Total Trihalomethanes (TTHMs) in Colorado Drinking Water
243 public water systems in Colorado have historical EPA violation records associated with total trihalomethanes (tthms) in the Q2 2026 snapshot.
638
Historical Records in Colorado
243
Systems With Records
About Total Trihalomethanes (TTHMs)
- EPA Limit
- 80 ppb
- Category
- Disinfection Byproducts
- Health Effects
- Liver, kidney, nervous system problems; increased cancer risk
- Common Treatment Approaches
- Activated carbon filters
Colorado Systems With the Most Total Trihalomethanes (TTHMs) Records
FORT BELKNAP AGENCY WATER SYSTEM
2,600 served44 historical records
F
TWIN BUTTES WATER PLANT
792 served10 historical records
C
FORT THOMPSON WATER SYSTEM
1,357 served8 historical records
B
FOUR BEARS WATER SYSTEM
1,200 served8 historical records
C
ETHETE WATER SYSTEM
1,950 served7 historical records
C
TOWAOC WATER SYSTEM
2,020 served6 historical records
D
WHITE SHIELD WATER TREATMENT PLANT
952 served6 historical records
A
STANDING ROCK RURAL WATER SYSTEM
6,839 served5 historical records
C
POTATO CREEK WATER SYSTEM
95 served4 historical records
C
WHITEROCKS WATER SYSTEM
812 served4 historical records
B
URIAH HEEPS SPRING WATER SYSTEM
3,750 served4 historical records
D
FORT WASHAKIE
2,620 served4 historical records
B
SICANGU MNI WICONI RURAL WATER SYSTEM
5,610 served3 historical records
C
WOUNDED KNEE DISTRICT SCHOOL
280 served3 historical records
D
WYOLA WATER SYSTEM
281 served2 historical records
C
AMERICAN HORSE SCHOOL
400 served2 historical records
B
DAKOTA MAGIC CASINO
2,360 served2 historical records
D
WOLF CREEK WATER SYSTEM
65 served2 historical records
B
ALLEN WATER SYSTEM
420 served2 historical records
B
HEART BUTTE SCHOOL
250 served2 historical records
C
These counts describe historical compliance records, not present concentrations or household test results. Confirm current conditions with the utility's latest Consumer Confidence Report.