Per- and polyfluoroalkyl substances (PFAS) are the contaminant of concern across the water industry. The Biden administration was active in its approach to PFAS regulation, announcing drinking water maximum contaminant levels, new Superfund regulation, new listings of PFAS as hazardous constituentsand more. Now that we are more than six months into President Trump's second term, his administration's approach and the reactions thereto are crystalizing. Determining the proper approach for regulating is significant and timely, as new data shows the ubiquity of PFAS, with at least 73 million Americans drinking water containing PFAS.
National Primary Drinking Water Regulation (NPDWR) Changes
On May 14, 2025, the Trump Environmental Protection Agency (EPA) announced it would be departing from the Biden administration NPDWR for PFAS. The Biden administration proposed to regulate a total of five PFAS individually through maximum contaminant levels (MCLs) as well as a combination of four PFAS. The MCLs were set to become enforceable in 2029.
The Trump EPA's announcement altered the Biden EPA's regulation in two key ways. The first is that it will no longer be pursing MCLs for PFHxS, PFNA, HFPO-DA (also called Gen X chemicals), or for the combination of PFAS. The second is that the MCLs for the two remaining PFAS, PFOA and PFOS, will be delayed to 2031.
Reactions
One reaction came from environmental groups, including the Natural Resources Defense Council (NRDC), have expressed a willingness to challenge the new regulation in court. The NRDC's press release cited to the Safe Drinking Water Act's anti-backsliding provision (42 U.S. Code § 300g-1 (b) (9)) as one ground for challenge. That provision provides that "each revision [of an NPDWR] shall maintain, or provide for greater, protection of the health of persons."
A second reaction, although one more indirect, is from states. Likely largely due to the combination of regulatory uncertainty due to the change in federal administration and the broader awareness of PFAS health risks, states have pushed ahead aggressively in 2025 with their own legislation. A list created by the Sierra Club shows over 350 new pieces of legislation this year. While "blue" states represent the majority of these listings, they do not comprise all of them. Roughly 37 states have introduced at least one PFAS bill, with "red" states across the country comprising a non-negligible amount of those, including Alabama, Montana, Texas, and Kentucky.
A third reaction, although one more downstream, is in the litigation challenging the Biden NPDWR. That litigation had been stayed, but, on July 22, 2025, the D.C. Circuit lifted the stay at the request of the EPA. Now, that legal challenge may move forward, although it is yet to be seen if the parties will change course based on the new NPDWR.
Trump's Affirmative Actions
At the same time the Trump administration is rolling back part of the existing NPDWR, it is also adopting an active approach to PFAS regulation. On April 25, 2025, the EPA announced a new suite of strategies to tackle PFAS contamination. This suite, which EPA states are the first, but not the last, steps it will take, are designed to "provide the foundation and investment necessary for a toolbox that will help states and communities dealing with PFAS contamination."
The suite is split into three categories – strengthening the science, fulfilling statutory obligations and enhancing communication, and building partnerships. The strengthening the science category includes designating a PFAS agency lead to improve coordination and ramping up the development of testing methods. The fulfilling statutory obligations and enhancing communication category includes develop effluent limitations guidelines for PFAS manufacturers and metal finishers (and to consider them for other groups), addressing compliance challenges, and establishing a clear liability framework that operates on polluter pays and protects passive receivers. The building partnerships category includes advancing remediation and cleanup efforts where drinking water supplies are impacted.
Conclusion
Evaluating the impact of the Trump administration's regulatory actions for PFAS is complicated. On one hand, the President generally prefers a deregulatory approach, as can be seen by his changes to the NPDWR. On the other, the President is clearly proud of creating the PFAS Action Plan (it is listed on every PFAS-related EPA announcement) and the suite of actions announced in April shows the EPA's plan is not to do nothing/solely deregulate.
Regardless of one's views on the changes to the NPDWR, there is plenty for drinking water providers to like in Trump's proposed actions. The EPA's focus on the polluter pays principle and protecting passive receivers is likely the highlight there though. Nearly all, if not literally all, water providers fall into that passive receiver category. While that would typically prevent liability from attaching, many environmental statutes are strict liability, which could mean that water providers could be held liable for their connections to PFAS even if they did nothing wrong. Any steps the President could take here would make a substantial impact.
The Trump administration is making a clear break from the Biden administration on PFAS, just as it is doing for just about every issue. Whether this new approach will ultimately benefit or harm water providers and the general public is yet to be determined.
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