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PFAS in Montana drinking water

40 community water systems tested

5%
of tested systems detected PFOA or PFOS
(2/40)

PFAS — “forever chemicals” — are synthetic compounds that accumulate in the body and are linked to cancer, liver damage and immune effects. In 2024 the EPA set enforceable limits of 4 parts per trillion each for PFOA and PFOS. These are the only nationwide PFAS measurements, from the EPA’s UCMR-5 program.

Water systems

PFAS value per system, 2023–2025. EPA limit — 4 ppt (0.004 µg/L) for PFOA and PFOS, set in 2024. Systems that detected PFOA or PFOS are highlighted and listed first. “Not detected” means the contaminant was measured but not found.
SystemCityPopulationPFAS (ug/L)
KALISPELL PUBLIC WORKS KALISPELL 25,000 0.0066 ug/L
ALPINE VILLAGE WUA WHITEFISH 125 0.0041 ug/L
BILLINGS CITY OF BILLINGS 114,000 Not detected
MISSOULA WATER MISSOULA 68,200 Not detected
GREAT FALLS CITY OF GREAT FALLS 60,000 Not detected
BOZEMAN CITY OF BOZEMAN 56,000 Not detected
BUTTE SILVERBOW WATER DEPT BUTTE 33,000 Not detected
HELENA WATER SYSTEM HELENA 32,091 Not detected
BILLINGS HEIGHTS CO WATER DIST OF BILLINGS 12,000 Not detected
BELGRADE CITY OF BELGRADE 10,460 Not detected
WHITEFISH CITY OF WHITEFISH 10,418 Not detected
HAVRE CITY OF HAVRE 9,921 Not detected
WEST YELLOWSTONE TOWN OF WEST YELLOWSTONE 9,899 Not detected
MILES CITY CITY OF MILES CITY 9,565 Not detected
MALMSTROM AIR FORCE BASE GREAT FALLS 8,850 Not detected
FLATHEAD COUNTY WATER AND SEWER KALISPELL 7,775 Not detected
LIVINGSTON CITY OF LIVINGSTON 7,500 Not detected
ANACONDA WATER DEPARTMENT ANACONDA 6,750 Not detected
LAUREL MUNICIPAL WATER SYSTEM LAUREL 6,339 Not detected
BIGFORK COUNTY WATER AND SEWER BIGFORK 6,100 Not detected
LEWISTOWN CITY OF LEWISTOWN 5,923 Not detected
LOCKWOOD WATER AND SEWER DISTRICT BILLINGS 5,900 Not detected
HAMILTON CITY OF HAMILTON 5,660 Not detected
POLSON CITY OF POLSON 5,300 Not detected
SIDNEY CITY OF SIDNEY 5,000 Not detected
LIBBY CITY OF LIBBY 4,892 Not detected
GLENDIVE CITY OF GLENDIVE 4,873 Not detected
TOWN OF BROWNING 4,671 Not detected
COLUMBIA FALLS CITY OF COLUMBIA FALLS 4,450 Not detected
DILLON CITY OF DILLON 4,300 Not detected
RIVER ROCK COUNTY WATER AND SEWER DIST BELGRADE 4,200 Not detected
BIG SKY COUNTY WATER AND SEWER DIST 363 BIG SKY 4,132 Not detected
SHELBY CITY OF SHELBY 3,970 Not detected
HARDIN CITY OF HARDIN 3,500 Not detected
SUN PRAIRIE VILLAGE COUNTY GREAT FALLS 1,800 Not detected
PHANTOM HILLS WATER SYSTEM MISSOULA 810 Not detected
PINESDALE TOWN OF PINESDALE 800 Not detected
FAIRFIELD TOWN OF FAIRFIELD 718 Not detected
BIG PINES TRAILER COURT MISSOULA 78 Not detected
BLACK ROCK ESTATES SUBDIVISION BILLINGS 75 Not detected