Selenium violations in Colorado
30 active public water systems in Colorado had a Selenium violation in the past three years, 4 of them in the latest quarter of EPA's data. What Selenium is and why it matters.
Systems with a Selenium violation
Latest quarter first, then largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Chemical Materials Activity West Pueblo County |
3,000 | 8 | 0 | |
|
Heartwood CO OP Housing La Plata County |
60 | 9 | 1 | |
|
Pacheco Trailer Park Rio Grande County |
36 | 13 | 3 | |
|
Deep Creek Mountain Valley Estates Mineral County |
31 | 11 | 4 | |
|
Grand County Water NO 1 Grand County |
5,400 | 11 | 0 | |
|
Debeque Town of Mesa County |
911 | 7 | 0 | |
|
Morrison Creek Metro District Routt County |
800 | 3 | 0 | |
|
Granada Town of Prowers County |
515 | 12 | 1 | |
|
Saguache Town of Saguache County |
504 | 9 | 1 | |
|
Empire Town of Clear Creek County |
500 | 3 | 0 | |
|
Encompass Preschool Parker · Douglas County |
364 | 7 | 2 | |
|
Sierra Grande School District Costilla County |
304 | 7 | 0 | |
|
Monarch Mountain Lodge Chaffee County |
247 | 14 | 5 | |
|
Mountaindale CG and Cabins Fremont County |
228 | 8 | 0 | |
|
Roaring Fork MHP Pitkin County |
200 | 10 | 0 | |
|
Altman Plants El Paso County |
188 | 8 | 1 | |
|
Castlewood Community Preschool Douglas County |
125 | 9 | 0 | |
|
Willow Brook Metro District Summit County |
120 | 9 | 0 | |
|
United Church of Christ Parker Hilltop Parker · Douglas County |
95 | 8 | 0 | |
|
Valley Mobile Home LLC Alamosa County |
85 | 12 | 1 | |
|
Asgard Subdivision WA Garfield County |
80 | 8 | 2 | |
|
Mill Creek Wia Clear Creek County |
67 | 4 | 0 | |
|
Hartman Town of Prowers County |
61 | 13 | 6 | |
|
Western Metals Recycling Englewood · Arapahoe County |
45 | 7 | 0 | |
|
Saddlehorn Ranch MD El Paso County |
39 | 8 | 1 | |
|
Vallecito Village La Plata County |
34 | 7 | 2 | |
|
G and M Mobile Home Park Rio Grande County |
30 | 11 | 0 | |
|
Ranch at Coulter Creek HOA Garfield County |
27 | 10 | 0 | |
|
E-470 Water System Plaza D Adams County |
25 | 5 | 0 | |
|
Mustang Water Authority Montrose County |
0 | 7 | 1 |
About this data
A system is counted once if any of its violations in the past three years involved Selenium, including monitoring and reporting lapses. Rules violated and status in the table are for the whole system, not Selenium 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 Colorado 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.