City Water Quality Rankings in Colorado
186 cities ranked by drinking water quality.
Popular city water quality comparisons
Trending Cities
#97
Alamosa
County, CO
87 B
#98 Brighton
County, CO
87 B
#99 Fort Collins
County, CO
87 B
#100 Lafayette
County, CO
87 B
#101 Milliken
County, CO
87 B
#102 Silt
County, CO
87 B
#103 Westcliffe
County, CO
87 B
#104 Aspen
County, CO
86 B
#105 Glenwood Springs
County, CO
86 B
#106 Morrison
County, CO
86 B
#107 Boulder
County, CO
85 B
#108 Eagle
County, CO
85 B
#109 Flagler
County, CO
85 B
#110 Fort Carson
County, CO
85 B
#111 Minturn
County, CO
85 B
#112 Center
County, CO
84 B
#113 Hudson
County, CO
84 B
#114 Eaton
County, CO
83 B
#115 Fraser
County, CO
83 B
#116 Wheat Ridge
County, CO
82 B
#117 Cripple Creek
County, CO
81 B
#118 Black Hawk
County, CO
80 B
#119 Kremmling
County, CO
80 B
#120 Mosca
County, CO
79 B
Frequently Asked Questions
How are city water quality rankings calculated in Colorado?
WaterQ city rankings are based on EPA SDWIS data across local public water systems, including contaminant detections, compliance violations, and recency-weighted score signals.
Can I compare two cities in Colorado?
Yes. Use the city comparison links on this page or open the Compare tool to evaluate two cities side by side on score, grade, and water system coverage.
How often does WaterQ refresh city data?
City-level metrics refresh when new EPA data is processed. Check city pages for latest score and violation context.