Water Quality in Denver, CO: 90 Violations - Grade N/A
35 water systems · 42 directly mapped ZIP records
Available EPA records report 90 violations across 42 directly mapped ZIP records with known counts for Denver. This is compliance evidence, not a property-level tap-water verdict.
Data: EPA Safe Drinking Water Information System (SDWIS)
Water Quality by ZIP Code in Denver
This table shows typed EPA water evidence only. Missing violation counts are displayed as N/A, not zero.
| ZIP Code | Violations | Health | |
|---|---|---|---|
| 80221 | 46 | 0 | View report → |
| 80216 | 43 | 0 | View report → |
| 80260 | 42 | 2 | View report → |
| 80210 | 40 | 1 | View report → |
| 80219 | 40 | 1 | View report → |
| 80223 | 40 | 1 | View report → |
| 80236 | 40 | 1 | View report → |
| 80226 | 35 | 0 | View report → |
| 80227 | 35 | 0 | View report → |
| 80232 | 35 | 0 | View report → |
| 80246 | 35 | 0 | View report → |
| 80202 | 34 | 0 | View report → |
| 80203 | 34 | 0 | View report → |
| 80204 | 34 | 0 | View report → |
| 80205 | 34 | 0 | View report → |
Violation Trend
EPA violations recorded for water systems serving Denver.
| Year | Total violations | Health-based |
|---|---|---|
| 2021 | 4 | 4 |
| 2022 | 1 | 1 |
| 2025 | 1 | 1 |
Water Quality Overview
Denver, Colorado has directly mapped EPA water-system data for 42 ZIP codes. This page reports typed compliance facts and does not relabel the multi-source Home Safety Score as a drinking-water grade.
The available EPA records report 90 violations, including 5 health-based violations across 42 directly mapped ZIP records with reported counts.
Lead Levels
The average 90th percentile lead level across Denver water systems is 0.0033 mg/L - within EPA limits. No exceedances appear among the 42 ZIP records with known lead status.
With 61% of homes built before 1986, Denver has a higher-than-average risk of lead from older plumbing. Lead solder was banned in 1986, and homes built before this date may have lead in pipes, solder joints, or fixtures.
Water Systems Serving Denver
Denver is served by 35 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 1,108,441 people across 69 ZIP codes.
Each water system is identified by a Public Water System ID (PWSID) and is required to:
- Test for over 90 regulated contaminants on a regular schedule
- Report results to the EPA and state regulators
- Issue an annual Consumer Confidence Report (CCR) to all customers
- Take corrective action when violations occur
The EPA has taken 368 enforcement actions against water systems serving Denver. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Denver
Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels and violation history
Request your CCR - your water utility must provide an annual Consumer Confidence Report with detailed test results for all monitored contaminants
Get a home test - certified kits cost $20–$50 and test for lead, bacteria, and common contaminants. Professional lab tests ($150–$400) cover a broader panel
Consider filtration - NSF-certified filters can remove specific contaminants. Reverse osmosis removes the broadest range; activated carbon is effective for chlorine and many organics
Check for advisories - monitor your local utility website and local news for boil water advisories or system alerts
Contaminants Detected in Denver Water Systems
The following contaminants have been detected or caused violations across Denver's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Fecal Coliform | Microbiological | N/A | 96 | 40 | No |
| Combined Radium | Radionuclides | 5 pCi/L | 42 | 40 | No |
| Atrazine | Organic | 0.003 mg/L | 36 | 36 | No |
| Benzene | Organic | 0.005 mg/L | 36 | 36 | No |
| E. coli | Microbiological | N/A | 20 | 7 | No |
| Lead and Copper Rule | Treatment Technique | N/A | 15 | 10 | No |
| Stage 1 DBP Rule | Treatment Technique | N/A | 11 | 6 | Yes |
| Surface Water Treatment Rule | Treatment Technique | N/A | 10 | 6 | No |
| Gross Alpha | Radionuclides | 15 pCi/L | 6 | 6 | No |
| Gross Beta | Radionuclides | 50 pCi/L | 6 | 6 | No |
| Stage 2 DBP Rule | Treatment Technique | N/A | 3 | 2 | No |
| Chlorine residual | Disinfectant | 4 mg/L | 2 | 2 | Yes |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 0.08 mg/L | 1 | 1 | No |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 0.06 mg/L | 1 | 1 | No |
MCL = Maximum Contaminant Level (EPA enforceable standard). Health-based violations indicate levels that may pose direct health risks.
Violation Trend Over Time
Year-by-year EPA violations recorded for water systems serving Denver:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2021 | 4 | 4 |
| 2022 | 1 | 1 |
| 2025 | 1 | 1 |
Violations have decreased from 4 in 2021 to 1 in 2025, indicating improving compliance.
EPA Enforcement History
The EPA and state regulators have taken 46 enforcement actions against water systems serving Denver. Recent actions:
| Date | Action Type |
|---|---|
| 2026-04-01 | State Informal Action |
| 2026-02-10 | State Informal Action |
| 2026-02-10 | State Informal Enforcement |
| 2026-01-06 | State Informal Action |
| 2025-11-06 | State Informal Action |
| 2025-11-06 | State Informal Enforcement |
| 2025-08-11 | State Informal Action |
| 2025-08-11 | State Informal Enforcement |
| 2025-08-11 | State Order Extension |
| 2025-07-25 | State Informal Action |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2026-04-01.
Denver vs. Nearby Colorado Cities
How Denver's water quality compares to similar cities in Colorado:
| City | Direct EPA ZIPs | Violations | Systems | Population |
|---|---|---|---|---|
| Denver | 42 | 90 | 35 | 1,108,441 |
| Colorado Springs | 31 | 301 | 24 | 613,448 |
| Aurora | 11 | 66 | 8 | 463,814 |
| Littleton | 10 | 101 | 16 | 318,691 |
Recommended Water Filters for Denver
Based on contaminants detected in Denver's water supply, these filter types are recommended:
Granular Activated Carbon (GAC, whole-house or under-sink)
- Removes: Disinfectant as Total Cl2
- Effectiveness: 95-99%
- Cost range: $100–$600
- Certification: NSF/ANSI 42
- Recommended products:
- Aquasana AQ-5200
- Waterdrop Chubby Pitcher
- Berkey Travel
Water Quality by ZIP Code in Denver
EPA coverage and recorded violations can differ across Denver's ZIP codes. Missing counts are shown as unavailable, not zero:
| ZIP Code | Violations | Health-Based |
|---|---|---|
| 80221 | 46 | 0 |
| 80216 | 43 | 0 |
| 80260 | 42 | 2 |
| 80210 | 40 | 1 |
| 80219 | 40 | 1 |
| 80223 | 40 | 1 |
| 80236 | 40 | 1 |
| 80226 | 35 | 0 |
| 80227 | 35 | 0 |
| 80232 | 35 | 0 |
| 80246 | 35 | 0 |
| 80202 | 34 | 0 |
| 80203 | 34 | 0 |
| 80204 | 34 | 0 |
| 80205 | 34 | 0 |
Common Questions About Denver Water
These are the most common questions residents search for about water quality in Denver, Colorado:
Is Denver water hard or soft? Water hardness varies by source. Denver's 35 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Denver tap water? City-level EPA records cannot determine safety at a specific tap. The measured subset contains 5 health-based violations; check the affected utility record and consider certified testing.
What is the best water filter for Denver? Based on detected contaminants, a granular activated carbon (gac, whole-house or under-sink) filter is most recommended. See our Water Filter Matcher for personalized recommendations.
Denver vs. Colorado Average
Understanding how Denver compares to the broader Colorado average helps contextualize your local water quality. Factors like water source, treatment methods, and infrastructure age all contribute to differences between cities in the same state.
To see how individual neighborhoods compare, check the ZIP code reports below - water quality can vary significantly even within Denver.
ZIP Codes in Denver
Denver spans 69 ZIP codes. EPA water-system coverage is available for 42 directly mapped ZIP codes. Check each ZIP code for detailed contaminant data, violation history, and system information.
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
- Enforcement: EPA ECHO database
- Filter recommendations: NSF/ANSI certified products
Source reporting periods vary. See each cited source for its publication schedule.