Water Quality in Cortez, CO: 15 Violations — Grade C
Grade C · Score 66/100 · 5 water systems · Updated 2026-05-03
Cortez's water has moderate compliance issues. Residents in affected areas should consider filtration.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
On record with EPA: Cortez, CO has 15 water violations.
Water Quality by ZIP Code in Cortez
Water quality varies across Cortez's 1 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 81321 | C | 66 | 15 | 1 | View report → |
Violation Trend
EPA violations recorded for water systems serving Cortez.
Water Quality Overview
Cortez, Colorado receives a water quality grade of C with an overall score of 66 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
The 5 water systems serving Cortez have accumulated 15 EPA violations, including 1 health-based violation. These violations are tracked across 1 ZIP codes serving approximately 9,756 people.
What Grade C Means
A grade of C indicates moderate compliance issues. Cortez's water systems have some violations that warrant attention. While the water may still be safe for most people, residents in affected ZIP codes should consider additional testing or filtration.
Lead Levels
The average 90th percentile lead level across Cortez water systems is 0.0022 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
With 61% of homes built before 1986, Cortez 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.
Radon Risk
Cortez is in EPA Radon Zone 1 (High risk). The EPA recommends all homes in Zone 1 areas be tested for radon. Radon is the second leading cause of lung cancer after smoking.
Water Systems Serving Cortez
Cortez is served by 5 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 9,756 people across 1 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 10 enforcement actions against water systems serving Cortez. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Cortez
Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels, violation history, and safety scores
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 Cortez Water Systems
The following contaminants have been detected or caused violations across Cortez's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Lead and Copper Rule | Treatment Technique | N/A | 6 | 1 | No |
| Stage 1 DBP Rule | Treatment Technique | N/A | 4 | 1 | No |
| Surface Water Treatment Rule | Treatment Technique | N/A | 2 | 1 | No |
| Stage 2 DBP Rule | Treatment Technique | N/A | 2 | 1 | Yes |
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 Cortez:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2024 | 1 | 1 |
| 2025 | 2 | 2 |
Violations have increased from 1 in 2024 to 2 in 2025. This trend warrants monitoring.
EPA Enforcement History
The EPA and state regulators have taken 6 enforcement actions against water systems serving Cortez. Recent actions:
| Date | Action Type |
|---|---|
| 2025-11-12 | State Informal Action |
| 2025-11-12 | State Informal Enforcement |
| 2025-09-29 | State Filed Suit |
| 2025-09-26 | State Informal Action |
| 2025-08-07 | State Informal Action |
| 2025-08-07 | State Informal Enforcement |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-11-12.
Cortez vs. Nearby Colorado Cities
How Cortez's water quality compares to similar cities in Colorado:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Cortez | C | 15 | 5 | 9,756 |
| Redvale | C | 12 | 2 | 9,825 |
| Parlin | D | 0 | 1 | 9,610 |
| Powderhorn | D | 0 | 1 | 9,610 |
Common Questions About Cortez Water
These are the most common questions residents search for about water quality in Cortez, Colorado:
Is Cortez water hard or soft? Water hardness varies by source. Cortez's 5 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Cortez tap water? Cortez's water receives a grade of C (66/100). There are 1 health-based violations — consider filtration.
What is the best water filter for Cortez? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Cortez vs. Colorado Average
Understanding how Cortez 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 Cortez.
ZIP Codes in Cortez
Cortez spans 1 ZIP code. The ZIP with the lowest water quality score is 81321. Each ZIP code has its own water quality profile based on the specific water system serving that area. 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
Updated daily.