Highlights
- Major trade associations and water systems filed suit to challenge the Biden-era U.S. Environmental Protection Agency's (EPA) National Primary Drinking Water Rule for six per- and polyfluoroalkyl substances (PFAS) under the Safe Drinking Water Act.
- After President Donald Trump took office, the EPA asked the court to stay the litigation until the agency could review the rule and consider its position on the litigation. Considering the EPA's PFAS priorities during the first Trump Administration, EPA Administrator Lee Zeldin's historic positions, and the common ground between the EPA and the challengers regarding some, but not all, of the Maximum Contaminant Levels (MCLs), it appears possible that the EPA could narrow the Rule to apply only to PFOS and PFOA.
During the Biden Administration, as specified in the EPA's 2021 PFAS Road Map and described in a previous Holland & Knight alert, the EPA finalized a National Primary Drinking Water Rule (the Rule) setting Maximum Contaminant Levels (MCLs), a Maximum Contaminant Level Goal (MCLG) or a Hazard Index Goal for six per- and polyfluoroalkyl substances (PFAS) under the Safe Drinking Water Act, including:
- perfluorooctanoic acid (PFOA)
- perfluorooctane sulfonic acid (PFOS)
- perfluorononanoic acid (PFNA)
- GenX chemicals: hexafluoropropylene oxide dimer acid (HFPO-DA)
- perfluorohexane sulfonic acid (PFHxS)
- perfluorobutane sulfonic acid (PFBS)
The Rule institutes a quarterly sampling requirement for larger public water systems and a biannual requirement for smaller systems to ensure that PFAS in public water supplies do not exceed the MCLs. Public water systems must meet this requirement by April 10, 2027, and begin notifying their served communities and take steps to reduce PFAS levels in their drinking water by April 10, 2029.
The EPA estimated that 6 percent to 10 percent of the 66,000 public drinking water systems subject to this Rule will need to take remedial measures to achieve compliance with the Rule by the mandated deadlines. Given the potential costs of implementing and complying with the MCLs, several trade associations representing public drinking water systems, chemical producers and manufacturers filed a lawsuit against EPA challenging the Rule. The challengers expressed concerns regarding the EPA's rush to finalize the Rule, the validity of the data purportedly supporting the Rule, and the consistency of the Rule with the requirements of the Safe Drinking Water Act. On April 8, 2025, the EPA filed an unopposed motion to continue a stay of the litigation for 30 days to allow the new EPA leadership to review the underlying Rule.
Where Will the EPA Go from Here?
During the first Trump Administration, the EPA established the 2019 PFAS Action Plan that called for the development of MCLs for only two PFAS compounds – PFOS and PFOA. However, in the final Rule, the Biden EPA issued MCLs, MCLGs or a Hazard Index for the aforementioned six PFAS compounds. The challengers of the Rule support the establishment of MCLs for PFOS and PFOA, but oppose the Rule's MCLs for PFNA, PFHxS, PFBS, and HFPO-DA and mixtures of PFAS compounds, alleging that they are unsound. In their opening brief and accompanying press release, the challengers state:
Petitioners support EPA's efforts to develop national primary drinking water regulations for PFOA and PFOS that cost-effectively protect public health. This rule, however, is neither feasible nor cost-effective, as required by the Act, and creates significant risks for water system compliance and water affordability.
Notably, the EPA relied, in part, on data collected between 2013 and 2015 through the Unregulated Contaminant Monitoring Rule 3, which sampled public water supplies for PFOA, PFOS, PFHxS, PFNA, PFBS and perfluoroheptanoic acid (PFHpA). The EPA also relied, in part, upon data from the Unregulated Contaminant Monitoring Rule 5 (UCMR 5), published in December 2021, that required sampling of the six PFAS subject to the Rule between 2023 and 2025. Given that UCMR 5 sampling is not yet complete, the EPA stated in the Rule:
While the complete UCMR 5 dataset was not available to inform this rule and thus not a basis for informing the agency's decisions for the final rule, the EPA acknowledges that the small subset of data released (7 percent of the total results that the EPA expects to receive) as of July 2023 confirms the EPA's conclusions supported by the extensive amount of data utilized in its UCMR 3, state data, and modelling analyses.
In the Rule, the EPA stated that "the state of the science and information has sufficiently advanced to the point to satisfy the statutory requirements and fulfill SDWA's purpose to protect public health by addressing contaminants in the nation's public water systems."
The agency indicated that it considered PFAS health effects information, evidence supporting dose-additive health concerns from co-occurring PFAS, as well as national and state data for the levels of multiple PFAS in finished drinking water. The EPA also stated that it had acted on the "best available" science, while acknowledging that the statute recognizes that the agency may act in the face of imperfect information and update standards as more science becomes available.
During his Senate confirmation hearing, EPA Administrator Lee Zeldin affirmed his commitment to mitigating PFAS exposure, with the caveat that the costs do not fall onto consumers. During his tenure in the House of Representatives, Zeldin supported the 2021 PFAS Action Plan, as well as Rep. Debbie Dingell's (D-Mich.) PFAS Action Act (H.R.2467), which supported the development of MCLs for PFOA and PFOS. Considering the EPA's PFAS priorities during the first Trump Administration, Zeldin's historic focus on PFOS and PFOA, and the common ground between EPA and the challengers regarding some, but not all, of the MCLs in the Rule, it appears possible that the EPA could narrow the Rule to apply only to PFOS and PFOA.
Other PFAS Regulatory Activity
The EPA is also reviewing the designation of PFOS and PFOA as hazardous substances (Designation) as defined in the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). Shortly after the Designation was finalized on April 19, 2024, it was also challenged. The EPA also asked for and was granted a 60-day stay of this litigation after the beginning of the current Trump Administration. That stay is due to expire on April 25, 2025.
A potential resolution of the challenge to the Designation is hard to predict because it appears to align with Trump's 2019 PFAS Action Plan. However, the Project 2025 Playbook calls for the EPA to "revisit" the Designation. Further, Republican leaders on the influential House Energy and Commerce Committee and the Senate Environment and Public Works Committee have expressed significant skepticism about the Designation. Legislators have voiced concern that the EPA did not adequately consider the costs such a Designation would impose on manufacturers, consumers, municipalities, landowners and disposal companies, especially without a corresponding waste management system. In addition, no PFAS have been designated as hazardous wastes under the Resource Conservation and Recovery Act (RCRA) – yet. At the same time, there is a push for bipartisan legislation protecting "passive receivers" of PFAS from CERCLA liability.
Ultimately, these concerns will likely be top of mind for the EPA as it determines its position regarding the Rule, Designation and pending challenges.
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