PFAS Contamination by State: Where Forever Chemicals Are Worst

The most direct measure of which states have the most PFAS in their water is EPA's own testing of public water systems. From 2023 to 2025 EPA had about 10,000 public water systems tested for PFAS, and the share over its new 4 ppt limit for PFOA or PFOS was highest in Connecticut and New Jersey (44% each), then Delaware, Florida and South Carolina (about one in three). Only seven states and Washington, D.C. had no tested system over the limit. Below is your state's number, your state's own limit, and how to look up the result for your own town.

Which states have the most PFAS in water?

Connecticut and New Jersey had the highest share of public water systems over EPA's 4 ppt limit for PFOA or PFOS, at 44% each. These numbers come from UCMR 5, the nationwide PFAS testing EPA ran from 2023 to 2025. It covered every water system serving more than 3,300 people plus a sample of smaller ones, and EPA released the final results in August 2026.

The numbers here count a system once if any of its sampling points averaged 4 ppt or more of PFOA or PFOS, the same way EPA's own summary counts them. The last column is the systems at 12 ppt or more, three times the limit.

A few things to keep in mind. A small state with few systems moves a lot on a handful of results: Delaware's 33% is 12 systems out of 36. A big state with many systems can look low: Texas had 27 systems over the limit, but out of 1,124 tested. Michigan, which has its own limits, had one of the lowest shares (5 of 319). EPA's own estimate for the whole country, weighted to account for the small systems it did not test, is 7.8% of systems over a PFAS limit, and 15.5% of large systems serving more than 10,000 people.

Why PFAS maps rank states differently

A PFAS map counts places, not the share of a state's water over the limit. The EWG PFAS map, from an environmental advocacy group, puts every water system with any PFAS detected on the same map as industrial and military sites: 9,728 sites in its March 5, 2026 update. EPA publishes its own map, the PFAS Analytic Tools. A state with many sites on a map will not always rank high on tested water over EPA's limit, so the two lists will not match. For the water you drink, the UCMR 5 numbers above and your utility's own results are the ones that matter.

Does my state have its own PFAS limit?

Several states set their own enforceable PFAS limits before EPA did, and until 2029 a utility answers to its state's limit, if it has one. EPA's 4 ppt limits for PFOA and PFOS apply in every state, but utilities have until April 26, 2029 to meet them. These are the states with their own numbers or a recent change:

After April 26, 2029, EPA's 4 ppt limits for PFOA and PFOS apply in every state, including the ones with higher state numbers.

How to find PFAS results for your town

If your city water system serves more than 3,300 people, its PFAS results from EPA's testing are already public. Three places to look, in order:

1. Search EPA's PFAS results for your utility

   Look up your water system by name in EPA's UCMR 5 Data Finder. It shows each PFAS your utility tested for and what it found. EPA lists results in micrograms per liter, where 0.004 is 4 ppt.

2. Read your annual water quality report

   Utilities that found PFAS in that testing had to list it in their water quality report (the Consumer Confidence Report). Starting in 2027, every community system puts its PFAS results there.

3. Test your tap water

   Your utility's results come from its own sampling points, not your tap. When a caller in Florida on city water asked me about PFAS, I said: "I would, uh, have a local testing lab check for PFAS." Our PFAS water test kit ($349) is a lab test for 14 PFAS by EPA Method 537.1.

PFAS in private wells

EPA's PFAS limits cover public water systems only, so a private well gets tested for PFAS only when its owner has it tested. New Jersey is the exception: a well has to be tested for PFOA, PFOS and PFNA when the home is sold or leased.

Wells are not safe from it because they are not on city water. In USGS's tap water study, at least one PFAS turned up in 40% of public-supply taps and 20% of private wells, at about the same levels in both. A well owner in New York with an old Air Force base down the road told me, "they test for PFOs now."

The complete well water test we sell does not include PFAS. A caller in Pennsylvania read me the answer off our page: "It says, 'Does this include PFAs and radiologicals?' And it says, 'No.'" The PFAS water test kit is the one that measures it.

Have a PFAS result in hand?

Text me your PFAS numbers

Send a photo of the lab report or your utility's results. I will tell you which numbers are over EPA's limits and what I would do next.

Text Aidan443-277-2204 Call800-460-5810Aidan

8 AM to 5 PM Eastern, seven days a week. A real person, not a call center.

PFAS near military bases

EPA lists firefighting foam, used in training and emergencies at military bases and airports, as a source of PFAS in drinking water. The foam the military used is called AFFF. The Defense Department's PFAS site tracks its investigation and cleanup at current and former military installations, with a progress chart updated through June 30, 2026, and a "PFAS Cleanup in Your Area" section. If you live near a base, check there first, then look up your water system or test your well as described above.

What to do if your PFAS is high

If your result is over 4 ppt for PFOA or PFOS, EPA's advice to well owners is to consider other water for drinking, cooking and baby formula, and a home filter certified to lower PFAS. On city water, your utility has to get under EPA's limit by 2029, and under your state's limit sooner if your state has one.

Reverse osmosis, activated carbon and PFAS resin all reduce PFAS. When people call me with a PFAS result, most of them go with carbon: "Carbon, most of our customers use carbon." None of the whole-house tanks or reverse osmosis units we sell is certified for PFAS; the one PFAS-certified item we sell is the Pentair FloPlus Protect 20BB cartridge. How to weigh carbon, resin and RO for your numbers is its own page: choosing a PFAS water filter. Our PFAS water filters are all on one page.

Frequently asked questions