Water Quality in San Miguel, CA: No Violations - Grade B
Grade B · Score 72/100 · 2 water systems · Updated 2026-07-18
San Miguel's water is mostly safe. Minor violations exist but are primarily monitoring-related.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-07-18
EPA compliance data for San Miguel, CA covers 2 water systems and returns the same result across every reporting period on file: zero violations documented, zero enforcement initiated, zero health-based findings registered anywhere in the federal dataset.
Water Quality by ZIP Code in San Miguel
San Miguel 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 | |
|---|---|---|---|---|---|
| 93451 | B | 72 | 0 | 0 | View report → |
Violation Trend
EPA violations recorded for water systems serving San Miguel.
Water Quality Overview
San Miguel, California receives a water quality grade of B with an overall score of 72 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
No EPA violations have been recorded for the 2 water systems serving San Miguel. 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 B Means
A grade of B indicates good compliance with EPA drinking water standards. While not perfect, San Miguel's water systems meet the vast majority of federal requirements. Minor violations may exist but typically relate to monitoring or reporting rather than health-based standards.
Lead Levels
Lead testing data for San Miguel is currently being collected. The EPA requires all community water systems to test for lead under the Lead and Copper Rule.
Radon Risk
San Miguel 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 Miguel
San Miguel is served by 2 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 5,007 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 9 enforcement actions against water systems serving San Miguel. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in San Miguel
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
Violation Trend Over Time
Year-by-year EPA violations recorded for water systems serving San Miguel:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2022 | 4 | 4 |
| 2023 | 5 | 5 |
| 2024 | 1 | 1 |
Violations have decreased from 4 in 2022 to 1 in 2024, indicating improving compliance.
EPA Enforcement History
The EPA and state regulators have taken 9 enforcement actions against water systems serving San Miguel. Recent actions:
| Date | Action Type |
|---|---|
| 2024-06-19 | State Order Extension |
| 2024-04-15 | State Filed Suit |
| 2024-02-27 | State Filed Suit |
| 2023-10-11 | State Filed Suit |
| 2023-08-14 | State Filed Suit |
| 2023-07-19 | State Order Extension |
| 2023-01-11 | State Filed Suit |
| 2022-10-04 | State Filed Suit |
| 2022-05-31 | State Filed Suit |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2024-06-19.
San Miguel vs. Nearby California Cities
How San Miguel's water quality compares to similar cities in California:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| San Miguel | B | 0 | 2 | 5,007 |
| Mather | A | 5 | 2 | 5,029 |
| Bonsall | B | 0 | 4 | 4,978 |
| Elverta | B | 5 | 2 | 4,974 |
Common Questions About San Miguel Water
These are the most common questions residents search for about water quality in San Miguel, California:
Is San Miguel water hard or soft? Water hardness varies by source. San Miguel's 2 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink San Miguel tap water? San Miguel's water receives a grade of B (72/100). No health-based violations have been recorded, but home testing is always recommended.
What is the best water filter for San Miguel? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
San Miguel vs. California Average
Understanding how San Miguel compares to the broader California 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 Miguel.
ZIP Codes in San Miguel
San Miguel 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.
Frequently Asked Questions
Your Water is Safe - Here's How to Keep It That Way
Grade B is excellent news. Here's what proactive homeowners do to maintain water quality:
Annual Water Testing
EPA recommends annual testing even with clean water. Home test kits: $20-$50. Catches changes before they become problems.
Maintenance Filtration
A basic carbon filter removes chlorine taste and catches emerging contaminants like PFAS that aren't yet fully regulated.
Plumbing Check
Even safe city water picks up lead from home pipes. If your home was built before 1986, a one-time pipe inspection is recommended.