, in the pre-remedial assessments. EPA and various other sources have published lists of industries and processes that generate PFAS; expect EPA to assess all potential sources.
• EPA or the designated agency will likely use the most recently approved EPA analytical methods in conducting pre-remedial data collection. For example, EPA recently approved Method 1633 for reporting 40 PFAS in most environmental media samples. You should assume that EPA will assess all PFAS reported by the analytical method. Remember that even if a PFAS is not a hazardous substance like PFOA and PFOA, if the chemical presents an imminent and substantial danger to public health or welfare, that PFAS may trigger CERCLA action.   

Sites on the NPL or Designated as SAA Sites

Much discussion has occurred in industry/regulatory media and amongst industry groups about the implications of the PFOA and PFOS hazardous substance designation on existing NPL and SAA sites, where site investigations/remediation of non-PFAS hazardous substances are ongoing, or remediation has been completed and the remediation costs have already been or are being addressed by a single party or through allocation. While industry representatives have voiced concerns due to additional site characterization/remediation requirements and commensurate costs associated with the PFOA and PFOS hazardous substance designation, the reality is that these hazardous substances will now need to be evaluated at NPL and SAA sites.

EPA has already established that they will not require pre-remedial program assessments on federal facility sites on the NPL. This is documented in the EPA Memorandum entitled, “EPA Guidance Clarifying the Use of CERCLA Remedial Investigations for Scoping Releases and Defining the Nature and Extent of Per- and Polyfluoroalkyl Substance and Other Contamination at Federal Facilities on the National Priorities List” (February 2023). The memo also provides insight into EPA’s plans for privately owned CERCLA sites, where it states: “At privately-owned and fund-lead (“non-Federal”) sites, EPA does not use the PA/SI after NPL listing. Any subsequent site characterization activities at NPL sites are then carried out using the Superfund remedial response process, starting with the RI/FS as described in NCP Section 300.430 and extending as necessary through the five-year review.” In practice, it should be expected that EPA will require an initial assessment, similar to the PA/SI process but part of the Remedial Investigation (RI), to identify potential PFAS release sites. It is again important to remember that EPA will be interested in assessing as many PFAS as analytical technologies will allow, since the list of PFAS needs to be evaluated to determine if they pose an imminent and substantial danger to public health or welfare.  

Thus, if you are a PRP associated with an active, privately owned NPL or SAA site requiring further assessment of PFAS, you should expect a requirement to conduct an RI, potentially followed by a Feasibility Study (FS), supporting remedy selection in a ROD. ROD amendments and Explanations of Significant Differences (ESDs) may also be used by EPA to document a remedial alternative selection to address PFAS, with ESDs considered if the PFAS remedy can be integrated into an existing remedy. Depending on the extent of PFAS in site environmental media, the time line from the initiation of the RI to remedy issuance will be variable but will likely take two to three years. ROD-required Remedial Design/Remedial Action should be anticipated after ROD issuance by the agency.

If you are a PRP associated with a privately owned NPL site or SAA site and are required to address PFOA, PFOS, or other PFAS releases, the following key items will need to be considered:

• Use the most recently approved EPA analytical methods; as discussed above, EPA recently approved Method 1633 for reporting 40 PFAS in most environmental media samples. Also consider that some states are still accepting older methods, and methods specific to certain matrices like drinking water also exist. EPA will expect that the most up-to-date and matrix-applicable analytical methodologies will be employed during the RI/FS process.
• Quality Assurance Project Plans (QAPPs) are an important component in EPA CERCLA actions. A QAPP, or QAPPs, documenting all sampling, analysis, and quality assurance/quality control requirements for PFAS, will need to be prepared to support all steps in the CERCLA process. 
• In the RI/FS process, EPA will expect an assessment of all PFAS reported by the applicable analytical methods.
• As everyone in the industry knows, PFAS-related scientific data, regulations, and policies change regularly. When initially evaluating potential human health impacts, use the most recently issued PFAS screening levels (e.g., the EPA Regional Screening Levels [RSLs], which are updated in May and November each year), and applicable regulatory criteria such as the recent drinking water Maximum Contaminant Levels (MCLs).
• Conduct human health and ecological risk assessments (HHRAs and ERAs) during the RI using the most up-to-date toxicological information available and document related uncertainties. AlterEcho has already evaluated HHRAs and ERAs for sites with PFAS releases; this is an agency expectation.
• Establishment of remediation goals (RGs) for use in FSs and RODs is, and will continue to be, challenging—especially for media like soil and sediment where there are mostly no promulgated standards to establish Applicable or Relevant and Appropriate Requitements (ARARs). As with HHRAs and ERAs, use the most up-to-date toxicological information available, and consider using EPA RSLs for soil and sediment.
• Development of remedial alternatives may also be challenging since many PFAS technologies are still considered to be at the innovative stage of development. However, EPA has specific procedures for evaluating remedial alternatives in the FS process (based on National Contingency Plan [NCP] requirements). These procedures are well established in RI/FS guidance and will need to be followed.

CERCLA site “re-openers” are one final key area of concern that have received considerable discussion in industry/regulatory media and amongst industry groups. CERCLA and the NCP require that actions that result in any hazardous substances, pollutants, or contaminants remaining at the site above levels that allow for unlimited use and unrestricted exposure be reviewed every five years to ensure protection of human health and the environment. (It should be noted that sites that meet unlimited use and unrestricted exposure criteria do not require these five-year assessments.) EPA’s Five-Year Review (FYR) guidance requires that “new contaminants and/or contaminant sources” be evaluated as part of the FYR technical assessment. PFAS fall into this assessment, and recent FYRs issued by EPA are identifying potential sources, or documented detections of, PFAS, as issues with commensurate recommendations in the FYR report. Similar to the discussion above on pre-remedial assessments, it is likely that EPA will evaluate all potential sources of PFOA, PFOS, and other PFAS at a site. Once PFAS have been identified as potential issues, it is likely that they will need to be characterized as part of the site’s long-term monitoring systems or in an RI, with impacts to human health and the environment potentially assessed through an HHRA and ERA, as discussed previously.

If the further site characterization or RI identifies the need to assess remedial alternatives to address PFOA, PFOS, and other PFAS, the CERCLA process described above will need to be followed.