PFAS Regulatory Alert: EPA Rolls Back RCRA Proposed Rule on “Hazardous Waste” but Does Not Disturb Proposed RCRA Rule on PFAS

Earlier this month, the U.S. Environmental Protection Agency (EPA) withdrew a February 2024 Biden administration proposed rule, “Definition of Hazardous Waste Applicable to Corrective Action for Releases From Solid Waste Management Units,” under the Resource Conservation and Recovery Act (RCRA).^[1] The withdrawn proposal would have revised RCRA corrective action regulations to expressly apply the broader statutory definition of “hazardous waste,” rather than only the narrower regulatory definition. Now, EPA is maintaining the status quo for corrective action under RCRA. However, EPA’s withdrawal of its proposed RCRA hazardous waste definition makes no mention of its corresponding proposal from 2024 to list nine per- and polyfluoroalkyl substances (PFAS) as RCRA hazardous constituents.^[2] This disjointed withdrawal, while providing some certainty for regulated entities, does not resolve how EPA plans to address PFAS under the RCRA program.

The 2024 Proposed RCRA Definition of “Hazardous Waste”

The 2024 proposed rule would have amended the definition in 40 C.F.R. § 260.10 to expressly apply the RCRA Section 1004(5)^[3] statutory definition of hazardous waste, a broader definition than what is currently in the regulations. The definition would apply to hazardous waste releases and corrective action from solid waste management units at permitted treatment, storage, and disposal facilities. EPA originally designed this change to close a perceived gap between the statutory and regulatory definitions of “hazardous waste” under 40 C.F.R. § 261.3 for corrective action purposes.^[4]

Now, EPA has concluded that the proposed definition change is not necessary because nearly all corrective actions involve existing regulatory hazardous waste and hazardous constituents. The agency has issued only a limited number of permits and Section 3008(h) orders addressing non-listed substances, making a formal regulatory expansion unnecessary. Additionally, EPA found that to the extent that releases of other RCRA statutory hazardous wastes and constituents have occurred and present a risk, EPA has other tools — namely, RCRA Section 3005(c)(3) and the omnibus authority — to address those concerns. EPA’s existing regulations require that all permits include conditions necessary to protect human health and the environment, including remediation for the release of substances that are not hazardous waste or hazardous constituents under the regulatory definition, if applicable. The regulations continue to reference only listed or characteristic hazardous wastes, even though EPA has long interpreted its corrective action authority as reaching all substances meeting the broader statutory definition.^[5] EPA specifically notes in its withdrawal that it is not reconsidering or modifying its interpretation of these statutory provisions, nor is it reinterpreting the scope of its RCRA corrective action authority.^[6]

EPA also cited several concerns raised by commenters, who noted that the proposed rule would, as a practical matter, result in confusion for owners and operators regarding which substances were subject to corrective action and which units were solid waste management units. Commenters argued that the broad statutory provision provides little guidance to the regulated community as to what is actually regulated under the statute. EPA agreed that its 2024 proposed rule could unnecessarily create uncertainty and disrupt implementation of corrective action.

The Proposed 2024 “Listing of Specific PFAS as Hazardous Constituents”

Alongside the 2024 RCRA “hazardous waste” proposed rule, EPA issued a proposed rule, “Listing of Specific PFAS as Hazardous Constituents,” that would list certain PFAS as hazardous constituents under RCRA.^[7] Despite its withdrawal of the RCRA hazardous waste rule, however, EPA has made no indication that it also intends to withdraw its proposal to list PFAS as hazardous constituents. The rule would explicitly identify nine PFAS substances for consideration in RCRA facility assessments, with potentially wide-reaching impacts. In fact, EPA included a list of 1,740 facilities that it identified as potentially subject to additional corrective action under its proposed rule.^[8]

Continued Uncertainty for RCRA and PFAS

EPA’s withdrawal of the amended hazardous waste definition indicates its willingness to maintain the status quo, providing some clarity for the regulated community. But doing so without mentioning its companion proposed PFAS rule leaves uncertainty on whether and how PFAS will be defined and regulated under RCRA.

The Trump administration has taken a mixed approach to PFAS thus far, repealing some Biden administration actions on PFAS but maintaining others. In September 2025, EPA confirmed that it will retain designation of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) as hazardous substances under Section 102(a) of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).^[9] By contrast, the agency announced last week that it plans to roll back some drinking water standards for PFAS.^[10] This policy approach fosters continued uncertainty for the regulated community, requiring diligence in monitoring and assessing EPA’s ongoing regulatory actions.