The Environmental Protection Agency’s (EPA) rulemaking process used to develop the regulations setting limits on per- and polyfluoroalkyl substances (PFAS) in drinking water was the focus of the oral arguments presented last month to a panel of three federal judges in the lawsuit challenging the rule and which petitioners seek to vacate.

Filed on June 7, 2024, the lawsuit—Association of Metropolitan Water Agencies (AMWA) and the American Water Works Association (AWWA) v. EPA and Lee M. Zeldin, Case No. 24-1188—was argued before judges Gregory Katsas, Patricia Millett and Cornelia Pillard of the U.S. Court of Appeals for the D.C. Circuit.

The AMWA’s and AWWA’s petition for review is focused on the initial EPA’s PFAS rule “PFAS National Primary Drinking Water Regulation” that was issued April 10, 2024 (and made available on the Federal Register on April 26, 2024). The rule sets drinking water standards for PFAS substances of from 4.0 parts per trillion to 10 parts per trillion. Those PFAS substances are perfluorooctanoic acid (PFOA); perfluorooctanesulfonic acid (PFOS), perfluorononanoic acid (PENA); perfluorohexanesulfonic acid (PFHxS); perfluorobutanesulfonic acid (PFBS); and hexafluoropropylene oxide dimer acid (HFPO-DA, also known as GenX chemicals).

In addition, On April 19, 2024, the EPA issued a second PFAS regulation designating PFOA and PFOS as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), also known as the “Superfund.”

The AMWA and AWWA’s petition challenges the science and methods used by EPA to justify the regulation, as well as its potential financial impact on communities and water suppliers.

Corinne Snow, one of three lawyers representing the petitioners seeking to vacate the regulations, during oral arguments said the 60 days provided by the EPA to comment on the proposed rule was not sufficient time. Furthermore, data continued to emerge about PFAS substances after the deadline passed to file comments on the proposed rule, but the additional data was not considered by the EPA, which constitutes “harmful prejudice,” according to Snow (harmful prejudice is also called legal prejudice and it means a specific, unfair disadvantage or tangible harm that damages a party’s legal rights or ruins their ability to present a fair case).

“Our argument here is certainly not that the agency must always wait for more data to come out in the future (before enacting a regulation),” said Snow, who added Congress created the “Unregulated Contaminant Monitoring Rule” (UCMR) as a method for the EPA to determine the extent of such a contaminant around the U.S.

“The UCMR is to give the agency the exact kind of nationally applicable occurrence data that it was going to need to justify its determinations and its regulations,” said Snow, who added, in this instance “the agency did not.”

The EPA had some “stale UCMR data,” but not for hexafluoropropylene oxide dimer acid (HFPO-DA), which is a PFAS chemical that the agency “decided (it) was not going to look at,” Snow said.

While the EPA said the PFAS regulation “was going to be nationally applicable and be on the right levels of analysis,” the regulation was “rushed forward based on some cobbled together, stale, updated, and piecemeal state data. And on that record, the agency could not meet its burden of showing that the (agency’s) determination to regulate” those chemicals “is suspected,” she argued.

However, Judge Pillard questioned the claim that 60 days was not sufficient time to file comments on the PFAS rules. “I’m not hearing this was more abbreviated than we (the public) would get” to comment on a proposed rule. she said. For EPA, a comment period of 60 days “is a normal time,” so “there’s nothing different here,” she said. Furthermore, that calls into question the claim that EPA committed harmful prejudice, according to Pillard.

Katherine O’Brien, a senior attorney for Earthjustice who represented communities in five states where the drinking water has been contaminated by PFAS substances, challenged the claims that 60 days to comment on the proposed rule was not sufficient time, and the petitioners suffered harmful prejudice as a result. She further said those claims do not effect the actual regulation of PFAS substances.

O’Brien also outlined the three steps EPA has to follow when producing a regulation, including:

• First, EPA has to publish a preliminary determination to regulate a substance based on certain criteria.
• Second, EPA has to provide an opportunity for public comment on the preliminary determination.
• Third, EPA has to publish a final determination of whether or not to regulate the substances based on these same criteria.

“It is clear from the record that EPA followed these three requirements for the regulatory determinations for each of the individual PFAS substances,” said O’Brien, who added, “assuming the petitioners and EPA could demonstrate that there were a statutory violation as to the timing that EPA promulgated the goals and the standards (of the rule when it was still proposed), and even assuming that they could show prejudice from that,” it “would have no effect on the regulatory determinations for any of the index PFAS because they have not alleged a violation of any of the statutory requirements for regulatory determinations,” O’Brien said.