On May 18, 2026, the Environmental Protection Agency (EPA) announced two proposed PFAS rules that represent a significant rollback of the Biden-era PFAS regulatory framework.1 Public comments on both new rules close on July 20, with a virtual public hearing on July 7.2
The Biden EPA promulgated PFAS regulations in April of 2024 that set Maximum Contaminant Levels (MCLs) for PFOA and PFOS at 4 parts per trillion (ppt) and MCLs for PFHxS, PFNA, HFPO-DA (GenX) at 10 ppt, as well as a hazard index of 1 for mixtures of these three short-chain PFAS and PFBS. The American Chemistry Council and the National Association of Manufacturers then filed a lawsuit against EPA, challenging these standards as “arbitrary, capricious, and an abuse of discretion.” This case is currently before the US Court of Appeals for the DC Circuit.3 The American Water Works Association and the Association of Metropolitan Water Agencies also sued EPA, arguing that the costs of compliance should not fall on water systems and ratepayers, but instead on the polluters themselves.4 In response to these suits, the Trump EPA argued that the rule should be vacated because EPA improperly issued its regulatory determination and final rule in tandem, in violation of the Safe Drinking Water Act (SDWA) that requires a specific sequential process, thus denying the public an opportunity to properly comment on and participate in the rulemaking process. Ultimately, the DC Circuit Court unanimously denied the request to vacate. The court explained that "[t]he merits of the parties' positions are not so clear as to warrant summary action,"5 and it refused to unwind the rule while the case proceeds on the merits. The decision keeps the Biden-era standards fully in place—for now.
In response, EPA has now proposed to rescind the MCLs for PFHxS, PFNA, HFPO-DA (GenX), and the hazard index for mixtures of these three compounds and PFBS. EPA touts that, if finalized, this new rule would save public water systems (PWS) approximately $82 million annually in compliance costs for monitoring, treatment, and reporting of these chemicals, though EPA acknowledges that rescission would also likely forego approximately $6.7 million annually in public health benefits.6 EPA has promised, after recission, to reevaluate the MCLs for these compounds, and has indicated that re-regulation may lead to more stringent standards.
In addition, while proposing to keep the 4 ppt MCLs for PFOA and PFOS unchanged, the second proposed rule would extend the compliance deadlines associated with those two PFAS compounds. The new rule proposes to enact a federal exemption framework to allow eligible PWS up to two additional years to achieve compliance with the contamination limits.7 In order for a PWS to qualify for an exemption, it must: (1) be located in a state that has not yet obtained primacy for the PFOA and PFOS MCLs; (2) have been in operation on or before June 25, 2024; and (3) not hold a variance from the PFOA/PFOS requirements set in 2024.8 Approximately 66,000 PWS are expected to be eligible under this framework, including community water systems, non-transient non-community water systems, and tribal and state agencies.9 PWS must also certify that compliance by April of 2029 is not possible due to economic or other compelling factors, that restructuring cannot reasonably achieve compliance, and that alternative water sources are unavailable for consumers. These exemptions are on an opt-in basis, do not apply automatically, and do not affect most PWS. Those systems that are granted an extension and that have PFOA/PFOS levels of 12ppt or more, however, must implement at least two different mitigation strategies while they work on compliance, such as distributing water filtration pitchers, installing point-of-use or point-of-entry filtration devices, distributing public education materials, or providing alternative water sources such as bottled water. Smaller systems (those serving 3,300 people or less) that face financial difficulties may apply for further exemptions, not to exceed six years total.10
These new rules already face challenges by both industry and environmental groups. First, the SDWA’s anti-backsliding provision (§ 1412(b)(9)) prohibits EPA from weakening a drinking water standard once set—any revision to a rule must “maintain, or provide for greater, protection of the health of persons.”11 Critics and public health advocacy groups have argued that rescinding MCLs may violate this rule, though EPA has attempted to frame the recission as a procedural correction, not a reassessment of the scientific and public health findings underlying the rule.12 Notably, the anti-backsliding provision has never been tested in court. These same environmental advocacy groups further argue that the rollbacks prioritize economic and chemical industry concerns over those of consumers, and are calling for expanded PFAS testing requirements, stricter cleanup standards, and stronger community protection for those living near industrial pollution sites.13
In addition to challenging the proposed MCL rollbacks, environmental advocacy groups have also challenged the extension of deadlines for PWS to meet the MCLs for PFOA and PFOS. These groups point out that the law allows a maximum of five years for PWS to comply with drinking water standards, making the proposed exemption framework potentially unlawful on its face.14
Due to the uncertainty created by fluctuating federal regulations and the Trump Administration’s policy of deregulation, individual states have begun to promulgate their own PFAS drinking water standards, which differ wildly between jurisdictions. As a result, water utilities and corporations face uncertainty as they determine the infrastructure and investments needed to meet the potential new standards. Companies are advised to map where PFAS exists across their packaging, products, and imports; preserve documents and identify potential witnesses; monitor ongoing litigation; and track state and federal regulatory developments without assuming deadline delays.15
MG+M Law Clerk Madeline Graf is a contributing author of this article.
1 Willis Han, Trump Administration Proposes Two New PFAS Rules – Part I, Nossaman LLP via JDSupra (June 9, 2026), https://www.jdsupra.com/legalnews/trump-administration-proposes-two-new-5081046/
2 Id.
3 Bea Calapano, Trump EPA scraps major 'forever chemical' protections, critics warn of health risks, MSN (May 30, 2026), https://www.msn.com/en-us/money/general/trump-epa-scraps-major-forever-chemical-protections-critics-warn-of-health-risks/ar-AA24rkFV
4 Id.
5 Motion for leave to file revised and expanded intervenor brief ruling at 1, National Association of Manufacturers v. United States Environmental Protection Agency, No. 24-1188 (D.C. Cir. Jan. 20, 2026).
6 Id.
7 EPA Press Office, Proposed PFOA and PFOS Compliance Extension Rule, U.S. EPA (May 18, 2026), https://www.epa.gov/sdwa/proposed-pfoa-and-pfos-compliance-extension-rule
8 Han, supra n. 1.
9 Id.
10 Id.
11 LaMott, supra n. 5.
12 Matthew D. Thurlow, EPA Proposes Two New Rulemakings Set to Shape Safe Drinking Water Act Regulation of PFAS, Morgan Lewis (June 12, 2026), https://www.morganlewis.com/pubs/2026/06/epa-proposes-two-new-rulemakings-set-to-shape-safe-drinking-water-act-regulation-of-pfas
13 Id.
14 Han, supra n. 1.
15 Brian Gross, PFAS Regulation and Litigation Continues to Evolve: Companies Should Plan Ahead Now, MG+M The Law Firm via JDSupra (June 10, 2026), https://www.jdsupra.com/legalnews/pfas-regulation-and-litigation-5730330/
