The EPA PFAS drinking water rule explained: limits, deadlines and what is proposed

What is the status of the EPA PFAS drinking water rule today?

EPA’s 2024 rule is in place, and two May 2026 proposals would change parts of it. One would let water systems request until 2031 to meet the PFOA and PFOS limits. The other would remove limits for four other PFAS. Neither is final in the EPA pages checked today.

Status as of October 30, 2026

• In place: EPA announced the final PFAS drinking water rule on April 10, 2024. It covers six PFAS.
• Proposed, not final: On May 18, 2026, EPA proposed to uphold the PFOA and PFOS limits and let water systems request two more years, to 2031.
• Proposed, not final: A separate proposal would rescind the regulations for PFHxS, PFNA, HFPO-DA and Hazard Index mixtures of these three PFAS plus PFBS.
• Comment period: Closed July 20, 2026 for both proposals.
• Sources: EPA’s rule page and proposed-rule pages (EPA’s extension and rescission pages were last updated October 8, 2026) and the Federal Register notice published May 20, 2026.

Rules change. Check EPA’s pages before you act on a deadline.

This guide reports what those pages say. It does not predict how EPA will finish either proposal. Our blog post on the 2031 proposal follows the same story as a news item.

What does the 2024 PFAS drinking water rule require?

It sets legally enforceable limits, called maximum contaminant levels, for six PFAS in public drinking water. EPA says PFOA and PFOS are limited to 4.0 parts per trillion each. The rule sets monitoring and treatment duties for public water systems.

Here are the limits EPA published in April 2024. The MCL column is the enforceable level. The goal column is a health-based target that is not enforceable.

EPA says compliance is judged by running annual averages at the sampling point. The table is the rule as written in 2024. The rescission proposal covers the bottom four rows, as the status box notes.

What are the deadlines?

Water systems must finish initial monitoring by 2027 and meet the limits by 2029 under the 2024 rule. EPA proposed that systems could request until April 26, 2031 for PFOA and PFOS only. Monitoring and reporting dates stay the same.

Two details matter. First, the extension would be a request, not an automatic delay. The Federal Register notice says it would apply to systems that submit a request. Second, it would cover PFOA and PFOS, not the other regulated PFAS.

What would the proposed rules change for me?

Little changes for you today, but your utility could get more time. EPA proposes that systems with PFOA or PFOS at or above 12 ppt would have to take short-term steps to cut exposure while an exemption lasts. Customers would hear about any extension.

EPA’s proposal includes protections for customers:

• Systems granted an extension must notify the people they serve.
• Systems with a PFOA or PFOS result at or above 12 ppt must take short-term mitigation actions.
• Systems at or above the 4.0 ppt limits must still do the most frequent monitoring.
• Community systems must give customers sample results annually or biannually, per EPA.
• Notices must say why the extension exists and how the system will comply by April 2031.

EPA also says the proposal does not change the 4.0 ppt limits for PFOA and PFOS. It describes the aim as giving systems time to collect data, choose a fix, build and test controls, finance changes and staff the work.

On the second proposal, EPA says its rescission of the other four PFAS limits is solely based on a need to correct the process used to issue them, and that it will take steps to evaluate additional PFAS for future regulation once it takes final action. EPA also says it cannot predict the outcome.

Does the rule cover private wells or only public water?

It covers public water systems only. EPA says the rule’s duties fall on public water systems, and that it does not regulate or provide recommended standards for private wells. Well owners must test on their own and decide what to do.

If your home uses a private well, our PFAS testing guide for property owners shows how to find a lab, how sampling works and how to compare results. EPA’s lab method page says to contact your state laboratory certification program for PFAS-capable labs.

If you use a public system, your best first step is to ask the utility for its PFOA and PFOS results. Missouri DNR also keeps a PFAS Viewer Tool that maps voluntary sampling at public systems.

How do water systems meet a 4.0 ppt limit?

They add treatment that captures PFAS or switch to a cleaner source. AES’s water treatment page lists granular activated carbon, ion exchange and reverse osmosis as the main technologies, and says testing data decides the right design for each site.

AES describes each option this way:

AES also says it partners with certified facilities for safe destruction and disposal of treatment residuals.

The right choice depends on water chemistry, flow rate and the PFAS present. That is why testing comes first. AES’s PFAS water treatment page explains its approach, and the PFAS drinking water page covers how PFAS reach water supplies.

Where can I follow rule changes?

Use EPA’s rule page and its two proposed-rule pages, plus the Federal Register. EPA’s pages list the dockets, hearing materials and notices. The Federal Register entries show the official text and dates.

The status box above shows the date this guide was last checked against those pages.

How did the rule get here?

EPA moved from a 2021 decision to regulate PFOA and PFOS, to a 2023 proposal, to the final 2024 rule, to the 2026 proposals. The table below walks through the steps EPA lists on its pages.

EPA says it evaluated over 120,000 public comments on the 2023 proposal before it finalized the rule.

What is a Hazard Index limit?

It is one combined limit for mixtures of PFAS. EPA says it uses a Hazard Index to account for the combined and co-occurring levels of PFAS in drinking water. The limit covers mixtures with at least two of PFHxS, PFNA, HFPO-DA and PFBS.

A single number is easy to read. A mixture limit adds the effect of several PFAS together. EPA lists the Hazard Index in the table above as a unitless value of 1. The rescission proposal would remove this limit, along with the individual limits for PFHxS, PFNA and HFPO-DA.

What should a property owner or business do now?

Do not wait for the final rule. Know your water source, get your own data and plan treatment if results are high. EPA says the 4.0 ppt limits for PFOA and PFOS stay under the proposal, so planning for them is safe.

1. Find your water source. Public system or private well?
2. Ask for results. Public customers can request the utility’s PFOA and PFOS data.
3. Test private water. Use a certified lab. See the testing guide.
4. Compare to 4.0 ppt. Use it as a yardstick for PFOA and PFOS.
5. Plan treatment early. EPA says systems need time to diagnose, design, build and test controls, so lead times are long.
6. Keep records. Save lab reports, dates and invoices.

For health questions, talk to your doctor. EPA points people who remain concerned to its page on meaningful and achievable steps to reduce risk.

Why does the limit matter if my water looks and tastes fine?

PFAS cannot be seen, tasted or smelled in water, so only a lab test shows them. Missouri DNR says some PFAS in the environment may be linked to harmful health effects and can build up in people and animals over time. That is why the limits are so low.

DNR also notes that PFAS can be found in water, soil, air and food, as well as in materials in homes and workplaces. A drinking water limit covers one pathway. Your utility’s results tell you about that pathway, not about every exposure.

Next step

If you manage a water system, a facility or a property with PFAS concerns, call AES at (314) 865-2662 or use the quote form at /contact. Start with the PFAS water treatment page. AES says its team is available 24/7 for urgent cleanup needs.