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 ranks 20th among all U.S. states for total drinking water violations, out of 51 states tracked. The state has 26,078 EPA Safe Drinking Water Act violations on record across 764 water systems serving 196 cities. Of those, 2,547 are health-based violations, meaning a regulated contaminant was measured above the EPA-established safe level. Idaho's total violation count is 27% below the national average. Water systems in Idaho serve approximately 1,565,041 people. The most frequently cited contaminants in Idaho violations include HAA5, Haloacetic Acids, Barium, Gross Alpha, Fecal Coliform.
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 |
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 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 Montana 20,202 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.