Regulatory Alert: EPA to Maintain Biden-era Drinking Water Standards for PFOA/PFOS Chemicals
May 14, 2025
Today, the U.S. Environmental Protection Agency (EPA) announced that the agency intends to maintain the current national drinking water standards for two PFAS chemicals, PFOA and PFOS, which have been included in aqueous film forming foam (AFFF) that the Federal Aviation Administration has required airports to use for decades. The drinking water standards were issued by the Biden administration last year through a National Primary Drinking Water Regulation (NPDWR). Since President Trump took office, questions have arisen whether the new administration would seek to roll back the NPDWR on PFAS chemicals, which is being challenged in a federal court by some industry groups.
While EPA intends to maintain the standards for PFOA and PFOS, the agency indicated that it will make 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. In addition, EPA emphasized that the agency intends to work with Congress to ensure the “polluters,” not passive receivers, pay for the costs associated with upgrading public water systems to ensure their compliance with the PFOA/PFOS standards.
You can read EPA’s press release with the announcement here.
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 NPDWRs, which contain maximum contaminant levels (MCL) for specific contaminants in drinking water or required methods for treating the water to remove contaminants. The MCL is the highest level of a contaminant allowed in drinking water that is delivered to users of a public water system.
In April 2024, the Biden administration issued a final rule that included the first-ever national drinking water standards for six PFAS chemicals. EPA established an enforceable MCL of 4 ppt for PFOA and PFOS, which the agency believes is the level at which the chemicals can be reliably measured. The agency set an MCL of 10 ppt for each of the following: PFHxS, PFNA, and HFPO-DA (known as GenX chemicals). In addition, for any PFAS mixtures containing at least 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.
What’s Next? With the announcement today, EPA plans to defend the MCL for PFOA and PFOS in the ongoing legal proceedings involving the NPDWR. However, the agency will rescind and reconsider the MCL of 10 ppt for the other four PFAS chemicals. EPA stated it will issue a proposed rule later this year to extend the deadline—from 2029 to 2031—for public water systems to comply with the PFOA/PFOS standards. The extension is expected to be finalized in the spring of 2026. In the meantime, EPA has also created a new program, “PFAS OUTreach Initiative (PFAS OUT),” to provide communities with resources, tools, funding, and technical assistance to help them come into compliance by the 2031 deadline.
Today, the U.S. Environmental Protection Agency (EPA) announced that the agency intends to maintain the current national drinking water standards for two PFAS chemicals, PFOA and PFOS, which have been included in aqueous film forming foam (AFFF) that the Federal Aviation Administration has required airports to use for decades. The drinking water standards were issued by the Biden administration last year through a National Primary Drinking Water Regulation (NPDWR). Since President Trump took office, questions have arisen whether the new administration would seek to roll back the NPDWR on PFAS chemicals, which is being challenged in a federal court by some industry groups.
While EPA intends to maintain the standards for PFOA and PFOS, the agency indicated that it will make 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. In addition, EPA emphasized that the agency intends to work with Congress to ensure the “polluters,” not passive receivers, pay for the costs associated with upgrading public water systems to ensure their compliance with the PFOA/PFOS standards.
You can read EPA’s press release with the announcement here.
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 NPDWRs, which contain maximum contaminant levels (MCL) for specific contaminants in drinking water or required methods for treating the water to remove contaminants. The MCL is the highest level of a contaminant allowed in drinking water that is delivered to users of a public water system.
In April 2024, the Biden administration issued a final rule that included the first-ever national drinking water standards for six PFAS chemicals. EPA established an enforceable MCL of 4 ppt for PFOA and PFOS, which the agency believes is the level at which the chemicals can be reliably measured. The agency set an MCL of 10 ppt for each of the following: PFHxS, PFNA, and HFPO-DA (known as GenX chemicals). In addition, for any PFAS mixtures containing at least 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.
What’s Next? With the announcement today, EPA plans to defend the MCL for PFOA and PFOS in the ongoing legal proceedings involving the NPDWR. However, the agency will rescind and reconsider the MCL of 10 ppt for the other four PFAS chemicals. EPA stated it will issue a proposed rule later this year to extend the deadline—from 2029 to 2031—for public water systems to comply with the PFOA/PFOS standards. The extension is expected to be finalized in the spring of 2026. In the meantime, EPA has also created a new program, “PFAS OUTreach Initiative (PFAS OUT),” to provide communities with resources, tools, funding, and technical assistance to help them come into compliance by the 2031 deadline.
