TTHM (Total Trihalomethanes) violations in Wyoming
34 active public water systems in Wyoming had a TTHM (Total Trihalomethanes) violation in the past three years, 2 of them in the latest quarter of EPA's data. What TTHM (Total Trihalomethanes) is and why it matters.
Systems with a TTHM (Total Trihalomethanes) violation
Latest quarter first, then largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Kemmerer-Diamondville Jpb Kemmerer · Lincoln County |
3,348 | 1 | 0 | |
|
Tata Chemicals Soda Ash Partners, LLC Green River · Sweetwater County |
701 | 1 | 0 | |
|
Cody, City of Cody · Park County |
10,224 | 2 | 0 | |
|
Ynp-Old Faithful Yellowstone Np · Teton County |
7,745 | 5 | 0 | |
|
Powell, City of Powell · Park County |
6,310 | 1 | 0 | |
|
Ynp Lake Village Yellowstone Nt · Teton County |
5,925 | 5 | 1 | |
|
Mills, City of Mills · Natrona County |
4,050 | 1 | 0 | |
|
Star Valley Ranch, Town of Star Valley Ranch, Thayne · Lincoln County |
2,894 | 3 | 1 | |
|
Rafter J Subdivision HOA Jackson · Teton County |
1,500 | 5 | 1 | |
|
Cokeville, Town of Cokeville · Lincoln County |
535 | 9 | 0 | |
|
Farson Eden School Farson · Sweetwater County |
530 | 6 | 0 | |
|
Baggs, Town of Baggs · Carbon County |
400 | 3 | 0 | |
|
Jubys Mobile Home Park Cody · Park County |
300 | 2 | 0 | |
|
Glendo, Town of Glendo · Platte County |
289 | 5 | 1 | |
|
Cathedral Home Laramie · Albany County |
275 | 1 | 0 | |
|
Exxon Mobil Shute Creek Gas Plant Kemmerer · Lincoln County |
250 | 3 | 0 | |
|
Rock River, Town of Rock River · Albany County |
211 | 1 | 0 | |
|
Medicine Waters Village Saratoga · Carbon County |
200 | 4 | 1 | |
|
Bridger Coal Company-Admin Point Of Rocks · Sweetwater County |
191 | 1 | 0 | |
|
Elk Mountain, Town of Elk Mountain · Carbon County |
191 | 3 | 0 | |
|
Sweetwater County Airport Rock Springs · Sweetwater County |
189 | 1 | 0 | |
|
Frannie, Town of Frannie · Big Horn County |
160 | 1 | 0 | |
|
Granger, Town of Granger · Sweetwater County |
139 | 3 | 2 | |
|
North Gurley Mobile Home Park Campbell County |
128 | 3 | 0 | |
|
Dixon, Town of Dixon · Carbon County |
114 | 1 | 0 | |
|
Red Lane Domestic Water, Inc. Thermopolis · Hot Springs County |
110 | 6 | 2 | |
|
Stone Creek HOA Torrington · Goshen County |
100 | 9 | 1 | |
|
Hilcorp Carter Creek Gas Plant Evanston · Uinta County |
80 | 1 | 0 | |
|
Lance Creek Water District Lance Creek · Niobrara County |
55 | 5 | 2 | |
|
Copperleaf Water System Cody · Park County |
42 | 1 | 0 | |
|
Oakley Water, LLC Kemmerer · Lincoln County |
39 | 4 | 0 | |
|
Evergreen Mobile Home Park Cheyenne · Laramie County |
35 | 10 | 2 | |
|
Broken Wrench LLC Casper · Natrona County |
30 | 6 | 0 | |
|
Hagens Estates Gillette · Campbell County |
29 | 9 | 0 |
About this data
A system is counted once if any of its violations in the past three years involved TTHM (Total Trihalomethanes), including monitoring and reporting lapses. Rules violated and status in the table are for the whole system, not TTHM (Total Trihalomethanes) alone.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Wyoming records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet.