Montana utilities with very hard water.

Above 180 mg/L (10.5 grains per gallon). 60 utilities serving 63,863 people as they report it, largest first.

All 60, by people served

Montana utilities with very hard water, 1 to 60
Utility	Based in	Serves	Hardness, mg/L	Grains per gallon
Kalispell Public Works	Kalispell	25,000	204	11.9
City of Columbia Falls	Columbia Falls	4,450	252	14.7
River Rock County Water and Sewer Dist	Belgrade	4,200	229	13.4
City of Shelby	Shelby	3,970	247	14.4
Lolo Water and Sewer Dist	Lolo	3,315	196	11.5
Dry Prairie Rural Water Authority	Culbertson	3,005	247	14.4
City of Colstrip	Colstrip	2,350	191	11.1
Rae Water and Sewer Dist 313	Bozeman	2,325	228	13.3
City of Malta	Malta	1,800	385	22.5
City of Choteau	Choteau	1,691	337	19.7
El Mar Estates Msla Co Water	Frenchtown	1,350	200	11.7
Valley Grove Subdivision	Bozeman	825	259	15.2
Phantom Hills Water System	Missoula	810	218	12.7
Town of Cascade	Cascade	650	237	13.9
Ptarmigan Village Inc	Whitefish	600	262	15.3
Vaughn Cascade County Water and Sewer	Vaughn	585	240	14
Gore Hill County Water Dist	Great Falls	500	726	42.4
Town of Fromberg	Fromberg	498	609	35.6
Wylie Creek Estates Subdivision	Belgrade	400	268	15.7
Stone Creek Subdivision	Billings	378	688	40.2
Sundance Subdivision	Billings	378	862	50.4
Cooke City Water District	Cooke City	300	197	11.5
Town of Ryegate	Ryegate	270	497	29.1
Country Lake Homes Whitefish	Whitefish	260	300	17.5
Granite Park Water Association	Billings	250	1060	62
Wilsall Water District	Wilsall	250	275	16.1
Wells Garden Estates	Billings	240	833	48.7
Skycrest Estates Subdivision	Billings	235	1020	59.6
Huntley Yellowstone Co Water and Sewer	Huntley	230	259	15.2
Crystal Springs Water System	Billings	225	512	29.9
Belfry Carbon Co Water and Sewer Dist	Belfry	205	331	19.3
Oak Ridge Estates	Billings	200	917	53.6
West Valley Pines HOA Inc	Kalispell	130	226	13.2
Two Mile Tract HOA	Kalispell	128	256	15
West Mountain Estates	Alberton	125	250	14.6
The Benches	Whitefish	123	190	11.1
Town of Opheim	Opheim	111	206	12
Town of Grass Range	Grass Range	102	203	11.9
Aldinger Acres Subdivision	Billings	100	667	39
River Grove Estates Tr CT	Billings	100	744	43.5
Springwater Colony	Harlowton	100	418	24.5
Buffalo Mountain Subdivision	Whitefish	90	192	11.2
Town of Flaxville	Flaxville	82	408	23.9
Aspen Knoll	Kalispell	75	255	14.9
Black Rock Estates Subdivision	Billings	75	638	37.3
Duck Creek Mobile Home Park	Billings	70	422	24.7
Wood Ridge HOA	Kalispell	70	260	15.2
Hillcrest Community Water	Kalispell	65	308	18
Sweetgrass Ranch Subdivision	Kalispell	65	266	15.6
Dwaynes Village	Marion	63	228	13.3
Blue Grass Water Users Association	Billings	60	888	51.9
South Chester Water Dist	Chester	55	240	14
Fieldstone Subdivision	Whitefish	52	194	11.3
Crane Mountain Estates	Bigfork - Lake Co	50	271	15.8
Stone Ridge Water Company	Polson	50	210	12.3
Whitefish Hills Village	Whitefish	50	240	14
Timbers at Whitefish the	Kalispell	40	212	12.4
Brook Drive Water Assn	Kalispell	32	236	13.8
Timber Ridge HOA	Columbia Falls	30	276	16.1
East View Acres Water System	Missoula	25	258	15.1

Source: Montana Department of Environmental Quality, Public Water Supply, 104 utilities, results from Jan. 8, 2015 to Aug. 18, 2026, read Oct. 18, 2026. Each sampling point is taken at its median; a figure is typical where every point falls in one band.

Bands are the U.S. Geological Survey’s, at 17.1 mg/L to the grain. People served is what each utility reports; where one sells water to another, the same people can be counted twice. How hardness is measured here.

All 60, by people served

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