The EPA is rolling back drinking water limits for 4 PFAS. Thousands more remain unregulated. todayheadline

Last week, environmental groups decried plans from the Environmental Protection Agency to rescind and “reconsider” drinking water limits for four per- and polyfluoroalkyl substances, or PFAS, compounds linked to cancer and damage to the immune and endocrine systems, among other health effects. 

The limits had been finalized by the Biden administration last April as part of an effort to limit people’s exposure to hazardous “forever chemicals.” Out of a total of more than 10,000 known PFAS, they targeted just six of the most concerning ones. The Trump administration’s EPA said it would retain the limits for two of the PFAS but give utilities more time to comply with them, and scrap the others. One advocate called the EPA’s move a loss for public health and a “victory for chemical companies.” 

But how protective were the Biden regulations to begin with? And how much of a difference will it make to pare them back?

On the one hand, experts agree that backtracking is not in the public’s interest. Virtually everyone has PFAS coursing through their veins, and specific kinds like PFOS and PFOA are known or likely to contribute to kidney and testicular cancers. The other compounds originally regulated by the Biden administration have been linked to elevated cholesterol, heart disease, and an increased risk of diabetes.

The chemicals have become so ubiquitous in people and the environment because of their use in everything from outdoor clothing to cooking utensils and food packaging. Runoff from firefighting foam, infused with the chemicals, has contributed to widespread drinking water contamination, along with manufacturers’ deliberate dumping of the chemicals into rivers — despite knowing about their health risks. 

Once they’re created, PFAS don’t break down naturally; hence the moniker “forever chemicals.” Regulating them is an “important win,” experts have said, one that “allows the country to begin cleaning up the mess in its water.” 

But the fight over drinking water limits for individual PFAS distracts from the larger context that there are thousands of types, and scientists suspect they all have similar health effects. Even last year, when the Biden administration first announced its national drinking water standards, scientists criticized it for addressing PFAS on a chemical-by-chemical basis. “The EPA is trying to regulate six forever chemicals. Just 10,000 to go,” as the title of an op-ed by one Harvard researcher put it.

Erik Olson, a senior strategist for the nonprofit Natural Resources Defense Council, said the U.S. is “stuck in a Whac-a-Mole game” with PFAS, in which only the best researched compounds are regulated. Lesser-known compounds may be just as toxic — thanks to their similar chemical structures — but escape regulations just because they haven’t been studied, he added. “What we need to do is control PFAS as a class.”

Of the six forever chemicals targeted by the Biden administration’s original policy, PFOA and PFOS are the most prevalent and, consequently, they’ve been researched the most extensively. Those compounds got the strictest drinking water limits of 4 parts per trillion, the lowest level at which they can be detected, reflecting scientists’ understanding that there is no safe exposure level for them. Three additional compounds — PFNA, PFHxS, and GenX — were given a contamination limit of 10 parts per trillion. Water utilities were instructed to use a “hazard index” to monitor a sixth chemical, called PFBS, as well as mixtures of the chemicals.

The Trump EPA said it would keep the PFOA and PFOS drinking water limits but give utilities until 2031 to comply with them, instead of 2029. The rules for the other four compounds will be scrapped and reevaluated. The EPA said it intends to finalize its replacement regulations by next spring.

A statement from EPA Administrator Lee Zeldin said the extended timeline for PFOA and PFOS would provide “common-sense flexibility” to utilities, some of which sued the EPA over its regulations last year. The utilities said the EPA’s new rule was too strict and would cause unreasonable compliance costs. 

A spokesperson for the EPA told Grist that the process by which the agency had “promulgated the preliminary regulatory determinations simultaneously with the proposed regulation” for PFNA, PFHxS, GenX, and PFBS under the Biden administration “was inappropriate and may not comply with the statutory requirements of [the] Safe Drinking Water Act.” With regard to the rescissions, they said that, “while EPA cannot pre-determine the outcome, it is possible” that the agency will issue more stringent requirements this spring.

Daniel Jones, an emeritus professor of molecular biology at Michigan State University, said the impacts of the Trump administration’s reversal will depend on geography. Communities primarily affected by PFOS and PFOA may not be greatly affected, since the standards for those chemicals remain in place — albeit with an extended timeline for compliance. To meet the standards, water utilities will likely have to install something like an activated carbon filtration system, he said, which is effective at removing “long-chain” PFAS like PFOA and PFOS, which have a larger chemical structure than compounds like GenX.

Putting these filtration systems into place will thankfully sweep up more PFAS than just PFOA and PFOS, Jones said.

States like North Carolina, Ohio, and West Virginia, however, face disproportionate contamination from GenX due to production facilities concentrated there. This contamination could continue unabated if the standard for the compound is eliminated. According to Olson, some of the technologies that remove PFOS and PFOA are not as effective at attracting GenX. “To really control the full suite of PFAS, we need to go to more advanced technologies like tight membranes, like reverse osmosis,” he said.

Some water utilities may opt for these more advanced — and expensive — technologies if they believe that they will eventually be required to test for and limit a much larger number of PFAS, Olson added.

Although Jones is disappointed that the EPA intends to drop regulations for the four PFAS, he said he is more concerned about a single clause in the EPA’s press release, about the EPA’s intent to establish a “federal exemption framework” for the PFOS and PFOA limits. The release contains no further information about what this would entail, but Jones worries it could allow water utilities to circumvent the federal government’s water quality requirements altogether. “It seems that an exemption framework is likely to open the door to say, ‘This is going to cost too much, you don’t have to do it,’” he said.

The EPA spokesperson said exemptions would not allow utilities to violate regulations: “Rather, they allow additional time to find a compliance solution.”

Jones also raised concerns about funding for further PFAS research, including investigations on how exposure to mixtures of the chemicals may impact human health. One of his federal grants for PFAS research was recently cut by the Trump administration, he said, and a colleague at Michigan State University studying PFAS on farms has also had his funding rescinded.

In addition to regulating PFAS by groups or as a class, Jones said the EPA should set pollution standards using what’s known as the “precautionary principle,” which doesn’t require definitive evidence about a chemical’s harms before it can be regulated. “In some countries, if you want to release a chemical into the environment you have to show it’s safe,” he said. “The U.S. usually takes the opposite approach and says, ‘You can use these chemicals … and if we find that there’s a problem, then we’ll come up and regulate [them].’”

Olson believes the EPA’s alterations to the PFAS rules are in violation of the Safe Drinking Water Act’s “anti-backsliding provision,” which says any revision the EPA proposes to a drinking water standard must be at least as protective of public health as the previous one. The law also caps compliance timelines at five years, whereas postponing the PFOS and PFOA compliance deadline to 2031 would give water utilities seven years. 

“Ultimately, we need to be phasing these chemicals out,” Olson added. “We have to turn off the spigot and stop using these things so that five generations from now, our great-great-great grandchildren won’t be dealing with them.”

Editor’s note: The Natural Resources Defense Council is an advertiser with Grist. Advertisers have no role in Grist’s editorial decisions.