State drinking water records
Montana drinking water systems
848 community water systems serve Montana and are listed below under 55 counties and on the pages of 298 cities and towns. Their own population figures add up to 822,886 people, a sum that counts people twice where one system sells water to another.
167 of them (20%) had at least one health-based violation in the last 10 years. 100 systems still have one unresolved.
715 rely mainly on groundwater and 133 on surface water, counting water bought from other systems.
793 systems filed a lead service line inventory listing 483 lead lines, 2,766 galvanized lines that must be replaced and 71,563 lines of unknown material.
213 systems are placed by mailing address or by the county their records name: EPA has no service area map for 202 of them, and 11 have one that does not line up with their own records.
- Community water systems
- 848
- People served, sum of each system's own figure
- 822,886
- Systems with a health-based violation, last 10 years
- 167
- Systems with one unresolved
- 100
- Lead service lines in inventories
- 483
Counties
55 countiesEach county counts the systems whose service area map reaches it. Systems placed only by a mailing address are listed on the county pages but not counted here.
| County | Systems | People served | With a health-based violation, 10 years | With one unresolved |
|---|---|---|---|---|
| Beaverhead County | 9 | 5,574 | 3 | 0 |
| Big Horn County | 8 | 7,759 | 4 | 6 |
| Blaine County | 10 | 6,125 | 6 | 2 |
| Broadwater County | 2 | 2,150 | 0 | 0 |
| Carbon County | 8 | 4,603 | 1 | 3 |
| Carter County | 1 | 400 | 0 | 0 |
| Cascade County | 30 | 79,291 | 8 | 4 |
| Chouteau County | 9 | 5,798 | 4 | 0 |
| Custer County | 1 | 9,565 | 1 | 0 |
| Daniels County | 2 | 1,108 | 1 | 0 |
| Dawson County | 8 | 7,339 | 2 | 1 |
| Deer Lodge County | 4 | 7,799 | 0 | 1 |
| Fallon County | 4 | 2,185 | 1 | 1 |
| Fergus County | 9 | 7,276 | 2 | 2 |
| Flathead County | 91 | 72,198 | 5 | 10 |
| Gallatin County | 48 | 102,972 | 5 | 2 |
| Garfield County | 1 | 364 | 0 | 1 |
| Glacier County | 13 | 12,035 | 7 | 2 |
| Golden Valley County | 1 | 270 | 1 | 0 |
| Granite County | 1 | 1,360 | 1 | 1 |
| Hill County | 9 | 15,798 | 3 | 0 |
| Jefferson County | 12 | 5,263 | 4 | 2 |
| Judith Basin County | 3 | 675 | 0 | 0 |
| Lake County | 34 | 15,699 | 8 | 2 |
| Lewis and Clark County | 46 | 45,386 | 12 | 4 |
| Liberty County | 4 | 1,180 | 1 | 1 |
| Lincoln County | 13 | 10,094 | 6 | 0 |
| Madison County | 7 | 8,538 | 2 | 0 |
| McCone County | 1 | 644 | 0 | 0 |
| Meagher County | 2 | 1,075 | 0 | 1 |
| Mineral County | 7 | 1,951 | 2 | 0 |
| Missoula County | 71 | 83,871 | 11 | 8 |
| Musselshell County | 3 | 2,145 | 0 | 1 |
| Park County | 14 | 9,992 | 2 | 1 |
| Petroleum County | 1 | 187 | 0 | 1 |
| Phillips County | 6 | 2,364 | 1 | 1 |
| Pondera County | 10 | 4,978 | 4 | 1 |
| Powder River County | 1 | 450 | 0 | 0 |
| Powell County | 1 | 2,900 | 0 | 0 |
| Ravalli County | 22 | 11,071 | 3 | 1 |
| Richland County | 5 | 6,280 | 1 | 1 |
| Roosevelt County | 9 | 12,866 | 0 | 3 |
| Rosebud County | 7 | 8,626 | 6 | 0 |
| Sanders County | 15 | 6,679 | 5 | 1 |
| Sheridan County | 5 | 2,627 | 0 | 0 |
| Silver Bow County | 3 | 35,062 | 1 | 0 |
| Stillwater County | 5 | 3,220 | 0 | 1 |
| Sweet Grass County | 3 | 1,760 | 1 | 0 |
| Teton County | 7 | 3,228 | 2 | 2 |
| Toole County | 7 | 5,113 | 3 | 4 |
| Treasure County | 1 | 262 | 1 | 0 |
| Valley County | 9 | 5,899 | 4 | 2 |
| Wheatland County | 4 | 1,326 | 0 | 0 |
| Wibaux County | 1 | 550 | 1 | 1 |
| Yellowstone County | 31 | 146,114 | 9 | 2 |
Largest systems
| System | Main county | People served | Main source | Health-based violations, 10 years | Unresolved | Lead lines |
|---|---|---|---|---|---|---|
| City of Billings | Yellowstone County | 114,000 | Surface water | 0 | 0 | 0 |
| Missoula Water | Missoula County | 68,200 | Groundwater | 0 | 0 | 0 |
| City of Great Falls | Cascade County | 60,000 | Surface water | 5 | 0 | 156 |
| City of Bozeman | Gallatin County | 56,000 | Surface water | 0 | 0 | 0 |
| Butte Silverbow Water Dept | Silver Bow County | 33,000 | Surface water | 1 | 0 | 20 |
| Helena Water System | Lewis and Clark County | 32,091 | Surface water | 3 | 0 | 0 |
| Kalispell Public Works | Flathead County | 25,000 | Groundwater | 0 | 0 | 40 |
| Billings Heights Co Water Dist of | Yellowstone County | 12,000 | Purchased surface water | 0 | 0 | 0 |
| City of Belgrade | Gallatin County | 10,460 | Groundwater | 0 | 0 | 0 |
| City of Whitefish | Flathead County | 10,418 | Surface water | 0 | 0 | 0 |
| City of Havre | Hill County | 9,921 | Surface water | 2 | 0 | 140 |
| Town of West Yellowstone | Gallatin County | 9,899 | Groundwater | 1 | 0 | 0 |
| City of Miles City | Custer County | 9,565 | Surface water | 3 | 0 | 0 |
| Malmstrom Air Force Base | Cascade County | 8,850 | Purchased surface water | 2 | 0 | 0 |
| Flathead County Water and Sewer | Flathead County | 7,775 | Groundwater | 0 | 0 | 0 |
Systems with unresolved health-based violations
100 systems| System | Main county | People served | Main source | Health-based violations, 10 years | Unresolved | Lead lines |
|---|---|---|---|---|---|---|
| Town of Philipsburg | Granite County | 1,360 | Surface water | 19 | 9 | 0 |
| Wegner Water Service Hauler | Big Horn County | 50 | Purchased surface water | 0 | 7 | 0 |
| Big Bend Ranch Subdivision | Cascade County | 100 | Groundwater | 1 | 4 | 0 |
| Prairie Water Company | Cascade County | 1,000 | Purchased surface water | 0 | 3 | 0 |
| Wyola Water System | Big Horn County | 281 | Groundwater | 3 | 3 | 0 |
| Casitas Del Rio | Dawson County | 216 | Purchased surface water | 0 | 3 | No inventory |
| Sand Coulee Water Users District | Cascade County | 180 | Groundwater | 1 | 3 | No inventory |
| C & C Community Inc | Yellowstone County | 145 | Purchased surface water | 0 | 3 | 0 |
| Town of Dodson | Phillips County | 120 | Groundwater | 3 | 3 | No inventory |
| Spring Tree Ridge | Cascade County | 80 | Groundwater | 1 | 3 | 0 |
| Fishermans Village Subdivision | Gallatin County | 25 | Groundwater | 5 | 3 | 0 |
| City of Poplar | Roosevelt County | 3,025 | Purchased surface water | 0 | 2 | 0 |
| City of Harlem | Blaine County | 820 | Surface water | 40 | 2 | 0 |
| Worden Ballantine Yellowstone | Yellowstone County | 800 | Groundwater under direct influence | 8 | 2 | 0 |
| Town of Wibaux | Wibaux County | 550 | Groundwater | 1 | 2 | 9 |
| Pryor Water System | Big Horn County | 406 | Groundwater | 2 | 2 | 0 |
| Town of Jordan | Garfield County | 364 | Groundwater | 0 | 2 | 0 |
| Heart Butte School | Pondera County | 250 | Groundwater under direct influence | 7 | 2 | 0 |
| Elkhorn Health and Rehabilitation LLC | Jefferson County | 89 | Groundwater | 0 | 2 | 0 |
| South Chouteau County Water Dist | Chouteau County | 80 | Groundwater | 1 | 2 | 0 |
| Devon Water Inc | Toole County | 75 | Purchased groundwater | 2 | 2 | 0 |
| Bonnie's Place, Inc | Missoula County | 60 | Groundwater | 0 | 2 | 0 |
| Sky View Estates | Flathead County | 60 | Groundwater | 0 | 2 | 0 |
| Elk Park Village | Flathead County | 35 | Groundwater | 0 | 2 | 0 |
| Bahny Brae Subdivision | Lewis and Clark County | 35 | Groundwater | 1 | 2 | 0 |
| City of Shelby | Toole County | 3,970 | Groundwater | 0 | 1 | 3 |
| Dry Prairie Rural Water Authority | Roosevelt County | 3,005 | Purchased surface water | 0 | 1 | No inventory |
| Crow Agency Water System | Big Horn County | 2,057 | Surface water | 17 | 1 | 0 |
| City of White Sulphur Springs | Meagher County | 1,000 | Surface water | 0 | 1 | 0 |
| Meadow Lake Co Water and Sewer District | Flathead County | 950 | Groundwater | 0 | 1 | 0 |
| Westview Mobile Home Park | Missoula County | 947 | Groundwater | 1 | 1 | 0 |
| Town of Chester | Liberty County | 870 | Surface water | 0 | 1 | 2 |
| Jefferson Hills WUA | Jefferson County | 780 | Groundwater | 1 | 1 | 0 |
| Ten Mile and Pleasant Valley WUA | Lewis and Clark County | 750 | Groundwater | 1 | 1 | 0 |
| Montana State Hospital Complex | Deer Lodge County | 721 | Groundwater | 0 | 1 | 0 |
| Genesis Business Park | Gallatin County | 670 | Groundwater | 0 | 1 | No inventory |
| Town of Joliet | Carbon County | 600 | Groundwater | 0 | 1 | 0 |
| Cherry Creek Estates LLC | Yellowstone County | 600 | Purchased surface water | 0 | 1 | 0 |
| Busby Community Water System | Big Horn County | 535 | Groundwater | 3 | 1 | 0 |
| Windsor Estates | Yellowstone County | 530 | Purchased surface water | 0 | 1 | 0 |
| Missoula KOA & El Mar TLR Village | Missoula County | 499 | Groundwater | 1 | 1 | 0 |
| Town of Fromberg | Carbon County | 498 | Groundwater | 2 | 1 | 0 |
| Country Estates Water Supply | Flathead County | 490 | Groundwater | 0 | 1 | 0 |
| McHugh Mobile Home Park | Lewis and Clark County | 490 | Groundwater | 0 | 1 | 0 |
| Town of Lodge Grass | Big Horn County | 480 | Groundwater | 0 | 1 | 0 |
| Coram County Water and Sewer District | Flathead County | 450 | Groundwater | 0 | 1 | 0 |
| Meadow Manor | Flathead County | 410 | Purchased groundwater | 0 | 1 | 0 |
| La Casa Grande Water and Sewer District | Lewis and Clark County | 404 | Groundwater | 0 | 1 | 0 |
| Town of Bainville | Roosevelt County | 350 | Purchased surface water | 0 | 1 | 0 |
| Town of Dutton | Teton County | 338 | Groundwater | 1 | 1 | 0 |
| Town of Nashua | Valley County | 300 | Purchased surface water | 0 | 1 | 0 |
| Jette Lake Landowners Association | Lake County | 295 | Groundwater | 0 | 1 | No inventory |
| Town of Winifred | Fergus County | 274 | Groundwater | 1 | 1 | 0 |
| Alpine Pacific Utilities | Flathead County | 270 | Groundwater | 0 | 1 | 0 |
| Blue Sky Heights WUA Clancy | Jefferson County | 250 | Groundwater | 0 | 1 | 0 |
| Hinsdale Water Department | Valley County | 250 | Groundwater | 2 | 1 | 0 |
| Hilltop Terrace Subdivision | Flathead County | 230 | Groundwater | 1 | 1 | 0 |
| Sage Creek Co Water District | Liberty County | 225 | Groundwater | 0 | 1 | 0 |
| Flathead County Water Dist 101 | Flathead County | 210 | Groundwater | 0 | 1 | 0 |
| Belfry Carbon Co Water and Sewer Dist | Carbon County | 205 | Groundwater | 0 | 1 | 0 |
| Town of Winnett | Petroleum County | 187 | Groundwater | 0 | 1 | 0 |
| Town of Moore | Fergus County | 186 | Groundwater | 0 | 1 | 0 |
| Town of Melstone | Musselshell County | 170 | Groundwater | 0 | 1 | 0 |
| Martinsdale Colony | Wheatland County | 150 | Groundwater | 0 | 1 | 0 |
| Holbrook Estates | Flathead County | 120 | Groundwater | 0 | 1 | 0 |
| Wettington Water District Inc | Flathead County | 119 | Groundwater | 1 | 1 | No inventory |
| Mt Ellis Academy | Gallatin County | 106 | Groundwater | 2 | 1 | 0 |
| Sweetgrass Water Users Assn | Toole County | 100 | Purchased surface water | 1 | 1 | 0 |
| Bynum - Teton Co W & S District | Teton County | 100 | Groundwater | 0 | 1 | 0 |
| Paradise Pines | Lake County | 95 | Groundwater | 0 | 1 | 0 |
| Camrose Colony | Toole County | 95 | Purchased surface water | 2 | 1 | 0 |
| Piegan Border Station | Glacier County | 94 | Surface water | 0 | 1 | 0 |
| Nine Mile Co Water and Sewer District | Toole County | 90 | Purchased groundwater | 0 | 1 | 0 |
| Springdale Hutterite Colony | Meagher County | 87 | Groundwater | 0 | 1 | 0 |
| Richland Co Valley View WUA | Richland County | 85 | Groundwater | 10 | 1 | 0 |
| Fallon County Water District | Fallon County | 85 | Purchased groundwater | 0 | 1 | 0 |
| Elk Creek Colony | Lewis and Clark County | 84 | Groundwater | 7 | 1 | 0 |
| Valley Water System the | Missoula County | 82 | Groundwater | 0 | 1 | 0 |
| Hidden Lake Colony | Glacier County | 80 | Groundwater | 2 | 1 | 0 |
| Big Pines Trailer Court | Missoula County | 78 | Groundwater | 0 | 1 | No inventory |
| Montana Trailer Court | Missoula County | 73 | Groundwater | 0 | 1 | No inventory |
| Rapelje Water District | Stillwater County | 70 | Groundwater | 0 | 1 | 0 |
| Missoula Village West TR CT | Missoula County | 68 | Groundwater | 1 | 1 | No inventory |
| Blackfeet Dorm. Water System | Glacier County | 66 | Groundwater | 1 | 1 | 0 |
| CSKT Division of Fire Management | Lake County | 60 | Groundwater | 0 | 1 | 0 |
| King Ranch Colony | Fergus County | 56 | Groundwater | 22 | 1 | 0 |
| Hot Springs Court | Sanders County | 55 | Groundwater | 21 | 1 | 0 |
| Mountain Shadows Estates Stevensville | Ravalli County | 55 | Groundwater | 1 | 1 | 0 |
| Skyview Park | Flathead County | 55 | Purchased groundwater | 1 | 1 | 0 |
| Pine Crest TR Pk | Park County | 54 | Groundwater | 4 | 1 | 0 |
| Deerfield Hutterite Colony | Fergus County | 51 | Groundwater | 0 | 1 | 0 |
| Turner Colony | Blaine County | 50 | Groundwater | 14 | 1 | 0 |
| Pinnacle Estates of Glendive | Dawson County | 50 | Groundwater | 6 | 1 | 0 |
| Hawarden Square Butte Water | Chouteau County | 50 | Purchased groundwater | 0 | 1 | 0 |
| Renae Court Subdivision | Missoula County | 36 | Groundwater | 0 | 1 | 0 |
| Big Sky Mobile Manor | Flathead County | 35 | Purchased groundwater | 0 | 1 | 0 |
| Rainbow Estates | Dawson County | 30 | Groundwater | 2 | 1 | 0 |
| Swan Ridge HOA | Flathead County | 28 | Groundwater | 1 | 1 | 0 |
| Ashley Trails | Flathead County | 27 | Groundwater | 0 | 1 | 0 |
| East View Acres Water System | Missoula County | 25 | Groundwater | 2 | 1 | 0 |
Counties come from the counties EPA lists each system serving, matched to 2024 Census counties; where EPA lists none, from the county coded in the system's ID, its service area map, or its mailing address. A county holding at least a fifth of a system's service area map is added when at least a fifth of that map lies in those counties. Towns are the ones EPA lists and the Census places such a map covers, always inside those counties. In New England, where EPA's town names a whole Town, it is not matched to the village of the same name. A system is not listed in a county holding less than a fifth of its map, or in a county or town its map reaches when the map lies mostly outside the counties EPA lists, so a page can leave out a system that serves part of the area. Methodology and limitations