Water Quality in San Carlos, AZ: No Violations - Grade D
Grade D · Score 53/100 · 1 water system · Updated 2026-07-18
San Carlos's water has significant violations. Water testing and filtration are recommended.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-07-18
For households in San Carlos, AZ, the EPA compliance record offers a straightforward finding: 1 water system is on file, zero violations documented across the entire dataset, and no regulatory actions have been taken against any local utility under the federal Safe Drinking Water Act in any reporting period covered by available SDWIS data.
Water Quality by ZIP Code in San Carlos
San Carlos is covered by a single ZIP code, so one water-quality profile applies citywide. See the contaminant data below.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 85550 | D | 53 | 0 | 0 | View report → |
Water Quality Overview
San Carlos, Arizona receives a water quality grade of D with an overall score of 53 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
No EPA violations have been recorded for the 1 water system serving San Carlos. This is a positive indicator, though it does not guarantee the absence of all contaminants - some substances (like PFAS) are not yet fully regulated.
What Grade D Means
A grade of D indicates significant compliance issues. San Carlos's water systems have accumulated violations that suggest ongoing water quality challenges. Residents should check their specific ZIP code report and consider water testing or filtration.
Lead Levels
Lead testing data for San Carlos is currently being collected. The EPA requires all community water systems to test for lead under the Lead and Copper Rule.
With 42% of homes built before 1986, San Carlos 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
San Carlos is in EPA Radon Zone 2 (Moderate risk). Testing is recommended, especially for homes with basements or ground-level living spaces.
Water Systems Serving San Carlos
San Carlos is served by 1 community water system regulated under the Safe Drinking Water Act. These systems collectively serve approximately 5,619 people across 1 ZIP code.
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 San Carlos. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in San Carlos
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
EPA Enforcement History
The EPA and state regulators have taken 10 enforcement actions against water systems serving San Carlos. Recent actions:
| Date | Action Type |
|---|---|
| 2025-11-26 | State Informal Action |
| 2025-11-26 | State Order Extension |
| 2025-10-24 | State Informal Action |
| 2025-10-24 | State Informal Enforcement |
| 2024-12-20 | State Order Extension |
| 2024-12-17 | State Order Extension |
| 2024-12-16 | State Order Extension |
| 2024-12-16 | State Informal Action |
| 2024-11-26 | State Informal Action |
| 2024-11-26 | State Order Extension |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-11-26.
San Carlos vs. Nearby Arizona Cities
How San Carlos's water quality compares to similar cities in Arizona:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| San Carlos | D | 0 | 1 | 5,619 |
| Sells | D | 0 | 1 | 5,667 |
| Fort Defiance | D | 0 | 1 | 5,905 |
| Oracle | B | 0 | 1 | 5,235 |
Common Questions About San Carlos Water
These are the most common questions residents search for about water quality in San Carlos, Arizona:
Is San Carlos water hard or soft? Water hardness varies by source. San Carlos's 1 water system uses a single source. Check your ZIP code report for specific hardness data.
Can I drink San Carlos tap water? San Carlos's water receives a grade of D (53/100). No health-based violations have been recorded, but home testing is always recommended.
What is the best water filter for San Carlos? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
San Carlos vs. Arizona Average
Understanding how San Carlos compares to the broader Arizona 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 San Carlos.
ZIP Codes in San Carlos
San Carlos spans 1 ZIP code. 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.