Water Quality in Denver, CO: 90 Violations Recorded for Mapped Water Systems
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 → |
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 of the reported 90th-percentile lead results across the ZIP codes of Denver is 0.0029 mg/L; the EPA action level of 0.015 mg/L applies to a water system's own 90th-percentile result and is not a safety threshold (EPA's health goal for lead is zero). No exceedances appear among the 40 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. About 1,108,441 people live in the area (69 ZIP codes, Census); this is not the systems' reported service population.
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
EPA records list 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 |
|---|---|---|---|---|---|
| Interim Enhanced Surface Water Treatment Rule | Treatment Technique | N/A | 96 | 40 | No |
| Combined Uranium | Radionuclides | 0.03 mg/L | 42 | 40 | No |
| Di(2-ethylhexyl) phthalate | Organic | 0.006 mg/L | 36 | 36 | No |
| Atrazine | Organic | 0.003 mg/L | 36 | 36 | No |
| Surface Water Treatment Rule | Treatment Technique | N/A | 20 | 7 | No |
| Public Notice Rule | Reporting | N/A | 15 | 10 | No |
| Lead and Copper Rule | Treatment Technique | N/A | 11 | 6 | Yes |
| Consumer Confidence Rule | Reporting | N/A | 10 | 6 | No |
| Gross Alpha (excl. radon and uranium) | Radionuclides | 15 pCi/L | 6 | 6 | No |
| Combined Radium (-226 and -228) | Radionuclides | 5 pCi/L | 6 | 6 | No |
| Lead and Copper Rule Revisions | Treatment Technique | N/A | 3 | 2 | No |
| Stage 1 Disinfectants and Disinfection Byproducts Rule | Treatment Technique | N/A | 2 | 2 | Yes |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 0.06 mg/L | 1 | 1 | No |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 0.08 mg/L | 1 | 1 | No |
The standard column shows the EPA Maximum Contaminant Level (MCL) except for lead and copper, whose value is an action level that triggers corrective steps and is not an MCL. Health-based violations are MCL, MRDL and treatment-technique violations.
Violation Trend Over Time
Year-by-year health-based EPA violations recorded for water systems serving Denver (this history covers health-based records only):
| Year | Health-based violations |
|---|---|
| 2021 | 4 |
| 2022 | 1 |
| 2025 | 1 |
Health-based violations have decreased from 4 in 2021 to 1 in 2025, indicating improving compliance.
EPA Enforcement History
The EPA and state regulators have taken 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 |
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? A NSF/ANSI 53-certified filter for lead removal is a good general choice. 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.