PFAS in Montana drinking water
EPA's final UCMR 5 data covers 45 public water systems in Montana, serving about 604,723 people. PFAS turned up in 5 of them (11%). 0 averaged above at least one EPA limit at a sampling point.
Every tested system in Montana
Largest first. PFOA and PFOS columns show the average at each system's worst sampling point; EPA's limit for each is 4 ppt. Filter by name:
| Water system | People | PFOA | PFOS | PFAS found | Result |
|---|---|---|---|---|---|
| City of Billings · Billings | 114,000 | - | - | 0 | None found |
| Missoula Water · Missoula | 68,200 | - | - | 0 | None found |
| City of Great Falls · Great Falls | 60,000 | - | - | 0 | None found |
| City of Bozeman · Bozeman | 56,000 | - | - | 0 | None found |
| Butte Silverbow Water Dept · Butte | 33,000 | - | - | 0 | None found |
| Helena Water System · Helena | 32,091 | - | - | 0 | None found |
| Kalispell Public Works · Kalispell | 25,000 | - | 3.3 | 2 | Sample at limit |
| Montana State University Bozeman · Bozeman | 19,200 | - | - | 0 | None found |
| University of Montana · Missoula | 15,000 | - | - | 0 | None found |
| CO Water Dist of Billings Heights · Billings | 12,000 | - | - | 0 | None found |
| City of Belgrade · Belgrade | 10,460 | - | - | 0 | None found |
| City of Whitefish · Whitefish | 10,418 | - | - | 0 | None found |
| City of Havre · Havre | 9,921 | - | - | 0 | None found |
| Town of West Yellowstone · West Yellowstone | 9,899 | - | - | 0 | None found |
| City of Miles City · Miles City | 9,565 | - | - | 0 | None found |
| Malmstrom Air Force Base · Malmstrom Air Force Base | 8,850 | - | - | 1 | Below limits |
| Flathead County Water and Sewer · Kalispell | 7,775 | - | - | 0 | None found |
| City of Livingston · Livingston | 7,500 | - | - | 0 | None found |
| Anaconda Water Department · Anaconda | 6,750 | - | - | 0 | None found |
| Laurel Municipal Water System · Laurel | 6,339 | - | - | 0 | None found |
| Bigfork County Water and Sewer · Bigfork | 6,100 | - | - | 0 | None found |
| City of Lewistown · Lewistown | 5,923 | - | - | 0 | None found |
| Lockwood Water and Sewer District · Billings | 5,900 | - | - | 0 | None found |
| Rocky Mountain College · Billings | 5,700 | - | - | 0 | None found |
| City of Hamilton · Hamilton | 5,660 | - | - | 1 | Below limits |
| City of Polson · Polson | 5,300 | - | - | 0 | None found |
| City of Sidney · Sidney | 5,000 | - | - | 0 | None found |
| City of Libby · Libby | 4,892 | - | - | 0 | None found |
| City of Glendive · Glendive | 4,873 | - | - | 0 | None found |
| City of Columbia Falls · Columbia Falls | 4,450 | - | - | 0 | None found |
| City of Dillon · Dillon | 4,300 | - | - | 0 | None found |
| River Rock County Water and Sewer Dist · Belgrade | 4,200 | - | - | 0 | None found |
| Big Sky County Water and Sewer Dist 363 · Big Sky | 4,132 | - | - | 1 | Below limits |
| City of Shelby · Shelby | 3,970 | - | - | 0 | None found |
| City of Hardin · Hardin | 3,500 | - | - | 0 | None found |
| Montana State University Billings · Billings | 2,999 | - | - | 0 | None found |
| Sun Prairie Village County · Great Falls | 1,800 | - | - | 0 | None found |
| Culligan Water Conditioning Great Falls · Great Falls | 900 | - | - | 0 | None found |
| Phantom Hills Water System · Missoula | 810 | - | - | 0 | None found |
| Town of Pinesdale · Pinesdale | 800 | - | - | 0 | None found |
| Town of Fairfield · Fairfield | 718 | - | - | 0 | None found |
| Frenchtown High School · Frenchtown | 550 | - | - | 0 | None found |
| Alpine Village Wua · Columbia Falls | 125 | - | 2.1 | 1 | Sample at limit |
| Big Pines Trailer Court · Missoula | 78 | - | - | 0 | None found |
| Black Rock Estates Subdivision · Billings | 75 | - | - | 0 | None found |
On a private well in Montana?
EPA's program only covers public systems. Private wells are never part of UCMR 5, so the only way to know is to test. Our well testing guide covers which lab tests to order, and the best well water systems covers what to install once you have results.
Cite this page
Well & Tap. "PFAS in Montana drinking water: results for 45 systems." Data: U.S. EPA UCMR 5, final release August 2026. https://wellandtap.com/pfas/montana/
Source: EPA UCMR 5 final occurrence data (August 2026); population from EPA SDWIS. Method.