Overview
EWG's drinking water quality report for Montana shows results of tests conducted by the water utilities in Montana and provided to EWG by the Montana Department of Environmental Quality.
Large utilities in Montana
Below are utilities in Montana serving over 10,000 people, listed alphabetically.
| Utility | Location | People Served |
|---|
| Belgrade, City of | Belgrade, MT | 10,460 |
| Butte-Silver Bow Water Department | Butte, MT | 33,000 |
| City of Billings | Billings, MT | 114,000 |
| City of Bozeman | Bozeman, MT | 56,000 |
| City of Great Falls | Great Fall, MT | 60,000 |
| Co Water District of Billings Heights | Billings, MT | 12,000 |
| Helena Water System | Helena, MT | 31,005 |
| Kalispell Public Works | Kalispell, MT | 20,008 |
| Mountain Water Company | Missoula, MT | 68,200 |
| Whitefish, City of | Whitefish, MT | 10,418 |
Utilities that accumulated/accrued the most violation points as of July 2021 to June 2024 in Montana
The Environmental Protection Agency's Enforcement and Compliance History Online (ECHO) database collects compliance and enforcement-related information for drinking water utilities nationwide. ECHO water quality violation scores take into account federal health-based water quality standards, as well as monitoring, reporting and other drinking water quality requirements. Points are accrued based on specific problems at the utility - violations of health-based drinking water standards receive more points than monitoring and reporting violations - and the length of time until the violations were corrected.
| Utility | Location | People Served | Violation Points |
|---|
Large utilities that accumulated/accrued the most violation points as of July 2021 to June 2024 in Montana
The Environmental Protection Agency's Enforcement and Compliance History Online (ECHO) database collects compliance and enforcement-related information for drinking water utilities nationwide. ECHO water quality violation scores take into account federal health-based water quality standards, as well as monitoring, reporting and other drinking water quality requirements. Points are accrued based on specific problems at the utility - violations of health-based drinking water standards receive more points than monitoring and reporting violations - and the length of time until the violations were corrected.
| Utility | Location | People Served | Violation Points |
|---|
| Butte-Silver Bow Water Department | Butte, MT | 33,000 | 1 |
Contaminants found in Montana above health guidelines
| Found above health guidelines | Found | |||
|---|---|---|---|---|
| Contaminant | # of Utilities | People Served | # of Utilities | People Served |
| Total trihalomethanes (TTHMs) | 282 | 585,484 | 290 | 612,507 | ||
| Haloacetic acids (HAA5) | 253 | 581,532 | 259 | 610,790 | ||
| Arsenic | 248 | 522,613 | 248 | 522,613 | ||
| Bromodichloromethane | 235 | 505,842 | 238 | 576,492 | ||
| Dichloroacetic acid | 197 | 476,140 | 201 | 482,112 | ||
| Bromochloroacetic acid | 206 | 475,930 | 207 | 486,348 | ||
| Chloroform | 193 | 466,934 | 245 | 564,823 | ||
| Trichloroacetic acid | 179 | 466,042 | 182 | 470,392 | ||
| Dibromoacetic acid | 218 | 461,398 | 222 | 538,006 | ||
| Nitrate & nitrite | 431 | 421,896 | 710 | 721,422 | ||
| Haloacetic acids (HAA9) | 42 | 403,630 | 42 | 403,630 | ||
| Dibromochloromethane | 224 | 386,885 | 231 | 464,552 | ||
| Chromium (hexavalent) | 24 | 306,856 | 49 | 418,718 | ||
| Radium, combined (-226 & -228) | 275 | 212,181 | 323 | 226,945 | ||
| Uranium, combined (pCi/L) | 290 | 123,186 | 417 | 311,802 | ||
| Nitrate | 65 | 105,423 | 147 | 216,131 | ||
| Bromoform | 49 | 40,883 | 125 | 161,175 | ||
| Perfluorohexane sulfonate (PFHXS) | 1 | 20,008 | 1 | 20,008 | ||
| Manganese | 20 | 14,557 | 245 | 552,106 | ||
| Cadmium | 2 | 950 | 2 | 950 | ||
| Chloromethane | 1 | 750 | 3 | 1,330 | ||
| Carbon tetrachloride | 1 | 750 | 1 | 750 | ||
| Bromochloromethane | 1 | 650 | 1 | 650 | ||
| Benzene | 2 | 625 | 2 | 625 | ||
| 1,2,3-Trichloropropane | 1 | 483 | 1 | 483 | ||
| Antimony | 1 | 67 | 4 | 2,101 | ||
| Thallium | 1 | 60 | 1 | 60 | ||
| Di(2-ethylhexyl) phthalate | 1 | 45 | 18 | 2,180 |
Contaminants found in Montana above legal limits
| Contaminant | # of Utilities | People Served |
|---|
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