Public Water Systems
2,263 active public water systems in MT, tracked from EPA's Safe Drinking Water Information System (SDWIS) across all 50 states. See our methodology.
| System Name | Location | Population | Violations | PFAS |
| Valier Town Of | Valier, MT | 452 | 133 | - |
| Broadus Town Of | Broadus, MT | 450 | 160 | - |
| Consolidated Charlo Lake Co W and S Dist | Charlo, MT | 450 | 179 | - |
| Coram County Water and Sewer District | Coram, MT | 450 | 46 | - |
| Froid Town Of | Froid, MT | 450 | 107 | - |
| Greenacres County Water and Sewer Dist | Kalispell, MT | 450 | 9 | - |
| Corvallis Primary School | Corvallis, MT | 450 | 73 | - |
| Baxter Creek No 2 HOA | Belgrade, MT | 450 | 288 | - |
| North Valley County Water and Sewer Dist | Glasgow, MT | 450 | 134 | - |
| Andesite Ridge Water System | Big Sky, MT | 450 | 34 | - |
| Fort Smith Water and Sewer District | Fort Smith, MT | 450 | 830 | - |
| Showdown Ski Lift Inc | Neihart, MT | 448 | 26 | - |
| Sanders County Harvest Foods | Polson, MT | 445 | 284 | - |
| Country Estates Water Supply | Kalispell, MT | 430 | 112 | - |
| Stanford Town Of | Stanford, MT | 425 | 859 | - |
| Bushard Water Company | Black Eagle, MT | 425 | 18 | - |
| Twin Bridges Town Of | Twin Bridges, MT | 424 | 18 | - |
| Culligan Water Facility Butte | Butte, MT | 423 | 113 | - |
| Mountain View Co-Op Ulm | Black Eagle, MT | 421 | 56 | - |
| Bonner School District No 14 | Bonner, MT | 420 | 272 | - |
| Elder Grove School Buildings 1 & 2 | Billings, MT | 420 | 13 | - |
| Woodys Country Store | Kalispell, MT | 418 | 108 | - |
| Chico Hot Springs | Belgrade, MT | 415 | 419 | - |
| Clearwater Bar Paws Up Ranch | Greenough, MT | 413 | 84 | - |
| Blacktail Grocery | Polson, MT | 413 | 18 | - |
| Anderson Stevenson Wilke Funeral Home | Helena, MT | 411 | 10 | - |
| Meadow Manor | Kalispell, MT | 410 | 20 | - |
| Bannack St Park Visitor Center | Dillon, MT | 410 | 13 | - |
| Libby Christian Church | Libby, MT | 406 | 11 | - |
| Fics Kwik Six | Deer Lodge, MT | 405 | 18 | - |
| La Casa Grande Water and Sewer District | East Helena, MT | 404 | 48 | - |
| Seeley Lake Campground | Seeley Lake, MT | 404 | 16 | - |
| Discovery Ski Area | Phillipsburg, MT | 401 | 100 | - |
| Ekalaka Town Of | Ekalaka, MT | 400 | 58 | - |
| Round Butte Water Company | Ronan, MT | 400 | 38 | - |
| Ashland Water and Sewer Dist | Ashland, MT | 400 | 650 | - |
| Trail Star Cafe and Truck Stop | Glendive, MT | 400 | 64 | - |
| Manhattan Christian Schools | Manhattan, MT | 400 | 464 | - |
| Hysham Rest Area Eastbound | Billings, MT | 400 | 9 | - |
| Custer Rest Area Eastbound | Billings, MT | 400 | 31 | - |
| Custer Rest Area Westbound | Billings, MT | 400 | 43 | - |
| Bridger Rest Area | Billings, MT | 400 | 63 | - |
| Lake McDonald Lodge | West Glacier, MT | 400 | 1 | - |
| Rising Sun Campground | West Glacier, MT | 400 | 3 | - |
| Troy Rest Area | Kalispell, MT | 400 | 10 | - |
| Swiftcurrent Campground | West Glacier, MT | 400 | 6 | - |
| The Historic Florence | Missoula, MT | 400 | 228 | - |
| Wylie Creek Estates Subdivision | Bozeman, MT | 400 | 10 | - |
| Skyview Water and Sewer Utility | East Helena, MT | 400 | 69 | - |
| Golden Estates Homeowners Association | East Helena, MT | 400 | 357 | - |