Montana County Drinking Water Report Cards
Compare county Drinking Water Violation Exposure Scores in Montana. Scores combine health-based violations per 100,000 people served and the share of active systems with unresolved health-based violations. View methodology or download the CSV.
| Score | Grade | County | Systems | Population | Health Violations | Per 100K | Active Health Systems |
|---|---|---|---|---|---|---|---|
| 7 | F | Blaine County | 12 | 2,672 | 95 | 3555.4 | 2 |
| 13 | F | Sweet Grass County | 15 | 7,279 | 33 | 453.4 | 2 |
| 20 | F | Fergus County | 20 | 11,162 | 198 | 1773.9 | 2 |
| 25 | F | Valley County | 13 | 6,060 | 15 | 247.5 | 1 |
| 26 | F | Park County | 58 | 15,803 | 48 | 303.7 | 4 |
| 27 | F | Lincoln County | 89 | 18,871 | 57 | 302.1 | 6 |
| 27 | F | Richland County | 15 | 7,044 | 35 | 496.9 | 1 |
| 28 | F | Powell County | 16 | 6,156 | 9 | 146.2 | 1 |
| 30 | F | Jefferson County | 42 | 10,086 | 149 | 1477.3 | 2 |
| 30 | F | Granite County | 20 | 7,959 | 30 | 376.9 | 1 |
| 31 | F | Gallatin County | 205 | 147,354 | 180 | 122.2 | 9 |
| 31 | F | Big Horn County | 23 | 10,335 | 11 | 106.4 | 1 |
| 32 | F | Glacier County | 26 | 10,437 | 9 | 86.2 | 1 |
| 34 | F | Lewis and Clark County | 162 | 67,948 | 209 | 307.6 | 5 |
| 34 | F | Dawson County | 32 | 10,547 | 31 | 293.9 | 1 |
| 34 | F | Carbon County | 35 | 9,058 | 20 | 220.8 | 1 |
| 35 | F | Missoula County | 243 | 138,758 | 163 | 117.5 | 6 |
| 35 | F | Ravalli County | 129 | 30,657 | 75 | 244.6 | 3 |
| 36 | F | Beaverhead County | 48 | 9,494 | 133 | 1400.9 | 1 |
| 36 | F | Cascade County | 98 | 96,521 | 79 | 81.8 | 2 |
| 36 | F | Madison County | 45 | 14,392 | 26 | 180.7 | 1 |
| 37 | F | Yellowstone County | 116 | 168,956 | 151 | 89.4 | 2 |
| 38 | F | Flathead County | 321 | 101,958 | 79 | 77.5 | 4 |
| 38 | F | Lake County | 90 | 19,741 | 59 | 298.9 | 1 |
| 40 | F | Rosebud County | 15 | 7,415 | 71 | 957.5 | 0 |
| 40 | F | Stillwater County | 31 | 8,417 | 37 | 439.6 | 0 |
| 40 | F | Teton County | 16 | 4,952 | 27 | 545.2 | 0 |
| 40 | F | Sanders County | 43 | 9,150 | 24 | 262.3 | 0 |
| 40 | F | Custer County | 11 | 10,579 | 23 | 217.4 | 0 |
| 40 | F | Toole County | 17 | 6,408 | 20 | 312.1 | 0 |
| 40 | F | Pondera County | 12 | 4,664 | 20 | 428.8 | 0 |
| 40 | F | Hill County | 16 | 14,962 | 17 | 113.6 | 0 |
| 40 | F | Chouteau County | 12 | 3,456 | 14 | 405.1 | 0 |
| 40 | F | Mineral County | 35 | 16,617 | 9 | 54.2 | 0 |
| 40 | F | Broadwater County | 20 | 9,301 | 8 | 86.0 | 0 |
| 40 | F | Silver Bow County | 23 | 42,630 | 7 | 16.4 | 0 |
| 40 | F | Deer Lodge County | 15 | 9,563 | 4 | 41.8 | 0 |
| 40 | F | Phillips County | 12 | 2,773 | 3 | 108.2 | 0 |