States Float PFAS Drinking Water Limits as EPA Weighs Biden Rule

State lawmakers are proposing new limits on per- and polyfluoroalkyl substances in tap water as questions emerge about the Trump administration’s stance on regulating the chemicals.

Democratic lawmakers in at least five states have introduced bills to set maximum contaminant levels (MCLs) for PFAS in drinking water. The class of chemicals, which has been linked to liver issues and certain cancers, does not break down naturally in the environment and is known as “forever chemicals.”

The proposed laws vary in the levels they would allow in drinking water.

Some, like California’s and Connecticut’s, would set the state’s first enforceable MCL for the chemicals. Others, like New York’s, Vermont’s, and Pennsylvania’s, would make existing standards stricter. Vermont’s proposed bill is the strictest, suggesting the complete elimination of six types of PFAS and a 20 parts-per-trillion (ppt) total limit for any remaining testable PFAS.

“There has been a fairly noticeable uptick in states that are, in my view, directly taking action because of a fear of the federal MCLs being completely clawed back or modified,” said John Gardella, chair of CMBG3’s PFAS practice group.

It’s unclear exactly how the Trump administration, which has taken a skeptical stance on Biden’s regulations, feels about the standards—though more than a hundred business groups asked President Donald Trump in December to reconsider the drinking water rule and other measures.

“EPA will continue to evaluate PFAS contamination and how we can cooperatively work with States and others to provide clean, safe drinking water for all,” the Environmental Protection Agency said in an emailed statement.

Former President Joe Biden’s administration last year finalized the country’s first enforceable drinking water standard for PFAS, setting a limit of 4-ppt—thought to be the lowest detectable level—for the two most common PFAS and a 10-ppt limit for four others. Water systems and industry groups challenged the rule in federal court shortly after, and both cases are on pause at the Trump EPA’s request.

Shoring Up State Protections

An estimated 45% of the nation’s tap water contains one or more types of PFAS, according to a 2023 study by the US Geological Survey. The compounds have been linked to certain cancers, developmental issues, and other health conditions.

Momentum for addressing PFAS in general is building nationwide, but the drinking water bills are especially pertinent as the federal government continues its deregulatory push, said Sarah Doll, national director of Safer States, which tracks PFAS policy nationwide.

“Just in case there’s a move to undo that regulation at the federal level, the state has still made it so that there’s a regulatory flag in the sand that says, this is a scientifically grounded threshold that we want to keep,” she said.

Vermont state Rep. Jim Masland (D), who sponsored the 0-ppt bill, said it’s unlikely that the legislation will pass as introduced since it’s so bold. But he hopes it will start a conversation, since “at the end of the day, it’s unclear to me and many of us here what is a safe level” of the chemicals, he said.

Masland said he drafted his Vermont bill before he knew Trump would take office. But he also sees how it could have more impact post-election: “It doesn’t behoove us to wait for the Trump administration to put their flag in the sand,” he said.

Another bill in California seeks to make Biden’s drinking water PFAS levels the minimum for state regulation. This would guard drinking water even if the Trump administration rolls back the rule, said state Assemblymember Jesse Gabriel (D).

Down the line, regulators could enforce stricter standards if the science evolves—but they couldn’t dial them back, he said.

“Hopefully the federal rule will stay where it is,” Gabriel said. “‘But we don’t want there to be any concern in California that people would be without that protection.”

Efforts to set MCLs for PFAS in drinking water have been going on for years and were seen in the first Trump administration, Gardella said. Right now, eleven states, including Michigan and Massachusetts, have the limits—though no state has gone as far as the Biden rule.

Pennsylvania state Rep. Mary Isaacson (D) said she introduced her PFAS drinking water bill, which sets a 10-ppt limit, last session. Her district falls along the Delaware River in Philadelphia, so constituents are “very highly aware” of environmental issues like PFAS pollution, she said.

“We need to do something about being able to protect the water,” she said.