B77/100
Denver Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 1,358,630 residents · Colorado
What's In Denver's Tap Water?
76
Contaminants Tested
0
Exceed EPA Limits
1
Above EPA Goals
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.004 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
3
Violations (last 5yr)
0
Unresolved
0
Health-Related
TIER 3Resolved
Missed required monitoring deadline
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: March 1, 2024 – March 31, 2024Rule: Surface Water Treatment RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved
Exceeded the MCL for disinfection byproducts
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: January 1, 2024 – March 31, 2024Enforcement: Resolving — corrective action underway
TIER 3Resolved
Missed required monitoring deadline
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: September 1, 2022 – September 30, 2022Rule: Surface Water Treatment RuleEnforcement: Resolving — corrective action underway
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Water Utility Details
NORTH WASHINGTON STREET WSD
Population Served
14,500
Water Source
Purchased Surface Water
System ID
CO0101105
CRESTVIEW WSD
Population Served
23,756
Water Source
Purchased Surface Water
System ID
CO0101040
EASTERN ADAMS CO MD
Population Served
2,485
Water Source
Groundwater
System ID
CO0101234
DENVER WATER BOARD
Population Served
1,287,000
Water Source
Surface Water
System ID
CO0116001
ADVENIR FRENCH QUARTER
Population Served
3,447
Water Source
Purchased Surface Water
System ID
CO0116104
CHERRY CREEK VALLEY WSD
Population Served
22,000
Water Source
Purchased Surface Water
System ID
CO0116175
NORTH PECOS WSD
Population Served
2,500
Water Source
Purchased Surface Water
System ID
CO0116553
PALMS OF ARCHER
Population Served
1,092
Water Source
Groundwater
System ID
FL2010042
WEST OLIVE ESTATES
Population Served
1,850
Water Source
Groundwater
System ID
MI0040614
Frequently Asked Questions About Denver Water
Is Denver tap water safe to drink?
Denver, Colorado tap water receives a grade of B (77/100), which is considered good. Out of 76 contaminants tested, none exceed EPA maximum contaminant levels (MCLs) and 1 exceed health guidelines (MCLGs). While the water meets federal standards, some residents may still choose to use a filter for additional peace of mind.
What contaminants are in Denver's water?
Of the 76 contaminants tested in Denver's water supply, the most notable include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Denver have any water quality violations?
Yes, Denver has 191 EPA violation(s) on record, with the most recent in 2024. Violation types include RPT, TT, MR. 7 of these are health-based violations, which are the most serious category.
Do I need a water filter in Denver?
Denver water meets EPA standards, so a filter is not strictly necessary. However, some residents prefer the added security of a water filter. EPA health goals (MCLGs) are stricter than legal limits and are set at levels with zero expected health risk. 1 contaminant(s) exceed these stricter goals.
Where does Denver's tap water come from?
Denver's drinking water is sourced from purchased surface water and supplied by NORTH WASHINGTON STREET WSD and 8 other water system(s). The system serves approximately 1,358,630 people. Surface water sources include rivers, lakes, and reservoirs.
How often is Denver's water tested?
Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Denver's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.
How does Denver's water compare to other cities in Colorado?
Denver's water quality score of 77/100 earns a grade of B, which is considered good. This is an above-average score compared to many cities nationwide. Visit our Colorado state page to see how all cities in the state compare.
What should I do if I'm concerned about Denver's water quality?
If you have concerns about Denver's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (NORTH WASHINGTON STREET WSD) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.