Rule tracker
The EPA PFAS rule, and what is only a proposal
The federal position on PFAS moved twice in 2026 and a lot of coverage got it wrong. Here is the split that matters: what is enforceable today, and what EPA has only proposed.
Evidence last checked . Spot something out of date?
The short version
The 4 ppt limits for PFOA and PFOS are still law. EPA kept them. What EPA proposed in May 2026 was two more years for water systems to comply, plus dropping the limits on four other PFAS. Neither proposal is final, so all six limits stand today.
Enforceable right now
These come from the National Primary Drinking Water Regulation finalised in April 2024. They apply to public water systems, not to private wells.
| Compound | Limit | Type |
|---|---|---|
| PFOA | 4.0 ppt | Individual limit |
| PFOS | 4.0 ppt | Individual limit |
| PFHxS | 10 ppt | Individual limit |
| PFNA | 10 ppt | Individual limit |
| HFPO-DA (GenX) | 10 ppt | Individual limit |
| Hazard Index | 1.0 (unitless) | For mixtures of PFHxS, PFNA, HFPO-DA and PFBS |
ppt means parts per trillion. It is the same unit as ng/L. Four parts per trillion is roughly four drops in a thousand Olympic swimming pools.
The deadlines
- By 2027
- Public water systems must finish initial PFAS monitoring, and public notification of results begins.
- By April 2029
- Public water systems must meet the limits. This is the compliance date in force today.
- April 2031
- Only if the proposed extension is finalised. Systems could request two extra years. Not law yet.
Proposed, not final
EPA announced both of these on 18 May 2026. The comment period closed on 20 July 2026 after a public hearing on 7 July 2026. Neither has been finalised, so neither changes anything yet.
1. Two more years to comply with the PFOA and PFOS limits
Systems could ask for an extension from April 2029 to April 2031. The 4 ppt limits themselves are not changed by this. EPA has said systems running at or above 12 ppt would have to put interim measures in place during any extension.
2. Rescinding the limits on four other PFAS
This would remove the drinking water regulations for PFHxS, PFNA, HFPO-DA (GenX) and the Hazard Index for mixtures. PFOA and PFOS are not part of it. Until it is finalised, all four limits still apply.
What this means for your tap
Less than you might think. The rule governs water systems, not households. Three practical points:
- Your utility may be years from compliance. The deadline is 2029, and could become 2031. A system over the limit today is not breaking the law today.
- Wells are not covered. No limit applies to a private well and nobody tests it for you.
- A certified filter is not a guarantee of 4 ppt. EPA says plainly that current filter certification standards do not yet show a filter will get PFAS down to the levels EPA has set. We explain why that gap exists here.
Common questions
Is the 4 ppt PFAS limit still law?
Yes. The 4.0 parts per trillion limits for PFOA and PFOS are in force. EPA announced it will keep them. What EPA proposed in May 2026 was extra time to comply, not a weaker number.
Did EPA cancel the PFAS rule?
No. EPA proposed rescinding the limits for four of the six regulated PFAS: PFHxS, PFNA, HFPO-DA (GenX) and the Hazard Index for mixtures. That proposal is not final. Those limits remain on the books today. The PFOA and PFOS limits were never part of the rescission proposal.
When do water systems have to comply?
Public water systems must finish initial monitoring by 2027 and meet the limits by April 2029. EPA has proposed letting systems request two more years, to April 2031, but that extension is not final.
Does this rule cover my private well?
No. The federal rule applies to public water systems. If you are on a private well, nobody is required to test your water and no limit applies to it. Testing is up to you.
Will my water be under 4 ppt once my utility complies?
That is the target for public water systems. It does not describe what a home filter will do. EPA says current filter certification standards do not yet show that a filter will bring PFAS down to the levels EPA has set.