Regulatory Alert: EPA Proposes to Extend Compliance Deadline for PFOA/PFOS Drinking Water Standards, Rescind Other PFAS Limits

May 18, 2026

Today, the U.S. Environmental Protection Agency (EPA) released a proposed rule that would extend the deadline for water utility providers to comply with Biden-era national drinking water standards for two PFAS chemicals, PFOA and PFOS. These chemicals have been included in aqueous film forming foam (AFFF) that the Federal Aviation Administration has required airports to use for decades. Under the proposal, a utility provider would have the option to extend its compliance deadline from 2029 to 2031, subject to approval by the EPA.

In a separate action today, EPA released a second proposed rule that would rescind the regulatory determinations and national drinking water standards associated with four other PFAS chemicals (PFHxS, PFNA, HFPO-DA, and mixtures of these three PFAS plus PFBS). EPA contends the rulemaking is necessary to correct an “unlawful procedure” that was used to promulgate the standards under the Biden administration. Once the rescission is complete, EPA indicated that it would evaluate additional PFAS in drinking water for future regulation.

You can view EPA’s press release and announcement (here), along with the agency’s PFOA/PFOS compliance extension proposal (here) and rescission proposal (here). The public will have 60 days to comment on both of the proposed rules after they are published in the Federal Register, which is expected soon.

Background. The Safe Drinking Water Act (SDWA) regulates the country’s public drinking water supply and its sources, including rivers, lakes, reservoirs, springs, and groundwater wells. Under the SDWA, EPA establishes the National Primary Drinking Water Regulations (NPDWRs), which contain maximum contaminant levels (MCLs) for specific contaminants in drinking water or required methods for treating the water to remove contaminants. An MCL is the highest level of a contaminant allowed in drinking water that is delivered to users of a public water system.

In 2024, the EPA issued a rule that included national drinking water standards for six PFAS chemicals. The agency established an enforceable MCL of 4 ppt for PFOA and PFOS, the level at which the chemicals could be reliably measured. The agency set an MCL of 10 ppt for PFHxS, PFNA, and HFPO-DA (known as GenX chemicals). In addition, for any PFAS mixtures containing two or more of PFHxS, PFNA, HFPO-DA, and PFBS, water systems must use an established method, called a hazard index calculation, to determine if the combined levels of these PFAS pose a potential risk.

Pivot Under Trump Administration. Last year, the Trump administration announced that the EPA would maintain the current national drinking water standards for PFOA and PFOS. However, the agency also signaled two notable changes to the Biden-era NPDWR: (a) rescind the regulations and reconsider the regulatory determinations for the standards that were developed for four other PFAS chemicals (aside from PFOA and PFOS), and (b) conduct a rulemaking to extend the date for public water systems to comply from 2029 to 2031. The proposals released today follow last year’s announcement.

What’s Next? In the coming days, EPA will be publishing both proposed rules in the Federal Register, triggering a 60-day comment period. The agency will also be holding a virtual public hearing on Tuesday, July 7 to gather verbal comments on the proposals. You can find more information about how to participate in the public hearing here. EPA is expected to finalize these proposals sometime in 2027.