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 |
| Alfresco RV & Storage | Libby, MT | 44 | 47 | - |
| Moonlight Estates HOA | Helena, MT | 44 | 74 | - |
| Lake Mary Ronan State Park | Kalispell, MT | 44 | 19 | - |
| Avista Utilities Noxon Rapids Dam | Noxon, MT | 43 | 17 | - |
| Milltown Community PWS System | Bonner, MT | 43 | 29 | - |
| Birchwood Duplexes | Missoula, MT | 43 | 27 | - |
| Fort Three Forks Motel and RV Pk | Three Forks, MT | 43 | 40 | - |
| HI Country Tavern and Grill | Saint Cloud, MT | 43 | 97 | - |
| Crown Passage Northwest LLC Girls | Heron, MT | 43 | 114 | - |
| North Big Arm Bay Loa | Elmo, MT | 43 | 6 | - |
| Lewellen Enterprises LLC | Whitefish, MT | 43 | 90 | - |
| Stray Bullet Commercial Bldg | Ovando, MT | 43 | 12 | - |
| Lil Sprouts Daycare | Florence, MT | 43 | 72 | - |
| Mountain View Trailer Court | Missoula, MT | 42 | 339 | - |
| Hansen Family Campground & Storage LLC | Havre, MT | 42 | 19 | - |
| North Harlem Colony | Harlem, MT | 42 | 132 | - |
| Summit Mountain Lodge | East Glacier Park, MT | 42 | 217 | - |
| Great Beginnings Montessori Foothills | Bozeman, MT | 42 | 92 | - |
| Tamarack of the Wildwood | Lakeside, MT | 42 | 15 | - |
| Hearts and Hands Montessori | Belgrade, MT | 42 | 460 | - |
| Sunset Camping LLC | Plentywood, MT | 42 | 93 | - |
| Thompson Falls Mt State Park | Kalispell, MT | 42 | 6 | - |
| Lost Johnny Point Campground | Kalispell, MT | 42 | 22 | - |
| Yaak River Campground | Troy, MT | 42 | 67 | - |
| Big Creek Campground | Kalispell, MT | 42 | 29 | - |
| M & D Sprinklers | Glendive, MT | 41 | 92 | - |
| Laib Ation Station | Helena, MT | 41 | 63 | - |
| Prairie Falcon Acres | Columbia Falls, MT | 41 | 24 | - |
| Rocky Cliff Industrial Park | Kalispell, MT | 41 | 9 | - |
| Rockhaven Camp and Retreat | Bozeman, MT | 41 | 56 | - |
| Hansons Trailer Court | Kalispell, MT | 40 | 18 | - |
| Silver Gate Water Association Inc | Billings, MT | 40 | 141 | - |
| Drummond Motel | Drummond, MT | 40 | 57 | - |
| Centerville Bar | Sand Coulee, MT | 40 | 252 | - |
| Farmers State Bank Victor | Victor, MT | 40 | 133 | - |
| Cottonwood Country Club Glndv | Glendive, MT | 40 | 103 | - |
| Cinnamon Lodge and Adventures | Gallatin Gateway, MT | 40 | 388 | - |
| Forsyth Country Club | Forsyth, MT | 40 | 59 | - |
| Red Rooster Bar | Shepherd, MT | 40 | 97 | - |
| Gallatin River Apartments | Townsend, MT | 40 | 179 | - |
| Templed Hills Baptist Camp | Billlings, MT | 40 | 282 | - |
| Southside RV Park Well No 1 | Dillon, MT | 40 | 20 | - |
| Elevation Newco, LLC | Dillon, MT | 40 | 188 | - |
| Firehole Guest Ranch | West Yellowstone, MT | 40 | 157 | - |
| Southside RV Park Well No 2 | Dillon, MT | 40 | 16 | - |
| American Water Technologies | Billings, MT | 40 | 27 | - |
| Albertsons Belgrade No 2009 | Oceanside, MT | 40 | 9 | - |
| Gallatin River Lodge | Wayzata, MT | 40 | 113 | - |
| Old Mill Peninsula HOA | Missoula, MT | 40 | 6 | - |
| Mickeys The | Huntley, MT | 40 | 150 | - |