When do utilities have to comply with PFAS MCLs?

Utilities must complete initial monitoring by April 2026 and achieve compliance with MCLs by April 2029.

Which PFAS compounds now have federal limits?

PFOA and PFOS each have an MCL of 4 parts per trillion. PFNA, PFHxS, and HFPO-DA (GenX) have individual MCLs. There is also a hazard index limit for mixtures of PFNA, PFHxS, HFPO-DA, and PFBS.

What happens if a utility exceeds the MCL during the compliance window?

Utilities must notify customers and begin planning compliance actions. Formal enforcement actions typically follow after the 2029 compliance deadline.

Are smaller utilities covered by the PFAS rule?

Yes. The rule applies to all community water systems and non-transient non-community systems, regardless of size.

Where can I find my utility's PFAS monitoring data?

EPA's UCMR 5 database contains monitoring data collected since 2023. Your utility's CCR and Water Utility Report also display official records.

Policy & Records·5 min read·2026-05-01

PFAS Drinking Water Rules in 2026: What Has Changed

PFASMCLEPA rulecompliance

Key Takeaways

1
EPA finalized Maximum Contaminant Levels for six PFAS compounds in April 2024.
2
Utilities have until 2029 to comply — the rule is in effect, but systems are not yet required to meet limits.
3
PFOA and PFOS limits are set at 4 parts per trillion individually.
4
Utilities must begin monitoring and public notification under the new rule.

EPA's April 2024 PFAS drinking water rule established the first-ever federal limits for PFAS in public water supplies. As of 2026, utilities are in the monitoring and transition phase. Here is what the rule requires and what it means for records you may see on Water Utility Report.

What the 2024 rule established

The National Primary Drinking Water Regulation for PFAS set MCLs for six compounds: PFOA (4 ppt), PFOS (4 ppt), PFNA, PFHxS, HFPO-DA (GenX), and a hazard index for mixtures of PFNA, PFHxS, HFPO-DA, and PFBS.

The compliance timeline

Utilities had until April 2026 to complete initial monitoring. They have until April 2029 to install treatment or make operational changes needed to meet the MCLs. During this window, utilities may have monitoring records showing PFAS detections without being in formal violation.

Monitoring records from 2024–2029 reflect the transition period. A utility with PFAS detections on record may be actively planning compliance actions. Water Utility Report displays official monitoring records — not compliance determinations.

What this does not mean

A monitoring record showing PFAS above 4 ppt does not automatically mean a utility is violating its permit during the compliance transition period.
Water Utility Report does not assess whether a water supply meets current standards.
These records do not describe treatment currently in use at your utility.

What to check next

Check your utility's PFAS monitoring records on Water Utility Report.
Look for public notice records — utilities must notify customers if PFAS exceed certain levels.
Review your utility's Consumer Confidence Report for information on treatment and compliance plans.
Contact your utility for information on their PFAS compliance timeline.

Frequently Asked Questions

Sources

Last updated: 2026-05-01 · Water Utility Report

Contaminants & Records

UCMR 5 PFAS Sampling: What the Records Actually Show

6 min

Contaminants & Records

PFAS Detected But No Violation Listed: Why That Happens

5 min

Contaminants & Records

MRL vs. MCL: What Those Numbers in Water Records Actually Mean

4 min

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