Overview
EWG's drinking water quality report for Idaho shows results of tests conducted by the water utilities in Idaho and provided to EWG by the Idaho Department of Environmental Quality.
Large utilities in Idaho
Below are utilities in Idaho serving over 10,000 people, listed alphabetically.
| Utility | Location | People Served |
|---|
Utilities that accumulated/accrued the most violation points as of July 2021 to June 2024 in Idaho
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 Idaho
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 |
|---|
| City of Twin Falls | Twin Falls, ID | 50,197 | 17 |
| City of Jerome | Jerome, ID | 11,500 | 12 |
| City of Mountain Home | Mountain Home, ID | 14,000 | 6 |
| City of Nampa | Nampa, ID | 100,200 | 4 |
| City of Caldwell | Caldwell, ID | 65,000 | 3 |
| Garden City Water and Sewer System | Garden City, ID | 12,500 | 2 |
| City of Kuna | Kuna, ID | 32,038 | 2 |
| City of Pocatello | Pocatello, ID | 57,092 | 2 |
| Burley Water Department | Burley, ID | 10,345 | 1 |
| East Greenacres Irrigation District | Post Falls, ID | 10,600 | 1 |
| City of Ammon | Ammon, ID | 17,338 | 1 |
| Lewiston Orchards Irrigation District | Lewiston, ID | 20,000 | 1 |
| City of Rexburg | Rexburg, ID | 39,409 | 1 |
Contaminants found in Idaho above health guidelines
| Found above health guidelines | Found | |||
|---|---|---|---|---|
| Contaminant | # of Utilities | People Served | # of Utilities | People Served |
| Nitrate | 460 | 1,288,890 | 600 | 1,371,578 | ||
| Uranium, combined (pCi/L) | 346 | 1,199,316 | 436 | 1,315,680 | ||
| Arsenic | 259 | 1,145,607 | 259 | 1,145,607 | ||
| Radium, combined (-226 & -228) | 261 | 1,091,953 | 296 | 1,200,739 | ||
| Total trihalomethanes (TTHMs) | 194 | 1,072,849 | 205 | 1,126,929 | ||
| Chromium (hexavalent) | 25 | 987,756 | 28 | 1,046,256 | ||
| Haloacetic acids (HAA5) | 143 | 938,787 | 147 | 963,902 | ||
| Haloacetic acids (HAA9) | 21 | 881,641 | 22 | 907,641 | ||
| Nitrate & nitrite | 94 | 726,187 | 107 | 734,283 | ||
| Dibromochloromethane | 29 | 711,377 | 33 | 733,593 | ||
| Bromodichloromethane | 34 | 624,604 | 34 | 624,604 | ||
| Dibromoacetic acid | 23 | 623,502 | 24 | 624,027 | ||
| Chloroform | 27 | 400,125 | 34 | 581,035 | ||
| Bromoform | 14 | 283,101 | 24 | 703,235 | ||
| Dichloroacetic acid | 22 | 276,411 | 24 | 429,031 | ||
| Trichloroacetic acid | 18 | 273,290 | 19 | 276,599 | ||
| Tetrachloroethylene (perchloroethylene) | 8 | 271,668 | 9 | 328,760 | ||
| Perfluorohexane sulfonate (PFHXS) | 7 | 30,652 | 7 | 30,652 | ||
| Perfluorooctane sulfonate (PFOS) | 5 | 22,228 | 5 | 22,228 | ||
| Perfluorononanoic acid (PFNA) | 2 | 21,500 | 2 | 21,500 | ||
| Manganese | 4 | 11,377 | 47 | 1,044,058 | ||
| Perfluorooctanoic acid (PFOA) | 3 | 9,425 | 3 | 9,425 | ||
| Carbon tetrachloride | 1 | 478 | 1 | 478 | ||
| Cadmium | 1 | 60 | 1 | 60 |
Contaminants found in Idaho above legal limits
| Contaminant | # of Utilities | People Served |
|---|
Arsenic | 9 | 8,176 | |
Haloacetic acids (HAA5) | 1 | 3,158 | |
Uranium | 3 | 998 | |
Nitrate | 3 | 252 | |
Fluoride | 1 | 78 |
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