The EPA is rolling back PFAS limits

What the 2024 rule established

In April 2024, the Biden administration finalized the first-ever National Primary Drinking Water Regulation for PFAS. The rule set enforceable Maximum Contaminant Levels for six compounds: PFOA and PFOS at 4 parts per trillion individually; PFNA, PFHxS, and HFPO-DA (GenX) at 10 parts per trillion individually; and a hazard index for mixtures of PFNA, PFHxS, HFPO-DA, and PFBS. Water systems were given until 2027 to achieve compliance, with testing requirements beginning earlier.

The 4 parts-per-trillion limit for PFOA and PFOS represented the lowest enforceable drinking water standard in EPA history. The rule required approximately 66,000 public water systems to test and, where necessary, treat or blend water sources to meet the new limits.

What the 2026 revision changed

The Trump EPA's 2026 revision retained the PFOA and PFOS limits at 4 parts per trillion with the original 2027 compliance deadline. The revision extended compliance deadlines to 2031 for the four remaining compounds — PFNA, PFHxS, HFPO-DA (GenX), and the mixture hazard index — and rescinded the enforceable MCLs for those four, replacing them with non-enforceable health advisory levels while the agency conducts additional review.

The practical effect: utilities that had begun treatment upgrades for the four rescinded compounds have uncertain regulatory futures. Households on systems where those compounds are the primary PFAS concern face a longer wait for utility-level treatment.

PFOA and PFOS, however, cover the majority of detections in the UCMR 5 data — an estimated 176 million people are exposed to PFAS at detectable levels, with PFOA and PFOS accounting for most detected systems. The retained 2027 deadline means utilities serving those households are still under enforceable obligation to achieve compliance within the next year.

What state regulation looks like

Several states had enacted PFAS standards before or alongside the federal rule, and those state standards are unaffected by the federal revision. Massachusetts enforces a 20 parts-per-trillion combined limit for six PFAS compounds. California set limits across 10 compounds in 2023. New York, Vermont, and New Hampshire all have active state-level PFAS programs with compliance deadlines independent of federal action.

If you are in a state with its own PFAS standard, your utility is operating under requirements that may be stricter than the current federal minimum. Check your state drinking water agency's website for the current applicable standard — the picture varies significantly by state.

What to do now, independent of regulation

The regulatory timeline — whether 2027 or 2031 — does not change what is in the water coming out of your tap today. For households concerned about PFAS exposure, the two actions that matter now are the same regardless of where the federal compliance deadline lands.

Test your water. SimpleLab's Tap Score PFAS panel uses EPA Methods 537.1 and 533 to test your specific tap water — not the utility's monitoring point, but the water at your faucet, which may differ due to household plumbing and building age. Results arrive in five to ten business days and are benchmarked against current EPA MCLs and independent health guidance values.

Filter with certified technology. An NSF/ANSI 53-certified carbon filter or NSF/ANSI 58-certified reverse osmosis system reduces PFAS at the point of use today, without waiting for utility compliance in 2027 or 2031. The certified filter is the household tool that exists now, independent of what regulators do next.

What to do right now

1. 1 Read your utility's Consumer Confidence Report. Required to be mailed or posted online by July 1 each year, it now includes UCMR 5 PFAS monitoring results. Look for PFOA and PFOS specifically — those are the compounds with the retained 2027 deadline.
2. 2 Test your tap if your CCR shows detectable PFAS. A Tap Score or SimpleLab PFAS panel (~$200 to $250) tells you what is arriving at your specific faucet. Utility averages do not reflect your household's exact exposure.
3. 3 Do not wait for 2027 or 2031. A quality under-sink RO system certified to NSF 58 costs $150 to $300 and is available now. The regulatory timeline determines when your utility must act — it has no bearing on when you can act yourself.
4. 4 Check your state's standard. If you are in California, Massachusetts, New York, Vermont, or New Hampshire, your utility may already be under a stricter compliance obligation than the current federal standard. Your state drinking water agency's website has current applicable limits.