Water Quality in Idaho
764 water systems • 196 cities • EPA SDWIS Data
764
Water Systems
26,078
Total Violations
2,547
Health-Based Violations
1,565,041
Population Served
Overview
Idaho has 764 active community water systems serving 1,565,041 people. These systems have accumulated 26,078 EPA Safe Drinking Water Act violations on record, of which 2,547 are health-based violations (meaning a contaminant exceeded safe levels).
Common contaminants found in violations: HAA5, Haloacetic Acids, Barium, Gross Alpha, Fecal Coliform, Chlorine Dioxide, Stage 2 DBP, Nitrate, Disinfection Byproducts, E. coli.
Cities with Most Violations in Idaho
| # | City | Violations | Health-Based | Water Systems | Population |
|---|---|---|---|---|---|
| 1 | Rexburg | 1,890 | 85 | 8 | 41,645 |
| 2 | Pocatello | 1,450 | 11 | 14 | 59,491 |
| 3 | Boise | 1,306 | 83 | 40 | 285,954 |
| 4 | Nampa | 1,154 | 84 | 41 | 104,636 |
| 5 | Caldwell | 922 | 116 | 21 | 77,542 |
| 6 | Idaho Falls | 801 | 34 | 27 | 96,603 |
| 7 | Mountain Home | 713 | 28 | 13 | 16,107 |
| 8 | Preston | 695 | 46 | 9 | 7,989 |
| 9 | Idaho City | 539 | 14 | 2 | 641 |
| 10 | Post Falls | 512 | 4 | 12 | 42,169 |
Largest Cities in Idaho
| # | City | Population | Violations | Water Systems |
|---|---|---|---|---|
| 1 | Boise | 285,954 | 1,306 | 40 |
| 2 | Meridian | 148,669 | 84 | 7 |
| 3 | Nampa | 104,636 | 1,154 | 41 |
| 4 | Idaho Falls | 96,603 | 801 | 27 |
| 5 | Caldwell | 77,542 | 922 | 21 |
| 6 | Pocatello | 59,491 | 1,450 | 14 |
| 7 | Coeur D Alene | 56,446 | 354 | 12 |
| 8 | Twin Falls | 56,296 | 99 | 3 |
| 9 | Post Falls | 42,169 | 512 | 12 |
| 10 | Rexburg | 41,645 | 1,890 | 8 |
All Cities in Idaho
| City | Population | Violations | Health Violations | Contaminants |
|---|---|---|---|---|
| Boise | 285,954 | 1,306 | 83 | Chlorine Dioxide, Disinfection Byproducts, E. coli +6 more |
| Meridian | 148,669 | 84 | 25 | Chlorine Dioxide, E. coli, HAA5 +2 more |
| Nampa | 104,636 | 1,154 | 84 | Barium, Chlorine Dioxide, E. coli +4 more |
| Idaho Falls | 96,603 | 801 | 34 | Chlorine Dioxide, Disinfection Byproducts, E. coli +1 more |
| Caldwell | 77,542 | 922 | 116 | Barium, Chlorine Dioxide, E. coli +3 more |
| Pocatello | 59,491 | 1,450 | 11 | Chlorine Dioxide, E. coli, Gross Alpha +2 more |
| Coeur D Alene | 56,446 | 354 | 35 | Barium, E. coli, Fecal Coliform |
| Twin Falls | 56,296 | 99 | 18 | Barium, Chlorine Dioxide, E. coli +2 more |
| Post Falls | 42,169 | 512 | 4 | E. coli |
| Rexburg | 41,645 | 1,890 | 85 | Chlorine Dioxide, E. coli |
| Lewiston | 36,074 | 384 | 45 | Chlorine Dioxide, E. coli, Gross Alpha +2 more |
| Moscow | 34,998 | 77 | 5 | Chlorine Dioxide, Stage 2 DBP |
| Kuna | 32,855 | 372 | 1 | Gross Alpha |
| Rathdrum | 25,016 | 162 | 14 | Chlorine Dioxide, E. coli, Fecal Coliform +1 more |
| Hayden | 22,142 | 132 | 1 | Stage 2 DBP |
| Sandpoint | 18,217 | 273 | 23 | Chlorine Dioxide, E. coli, Fecal Coliform +3 more |
| Ammon | 17,383 | 308 | 80 | Selenium |
| Mountain Home | 16,107 | 713 | 28 | Barium, Chlorine Dioxide, E. coli +1 more |
| Chubbuck | 16,102 | 18 | 3 | Chlorine Dioxide, Stage 2 DBP |
| Star | 14,000 | 4 | 0 | |
| Middleton | 13,977 | 112 | 3 | Chlorine Dioxide, E. coli |
| Jerome | 13,842 | 162 | 5 | Chlorine Dioxide, Stage 2 DBP |
| Blackfoot | 13,202 | 302 | 12 | E. coli, Stage 2 DBP |
| Eagle | 12,857 | 111 | 4 | Chlorine Dioxide, E. coli |
| Garden City | 12,741 | 58 | 6 | Chlorine Dioxide, E. coli |
| Burley | 10,762 | 143 | 14 | Chlorine Dioxide, E. coli |
| Bonners Ferry | 9,837 | 419 | 225 | Chlorine Dioxide, E. coli, Fecal Coliform +6 more |
| Hailey | 8,548 | 61 | 0 | |
| Payette | 8,182 | 8 | 2 | Chlorine Dioxide |
| Preston | 7,989 | 695 | 46 | Chlorine, Chlorine Dioxide, E. coli +2 more |
| Mountain Home Afb | 7,500 | 310 | 16 | Selenium |
| Fruitland | 7,205 | 73 | 36 | Barium, Total Haloacetic Acids (HAA5) |
| Rigby | 7,112 | 138 | 10 | Chlorine Dioxide, Stage 2 DBP |
| Emmett | 6,912 | 260 | 5 | Chlorine Dioxide, E. coli |
| Kellogg | 6,198 | 10 | 2 | Chlorine Dioxide, Fecal Coliform |
| Rupert | 6,188 | 77 | 6 | Chlorine Dioxide |
| Weiser | 5,630 | 69 | 0 | |
| Kimberly | 5,429 | 30 | 4 | Chlorine Dioxide |
| Shelley | 5,314 | 183 | 5 | E. coli |
| Coeur D'Alene | 5,213 | 155 | 29 | Chlorine Dioxide, Disinfection Byproducts, E. coli +2 more |
| American Falls | 5,155 | 223 | 21 | Barium, Stage 2 DBP |
| Ketchum | 4,969 | 486 | 18 | Chlorine Dioxide, E. coli, Haloacetic Acids +2 more |
| Mccall | 4,819 | 235 | 33 | Disinfection Byproducts, E. coli, TTHM +1 more |
| Buhl | 4,792 | 183 | 5 | Chlorine Dioxide, Lead, Stage 2 DBP |
| St Maries | 4,561 | 24 | 13 | Barium, Fecal Coliform, Gross Alpha +2 more |
| Orofino | 4,532 | 23 | 5 | Chlorine Dioxide, E. coli, Stage 2 DBP |
| Athol | 4,019 | 82 | 23 | Barium, Chlorine Dioxide, E. coli +1 more |
| Wilder | 3,940 | 14 | 1 | Chlorine Dioxide |
| St Anthony | 3,886 | 161 | 0 | |
| Gooding | 3,766 | 29 | 0 | |
| Spirit Lake | 3,538 | 118 | 0 | |
| Salmon | 3,535 | 146 | 20 | E. coli, Stage 2 DBP, TTHM +1 more |
| Driggs | 3,501 | 52 | 6 | Chlorine Dioxide, Disinfection Byproducts, Stage 2 DBP |
| Sun Valley | 3,475 | 100 | 1 | Stage 2 DBP |
| Soda Springs | 3,421 | 53 | 1 | E. coli |
| Wallace | 3,273 | 4 | 4 | Chlorine Dioxide, Fecal Coliform |
| Grangeville | 3,240 | 70 | 20 | Chlorine Dioxide, Surface Water Treatment |
| Heyburn | 3,150 | 107 | 19 | Chlorine Dioxide, E. coli |
| Wendell | 3,000 | 5 | 0 | |
| Homedale | 2,999 | 9 | 0 | |
| Iona | 2,952 | 40 | 11 | Chlorine Dioxide, E. coli, Gross Alpha |
| Sugar City | 2,905 | 12 | 0 | |
| Filer | 2,858 | 77 | 23 | Barium |
| Montpelier | 2,772 | 9 | 0 | |
| Bellevue | 2,747 | 103 | 22 | Chlorine Dioxide |
| Dalton Gardens | 2,598 | 7 | 3 | E. coli |
| Victor | 2,419 | 67 | 2 | Chlorine Dioxide |
| Priest River | 2,330 | 14 | 0 | |
| Kamiah | 2,280 | 98 | 3 | E. coli, Fecal Coliform |
| Malad | 2,200 | 1 | 0 | |
| Aberdeen | 2,088 | 4 | 0 | |
| New Plymouth | 2,075 | 43 | 9 | Endrin |
| Pinehurst | 2,030 | 0 | 0 | |
| Sagle | 1,957 | 304 | 58 | Chlorine Dioxide, Disinfection Byproducts, Stage 2 DBP |
| Cottonwood | 1,602 | 20 | 1 | Gross Alpha |
| Plummer | 1,490 | 290 | 2 | Chlorine Dioxide |
| Marsing | 1,473 | 67 | 5 | Chlorine Dioxide, E. coli |
| Worley | 1,416 | 70 | 8 | Chlorine Dioxide, Disinfection Byproducts, E. coli +1 more |
| Shoshone | 1,398 | 0 | 0 | |
| New Meadows | 1,382 | 217 | 0 | |
| Hauser | 1,350 | 14 | 0 | |
| Hansen | 1,350 | 8 | 2 | Chlorine Dioxide |
| Oakley | 1,321 | 102 | 24 | Chlorine Dioxide, Disinfection Byproducts, E. coli +1 more |
| Ucon | 1,302 | 158 | 6 | Chlorine Dioxide |
| Glenns Ferry | 1,282 | 4 | 0 | |
| Kingston | 1,265 | 5 | 1 | Disinfection Byproducts |
| Paul | 1,195 | 7 | 0 | |
| Bayview | 1,175 | 4 | 0 | |
| Moyie Springs | 1,173 | 27 | 1 | Barium |
| Arco | 1,139 | 12 | 2 | E. coli |
| Ashton | 1,129 | 38 | 22 | Selenium |
| Blanchard | 1,120 | 7 | 0 | |
| Hagerman | 1,085 | 14 | 0 | |
| Garden Valley | 1,081 | 159 | 52 | Chlorine Dioxide, Disinfection Byproducts, E. coli +3 more |
| Franklin | 1,075 | 40 | 7 | E. coli, Fecal Coliform |
| Potlatch | 1,064 | 19 | 6 | Chlorine Dioxide, Disinfection Byproducts, Gross Alpha +1 more |
| Grace | 1,045 | 16 | 2 | Disinfection Byproducts |
| Genesee | 1,044 | 7 | 1 | Selenium |
| Challis | 1,025 | 134 | 0 | |
| Notus | 1,021 | 46 | 4 | Chlorine Dioxide |
| Cascade | 1,000 | 10 | 2 | Chlorine Dioxide |
| Carey | 993 | 10 | 0 | |
| Hazelton | 954 | 35 | 6 | Chlorine Dioxide |
| Council | 900 | 3 | 0 | |
| Dover | 865 | 2 | 1 | Stage 2 DBP |
| Troy | 850 | 68 | 5 | E. coli, Total Haloacetic Acids (HAA5) |
| Greenleaf | 846 | 4 | 0 | |
| Inkom | 844 | 9 | 0 | |
| Donnelly | 816 | 96 | 7 | Chlorine Dioxide, E. coli |
| Horseshoe Bend | 801 | 73 | 6 | E. coli, Gross Alpha |
| Mccammon | 800 | 3 | 0 | |
| Teton | 735 | 2 | 0 | |
| Clark Fork | 730 | 0 | 0 | |
| Fish Haven | 700 | 16 | 1 | E. coli |
| Uconn | 680 | 4 | 0 | |
| Roberts | 680 | 91 | 0 | |
| Ririe | 656 | 11 | 0 | |
| Fernwood | 645 | 3 | 1 | Fecal Coliform |
| Idaho City | 641 | 539 | 14 | Chlorine Dioxide, E. coli |
| Coolin | 632 | 22 | 0 | |
| Downey | 625 | 3 | 0 | |
| Juliaetta | 624 | 112 | 81 | Contaminant 2920, Disinfection Byproducts, Selenium |
| Orem | 613 | 77 | 2 | Stage 2 DBP |
| Kooskia | 607 | 4 | 0 | |
| Melba | 576 | 13 | 0 | |
| Mackay | 566 | 8 | 0 | |
| Dayton | 560 | 22 | 5 | Chlorine Dioxide |
| Riggins | 554 | 11 | 2 | Chlorine Dioxide |
| Old Town | 545 | 50 | 0 | |
| Hope | 537 | 94 | 0 | |
| Paris | 535 | 4 | 0 | |
| Deary | 529 | 2 | 0 | |
| Weippe | 527 | 2 | 0 | |
| Firth | 511 | 0 | 0 | |
| Dubois | 511 | 4 | 2 | Chlorine Dioxide |
| Craigmont | 501 | 32 | 0 | |
| Richfield | 501 | 8 | 0 | |
| Weston | 490 | 1 | 0 | |
| Georgetown | 476 | 5 | 3 | E. coli |
| Moreland | 474 | 5 | 0 | |
| Pierce | 467 | 28 | 4 | Contaminant 2920 |
| Nezperce | 460 | 12 | 1 | Stage 2 DBP |
| Grand View | 452 | 56 | 3 | Selenium, Stage 2 DBP |
| Fairfield | 441 | 29 | 7 | Chlorine Dioxide, E. coli |
| Lava Hot Springs | 421 | 16 | 0 | |
| Clifton | 413 | 18 | 4 | E. coli |
| Eden | 411 | 31 | 0 | |
| Tetonia | 409 | 31 | 0 | |
| Winchester | 400 | 62 | 0 | |
| Bliss | 384 | 30 | 5 | Chlorine Dioxide |
| Culdesac | 382 | 20 | 0 | |
| Arimo | 368 | 10 | 3 | E. coli |
| Monteview | 358 | 3 | 0 | |
| Port Orchard | 354 | 24 | 3 | Chlorine Dioxide |
| Bancroft | 350 | 5 | 1 | E. coli |
| Newdale | 340 | 8 | 1 | E. coli |
| Cambridge | 335 | 21 | 0 | |
| Dietrich | 332 | 8 | 1 | Stage 2 DBP |
| Lapwai | 325 | 56 | 0 | |
| Albion | 325 | 56 | 6 | Chlorine Dioxide |
| Parker | 322 | 28 | 4 | Chlorine Dioxide |
| Elk City | 320 | 150 | 114 | Chlorine Dioxide, Contaminant 2920, TTHM |
| Priest Lake | 318 | 304 | 2 | Chlorine Dioxide |
| Kendrick | 313 | 138 | 0 | |
| Rockland | 302 | 25 | 11 | Chlorine Dioxide, E. coli |
| Cataldo | 300 | 19 | 6 | Barium, Chlorine Dioxide, Fecal Coliform |
| Declo | 300 | 4 | 1 | Chlorine Dioxide |
| Spokane | 286 | 274 | 0 | |
| Jackson | 282 | 4 | 0 | |
| Castleford | 275 | 4 | 0 | |
| Hayden Lake | 265 | 0 | 0 | |
| Bovill | 256 | 10 | 2 | Chlorine Dioxide |
| Stites | 253 | 17 | 1 | Gross Alpha |
| Bennington | 250 | 211 | 1 | Stage 2 DBP |
| Moore | 223 | 10 | 0 | |
| Bruneau | 220 | 55 | 6 | Chlorine Dioxide, E. coli |
| Hollister | 220 | 9 | 0 | |
| Peck | 210 | 3 | 0 | |
| Bloomington | 206 | 6 | 0 | |
| Ribgy | 193 | 43 | 0 | |
| St. Charles | 191 | 1 | 0 | |
| Provo | 175 | 138 | 2 | Chlorine Dioxide |
| Elk River | 165 | 22 | 6 | Total Haloacetic Acids (HAA5) |
| Seattle | 156 | 6 | 2 | E. coli |
| Paso Robles | 150 | 0 | 0 | |
| Tensed | 146 | 47 | 1 | Stage 2 DBP |
| Lenore | 140 | 72 | 28 | Barium, Chlorine Dioxide, Fecal Coliform +2 more |
| Ferdinand | 133 | 23 | 7 | E. coli, Selenium |
| Murtaugh | 130 | 12 | 1 | Chlorine Dioxide |
| Swan Valley | 129 | 20 | 0 | |
| White Bird | 125 | 182 | 0 | |
| San Diego | 120 | 48 | 12 | Chlorine Dioxide |
| Richland | 120 | 43 | 0 | |
| Minidoka | 120 | 69 | 4 | Chlorine Dioxide |
| Avery | 114 | 5 | 2 | Barium |
| Orange | 108 | 14 | 0 |
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.