Not health advice. Contact your local water utility for concerns.

Data from EPA Water Quality Reports. For official information, contact your water utility or health department.

Colorado Water Quality Reports

Water quality scores for 35 cities in Colorado

35
Cities Analyzed
76/100
Average Score
11
Cities with Concerns

Longmont

98,885 residents

A+
Quality Score96/100
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Steamboat Springs

13,932 residents

A+
Quality Score95/100
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Boulder

105,673 residents

A
Quality Score94/100
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Broomfield

74,112 residents

A
Quality Score93/100
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Erie

31,859 residents

A
Quality Score93/100
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Northglenn

38,697 residents

A
Quality Score93/100
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Greeley

108,649 residents

A
Quality Score92/100
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Grand Junction

65,560 residents

A
Quality Score90/100
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Centennial

108,418 residents

A-
Quality Score88/100
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Vail

5,305 residents

A-
Quality Score87/100
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Fort Collins

169,810 residents

A-
Quality Score86/100
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Lakewood

155,984 residents

B+
Quality Score84/100
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Brighton

41,886 residents

B+
Quality Score83/100
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Colorado Springs

478,961 residents

B+
Quality Score83/100
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Montrose

20,291 residents

B+
Quality Score82/100
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Commerce City

62,418 residents

B+
Quality Score81/100
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Fort Morgan

11,555 residents

B+
Quality Score81/100
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Evans

22,825 residents

B+
Quality Score80/100
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Littleton

46,729 residents

B+
Quality Score80/100
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Pueblo

111,876 residents

B
Quality Score77/100
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Denver

715,522 residents

B-
Quality Score74/100
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Englewood

34,840 residents

B-
Quality Score71/100
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Thornton

141,867 residents

B-
Quality Score71/100
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Aurora

386,261 residents

B-
Quality Score70/100
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Fountain

31,983 residents

C+
Quality Score68/100
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Loveland

82,329 residents

C+
Quality Score68/100
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Westminster

116,317 residents

C+
Quality Score68/100
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Castle Rock

73,158 residents

C+
Quality Score65/100
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Lafayette

31,962 residents

C+
Quality Score65/100
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Golden

21,254 residents

C-
Quality Score59/100
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Parker

58,512 residents

D
Quality Score53/100
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Durango

19,399 residents

D
Quality Score51/100
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Arvada

124,402 residents

F
Quality Score49/100
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Wheat Ridge

32,133 residents

F
Quality Score49/100
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Windsor

32,551 residents

F
Quality Score45/100
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About Colorado Water Quality

This state's water quality reflects local geographic conditions, industrial activities, and water infrastructure. Water quality can vary significantly between communities, with some areas enjoying excellent tap water while others face contamination challenges requiring treatment.

Based on our analysis of 35 cities in Colorado, the average water quality score is 76/100. 11 cities have water quality scores below 70, indicating potential concerns that residents should be aware of. The highest-rated city is Windsor with a score of 45/100, while Longmont has the most room for improvement at 96/100.

Water Sources in Colorado

Water sources typically include a combination of surface water (rivers, lakes, reservoirs) and groundwater. The specific sources serving your community depend on local geography and infrastructure. Check your local water utility's Consumer Confidence Report for details about your water source.

Common Water Contaminants in Colorado

These contaminants have been detected in various Colorado water systems

1Disinfection byproducts (chlorination)
2Lead (older infrastructure)
3Nitrates (agricultural areas)
4Naturally occurring minerals
5Industrial contaminants (varies by region)
6PFAS (emerging concern)

Colorado Water Regulations

State environmental and health agencies oversee drinking water quality in compliance with federal EPA standards. Public water systems are required to test regularly and report results to residents through annual Consumer Confidence Reports.

Health Considerations

Water quality concerns vary by location. Common issues include lead from older plumbing, agricultural runoff in rural areas, and industrial contamination near manufacturing sites. Check your local water quality report and consider testing if you have specific concerns.

Recommendations for Colorado Residents

Review your annual Consumer Confidence Report to understand local water quality. Consider having your water tested if you use a private well or have concerns about your plumbing. Water filters certified to remove specific contaminants can address most common water quality issues.

Frequently Asked Questions About Colorado Water Quality

Is Colorado's tap water safe to drink?

Water quality in Colorado varies by location. Our analysis shows an average score of 76/100 across 35 cities, with 11 cities showing potential concerns. We recommend checking your specific city's water quality report and considering filtration if needed.

What are the main water quality concerns in Colorado?

The most common water quality concerns in Colorado include disinfection byproducts (chlorination), lead (older infrastructure), nitrates (agricultural areas). These contaminants can come from natural sources, industrial activities, or aging infrastructure. Review your city's specific report to see which contaminants affect your area.

Should I use a water filter in Colorado?

Whether you need a water filter depends on your specific location and health concerns. With 11 cities in Colorado showing elevated contaminant levels, residents in those areas may benefit from filtration. Look for filters certified by NSF/ANSI to remove the specific contaminants found in your area.

Where can I find my Colorado water quality report?

Public water systems in Colorado are required to provide annual Consumer Confidence Reports (CCRs) to residents. You can usually find your report on your water utility's website, request it by phone, or access it through the EPA's database. Our city-level reports above summarize key information from these official sources.