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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.
Comprehensive water safety analysis • Updated June 2026
Denver's water quality score of 74/100 indicates fair quality with several contaminants worth monitoring.
•All 1 historical violation(s) in Denver have been resolved.
Some Concerns. Consider a water filter for extra protection. Score: 74/100.
Want to understand your score better? Learn how scores are calculated →
Is your neighbor's water better? See how Denver's grade of B- (74/100) stacks up.
Guides matched to the contaminants found in your water
8 contaminants tested • EPA SDWIS data • Click any contaminant for details
| Contaminant | Level Detected | EPA Limit | % of Limit | Status |
|---|---|---|---|---|
| Total Trihalomethanes | 27.10 ug/L | 80.00 ug/L | 33.9% | Safe |
| Nitrite | 0.249 mg/L | 1.00 mg/L | 24.9% | Safe |
| Mercury | 0.0004 mg/L | 0.0020 mg/L | 20.7% | Safe |
| Haloacetic Acids | 11.37 ug/L | 60.00 ug/L | 18.9% | Safe |
| Fluoride | 0.647 mg/L | 4.00 mg/L | 16.2% | Safe |
| Arsenic | 0.0015 mg/L | 0.010 mg/L | 15.0% | Safe |
| Lead | 0.0011 mg/L | 0.015 mg/L | 7.3% | Safe |
| Copper | 0.024 mg/L | 1.30 mg/L | 1.9% | Safe |
Based on detected contaminants in your water
There is no safe level of lead exposure. An NSF 53 certified filter or reverse osmosis system is strongly recommended.
Get APEC RO System (Removes 99% Lead) — ~$200 on AmazonRemoves chlorine, improves taste, and filters many organic compounds. Great starting point.
| Filter Type | Best For | Typical Price |
|---|---|---|
| Reverse Osmosis | Lead, PFAS, arsenic, nitrates (95-99% removal) | $150-300 |
| Under-sink carbon block | Chlorine, VOCs, many organics; some lead/PFAS models | $100-250 |
| Pitcher / faucet carbon | Chlorine, taste; NSF 53 models also reduce lead | $20-50 |
See our full water filter comparison for certified products matched to specific contaminants.
Our data covers your city's water system, but contaminants can vary at the tap. A home water test gives you exact results for your faucet.
Get a Certified Home Water Test — Tap ScoreWe may earn a commission when you purchase through our links, at no extra cost to you. All recommendations are based on our independent analysis of Denver's water quality data.
Specific to the contaminants found in Denver's EPA-reported water data
Lead has been detected in Denver's water supply. There is no safe level of lead exposure. In children, lead can cause developmental delays, learning difficulties, irritability, weight loss, hearing loss, and seizures. In adults, lead exposure contributes to cardiovascular problems, decreased kidney function, and reproductive issues. Pregnant women exposed to lead can transfer it to their developing fetus, increasing risk of premature birth and reduced growth. Use an NSF 53 certified filter and run cold water before drinking to reduce exposure.
Arsenic has been detected in Denver's water supply. Long-term arsenic exposure, even at levels near EPA limits, is associated with increased risk of skin, lung, bladder, kidney, and liver cancers. Arsenic exposure can also cause cardiovascular disease, diabetes, and neurological effects. Skin changes like thickening and pigmentation may indicate chronic exposure. Reverse osmosis filtration is highly effective at removing arsenic from drinking water.
Past violations for Denver's water system
monitoring
Lead - 2/4/2022
ResolvedHow to contact your water provider and access official reports
The primary water provider for Denver is DENVER WATER SYSTEM (Public Water System ID: CO238118), serving approximately 717,347 residents. This utility is responsible for treating, testing, and delivering drinking water that meets EPA standards under the Safe Drinking Water Act. As a regulated public water system, it is required to conduct regular testing for over 90 contaminants and publish results in an annual Consumer Confidence Report (CCR) that must be made available to all customers by July 1 each year.
Your water utility is legally obligated to notify customers within 24 hours of any violation that poses an immediate health risk, and within 30 days for less urgent violations. If you are concerned about your water quality, you have the right to request testing data from your utility at any time. For independent verification, you can have your water tested at the tap by a state-certified laboratory. The EPA maintains a list of certified labs by state at epa.gov/dwlabcert. Home testing is particularly important because it captures contamination from your household plumbing that utility testing at distribution points would not detect.
Denver Water Quality Score
Based on EPA contaminant data and compliance records
Even with good water quality, a filter removes trace contaminants and improves taste.
Best for Lead Removal
APEC Reverse Osmosis System
Multi-stage RO reduces 99%+ of lead — the EPA-recommended treatment for lead.
Check Price on AmazonLower-cost alternative
ZeroWater 5-Stage Pitcher
NSF 53 certified pitcher · ~$40
No-install option — NSF 53 certified for lead & chromium reduction.
Check Price on Amazon →Not sure what filter you need?
Get a lab-certified water test to know exactly what's in your tap water.
Test Your Water with Tap ScoreWe may earn a commission when you purchase through our links, at no extra cost to you.
Based on contaminants detected in your water, these resources may be helpful:
Find the right filter for your Denver water quality needs:
Understand the contaminants that may be present in Denver's water supply and their health effects.
Matched to the contaminants actually detected in Denver's water
Lead was detected in Denver's water — an NSF 53 certified filter or reverse osmosis system removes up to 99% of it.
We may earn a commission when you purchase through our links, at no extra cost to you.
Understand your water better with our in-depth guides on contaminants, filtration, and water safety.
Denver's drinking water is managed by DENVER WATER SYSTEM, which serves approximately 717,347 residents through surface water sources such as rivers, lakes, and reservoirs. Our analysis of 8 tested contaminants reveals a quality score of 74/100, placing Denver at a fair level relative to other Colorado communities.
Denver's water quality is strong across all tested parameters, with all contaminants well within EPA safety limits. This reflects effective water treatment and well-maintained infrastructure.
Denver's water system has 1 documented EPA violation in its compliance history. All have since been resolved, indicating the utility has addressed past issues. Compliance history is one of the factors in our scoring methodology.
This report is based on data from the EPA Safe Drinking Water Information System (SDWIS) and the EPA Enforcement and Compliance History Online (ECHO) database. Our scoring algorithm weighs contaminant analysis (50%), compliance history (30%), and infrastructure factors (20%). Data is sourced directly from public EPA records and Consumer Confidence Reports. We are an independent resource with no affiliation to water utilities or government agencies. Learn more about our methodology.
Common questions from Denver, Colorado residents about their drinking water
Denver's tap water has some concerns with a quality score of 74/100 (Grade B-). While all contaminants are technically within EPA limits, 0 are at elevated levels. We recommend using a certified water filter for drinking and cooking water, especially in households with children, pregnant women, or immunocompromised individuals.
Denver's water has been tested for 8 contaminants spanning inorganic chemicals, disinfection byproducts, organic compounds, radionuclides, and microorganisms. All tested contaminants are within safe limits, with 8 contaminants well below 50% of their respective EPA Maximum Contaminant Levels.' See the full contaminant breakdown table above for detailed measurements and EPA limit comparisons.
Denver has a water quality score of 74/100, earning a grade of B-. This score is calculated using EPA SDWIS data and weighs three factors: contaminant levels (50% of score), regulatory compliance history (30%), and infrastructure factors (20%). The national average is approximately 72/100. Denver's score of 74 is 2 points above the national average, indicating above-average water quality management. Learn more about how scores are calculated.
Based on Denver's water quality profile, we recommend a reverse osmosis (RO) system for the most comprehensive filtration. Lead has been detected, and RO systems remove over 99% of lead. Arsenic is present, and RO systems typically remove over 95% of arsenic. A quality RO system costs approximately $150-300 and is installed under the kitchen sink. Even in cities with good water quality, a filter provides an additional layer of protection against contaminants that may enter water from your home's plumbing. View our water filter comparison guide for specific product recommendations.
Denver's primary water system, DENVER WATER SYSTEM (PWS ID: CO238118), sources water from surface water such as rivers, lakes, or reservoirs. Surface water sources are more susceptible to contamination from agricultural runoff, industrial discharge, and stormwater, which is why extensive multi-step treatment including coagulation, sedimentation, filtration, and disinfection is required. This system serves approximately 717,347 residents.
Yes, lead has been detected in Denver's water supply. The EPA has established that there is no safe level of lead exposure, making this a priority concern especially for households with children or pregnant women. Lead typically enters drinking water through corrosion of lead service lines and lead solder in household plumbing, particularly in homes built before 1986. To reduce exposure: always use cold water for drinking and cooking, flush the tap for 30 seconds to 2 minutes after periods of non-use, and install an NSF 53 certified filter. Consider having your water independently tested at the tap, as lead levels can vary significantly from house to house depending on plumbing age and condition.
Yes, Denver's water system has 1 documented EPA violation in its compliance history. All violations have been resolved, indicating the utility has taken corrective action. Violations can include exceeding contaminant limits, failure to conduct required testing, or failure to properly notify customers. Water utilities are required by the Safe Drinking Water Act to address violations and notify affected customers. You can look up the full violation history through the EPA's ECHO database or by contacting your water utility directly.
There are several options for testing your water in Denver. For the most comprehensive results, use a state-certified laboratory (find one at epa.gov/dwlabcert). Home test kits like Tap Score provide EPA-certified lab analysis with easy-to-understand results. Basic test strips available at hardware stores can screen for common parameters like chlorine, pH, hardness, and lead, though they are less accurate than laboratory testing. You can also request the latest testing data directly from DENVER WATER SYSTEM. Testing at your tap is important because it captures contamination from your household plumbing that city-level monitoring at distribution points does not detect.