Water Quality in Montana
792 water systems • 193 cities • EPA SDWIS Data
792
Water Systems
20,202
Total Violations
1,220
Health-Based Violations
789,179
Population Served
Overview
Montana ranks 24th among all U.S. states for total drinking water violations, out of 51 states tracked. The state has 20,202 EPA Safe Drinking Water Act violations on record across 792 water systems serving 193 cities. Of those, 1,220 are health-based violations, meaning a regulated contaminant was measured above the EPA-established safe level. Montana's total violation count is 43% below the national average. Water systems in Montana serve approximately 789,179 people. The most frequently cited contaminants in Montana violations include Fecal Coliform, Total Haloacetic Acids (HAA5), Disinfection Byproducts, E. coli, TTHM.
Cities with Most Violations in Montana
| # | City | Violations | Health-Based | Water Systems | Population |
|---|---|---|---|---|---|
| 1 | Missoula | 1,134 | 47 | 75 | 79,904 |
| 2 | Bozeman | 969 | 8 | 27 | 66,478 |
| 3 | Kalispell | 778 | 12 | 70 | 39,933 |
| 4 | Helena | 775 | 79 | 38 | 39,611 |
| 5 | Great Falls | 739 | 19 | 18 | 65,624 |
| 6 | Malta | 545 | 0 | 2 | 1,847 |
| 7 | Billings | 496 | 27 | 37 | 139,577 |
| 8 | East Helena | 493 | 12 | 18 | 6,797 |
| 9 | West Yellowstone | 383 | 8 | 4 | 10,239 |
| 10 | Belgrade | 363 | 3 | 13 | 17,300 |
Largest Cities in Montana
| # | City | Population | Violations | Water Systems |
|---|---|---|---|---|
| 1 | Billings | 139,577 | 496 | 37 |
| 2 | Missoula | 79,904 | 1,134 | 75 |
| 3 | Bozeman | 66,478 | 969 | 27 |
| 4 | Great Falls | 65,624 | 739 | 18 |
| 5 | Kalispell | 39,933 | 778 | 70 |
| 6 | Helena | 39,611 | 775 | 38 |
| 7 | Butte | 33,090 | 27 | 2 |
| 8 | Belgrade | 17,300 | 363 | 13 |
| 9 | Whitefish | 14,046 | 35 | 7 |
| 10 | Miles City | 10,388 | 201 | 5 |
All Cities in Montana
| City | Population | Violations | Health Violations | Contaminants |
|---|---|---|---|---|
| Billings | 139,577 | 496 | 27 | Chlorine Dioxide, Disinfection Byproducts, Nitrate-Nitrite |
| Missoula | 79,904 | 1,134 | 47 | Chlorine Dioxide, Disinfection Byproducts, E. coli +1 more |
| Bozeman | 66,478 | 969 | 8 | Disinfection Byproducts, E. coli |
| Great Falls | 65,624 | 739 | 19 | Barium, Chlorine Dioxide, Disinfection Byproducts +2 more |
| Kalispell | 39,933 | 778 | 12 | Disinfection Byproducts, E. coli |
| Helena | 39,611 | 775 | 79 | Barium, Disinfection Byproducts, E. coli +3 more |
| Butte | 33,090 | 27 | 1 | Fecal Coliform |
| Belgrade | 17,300 | 363 | 3 | Chlorine Dioxide, E. coli, Gross Alpha |
| Whitefish | 14,046 | 35 | 0 | |
| Miles City | 10,388 | 201 | 23 | Fecal Coliform, Lead |
| Havre | 10,263 | 102 | 10 | Bromate, E. coli |
| West Yellowstone | 10,239 | 383 | 8 | E. coli |
| Anaconda | 9,080 | 17 | 1 | Fecal Coliform |
| Malmstrom Air Force Base | 8,850 | 18 | 2 | Total Haloacetic Acids (HAA5) |
| Columbia Falls | 8,805 | 271 | 5 | Chlorine Dioxide, Gross Alpha |
| Bigfork | 8,028 | 358 | 3 | Disinfection Byproducts, Gross Alpha |
| Livingston | 7,850 | 74 | 2 | Disinfection Byproducts |
| Glendive | 6,803 | 339 | 11 | TTHM |
| Laurel | 6,799 | 24 | 3 | E. coli |
| East Helena | 6,797 | 493 | 12 | Barium, Disinfection Byproducts, E. coli |
| Hamilton | 6,458 | 44 | 2 | Disinfection Byproducts |
| Polson | 6,390 | 94 | 1 | E. coli |
| Lewistown | 6,078 | 239 | 38 | Gross Alpha, Nitrate-Nitrite |
| Big Sky | 5,574 | 154 | 2 | Disinfection Byproducts, E. coli |
| Libby | 5,533 | 341 | 19 | Bromate, Chlorine Dioxide, E. coli +2 more |
| Dillon | 5,245 | 186 | 30 | Barium, E. coli |
| Sidney | 5,130 | 75 | 25 | TTHM |
| Deer Lodge | 5,000 | 15 | 0 | |
| Cut Bank | 4,336 | 249 | 2 | Barium, Nitrate-Nitrite |
| Shelby | 4,120 | 85 | 2 | TTHM, Total Haloacetic Acids (HAA5) |
| Glasgow | 3,883 | 237 | 0 | |
| Culbertson | 3,719 | 10 | 0 | |
| Lolo | 3,710 | 25 | 0 | |
| Hardin | 3,550 | 97 | 0 | |
| Ronan | 3,081 | 90 | 4 | E. coli, Fecal Coliform |
| Roundup | 3,075 | 12 | 0 | |
| Conrad | 2,722 | 23 | 0 | |
| Eureka | 2,550 | 72 | 4 | Disinfection Byproducts, E. coli, Fecal Coliform |
| Stevensville | 2,533 | 75 | 1 | Disinfection Byproducts |
| Troy | 2,458 | 56 | 1 | E. coli |
| Orem | 2,417 | 10 | 1 | Fecal Coliform |
| Manhattan | 2,388 | 110 | 2 | Nitrate-Nitrite |
| Colstrip | 2,350 | 28 | 6 | Fecal Coliform, TTHM |
| Forsyth | 2,260 | 2 | 0 | |
| Red Lodge | 2,236 | 163 | 0 | |
| Thompson Falls | 2,230 | 12 | 0 | |
| Townsend | 2,225 | 194 | 0 | |
| Pablo | 2,175 | 21 | 7 | E. coli |
| Baker | 2,055 | 194 | 1 | E. coli |
| Columbus | 2,025 | 96 | 0 | |
| Lakeside | 1,987 | 17 | 0 | |
| Choteau | 1,935 | 37 | 2 | Chlorine Dioxide, Disinfection Byproducts |
| Three Forks | 1,900 | 3 | 1 | Barium |
| Malta | 1,847 | 545 | 0 | |
| Hingham | 1,720 | 2 | 0 | |
| Big Timber | 1,710 | 4 | 2 | Disinfection Byproducts, Fecal Coliform |
| Plains | 1,700 | 2 | 0 | |
| Plentywood | 1,700 | 2 | 0 | |
| Black Eagle | 1,658 | 11 | 5 | Chlorine Dioxide, Total Haloacetic Acids (HAA5) |
| Lincoln | 1,630 | 54 | 0 | |
| West Glacier | 1,620 | 10 | 0 | |
| Ennis | 1,595 | 54 | 0 | |
| Fort Benton | 1,580 | 5 | 0 | |
| Seeley Lake | 1,575 | 5 | 0 | |
| Chester | 1,502 | 112 | 24 | Fecal Coliform, TTHM, Total Haloacetic Acids (HAA5) |
| Virginia City | 1,500 | 38 | 7 | Chlorine Dioxide |
| Whitehall | 1,500 | 101 | 87 | HAA5, Haloacetic Acids |
| Clancy | 1,470 | 160 | 20 | Haloacetic Acids |
| Boulder | 1,400 | 50 | 3 | Disinfection Byproducts, Fecal Coliform |
| Chinook | 1,400 | 12 | 7 | Total Haloacetic Acids (HAA5) |
| Philipsburg | 1,360 | 34 | 25 | Fecal Coliform, Total Haloacetic Acids (HAA5) |
| Fort Smith | 1,325 | 172 | 30 | Chlorine Dioxide, Disinfection Byproducts, Fecal Coliform +1 more |
| Fort Harrison | 1,275 | 16 | 0 | |
| Harlowton | 1,246 | 46 | 1 | Disinfection Byproducts |
| Gardiner | 1,220 | 30 | 1 | Disinfection Byproducts |
| Hungry Horse | 1,135 | 6 | 0 | |
| Darby | 1,125 | 78 | 2 | Disinfection Byproducts |
| Absarokee | 1,100 | 8 | 0 | |
| Superior | 1,100 | 2 | 0 | |
| White Sulphur Springs | 1,087 | 135 | 0 | |
| Ashland | 1,050 | 313 | 61 | Chlorine Dioxide, E. coli, TTHM |
| Somers | 1,035 | 13 | 0 | |
| Scobey | 1,026 | 8 | 0 | |
| Circle | 1,009 | 16 | 0 | |
| Fairview | 1,000 | 13 | 2 | Disinfection Byproducts |
| Sunburst | 973 | 176 | 11 | Chlorine Dioxide |
| Dallas | 950 | 51 | 0 | |
| Brady | 894 | 79 | 17 | TTHM, Total Haloacetic Acids (HAA5) |
| Harlem | 862 | 137 | 68 | Bromate, E. coli, TTHM +1 more |
| Valier | 804 | 59 | 3 | Barium, Nitrate-Nitrite |
| Bridger | 800 | 9 | 0 | |
| Pinesdale | 800 | 12 | 5 | Total Haloacetic Acids (HAA5) |
| St Ignatius | 765 | 67 | 3 | Chlorine Dioxide |
| Power | 764 | 30 | 0 | |
| Warm Springs | 721 | 10 | 0 | |
| Belt | 720 | 19 | 0 | |
| Cascade | 720 | 4 | 1 | Chlorine Dioxide |
| Gallatin Gateway | 720 | 13 | 0 | |
| Fairfield | 718 | 38 | 0 | |
| Huntley | 705 | 23 | 1 | Disinfection Byproducts |
| Ft. Peck | 663 | 6 | 6 | TTHM |
| Joliet | 645 | 32 | 0 | |
| Sheridan | 632 | 11 | 0 | |
| Alberton | 613 | 11 | 2 | E. coli |
| Big Sandy | 608 | 9 | 0 | |
| Hot Springs | 600 | 8 | 0 | |
| Medicine Lake | 600 | 10 | 0 | |
| Vaughn | 585 | 16 | 0 | |
| Wibuax | 550 | 48 | 3 | E. coli, Gross Alpha |
| Fort Shaw | 525 | 23 | 0 | |
| Sand Coulee | 510 | 47 | 2 | Chlorine Dioxide |
| Stanford | 505 | 31 | 1 | Chlorine Dioxide |
| Fromberg | 500 | 179 | 4 | E. coli |
| Bend | 499 | 8 | 1 | E. coli |
| Vancouver | 490 | 5 | 0 | |
| Lodge Grass | 480 | 121 | 0 | |
| Broadus | 450 | 14 | 0 | |
| Charlo | 450 | 17 | 0 | |
| Coram | 450 | 4 | 0 | |
| Froid | 450 | 8 | 0 | |
| Coeur D'Alene | 438 | 7 | 0 | |
| Twin Bridges | 424 | 1 | 0 | |
| Ekalaka | 400 | 20 | 0 | |
| Noxon | 373 | 7 | 0 | |
| Ryegate | 370 | 38 | 8 | Chlorine Dioxide, Disinfection Byproducts |
| Frenchtown | 368 | 13 | 1 | E. coli |
| Jordan | 364 | 210 | 0 | |
| Geraldine | 360 | 39 | 3 | Chlorine Dioxide |
| Highwood | 360 | 280 | 2 | E. coli |
| Port Orchard | 355 | 321 | 3 | Gross Alpha, Nitrate |
| Bainville | 350 | 16 | 1 | Disinfection Byproducts |
| Trout Creek | 350 | 2 | 0 | |
| Martin City | 340 | 1 | 0 | |
| Dutton | 338 | 130 | 2 | E. coli |
| Galata | 325 | 7 | 0 | |
| Broadview | 314 | 16 | 0 | |
| Stockett | 310 | 140 | 1 | Chlorine Dioxide |
| Clyde Park | 300 | 212 | 0 | |
| Cooke City | 300 | 144 | 3 | Fecal Coliform |
| Nashua | 300 | 81 | 3 | TTHM |
| Roberts | 300 | 14 | 1 | Disinfection Byproducts |
| Kodak | 300 | 41 | 5 | Barium |
| Kevin | 290 | 11 | 0 | |
| Lima | 279 | 4 | 0 | |
| Winifred | 274 | 27 | 1 | E. coli |
| Hysham | 262 | 114 | 19 | E. coli, Fecal Coliform |
| Eagle | 260 | 10 | 0 | |
| Denton | 255 | 166 | 155 | Bromate, Chlorine Dioxide, Fecal Coliform +1 more |
| Hinsdale | 250 | 21 | 2 | E. coli |
| Wilsall | 250 | 12 | 4 | Fecal Coliform, Nitrate-Nitrite |
| Hailey | 250 | 286 | 0 | |
| Fort Peck | 240 | 23 | 0 | |
| Neihart | 229 | 14 | 1 | Disinfection Byproducts |
| Carter | 228 | 65 | 9 | Fecal Coliform, TTHM, Total Haloacetic Acids (HAA5) |
| Martinsdale | 225 | 12 | 0 | |
| Zortman | 219 | 30 | 0 | |
| Houston | 216 | 169 | 0 | |
| Belfry | 205 | 5 | 1 | Gross Alpha |
| Basin | 200 | 40 | 3 | Disinfection Byproducts |
| San Diego | 200 | 10 | 2 | Disinfection Byproducts |
| Sweet Grass | 200 | 45 | 2 | TTHM |
| Knoxville | 200 | 1 | 0 | |
| Paradise | 200 | 13 | 0 | |
| Loma | 200 | 4 | 0 | |
| Winnett | 187 | 138 | 0 | |
| Moore | 186 | 8 | 0 | |
| Richey | 180 | 18 | 0 | |
| Saco | 180 | 9 | 0 | |
| Emigrant | 180 | 7 | 0 | |
| Huson | 175 | 47 | 2 | Chlorine Dioxide, Disinfection Byproducts |
| Westby | 172 | 9 | 0 | |
| Melstone | 170 | 19 | 0 | |
| Grass Range | 160 | 30 | 1 | Chlorine Dioxide |
| Rexford | 160 | 3 | 0 | |
| Heron | 154 | 9 | 0 | |
| Lambert | 150 | 53 | 0 | |
| Gildford | 150 | 118 | 0 | |
| Melville | 150 | 61 | 0 | |
| Plevna | 130 | 13 | 0 | |
| Marion | 130 | 7 | 1 | Disinfection Byproducts |
| Judith Gap | 126 | 14 | 0 | |
| Geyser | 125 | 5 | 0 | |
| Yellowtail | 125 | 11 | 0 | |
| Hobson | 125 | 12 | 0 | |
| Dodson | 120 | 164 | 2 | Chlorine Dioxide, E. coli |
| Thoimpson Falls | 115 | 16 | 2 | E. coli |
| Corvallis | 115 | 0 | 0 | |
| Opheim | 111 | 36 | 4 | E. coli |
| Roy | 110 | 20 | 0 | |
| Fortine | 109 | 60 | 1 | Disinfection Byproducts |
| Sun River | 105 | 1 | 0 | |
| Ulm | 105 | 5 | 0 | |
| Bynum | 100 | 40 | 0 |
Water Quality in Other States
Alabama 13,972 violations Alaska 73,527 violations Arizona 60,414 violations Arkansas 17,031 violations California 39,276 violations Colorado 42,596 violations Connecticut 28,800 violations Delaware 1,242 violations District of Columbia 115 violations Florida 36,335 violations Georgia 32,159 violations Hawaii 182 violations Idaho 26,078 violations Illinois 30,544 violations Indiana 18,261 violations Iowa 9,389 violations Kansas 19,480 violations Kentucky 9,427 violations Louisiana 32,039 violations Maine 6,830 violations Maryland 5,321 violations Massachusetts 10,561 violations Michigan 15,820 violations Minnesota 3,784 violations Mississippi 25,296 violations Missouri 25,377 violations Nebraska 5,134 violations Nevada 8,167 violations New Hampshire 6,968 violations New Jersey 19,332 violations New Mexico 37,115 violations New York 93,834 violations North Carolina 54,399 violations North Dakota 8,431 violations Ohio 61,604 violations Oklahoma 128,472 violations Oregon 0 violations Pennsylvania 199,265 violations Rhode Island 0 violations South Carolina 13,045 violations South Dakota 19,565 violations Tennessee 20,607 violations Texas 263,180 violations Utah 71,655 violations Vermont 12,362 violations Virginia 15,298 violations Washington 54,459 violations West Virginia 81,622 violations Wisconsin 18,533 violations Wyoming 13,783 violations
Data Sources
Drinking water data from the EPA Safe Drinking Water Information System (SDWIS). Only active community water systems (CWS) serving 100+ people are included.