Chlorine (MRDL) violations in Colorado
230 active public water systems in Colorado had a Chlorine (MRDL) violation in the past three years, 38 of them in the latest quarter of EPA's data. What Chlorine (MRDL) is and why it matters.
Systems with a Chlorine (MRDL) violation
Latest quarter first, then largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Cottonwood Wsd Douglas County |
10,867 | 7 | 0 | |
|
Inverness Wsd Arapahoe County |
8,140 | 5 | 0 | |
|
Florence City of Fremont County |
7,500 | 4 | 0 | |
|
Grand County Water NO 1 Grand County |
5,400 | 11 | 0 | |
|
Chemical Materials Activity West Pueblo County |
3,000 | 8 | 0 | |
|
Del Norte Town of Rio Grande County |
1,429 | 4 | 0 | |
|
Apple Tree Park Garfield County |
1,160 | 2 | 0 | |
|
Blanca Town of Costilla County |
469 | 2 | 0 | |
|
Skylark Mobile Home Community Boulder County |
342 | 3 | 0 | |
|
Ilium Valley WS San Miguel County |
322 | 2 | 1 | |
|
Aspen Equestrian Blue Creek Ranch Garfield County |
300 | 3 | 0 | |
|
Starwood Metropolitan District Pitkin County |
300 | 3 | 0 | |
|
Applewood MHC Logan County |
250 | 3 | 0 | |
|
Mile High Mobile Home Park Adams County |
209 | 3 | 0 | |
|
Buttermilk MD Pitkin County |
200 | 7 | 2 | |
|
Ophir Town of San Miguel County |
193 | 9 | 1 | |
|
Lazear Domestic WC Delta County |
178 | 8 | 2 | |
|
Longview Mobile Home Park Denver County |
147 | 3 | 0 | |
|
Huajatolla Valley Estates INC Huerfano County |
132 | 8 | 2 | |
|
Mountain Prairie LLC Bent County |
126 | 5 | 0 | |
|
Marble WC Gunnison County |
113 | 6 | 0 | |
|
A and B WA INC Prowers County |
100 | 4 | 1 | |
|
Crest Mobile Estates MHP El Paso County |
100 | 7 | 7 | |
|
Garcia Domestic Wua Costilla County |
100 | 4 | 0 | |
|
Eden Valley Institute Larimer County |
91 | 11 | 1 | |
|
CD Water Ordway · Crowley County |
89 | 4 | 0 | |
|
Alpine Village MHP Teller County |
80 | 4 | 0 | |
|
Blue Mesa Outpost Gunnison County |
76 | 2 | 0 | |
|
Minnesota Pipeline Paonia · Delta County |
72 | 5 | 3 | |
|
White Horse Springs WD Pitkin County |
70 | 2 | 0 | |
|
Westwinds WD Chaffee County |
63 | 3 | 1 | |
|
Escalante Village Durango · La Plata County |
62 | 7 | 5 | |
|
Hartman Town of Prowers County |
61 | 13 | 6 | |
|
Mountain Shadows MHP El Paso County |
56 | 6 | 2 | |
|
Blanca Forestry Products Fort Garland · Costilla County |
50 | 6 | 0 | |
|
Earles Subdivision WC Montrose County |
40 | 2 | 0 | |
|
Fox Run Meadows HOA Glenwood Springs · Eagle County |
36 | 2 | 0 | |
|
Mesa Mobile Park La Plata County |
30 | 5 | 1 | |
|
Aspen City of Pitkin County |
31,100 | 3 | 0 | |
|
Lafayette City of Boulder County |
28,700 | 4 | 0 | |
|
Csu Main and West Housing Campus Larimer County |
27,375 | 5 | 0 | |
|
Telluride Town of San Miguel County |
7,900 | 6 | 0 | |
|
Stratmoor Hills Wsd El Paso County |
6,500 | 6 | 0 | |
|
Winter Park Resort Snoasis Grand County |
5,001 | 2 | 0 | |
|
Hayden Town of Routt County |
3,982 | 4 | 0 | |
|
YMCA Rockies Wind River Larimer County |
3,730 | 7 | 2 | |
|
Orchard City Town of Delta County |
3,100 | 4 | 0 | |
|
Dillon Valley District Summit County |
3,063 | 2 | 0 | |
|
Palmer Lake Town of El Paso County |
2,686 | 4 | 0 | |
|
Rangeview MD Arapahoe County |
2,487 | 3 | 0 |
About this data
A system is counted once if any of its violations in the past three years involved Chlorine (MRDL), including monitoring and reporting lapses. Rules violated and status in the table are for the whole system, not Chlorine (MRDL) 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.