The final rule, however, extends that timeline to five years—public water systems have three years to complete initial testing and another two years to implement treatment or switch to an uncontaminated source of drinking water, if PFAS levels exceed one or more of the established MCLs.

On April 8, 2024, EPA Administrator Michael Regan signed a final rule setting limits for six PFAS in drinking water. The rule, which will become effective 60 days after publication in the Federal Register, establishes a National Primary Drinking Water Regulation (NPDWR) that will apply to all community water systems and non-transient non-community water systems regulated under the Safe Drinking Water Act and will preempt any state standards that are less stringent than the new EPA rule.

The Safe Water Drinking Act authorizes the EPA to establish enforceable maximum contaminant levels (MCLs) and non-enforceable maximum contaminant level goals (MCLGs). MCLs are the highest level of a contaminant that is allowed in drinking water. When establishing an MCL, the EPA is directed to take into consideration the best available treatment technology and the costs associated with meeting the MCL, as well as the ability of laboratories to measure the substance with high certainty. MCLGs, on the other hand, are based on the EPA’s assessment of health data and the potential impacts to the public only.

The EPA originally issued a proposed rule in March 2023. That proposal suggested setting individual MCLs for the two most widely studied PFAS—PFOA and PFOS—and regulating four additional PFAS—PFHxS, PFNA, HFPO-DA and PFBS—as a mixture using a hazard index MCL of 1 for any mixture containing two or more of those substances. The final NPDWR, however, establishes individual MCLs for five PFAS—PFOA, PFOS, PFHxS, PFNA and HFPO-DA—as well as applying a hazard index to mixtures containing two or more of PFHxS, PFNA, HFPO-DA, and PFBS. The table below sets forth the MCLs and MCLGs established by the new NPDWR.

The proposed rule suggested public water systems would have three years to come into compliance with the proposed NPDWR. The final rule, however, extends that timeline to five years—public water systems have three years to complete initial testing and another two years to implement treatment or switch to an uncontaminated source of drinking water, if PFAS levels exceed one or more of the established MCLs. “EPA estimates that between about 6% and 10% of the 66,000 public drinking water systems subject to this rule may have to take action to reduce PFAS to meet these new standards.” Public water systems will be required to provide the public with information on the levels of PFAS in their drinking water beginning in 2027.

The EPA estimates that the costs for public water systems to implement this regulation will be approximately $1.5 billion per year. The EPA acknowledges that this estimate is likely an underestimate as it does not include certain costs, like HFPO-DA, PFNA and PFBS treatment costs and increased costs associated with disposal of spent treatment media in the event that certain PFAS are designated as hazardous. In a related press release, the EPA announced that it is making $1 billion of funding available “through the Bipartisan Infrastructure Law to help states and territories implement PFAS testing and treatment at public water systems and to help owners of private wells address PFAS contamination. . . . An additional $12 billion is available through the Bipartisan Infrastructure Law for general drinking water improvements, including addressing emerging contaminants like PFAS.”

Despite this funding, state regulators are raising financial and other concerns about implementing the new rule. According to the Association of State Drinking Water Administrators, while the infrastructure law “is providing billions of dollars in assistance to water providers, significant rate increases will be required for most, if not all, of the systems impacted by the PFAS standards.” In addition, while supportive of the new regulation, state regulators are noting other concerns such as the increased workload the new rule imposes on regulators and competing priorities for other drinking water requirements (e.g., aging infrastructure, updated lead and copper rule, cybersecurity concerns, etc.).  

Pundits are already suggesting that the rule will be challenged. In addition to potentially challenging whether the EPA has sufficient data to support its rulemaking under the SDWA, comments to the proposed rule suggest some other potential battles as well, such as whether the EPA has the authority to regulate PFAS as a mixture, whether the EPA followed proper procedure under the SDWA with respect to its proposal to regulate PFHxS, PFNA, HFPO-DA and PFBS, or the EPA’s novel application of a hazard index.

The EPA currently plans to host three webinars for the public and water utilities to educate them on implementation of the new rule as follows:

• April 16, 2024 (2:00 p.m. to 3:00 p.m. EDT) General Overview of PFAS NDPWR for Communities
• April 23, 2024 (2:00 p.m. to 3:00 p.m. EDT) Drinking Water Professional Community Webinar on EPA’s Final PFAS National Primary Drinking Water Regulation
• April 30, 2024 (2:00 p.m. to 3:00 p.m. EDT) Small Drinking Water Systems Webinar Series: PFAS Drinking Water Regulation andTreatment Methods

The EPA is submitting the rule for publication in the Federal Register and will become effective 60 days after the date of publication. The pre-publication version of the rule can be found here.

About Duane Morris

Duane Morris has an active PFAS team to help organizations and individuals plan, respond to and execute on PFAS issues and initiatives in order to manage risk, ensure compliance and minimize litigation risk. We are available to discuss your concerns and objectives and how new rules, regulations and rulings might apply to you.

For More Information

If you have any questions about this Alert, please contact Lindsay Ann Brown, Phil Cha, Lori A. Mills, Brad A. Molotsky, any of the attorneys in our PFAS Group or the attorney in the firm with whom you are regularly in contact.

Disclaimer: This Alert has been prepared and published for informational purposes only and is not offered, nor should be construed, as legal advice. For more information, please see the firm's full disclaimer.