Loading water data...
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.
Water quality scores for 35 cities in Colorado
It depends on your utility. 2 of the 35 Colorado water systems we grade from EPA records have a health-based violation in the last five years; the state averages 94/100 (6 above the national 88). Lowest graded: Brighton (D). Highest: Pueblo (A).
Colorado's official certified-lab list, when to test well vs city water, typical lab prices, and how to take a first-draw lead sample.
Across the 35 Colorado water systems we can grade from EPA records, the average score is 94/100 — 6 points above the U.S. national average of 88/100. 86% of graded Colorado cities (30 of 35) score above that national benchmark, and 29 earn a Grade A. 2 cities have at least one health-based EPA violation in the last five years.
The contaminants most commonly flagged in Colorado water systems are heavy metals (legacy mine drainage), uranium and radium (naturally occurring) and selenium (western slope geology). See the full breakdown in our Colorado water quality rankings or compare against the cities with the best water quality in America.
See the top 20 cities with the cleanest, safest drinking water
Complete water quality rankings for every city in Colorado
114,070 residents
55,000 residents
51,515 residents
48,927 residents
48,648 residents
47,444 residents
38,288 residents
20,000 residents
19,305 residents
9,950 residents
91,077 residents
19,369 residents
166,080 residents
104,178 residents
33,787 residents
12,000 residents
464,111 residents
202,078 residents
132,310 residents
26,000 residents
23,500 residents
171,610 residents
28,700 residents
533,407 residents
179,901 residents
81,400 residents
75,559 residents
25,130 residents
1,287,000 residents
106,153 residents
110,298 residents
75,949 residents
57,332 residents
226,465 residents
56,304 residents
Colorado's water originates high in the Rocky Mountains, giving much of the state clean, snowmelt-fed surface water. The most distinctive water quality issues stem from the state's legacy of hard-rock mining, which left abandoned mines that can leach heavy metals into headwater streams, and from naturally occurring radionuclides and selenium in some groundwater basins.
Across the 35 Colorado cities graded from EPA records, the average water quality score is 94/100. 2 cities score below 70 (D or F) because of health-based violations, lead results, PFAS or historical readings near a limit. The highest-rated city is Pueblo with a score of 100/100, while Brighton has the most room for improvement at 64/100.
2 of the 35 Colorado cities we grade score below 70/100. If your city is one of them — or you just want extra protection — a certified filter is the fastest way to reduce exposure. The findings that drag a score down (lead, PFAS, arsenic, nitrate) are exactly the ones a basic carbon pitcher does not remove.
APEC ROES-50 Reverse Osmosis
Removes 95–99% of lead, arsenic, nitrate, fluoride and PFAS — the widest range of any filter type. The right choice if any city near you flags these.
Check Price on AmazonZeroWater 10-Cup Pitcher
NSF 53 certified to reduce lead, chromium & dissolved solids — no installation, the cheapest way to start filtering today (great for renters).
Check Price on AmazonWe may earn a commission when you purchase through our links, at no extra cost to you.
Colorado is a headwaters state, with the Colorado, Arkansas, Rio Grande, and South Platte rivers all originating within its borders. Front Range cities such as Denver, Colorado Springs, and Aurora rely on mountain reservoirs and transbasin diversions, while the Eastern Plains and San Luis Valley depend on groundwater aquifers.
These contaminants have been detected in various Colorado water systems
The Colorado Department of Public Health and Environment (CDPHE) administers drinking water programs and oversees cleanup of mine-impacted watersheds, including federal Superfund sites. Colorado has been active on PFAS sampling, particularly near military bases and the Colorado Springs area.
Communities near historic mining districts should be aware of heavy-metal contamination in source water, though treatment generally removes it before delivery. Naturally occurring uranium and radium affect some groundwater systems on the plains. PFAS has been detected near Peterson Space Force Base and parts of the Fountain Valley.
Colorado residents on private wells should test for uranium, radium, nitrate, and metals depending on their location. Reverse osmosis effectively removes uranium, radium, selenium, and most metals. Front Range residents on municipal supplies enjoy generally excellent water but should address lead plumbing in older homes.
Most Colorado cities we grade have tap water in good standing with EPA. With an average score of 94/100 across 35 graded cities, Colorado generally has good water quality. However, water quality varies by utility, so check your specific city's report.
The most common water quality concerns in Colorado include heavy metals (legacy mine drainage), uranium and radium (naturally occurring), selenium (western slope geology). 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.
Whether you need a water filter depends on your specific location and health concerns. With 2 Colorado cities grading D or F on EPA records, residents in those areas may benefit from filtration. Look for filters certified by NSF/ANSI to remove the specific contaminants found in your area.
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.
Lead can be present in Colorado water, primarily from older plumbing infrastructure. Homes built before 1986 may have lead pipes or lead solder. While water treatment plants remove lead, it can leach into water from service lines and home plumbing. Check your city's specific report for lead testing data, and consider having your tap water tested if you live in an older home.
PFAS ("forever chemicals") have been detected in water systems across the United States, including in Colorado. These chemicals are associated with industrial sites, military bases, and firefighting foam use. The EPA has set new PFAS limits effective 2024. Check individual Colorado city reports for PFAS testing results in your area.
On EPA records, Pueblo has the highest water quality score in Colorado at 100/100 (Grade A). However, "best" depends on your specific health concerns. View our Best Water Quality in Colorado page for a complete ranking.
Public water systems in Colorado are required by the EPA to test water regularly. Testing frequency depends on the contaminant: bacteria testing occurs daily to weekly, while chemical contaminants may be tested quarterly or annually. Results are published in annual Consumer Confidence Reports. Our site aggregates this data from EPA's SDWIS database.
Compare water quality across counties and find data for your area