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Tap water · PFAS

PFAS in tap water: EPA's tests by water system

EPA had water systems test for 29 PFAS (“forever chemicals”) and lithium between Jan. 3, 2023 and June 17, 2026 (UCMR 5). Here is where PFOA and PFOS, the two with EPA's 4.0 ppt limit from 2029, were found. Enter your ZIP code to find your water system.

PFAS: where EPA's tests found PFOA or PFOS at or above 4.0 ppt

AK58%ME10%WI6%VT0%NH43%WA25%ID13%MT4%ND0%MN9%IL5%MI4%NY14%MA32%OR8%NV16%WY3%SD2%IA14%IN10%OH39%PA45%NJ78%CT65%RI26%CA29%UT12%CO10%NE8%MO6%KY27%WV13%VA35%MD3%DE77%AZ15%NM5%KS4%AR0%TN13%NC46%SC54%DC0%OK12%LA10%MS4%AL32%GA19%HI0%TX28%FL52%PR61%GU80%MP100%AS0%VI0%
under 5%5 to 15%15 to 30%30 to 50%50% or moreShare of each state's people on a tested system with PFOA or PFOS at or above 4.0 ppt in at least one EPA test, 2023 to 2026.

1,693 of 9,952 community water systems tested had PFOA or PFOS at or above 4.0 ppt in at least one result (serving 81,132,333 people); PFAS of any kind were found at 3,503 systems. One-time EPA testing, not a compliance test: a result at or above a limit is not a violation.

How to read these results

UCMR 5 is EPA's one-time testing of 29 PFAS and lithium, to learn where they occur; it is not a compliance test. A result at or above a limit is not a violation: under the 2024 rule a system is judged on the running annual average at each entry point from 2029 (EPA proposed in May 2026 to let systems ask for two more years, to 2031, for PFOA and PFOS; not final). Labs report a result only at or above EPA's minimum reporting level (4.0 ppt for PFOA and PFOS); a lower amount is reported as not found. The tests covered all systems serving 3,300 people or more and a sample of smaller ones.

PFAS found most often (systems)

PFPeA2,009PFBA1,891PFHxA1,762PFBS1,671PFOS (EPA limit)1,319PFOA (EPA limit)1,273PFHxS (EPA limit)1,016PFHpA5396:2 FTS182PFNA (EPA limit)78

Systems with PFOA or PFOS at or above 4.0 ppt, highest result first

Source: EPA, UCMR 5 occurrence data (final data, file of Oct. 15, 2026); community water systems on EPA's current list. Limits: EPA's PFAS drinking water rule of April 2024. PFOA: Limit set by EPA in April 2024; water systems must meet it from April 26, 2029 (EPA proposed in May 2026 to allow until 2031). PFHxS: Limit set by EPA in April 2024; EPA proposed in May 2026 to rescind it.