Montana
Big Horn County drinking water quality
23 active public water systems serve 10,335 people in Big Horn County. 9 are compliant, 14 had at least one EPA violation in the past three years, 1 is a designated serious violator, and 2 carry a health flag.
Needs attention
Community water systems
5 systems, largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Hardin City of Hardin |
3,500 | 1 | 0 | |
|
Lodge Grass Town of Lodge Grass |
480 | 2 | 1 | |
|
Fort Smith Water and Sewer District Fort Smith |
450 | 0 | 0 | |
|
Yellowtail Dam GC System Hardin |
125 | 2 | 0 | |
|
Wegner Water Service Hauler Hardin |
50 | 3 | 2 |
Non-community systems (18: schools, campgrounds, workplaces, restaurants)
These systems serve places people visit rather than homes.
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Little Bighorn Battlefield NM Crow Agency |
2,020 | 0 | 0 | |
|
Hardin Eastbound Rest Area Hardin |
877 | 1 | 0 | |
|
Hardin Westbound Rest Area Hardin |
715 | 2 | 0 | |
|
Tongue River Campers Point Decker |
305 | 0 | 0 | |
|
Tongue River Pee Wee Point Decker |
300 | 0 | 0 | |
|
Chief Plenty Coups Museum Pryor |
262 | 0 | 0 | |
|
Big Horn CO Historical Museum Hardin |
206 | 0 | 0 | |
|
Spring Creek Coal Domestic Decker |
200 | 1 | 0 | |
|
Spring Creek Mine Decker |
200 | 0 | 0 | |
|
ST Charles School Pryor |
152 | 1 | 1 | |
|
7th Ranch RV Camp Garryowen |
102 | 1 | 0 | |
|
Hardin KOA Cistern Hardin |
100 | 1 | 1 | |
|
Cottonwood Camp Fort Smith Fort Smith |
85 | 3 | 1 | |
|
Absaloka Mine Hardin |
80 | 2 | 0 | |
|
Yellowtail Dam Powerplant and Visitor CE Hardin |
48 | 0 | 0 | |
|
East Decker Coal Mine Decker |
28 | 2 | 0 | |
|
Kirby Saloon Busby |
25 | 3 | 1 | |
|
Reese and Ray Iga Hardin Hardin |
25 | 0 | 0 |
Inactive systems (35, no longer operating or reporting)
Kept for the record and excluded from the county totals above. Browse inactive systems.
About this data
Totals cover active systems. Systems serving more than one county are counted in each county. EPA counts the rules a system was in violation of, not the individual violations; one rule can carry several.
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 Montana 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. Retrieved from ECHO on Oct 11, 2026.