PFAS in Montana tap water

2 of 45 tested systems measured above the federal limit. 5 had a detection of any kind.

Every public water system below was required by the EPA to test for 29 PFAS compounds. Sorted by the highest PFOA or PFOS reading, worst first. Find yours for the full set of readings and what removes them.

Water system	Highest PFOA	Highest PFOS	Found	Against the 4 ppt limit
Kalispell Public Works	none detected	6.6 ppt	2 of 29	Above
Alpine Village Wua	none detected	4.1 ppt	1 of 29	Above
Anaconda Water Department	none detected	none detected	0 of 29	Within
Belgrade City of	none detected	none detected	0 of 29	Within
Big Pines Trailer Court	none detected	none detected	0 of 29	Within
Big Sky County Water and Sewer Dist 363	none detected	none detected	1 of 29	Within
Bigfork County Water and Sewer	none detected	none detected	0 of 29	Within
Billings City of	none detected	none detected	0 of 29	Within
Black Rock Estates Subdivision	none detected	none detected	0 of 29	Within
Bozeman City of	none detected	none detected	0 of 29	Within
Butte Silverbow Water Dept	none detected	none detected	0 of 29	Within
Co Water Dist of Billings Heights	none detected	none detected	0 of 29	Within
Columbia Falls City of	none detected	none detected	0 of 29	Within
Culligan Water Conditioning Great Falls	none detected	none detected	0 of 29	Within
Dillon City of	none detected	none detected	0 of 29	Within
Fairfield Town of	none detected	none detected	0 of 29	Within
Flathead County Water and Sewer	none detected	none detected	0 of 29	Within
Frenchtown High School	none detected	none detected	0 of 29	Within
Glendive City of	none detected	none detected	0 of 29	Within
Great Falls City of	none detected	none detected	0 of 29	Within
Hamilton City of	none detected	none detected	1 of 29	Within
Hardin City of	none detected	none detected	0 of 29	Within
Havre City of	none detected	none detected	0 of 29	Within
Helena Water System	none detected	none detected	0 of 29	Within
Laurel Municipal Water System	none detected	none detected	0 of 29	Within
Lewistown City of	none detected	none detected	0 of 29	Within
Libby City of	none detected	none detected	0 of 29	Within
Livingston City of	none detected	none detected	0 of 29	Within
Lockwood Water and Sewer District	none detected	none detected	0 of 29	Within
Malmstrom Air Force Base	none detected	none detected	1 of 29	Within
Miles City City of	none detected	none detected	0 of 29	Within
Missoula Water	none detected	none detected	0 of 29	Within
Montana State University Billings	none detected	none detected	0 of 29	Within
Montana State University Bozeman	none detected	none detected	0 of 29	Within
Phantom Hills Water System	none detected	none detected	0 of 29	Within
Pinesdale Town of	none detected	none detected	0 of 29	Within
Polson City of	none detected	none detected	0 of 29	Within
River Rock County Water and Sewer Dist	none detected	none detected	0 of 29	Within
Rocky Mountain College	none detected	none detected	0 of 29	Within
Shelby City of	none detected	none detected	0 of 29	Within
Sidney City of	none detected	none detected	0 of 29	Within
Sun Prairie Village County	none detected	none detected	0 of 29	Within
University of Montana	none detected	none detected	0 of 29	Within
West Yellowstone Town of	none detected	none detected	0 of 29	Within
Whitefish City of	none detected	none detected	0 of 29	Within

All 45 systems the EPA tested in Montana, every one of them with its own page. Each was tested for 29 PFAS compounds.

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Source, the EPA’s fifth Unregulated Contaminant Monitoring Rule, final dataset published 2026-10-15. Original data →