Water Quality in Wyoming
323 water systems • 108 cities • EPA SDWIS Data
323
Water Systems
13,783
Total Violations
742
Health-Based Violations
536,350
Population Served
Overview
Wyoming has 323 active community water systems serving 536,350 people. These systems have accumulated 13,783 EPA Safe Drinking Water Act violations on record, of which 742 are health-based violations (meaning a contaminant exceeded safe levels).
Common contaminants found in violations: Disinfection Byproducts, Total Haloacetic Acids (HAA5), Chlorine Dioxide, E. coli, Fecal Coliform, Bromate, TTHM, HAA5, Nitrate-Nitrite, Nitrate.
Cities with Most Violations in Wyoming
| # | City | Violations | Health-Based | Water Systems | Population |
|---|---|---|---|---|---|
| 1 | Marbleton | 1,808 | 3 | 1 | 861 |
| 2 | Gillette | 1,070 | 41 | 47 | 45,958 |
| 3 | Grover | 904 | 15 | 9 | 3,179 |
| 4 | Jackson | 665 | 10 | 9 | 26,679 |
| 5 | Newcastle | 522 | 3 | 7 | 4,861 |
| 6 | Superior | 332 | 2 | 1 | 336 |
| 7 | Fort Collins | 323 | 15 | 2 | 1,261 |
| 8 | Cokeville | 323 | 17 | 1 | 535 |
| 9 | Burns | 313 | 0 | 1 | 1,024 |
| 10 | Wilson | 251 | 8 | 21 | 5,398 |
Largest Cities in Wyoming
| # | City | Population | Violations | Water Systems |
|---|---|---|---|---|
| 1 | Cheyenne | 77,707 | 135 | 14 |
| 2 | Casper | 66,524 | 192 | 14 |
| 3 | Gillette | 45,958 | 1,070 | 47 |
| 4 | Laramie | 33,950 | 71 | 6 |
| 5 | Rock Springs | 31,055 | 73 | 11 |
| 6 | Jackson | 26,679 | 665 | 9 |
| 7 | Sheridan | 23,785 | 35 | 3 |
| 8 | Cody | 17,896 | 25 | 4 |
| 9 | Yellowstone | 13,600 | 119 | 2 |
| 10 | Evanston | 12,362 | 8 | 2 |
All Cities in Wyoming
| City | Population | Violations | Health Violations | Contaminants |
|---|---|---|---|---|
| Cheyenne | 77,707 | 135 | 11 | Chlorine Dioxide, E. coli, Nitrate-Nitrite |
| Casper | 66,524 | 192 | 13 | Disinfection Byproducts, Fecal Coliform |
| Gillette | 45,958 | 1,070 | 41 | Chlorine Dioxide, Lead, Stage 2 DBP +1 more |
| Laramie | 33,950 | 71 | 1 | Bromate |
| Rock Springs | 31,055 | 73 | 1 | Stage 2 DBP |
| Jackson | 26,679 | 665 | 10 | Chlorine Dioxide, Disinfection Byproducts, E. coli |
| Sheridan | 23,785 | 35 | 5 | Disinfection Byproducts, Fecal Coliform, Total Haloacetic Acids (HAA5) |
| Cody | 17,896 | 25 | 1 | Stage 2 DBP |
| Yellowstone | 13,600 | 119 | 25 | Barium, Bromate, Disinfection Byproducts +1 more |
| Evanston | 12,362 | 8 | 3 | E. coli |
| Green River | 11,197 | 39 | 3 | E. coli |
| Riverton | 10,833 | 48 | 7 | Bromate, Chlorine Dioxide |
| Rawlins | 9,206 | 129 | 9 | Bromate, E. coli, Stage 2 DBP |
| Lander | 7,680 | 72 | 4 | E. coli |
| Torrington | 7,662 | 153 | 66 | Haloacetic Acids, Nitrate-Nitrite |
| Worland | 7,402 | 22 | 0 | |
| Douglas | 6,968 | 21 | 0 | |
| Powell | 6,781 | 5 | 0 | |
| Moose | 6,565 | 43 | 1 | Chlorine Dioxide |
| F.E. Warren Afb | 5,500 | 14 | 0 | |
| Wilson | 5,398 | 251 | 8 | Chlorine Dioxide, Disinfection Byproducts, Fecal Coliform |
| Newcastle | 4,861 | 522 | 3 | Chlorine Dioxide |
| Buffalo | 4,448 | 31 | 20 | Total Haloacetic Acids (HAA5) |
| Mills | 4,437 | 233 | 10 | Chlorine Dioxide, Stage 2 DBP, TTHM |
| Bar Nunn | 4,000 | 0 | 0 | |
| Thermopolis | 3,785 | 93 | 8 | Bromate, TTHM |
| Wheatland | 3,659 | 80 | 5 | Chlorine Dioxide, Haloacetic Acids |
| Greybull | 3,394 | 79 | 0 | |
| Kemmerer | 3,387 | 110 | 27 | TTHM, Total Haloacetic Acids (HAA5) |
| Grover | 3,179 | 904 | 15 | Chlorine Dioxide, E. coli, Fecal Coliform |
| Mountain View | 2,978 | 18 | 4 | Bromate, Total Haloacetic Acids (HAA5) |
| Yellowstone National Park | 2,600 | 5 | 0 | |
| Lovell | 2,510 | 8 | 0 | |
| Wright | 2,500 | 3 | 0 | |
| Pinedale | 2,480 | 11 | 1 | Disinfection Byproducts |
| Glenrock | 2,466 | 4 | 2 | Chlorine Dioxide |
| Afton | 2,281 | 213 | 7 | Chlorine Dioxide, Fecal Coliform |
| Lyman | 2,203 | 4 | 0 | |
| Star Valley Ranch | 2,030 | 18 | 5 | Chlorine Dioxide, E. coli, Gross Alpha |
| Little America | 2,004 | 29 | 26 | TTHM |
| Dubois | 1,938 | 172 | 1 | Disinfection Byproducts |
| Saratoga | 1,720 | 11 | 5 | Chlorine Dioxide |
| Alpine | 1,620 | 100 | 4 | Chlorine Dioxide |
| Farmington Hills | 1,590 | 2 | 0 | |
| Lusk | 1,576 | 62 | 3 | HAA5 |
| Basin | 1,360 | 11 | 1 | Chlorine Dioxide |
| Ranchester | 1,297 | 1 | 0 | |
| Pavillion | 1,281 | 93 | 17 | Chlorine Dioxide, Gross Alpha |
| Sundance | 1,279 | 3 | 1 | Chlorine Dioxide |
| Fort Collins | 1,261 | 323 | 15 | Chlorine Dioxide, Disinfection Byproducts, E. coli +1 more |
| Littleton | 1,260 | 27 | 2 | Bromate |
| Bear River | 1,200 | 9 | 4 | TTHM |
| Guernsey | 1,157 | 6 | 0 | |
| Upton | 1,100 | 1 | 1 | Chlorine Dioxide |
| Burns | 1,024 | 313 | 0 | |
| Moorcroft | 1,009 | 31 | 2 | Chlorine Dioxide |
| Teton Village | 906 | 4 | 0 | |
| Marbleton | 861 | 1,808 | 3 | Chlorine Dioxide |
| Hanna | 841 | 4 | 0 | |
| Cowley | 825 | 5 | 2 | Chlorine Dioxide |
| Dayton | 824 | 6 | 0 | |
| Bedford | 750 | 5 | 3 | Chlorine Dioxide |
| Smoot | 720 | 24 | 0 | |
| Byron | 593 | 4 | 0 | |
| Encampment | 580 | 34 | 1 | E. coli |
| Cokeville | 535 | 323 | 17 | Bromate, Chlorine Dioxide, E. coli +1 more |
| Shoshoni | 515 | 14 | 0 | |
| Wamsutter | 500 | 8 | 3 | Chlorine Dioxide |
| Lingle | 486 | 3 | 0 | |
| Sacramento | 475 | 11 | 0 | |
| Etna | 465 | 225 | 0 | |
| Hudson | 460 | 8 | 2 | Disinfection Byproducts, Fecal Coliform |
| Rolling Hills | 450 | 1 | 0 | |
| La Grange | 448 | 0 | 0 | |
| Big Piney | 445 | 46 | 1 | Chlorine Dioxide |
| Sinclair | 433 | 6 | 0 | |
| Hulett | 420 | 0 | 0 | |
| Midwest | 410 | 1 | 0 | |
| Baggs | 400 | 84 | 48 | Bromate, TTHM, Total Haloacetic Acids (HAA5) |
| Thayne | 400 | 43 | 2 | Chlorine Dioxide |
| Ten Sleep | 400 | 15 | 0 | |
| Cedaredge | 375 | 10 | 1 | Chlorine Dioxide |
| Meeteetse | 362 | 10 | 1 | Chlorine Dioxide |
| Burlington | 348 | 81 | 7 | Disinfection Byproducts |
| La Barge | 347 | 13 | 5 | Bromate, Fecal Coliform |
| Superior | 336 | 332 | 2 | Disinfection Byproducts |
| Glendo | 289 | 27 | 0 | |
| Kaycee | 263 | 5 | 0 | |
| East Thermopolis | 254 | 1 | 0 | |
| Osage | 240 | 17 | 1 | Chlorine Dioxide |
| Fort Laramie | 230 | 19 | 0 | |
| Rock River | 211 | 3 | 0 | |
| Chugwater | 200 | 73 | 2 | Chlorine Dioxide |
| Edgerton | 195 | 4 | 0 | |
| Elk Mountain | 191 | 222 | 2 | Chlorine Dioxide |
| Medicine Bow | 189 | 12 | 4 | Chlorine Dioxide |
| Albin | 181 | 121 | 3 | Chlorine Dioxide, Stage 2 DBP |
| Deaver | 176 | 1 | 0 | |
| Frannie | 160 | 5 | 0 | |
| Centennial | 150 | 16 | 2 | Chlorine Dioxide |
| American Fork | 148 | 0 | 0 | |
| Clearmont | 142 | 6 | 0 | |
| Granger | 139 | 34 | 6 | Bromate, E. coli, TTHM |
| Yoder | 131 | 3 | 1 | Gross Alpha |
| Evansville | 125 | 27 | 0 | |
| Shell | 120 | 2 | 0 | |
| Dixon | 114 | 106 | 93 | Bromate, TTHM, Total Haloacetic Acids (HAA5) |
| Dallas | 100 | 68 | 7 | Chlorine Dioxide, Disinfection Byproducts, Fecal Coliform +1 more |
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.