PFAS National Primary Drinking Water Regulation Rulemaking - Preliminary regulatory determination and proposed rule; request for public comment; notice of public hearing

Sep 15, 2026

Uploaded by Aldword

This notice by the U.S. Environmental Protection Agency proposes a National Primary Drinking Water Regulation to address per-and polyfluoroalkyl substances (PFAS) contamination and protect public health. EPA issues a preliminary regulatory determination to regulate PFHxS, HFPO-DA (GenX chemicals) and ammonium salt, PFNA, PFBS, and mixtures as contaminants under the Safe Drinking Water Act. The proposal includes health-based Maximum Contaminant Level Goals and Maximum Contaminant Levels, using an individual MCL approach for PFOA and PFOS and a Hazard Index framework for specified mixtures, and requests public comment for an upcoming virtual hearing.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages398

Reading Time16 h 43 min

AccessFree to download

PFAS National Primary Drinking Water Regulation Rulemaking

Agency, Action, and Summary

Dates and Public Hearing

Addresses for Submitting Comments

For Further Information

The EPA Administrator, Michael S. Regan, signed the following proposed rule on 3/13/2023, and EPA is submitting it for publication in the Federal Register (FR). While we have taken steps to ensure the accuracy of this Internet version of the proposed rule, it isnot the official version of the proposed rule for purposes of public comment. Please refer to the official version in a forthcoming FR publication, which will appear on the Government Printing Office’s FDsys website ([https://www.gpo.gov/fdsys/](https://www.gpo.gov/fdsys/)). It will also appear on [Regulations.gov](Regulations.gov) ([https://www.regulations.gov/](https://www.regulations.gov/)) in Docket No. EPA-HQ-OW-2022-0114 Once the official version of this document is published in the FR, this version will be removed from the Internet and replaced with a link to the official version. 6560-50-P ENVIRONMENTAL PROTECTION AGENCY 40 CFR Parts 141 and 142 [EPA-HQ-OW-2022-0114; FRL 8543-01-OW] RIN 2040-AG18 PFAS National Primary Drinking Water Regulation Rulemaking AGENCY: Environmental Protection Agency (EPA) . ACTION: Preliminary regulatory determination and proposed rule; request for public comment; notice of public hearing SUMMARY: The Environmental Protection Agency (EPA) is committed to using and advancing the best available science to tackle per-and polyfluoroalkyl substances (PFAS) pollution, protect public health, and harmonize policies that strengthen public health protections with infrastructure funding to help communities, especially disadvantaged communities, deliver safe drinking water. In March 2021, EPA issued a final regulatory determination to regulate perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) as contaminants under Safe Drinking Water Act (SDWA). In this notice, EPA is issuing a preliminary regulatory determination to regulate perfluorohexane sulfonic acid (PFHxS), hexafluoropropylene oxide dimer acid (HFPO-DA) and its ammonium salt (also known as a GenX chemicals) , perfluorononanoic acid (PFNA), and perfluorobutane sulfonic acid (PFBS), and mixtures of these PFAS as contaminants under SDWA. Through this action, EPA is also proposing a National Primary Drinking Water Regulation (NPDWR) and health-based Maximum Contaminant Level Goals (MCLG) for these four PFAS and their mixtures as well as for PFOA and PFOS. EPA is proposing to set the healthbased value, the MCLG, for PFOA and PFOS at zero. Considering feasibility, including currently available analytical methods to measure and treat these chemicals in drinking water, EPA is proposing individual MCLs of 4.0 nanograms per liter (ng/L) or parts per trillion (ppt) for PFOA and PFOS. EPA is proposing to use a Hazard Index (HI) approach to protecting public health from mixtures of PFHxS, HFPO-DA and its ammonium salt, PFNA, and PFBS because of their known and additive toxic effects and occurrence and likely co-occurrence in drinking water. EPA is proposing an HI of 1.0 as the MCLGs for these four PFAS and any mixture containing one or more of them because it represents a level at which no known or anticipated adverse effects on the health of persons is expected to occur and which allows for an adequate margin of safety. EPA has determined it is also feasible to set the MCLs for these four PFAS and for a mixture containing one or more of PFHxS, HFPO-DA and its ammonium salt, PFNA, PFBS asan HI of unitless 1.0. The Agency is requesting comment on this action, including this proposed NPDWR and MCLGs, and have identified specific areas where public input will be helpful for EPA in developing the final rule. In addition to seeking written input, the EPA will be holding a public hearing on May 4, 2023. DATES: Comments must be received on or before [INSERT DATE 60 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER] . Comments on the information collection provisions submitted to the Office of Management and Budget (OMB) under the Paperwork Reduction Act (PRA)

FAQs

Which PFAS does EPA propose to regulate under the Safe Drinking Water Act in this notice?

EPA proposes to regulate PFHxS, HFPO-DA and its ammonium salt (GenX chemicals), PFNA, PFBS, and mixtures of these PFAS as contaminants under the SDWA, alongside PFOA and PFOS.

How does EPA propose to set Maximum Contaminant Level Goals (MCLGs) and Maximum Contaminant Levels (MCLs)?

EPA proposes MCLGs for PFOA and PFOS at zero and proposes individual MCLs of 4.0 ng/L (parts per trillion). For mixtures of PFHxS, HFPO-DA (ammonium salt), PFNA, and PFBS, EPA proposes using a Hazard Index approach with an HI of 1.0 and corresponding unitless 1.0 MCLs.

How and where can the public submit comments, and when is the hearing?

Comments must be submitted to the docket identified by EPA-HQ-OW-2022-0114 via the Federal eRulemaking Portal or by mail/hand delivery as listed. EPA will hold a virtual public hearing on May 4, 2023.

Sep 15, 2026

Uploaded by Aldword