Tap Water Results

PFAS in US tap water

EPA's final UCMR 5 results: 9,934 community water systems tested for 29 PFAS from 2023 to 2025. 1,099 systems serving 54.2 million people had at least one entry-point average above a 2024 federal limit.

National report: what EPA's final UCMR 5 data shows →
State-by-state results, the largest systems above a limit, and how our counts compare with EPA's. Dated, with data and a suggested citation.

The limits

PFASLimitSystems overPeople served
PFOA4 ppt75538.1 million
PFOS4 ppt84945.7 million
PFHxS · proposed for rescission10 ppt634.3 million
PFNA · proposed for rescission10 ppt9163,771
HFPO-DA (GenX) · proposed for rescission10 ppt8190,246
PFAS Hazard Index · proposed for rescission1774.6 million

Largest systems above a PFAS limit

By state

Each state links to its dated PFAS report: chart, rankings, downloadable data and a citation. National report →

StateTestedAbove limitPeople served
Florida3941249.7 million
California6911298.9 million
New Jersey2451105.1 million
Pennsylvania360854.2 million
Texas1130282.8 million
North Carolina285662.5 million
South Carolina163532 million
New York322311.9 million
Virginia164121.8 million
Ohio331351.5 million
Puerto Rico96151.5 million
Alabama307561.4 million
Massachusetts261751.3 million
Georgia252271.3 million
Connecticut62291.2 million
Washington245201.2 million
Arizona15921845,012
Delaware3411637,113
Nevada373488,064
Illinois47913353,817
Tennessee27517344,152
Minnesota19710270,387
Oklahoma1678250,611
Alaska282226,251
Oregon1239226,133
New Hampshire499222,708
Michigan3115219,330
Rhode Island267207,864
Kentucky2309199,762
Wisconsin19618184,985
Indiana2196166,389
Maryland7613162,211
Guam51139,207
Colorado1584101,207
West Virginia991099,088
Iowa151185,791
Mississippi235584,633
Nebraska51383,158
Kansas102377,468
Missouri227673,399
Northern Mariana Islands1148,524
Maine39222,328
Idaho61221,500
Utah127214,975
Wyoming32110,330
Louisiana26316,354
New Mexico7712,286
American Samoa100
Arkansas17200
District of Columbia300
Hawaii4400
Montana4000
North Dakota4100
South Dakota5500
U.S. Virgin Islands200
Vermont3400

Questions

What are the PFAS limits for drinking water?

The April 2024 federal rule set limits of 4 ppt each for PFOA and PFOS, 10 ppt each for PFHxS, PFNA and HFPO-DA (GenX), and a Hazard Index of 1 for mixtures of PFHxS, PFNA, GenX and PFBS. In May 2026 EPA proposed keeping the PFOA and PFOS limits with a compliance date of 2031, and rescinding the other four. That proposal is not final.

Does a result above the limit mean my water is in violation?

No. Systems don't have to meet the PFAS limits until 2029 (or 2031 if EPA finalizes its proposal), and compliance will be based on four quarters of compliance monitoring. EPA says UCMR 5 results do not indicate compliance. They do show which systems have work to do.

How were these results calculated?

We average each entry point's UCMR 5 results (non-detects as zero, only full sets of 2 or 4 samples) and compare them to the limits with EPA's rounding, the same method EPA uses in its July 2026 data summary. Our counts match EPA's published table. Method.

What if my system was not tested?

EPA tested every community system serving more than 3,300 people and a sample of smaller ones. If yours was not tested there is no federal result: not tested is not the same as not detected. Ask your utility or state, or test your own tap with a certified lab.

Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.