The US Environmental Protection Agency (EPA) published on February 8, 2024 two proposed rules addressing per- and polyfluoroalkyl substances (PFAS) under the Resource Conservation and Recovery Act (RCRA). The rules, if finalized as proposed, would add nine PFAS, their salts, and their structural isomers to the RCRA hazardous constituents list and amend the regulatory definition of “hazardous waste” to require corrective action for substances meeting the statutory definition of “hazardous waste,” with the likely effect of increasing the scope of corrective action at existing and new sites.

The first rule, Listing of Specific PFAS as Hazardous Constituents (the Listing Rule), proposes to add nine specific PFAS, their salts, and their structural isomers to the list of RCRA hazardous constituents found at 40 CFR Part 261, Appendix VIII (Appendix VIII).

The second rule, Definition of Hazardous Waste Applicable to Corrective Action for Releases from Solid Waste Management Units (the Definition Rule), proposes to amend the RCRA definition of “hazardous waste” to expressly include, for purposes of RCRA corrective action, any substance that meets the statutory definition of hazardous waste.

Both rules were developed in response to a June 2021 petition filed by the governor of New Mexico that requested listing of PFAS as a class of chemicals as hazardous wastes under the RCRA Subtitle C regulations or, in the alternative, a listing of individual PFAS chemicals as hazardous wastes under RCRA.

In EPA’s October 2021 response to the petition, the agency noted that it intended to partially grant the petition by initiating a rulemaking process that would add perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorobutane sulfonic acid (PFBS), and hexafluoropropylene oxide-dimer acid (HFPO-DA or GenX) to Appendix VIII as hazardous constituents.

The proposed rules are EPA’s most recent steps toward regulating and reducing PFAS in the environment. In a February 1, 2024 press release, EPA characterized these two rules as an addition to the agency’s “comprehensive approach to tackling PFAS pollution across the country” that “will help deliver on President Biden’s agenda” with respect to public health and environmental justice.

KEY ELEMENTS

The Listing Rule proposes to classify a total of nine PFAS as well as their salts and structural isomers as hazardous constituents rather than just the four contemplated in EPA’s initial response to the petition. The nine PFAS are PFBS, PFOA, PFOS, GenX, perfluorobutanoic acid (PFBA), perfluorodecanoic acid (PFDA), perfluorohexanoic acid (PFHxA), perfluorohexanesulfonic acid (PFHxS), and perfluorononanoic acid (PFNA).

EPA has stated that this proposed listing is based on data from scientific studies showing that those substances have toxic, carcinogenic, mutagenic, or teratogenic effects on humans or other life forms. Importantly, listing the nine covered PFAS as hazardous constituents does not make them RCRA-listed hazardous wastes and as such would not trigger RCRA’s waste management and disposal requirements.

However, if listed as hazardous constituents, the nine covered PFAS would be included in the set of constituents expressly identified for consideration in RCRA facility assessments and, if necessary, investigation and cleanup through the RCRA corrective action process at RCRA treatment, storage, and disposal facilities (TSDFs).

EPA also notes in the Listing Rule’s preamble that it views hazardous constituent listing as a step toward a potential hazardous waste listing, and that this listing “would form part of the basis for any future action the Agency may take” to list the nine covered PFAS as hazardous wastes.

Such action would require EPA to demonstrate, in the case of a solid waste, that it exhibits a hazardous waste characteristic or is acutely hazardous or that EPA has concluded that it is capable of posing a substantial present or potential hazard to human health or the environment when managed based on the 11 regulatory factors set forth at 40 CFR § 261.11(a)(3).

If finalized as proposed, the Definition Rule would fully implement EPA’s statutory authority to require facilities to conduct corrective action to address not only releases of hazardous wastes that meet the existing regulatory definition and Appendix VIII hazardous constituents, but also releases of substances that meet the statutory definition of hazardous waste.

At present, RCRA’s implementing regulations do not expressly apply the definition of “hazardous waste” found in RCRA Section 1004(5)—which defines “hazardous waste” to include solid wastes that may pose a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported, or disposed of—to corrective action requirements.

IMPLICATIONS FOR REGULATED ENTITIES

Together, the Listing Rule and Definition Rule could subject a significant number of sites currently undergoing corrective action to additional requirements and increase the number of corrective action sites and the time and cost associated with closing out corrective action in the future.

According to the Listing Rule’s preamble, EPA has identified 1,740 facilities that could be subject to additional corrective action following finalization of the proposed rules to address releases not already subject to corrective action.

While EPA asserts that RCRA corrective action implementing authorities already have the authority to require investigation and cleanup at TSDFs for substances not identified as hazardous constituents, either through state cleanup regulations or the hazardous waste permit program authority, explicitly implementing that authority in regulations is likely to increase the number of facilities required to undergo corrective action and lead to longer, more expensive corrective action.

EPA has requested comments on both the Listing Rule and the Definition Rule. Comments on the Listing Rule will be due on April 8, 2024 (60 days after the February 8 publication date), and comments on the Definition Rule will be due on March 11, 2024 (30 days after the February 8 publication date). If finalized, both rules would become immediately effective in all states on the effective date.

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