Amid EPA upheaval, states fear losing strong federal limits on PFAS in drinking water

With the looming possibility that the Trump administration could reduce federal limits on toxic PFAS chemicals in drinking water, public health advocates are warning that people across the country would suffer.

Concerns for the future of the federal limits come amid ongoing litigation over the federal limits on six per- and polyfluoroalkyl substances (PFAS) in drinking water. A 60-day stay on the litigation granted in February ends Tuesday, after which the Trump administration could seek to make changes to the standards, which were put into place a year ago under the Biden administration.

The Biden-era rule requires public water systems to complete initial monitoring for the PFAS  chemicals by 2027, and to implement technologies for reducing PFAS in their water by 2029 if levels exceed the limit.

The nation’s first legally enforceable limits for PFAS in drinking water include limits of 4 parts per trillion (ppt) for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). PFOA has been classified as carcinogenic and PFOS has been classified as possibly carcinogenic to humans by an international cancer research group.

The rule has drawn widespread opposition from public utilities, which could face substantial costs for implementing new technologies, and penalties for failing to do so.

The American Water Works Association (AWWA) and the Association of Metropolitan Water Agencies (AMWA) sued the US Environmental Protection Agency (EPA) last June contending that the EPA broke the law when it established the limits.

The groups argue that the agency violated the Safe Drinking Water Act by cutting the rulemaking process short and failed to consider critical data.

The Trump administration has not stated if it will seek to rework the rule but those who helped fight for PFAS mitigation measures say they fear for its future.

“Once again we’re looking at millions of Americans that are going to be drinking unsafe drinking water if this standard goes away,” said Sarah Woodbury, the vice president for policy and advocacy at the Maine-based nonprofit Defend Our Health.

A gap in protections

Eleven states currently have standards in place that legally limit certain PFAS chemicals in drinking water and 12 states have adopted non-enforceable health advisories or guidelines designed to help limit PFAS. While these states would still have some protections in place against PFAS contamination in drinking water supplies, gaps exist between what the federal protections call for and what protections exist under state regulations, said Sarah Doll, the national director of Safer States, an alliance of environmental health groups from across the US.

New York, for example, has an enforceable limit of 10 ppt in drinking water for PFOS and PFOA, which is more than double the federal limit for those chemicals.

In a report published Thursday, the Environmental Working Group (EWG) estimated that 189 of New York’s state’s drinking water systems had PFOA and PFOS levels between 4 ppt and 10 ppt from 2023 to 2024. If the current federal limit is erased, about 1.3 million New Yorkers would lose protections, the report concluded.

“The flow of PFOA and PFOS pollution into the state’s water systems will inevitably lead to more frequent doctor visits, cancer treatments and years of chronic illness,” the EWG report asserts.

Some states are working to codify PFAS protections that mirror the federal rule. In February, California lawmakers introduced legislation that would direct the State Water Resources Control Board to set such regulations by Jan. 1, 2026.

In Maine, a 20 ppt interim standard exists for PFAS in drinking water, but a bill was recently introduced in the state’s legislature that would put the federal standards into statute.

Wisconsin has non-enforceable health advisories for 18 PFAS chemicals, and has enforceable state-level protections of 70 ppt in place for PFOA and PFOS in drinking water. That level is  not currently based on up-to-date science, said Amy Barrilleaux, communications director for the group Clean Wisconsin.

“If the EPA takes away these PFAS standards, we kind of go back to an earlier time when the 70 ppt standard was considered acceptable,” she said. “We know that it’s not acceptable now. We know that the health research shows that it’s not fully protective.”

Questioning the standard

The American Chemistry Council, one of over 100 manufacturing groups that signed a letter in December asking the Trump administration to pause the drinking water rule, said in a statement that the EPA’s limits are based on “severely flawed science.” The group added that it strongly supports establishing a drinking water standard for PFOS and PFOA.

Jack Vanden Heuvel, a professor of molecular toxicology at the Pennsylvania State University, said he doesn’t take issue with the science EPA analyzed to decide on the limits, but he agrees with opponents of the federal standards that the limits are too low.

“The [European Union] and Health Canada have the same data available to them and they didn’t regulate these compounds at that level,” said Vanden Heuvel.

The European Union (EU) and Canada have taken a different approach than the US to regulating PFAS in drinking water The EU’s Drinking Water Directive sets a limit of 100 ppt for the sum of 20 PFAS and 500 for the sum of all PFAS, while Canada has a limit of 30 ppt for the sum of 25 PFAS in drinking water.

The EPA issued its federal limits for PFAS “after reviewing extensive research and science on how PFAS affects public health, while engaging with the water sector and with state regulators to ensure effective implementation,” the agency said in a statement when it introduced the limits.

The latest science shows there is no level of exposure to PFAS without risk of health impacts, including certain cancers, said the EPA.

(Featured image by Getty Images for Unsplash.)