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When do EPA's PFAS limits take effect?

EPA's PFAS limits are final but not enforced until April 26, 2029. What they are, what EPA proposed in 2026, and how many utilities are over them now.

TapBuffUpdated 4 min read

The short answer

EPA set drinking water limits for six PFAS in April 2024, and utilities must meet them by April 26, 2029. Until then a result above one is not a violation. In May 2026 EPA proposed giving utilities that ask until 2031 to meet the PFOA and PFOS limits, and dropping the other four. Neither proposal is final, so the 2024 rule stands.

When do EPA's PFAS limits take effect?

The limits

EPA's April 2024 rule gave six PFAS an enforceable limit and a health goal. The limit is what a utility will have to meet. The health goal is the level below which EPA expects no risk to health, and it is not enforced.

PFASNew limitHealth goal
PFOA4.0 pptzero
PFOS4.0 pptzero
PFHxS10 ppt10 ppt
PFNA10 ppt10 ppt
HFPO-DA (GenX)10 ppt10 ppt
Mixtures of PFHxS, PFNA, GenX and PFBSHazard Index of 1Hazard Index of 1

The last line is the sixth. The Hazard Index adds up how close each of those four is to its own health-based level, so water can break it when two or more are present even if none is over its own limit.

PFOA and PFOS have a health goal of zero because EPA classifies both as likely to cause cancer and found no level below which there is no cancer risk. Their pages cover the other health effects EPA found.

Why the date is 2029

The rule was final in April 2024, but utilities were given time to test and then to build treatment:

  • By 2027: utilities finish their first round of PFAS monitoring and begin giving the public their results.
  • April 26, 2029: utilities must meet the limits. From then on, a utility over a limit has to bring it down and tell its customers about the violation.

Compliance is judged on a running annual average at each sampling point, not on one sample. So a single sample above 4.0 ppt is not a violation today, and would not by itself be one after 2029 either. That is why TapBuff's reports call such a result above EPA's new limit, which takes effect in 2029, and keep "above the legal limit" for limits already enforced.

What EPA proposed in May 2026

EPA published two proposals in the Federal Register on May 20, 2026.

PFOA and PFOS: the same limits, possibly more time. EPA proposed keeping both limits at 4.0 ppt, but letting utilities that request an exemption have until April 26, 2031. EPA ties the need for more time to things like finding a new water source, building and testing treatment, financing and staffing. A utility given the extra time would still monitor on the 2024 schedule, would have to tell its customers, and would have to take short-term steps where PFOA or PFOS is at or above 12 ppt.

PFHxS, PFNA, GenX and the Hazard Index: withdrawn. EPA proposed removing those four limits and their health goals. Its stated reason is procedural: EPA says the law did not allow it to decide to regulate these PFAS and set their limits in the same step. It is not a finding that they are safe. EPA says it will consider regulating more PFAS afterward, and that the result could be stricter.

Comments on both proposals closed July 20, 2026. As of October 17, 2026, the Federal Register shows no final rule on either. A proposal changes nothing until it is final, so for now the 2024 rule, with all six limits and the 2029 date, is what stands.

How many utilities are over them now

EPA's UCMR 5 program tested 9,947 utilities for 29 PFAS, with sampling from 2023 through 2025 and some samples collected into June 2026. At 1,665 of them, at least one sample of PFOA or PFOS was above 4.0 ppt. Those utilities report serving about 80 million people.

The other limits were crossed far less often. At least one sample was above 10 ppt at 167 utilities for PFHxS, 19 for PFNA and 17 for GenX.

These are single samples, not the annual averages the limits are judged by, and some utilities have added treatment since. Whether a utility complies will be decided by its own monitoring under the rule.

EPA's own comparison comes closer: its final UCMR 5 summary averages each sampling location's samples, two for a well and four for surface water. By that measure, 1,136 utilities had a location above a 2024 limit. TapBuff lists every one, state by state, with the data to download.

What it means for your water

The 2029 date sets when your utility must comply. It is not a date you have to wait for. Look up your utility to see each PFAS it found, against the new limit and the health goal:

What’s in your water?

Matched to your utility using EPA records.

If a result is above the new limit or the health goal, a filter certified to reduce PFOA and PFOS is one way to lower what you drink now. Do water filters remove PFAS? explains which certifications to look for and what they can't promise yet, and the PFAS filter picks list every filter TapBuff tracks with one of those claims.

Questions people ask

Is it a violation if my water is above 4 ppt today?
No. The limits are not enforced until April 26, 2029. Even then, a utility is judged on a running annual average at each sampling point, not on one sample.
Will the 2029 deadline be pushed back?
Possibly, for PFOA and PFOS. In May 2026 EPA proposed letting utilities that request it have until April 26, 2031. That proposal is not final. As of October 17, 2026, the Federal Register shows no final rule.
Do the limits for PFHxS, PFNA and GenX still apply?
Yes, for now. EPA proposed withdrawing them in May 2026, but a proposal changes nothing until it is final, and none has been published.
When will my utility tell me its PFAS results?
Under the 2024 rule, utilities finish their first round of PFAS monitoring by 2027 and begin giving the public their results that year. Most utilities serving more than 3,300 people already have results from EPA's UCMR 5 testing, and TapBuff shows them.

Sources

  1. Per- and Polyfluoroalkyl Substances (PFAS): Final PFAS National Primary Drinking Water Regulation, U.S. EPA. Checked Oct. 10, 2026.
  2. PFAS National Primary Drinking Water Regulation (final rule, April 26, 2024), Federal Register. Checked Oct. 10, 2026.
  3. Extending the Compliance Deadline for the PFOA and PFOS Maximum Contaminant Levels (proposed rule, May 20, 2026), Federal Register. Checked Oct. 10, 2026.
  4. Rescission of Regulatory Determinations and Removal of Related Provisions for Four PFAS Substances (proposed rule, May 20, 2026), Federal Register. Checked Oct. 10, 2026.
  5. Proposed PFOA and PFOS Compliance Extension Rule, U.S. EPA. Checked Oct. 10, 2026.
  6. Proposed PFAS Rescission Rule, U.S. EPA. Checked Oct. 10, 2026.
  7. Federal Register: EPA documents mentioning PFAS, newest first (no final rule on either 2026 proposal), Federal Register. Checked Oct. 13, 2026.
  8. The Fifth Unregulated Contaminant Monitoring Rule (UCMR 5) Data Summary: July 2026 (EPA 815-S-26-007), Table 4, U.S. EPA. Checked Oct. 13, 2026.
  9. EPA UCMR 5 occurrence data (the 2023 to 2025 program; samples collected January 2023 to June 2026; final dataset released August 2026), U.S. EPA. Checked Oct. 13, 2026.

Published · Last reviewed . Where every figure comes from and how it is checked: the methodology.

Spotted something wrong or out of date? Write to info@tapbuff.com.

How TapBuff checks this

Limits come from EPA, standards from NSF’s own documents, and certifications from the certifier’s listing, never the box. Every source is dated.

Methodology

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