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PFAS and the Transition to the Biden Administration: The Implications of Designating PFOA and PFOS as “Hazardous Substances” Under CERCLA

In recent years, there has been no shortage of interest and commentary dedicated to a group of chemicals known collectively as PFAS. As one example, the potential designation of certain PFAS — PFOA and PFOS (perfluorooctanoic acid and perfluorooctanesulfonic acid, respectively) — as “hazardous substances” under the Comprehensive Environmental Response, Compensation, and Liability Act (“CERCLA” or “Superfund”) continues to attract attention in both the regulatory and political arenas and, if such designation occurred, would present significant impacts to industries and companies alike. This article explores those potential effects.

Recent Indicators That EPA May Take Action to Designate PFOA and PFOS as “Hazardous Substances”

  • February 2019: EPA published its PFAS Action Plan in which it explained that it was “moving forward with how best to designate PFOA and PFOS as CERCLA ‘hazardous substances’ using one of the available statutory mechanisms.” EPA defended the proposal by claiming that a “hazardous substance” designation under CERCLA provided additional options for the federal government “to facilitate use of response and enforcement authorities.”
  • February 2021: EPA provided a program update and explained that it was still moving forward with the regulatory process for proposing designation of PFOA and PFOS as “hazardous substances” under CERCLA.
  • Campaign Trail: President Biden indicated his administration’s commitment and prioritization of tackling PFAS pollution by, among other things, “designating PFAS as a hazardous substance.”
  • January 2021: The Congressional PFAS Task Force sent the Biden administration a letter suggesting that he “[d]irect EPA to immediately designate two types of PFAS, PFOA and PFOS, as ‘hazardous substances’ under CERCLA and to revise groundwater clean-up standards” for such chemicals. A total of 132 Republican and Democratic members of Congress signed the letter.
  • March 2021: Michael Regan, the new head of EPA, in his first keynote address highlighted PFAS as an area where EPA will take further action.

Legal Background

CERCLA is a strict, joint-and-several liability regime for addressing hazardous substances in the environment. Any person held liable for a CERCLA site can potentially be held responsible for all cleanup costs. Those who are liable for cleanup costs can include (i) current owners and operators of a facility where hazardous substances have been released; (ii) former owners and operators who owned or operated the facility where hazardous substances were disposed of or released; (iii) generators and those who arranged for disposal of hazardous substances at a facility; and (iv) those who transported hazardous substances for disposal at the facility. Collectively, these four categories are considered potentially responsible parties (“PRPs”).

Although any individual PRP could, in theory, be held liable for the full cost of the cleanup, CERCLA also provides a mechanism where a PRP can recover a proportional share of the costs from other PRPs based on factors such as relative contribution to the contamination and ensuing cleanup costs. As a result, private parties and government entities routinely joust, both in negotiations and litigation, over how to apportion CERCLA site cleanup costs.

PFAS—PFOA and PFOS: What are they and where do they come from?

The term “PFAS” refers to a wide variety of man-made chemicals.  According to EPA, since the 1940s, PFAS have been manufactured and used in a variety of industries in the United States. Products containing PFAS include stain- and water-repellant fabrics, nonstick products, paints, waxes, cleaning products, and fire-fighting foams. PFAS may be found in groundwater or soil, including at or around sites that manufactured or used these products, depending on how their manufacture and use was managed. PFOA and PFOS are the two PFAS that have been the most extensively produced and the most studied. Both are persistent in the human body and the environment as they do not break down, thus accumulating over time.

Challenges of Designating PFOA and PFOS as “Hazardous Substances” under CERCLA

The potential designation of PFOA and PFOS as “hazardous substances” under CERCLA has many implications for industries and companies. At a more general level, there is ongoing debate and continued uncertainty regarding the levels at which the various PFAS, including PFOA and PFOS, pose a risk. Given this, remediation thresholds are difficult to determine. There are also open questions as to what the most effective methods are for addressing PFAS contamination in soil and groundwater and the impact this has upon cleanup choices. As a result, cleanup decisions are likely not only to be site-specific, but also contentious between PRPs.


“Closed” CERCLA Sites: The potential “reopening” of CERCLA sites is a risk following the potential designation of PFOA and PFOS as “hazardous substances.” At such sites, cleanup efforts may have been deemed completed or closed by regulatory authorities, subject only to periodic review and assessment that the remedies are being maintained. But the designation of new hazardous substances could upset those earlier closure decisions. Whether at a new site, or a previously closed site, much will depend on the level at which EPA determines these chemicals pose a risk.

New Sites: Refineries, airports, and military bases are examples of new sites more likely to be designated for cleanup if PFOA and PFOS are listed as “hazardous substances” based on their use of fire-fighting foams (or aqueous film forming foam, “AFFF”). AFFF is used to extinguish flammable liquid fires, such as from fuel spills. The Department of Defense’s use of AFFF to fight fuel fires and the subsequent release of PFAS compounds from training exercises and emergency responses is a major source of PFAS contamination on military bases (or former military bases that have been transferred to private use). Airports face a similar problem: AFFF is used extensively in aviation facilities across the world and, indeed, the U.S. Federal Aviation Administration at one point required that airports train with and use the best performing AFFF fire suppression systems.


If the EPA designated PFOA and PFOS as “hazardous substances” under CERCLA, it could result in an increase in costs at existing Superfund sites that are already undergoing cleanup for other contaminants, to the extent that additional remedial measures are required. Companies that were not originally responsible for hazardous substances at a site other than for PFOA and PFOS may find themselves paying for a share of the entire site costs if the contribution of PFOA and PFOS to the contamination is not divisible. Introducing PFOA and PFOS to CERCLA’s framework could amount to more dollars, more time, and more disputes as to what is required to protect human health and the environment. It could lead to more disagreements around which contaminants are the remedy drivers and more work to clean up those sites for potentially highly marginal or speculative risks due to the lack of data regarding these chemicals.

Designating PFOA and PFOS as “hazardous substances” would also provide the EPA with a mechanism to seek the cost of cleanup from a wider variety of PRPs. Even if the EPA were to fund the work in the first instance, this designation would allow the EPA to ultimately recover costs for the cleanup at many sites. Moreover, there is a risk that Congress could reimpose the Superfund tax on industry if there are too many PFOA- and PFOS-contaminated sites where there are no solvent PRPs to cover the remedial costs. One way or another, industry is likely to bear the lion’s share of the costs to address such contamination.


Given the extensive range of consumer and industrial products that PFOA and PFOS were used in, the number of entities that qualify as PRPs could be quite broad. At some Superfund sites, the PRPs for PFOA and PFOS cleanup will likely overlap with the PRPs for other contaminants present on the same site—for example, historic operators responsible for other hazardous substances may also have introduced PFOA and PFOS. New PRPs responsible for just PFOA and PFOS contamination, however, may also be identified at such sites. Current PRPs will have every incentive to identify such parties and then pursue them for contribution to site cleanup costs. Further, to the extent that the EPA sets new remediation targets for PFOA and PFOS at a particular site, it may have significant implications for the allocation of environmental response costs. As is common in CERCLA litigation, determining the appropriate share of costs for PFOA and PFOS cleanup is likely to involve expensive legal fights and the use of costly experts.


Following any designation of PFOA and PFOS as “hazardous substances,” it is likely that the EPA and its counterparts at the Department of Justice (“DOJ”) will begin taking enforcement action to identify PRPs and require them to cleanup sites. Although PFOA and PFOS are no longer widely used, it is expected that there are many sites with legacy pollution from such chemicals, especially for military bases and communities downstream from industrial dischargers. Companies and entities that own or have owned a site where PFOA and PFOS contamination is found, or who were involved in the manufacture, distribution, or disposal of PFOA and PFOS-containing products, which may have contributed to such contamination at CERCLA sites, may face a knock at the door from EPA and DOJ officials.


Designation of PFOA and PFOS as “hazardous substances” under CERCLA has widespread and potentially costly implications for entities that currently own or operate PFOA and PFOS-contaminated sites, or that have been involved in the manufacture, distribution, or disposal of PFOA and PFOS-containing products. Industries and companies should stay up-to-date with legal and regulatory developments, at both the federal and state level. Additionally, companies should consider evaluating their own PFOA and PFOS liability exposure, given the potential for future enforcement actions. This is particularly important given the uncertainty surrounding how regulatory agencies may implement contamination and remediation thresholds which, currently, are highly uncertain. In any case, as it is looking more likely than not that the designation of PFOA and PFOS as “hazardous substances” under CERCLA will occur, it is better to be prepared than not.

This information is provided by Vinson & Elkins LLP for educational and informational purposes only and is not intended, nor should it be construed, as legal advice.