On March 3, 2021, the Environmental Protection Agency (EPA) published the Fourth Regulatory Determinations in the Federal Register, including a determination to regulate perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) in drinking water. Per the Safe Drinking Water Act, following publication of the Regulatory Determination, the Administrator shall propose a maximum contaminant level goal (MCLG) and a national primary drinking water regulation (NPDWR) not later than 24 months after determination and promulgate a NPDWR within 18 months after proposal (the statute authorizes a 9-month extension of this promulgation date). The EPA issued a proposed national primary drinking water regulation for PFOA and PFOS as well as other PFAS on March 29, 2023, as part of this action. Finalization of the NPDWR reflects a key commitment in the EPA's "PFAS Strategic Roadmap: EPA's Commitments to Action 2021-2024." EPA held a public hearing on the proposed NPDWR on May 4, 2023. The public comment period closed May 30, 2023, and more than 120,000 comments were received. On April 8, 2024, the final PFAS NPDWR was signed by the EPA Administrator and published in the Federal Register on April 26, 2024.