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Colorado Water Quality
423
Utilities in database
7.1M
Residents served
25%
On private wells
3
Key contaminants tracked
Drinking Water in Colorado
Colorado has 423 community water systems serving approximately 7.1 million residents. Primary water sources include surface water. The most commonly reported contaminants include disinfection byproducts, lead, arsenic. 25% of Colorado residents rely on private wells. CDPHE holds primary enforcement authority under the Safe Drinking Water Act.
Utilities in Colorado
26–50 of 423Green Mountain Wsd
CO0130321 · 49,400 served
City of Northglenn
CO0101115 · 48,927 served
Southwest Metropolitan Wsd
CO0103723 · 48,648 served
Us Department of the Army Fort Carson
CO0221445 · 48,000 served
Bancroft Clover Wsd
CO0130133 · 44,000 served
Town of Erie
CO0162255 · 40,061 served
City of Golden
CO0130040 · 38,288 served
City of Canon City
CO0122100 · 34,800 served
Clifton Wd
CO0139180 · 34,500 served
City of Durango
CO0134150 · 33,787 served
City of Aspen
CO0149122 · 31,100 served
Arapahoe Cnty Wwwa
CO0203002 · 31,000 served
Bear Creek Wsd
CO0130138 · 30,000 served
Pueblo West Md
CO0151650 · 30,000 served
Cherokee Md
CO0121125 · 29,610 served
City of Lafayette
CO0107473 · 28,700 served
Town of Breckenridge
CO0159020 · 28,315 served
East Larimer County Wd
CO0135233 · 27,944 served
Town of Firestone
CO0162476 · 27,798 served
Widefield Wsd
CO0121900 · 27,640 served
Csu Main and West Housing Campus
CO0235184 · 27,375 served
Town of Johnstown
CO0162418 · 27,295 served
City of Grand Junction
CO0139321 · 26,000 served
Little Thompson Wd
CO0135477 · 25,654 served
City of Fountain
CO0121275 · 25,130 served
Key Contaminant Concerns in Colorado
Lead
Lead is a naturally occurring heavy metal that was widely used in plumbing infrastructure until it was banned for new installations in 1986. An estimated 9.2 million lead service lines still connect homes to public water mains across the United States, along with millions of homes with lead solder in their internal plumbing.
DBPs
When utilities add chlorine to water to kill pathogens, it reacts with dissolved organic matter — leaves, algae, soil — to produce disinfection byproducts (DBPs). Over 600 DBPs have been identified. The EPA regulates two groups: total trihalomethanes (TTHMs, including chloroform) and haloacetic acids (HAA5). DBP levels tend to be highest in surface water systems and in warm months when organic matter is elevated.
Arsenic
Arsenic (As) occurs naturally in rock and soil, dissolving into groundwater through natural weathering processes. Inorganic arsenic — the form found in drinking water — is a known human carcinogen. The western United States has particularly arsenic-rich geological formations, but elevated levels have been found in 48 states. Arsenic is tasteless and odorless.
Colorado Water FAQs
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Data source: Utility data from EPA SDWIS. 423 active community water systems ingested. CCR contaminant data ingestion in progress.
Last updated: 2026-04-18