Water Quality in San Ramon, CA: 32 Violations — Grade C
Grade C · Score 66/100 · 2 water systems · Updated 2026-05-03
San Ramon'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
The compliance history for San Ramon, CA includes 32 water violations on file with the EPA — a federal tally that spans health-based exceedances, monitoring failures, and enforcement actions logged under the Safe Drinking Water Act.
Water Quality by ZIP Code in San Ramon
Water quality varies across San Ramon's 2 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 94582 | D | 50 | 16 | 10 | View report → |
| 94583 | D | 53 | 16 | 10 | View report → |
Violation Trend
EPA violations recorded for water systems serving San Ramon.
Water Quality Overview
San Ramon, California 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 2 water systems serving San Ramon have accumulated 32 EPA violations, including 20 health-based violations. These violations are tracked across 2 ZIP codes serving approximately 160 people.
What Grade C Means
A grade of C indicates moderate compliance issues. San Ramon'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 San Ramon water systems is 0.0004 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
Water Systems Serving San Ramon
San Ramon is served by 2 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 160 people across 2 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 8 enforcement actions against water systems serving San Ramon. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in San Ramon
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 San Ramon Water Systems
The following contaminants have been detected or caused violations across San Ramon's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Combined Radium | Radionuclides | 5 pCi/L | 22 | 2 | Yes |
| Stage 1 DBP Rule | Treatment Technique | N/A | 4 | 2 | No |
| Stage 2 DBP Rule | Treatment Technique | N/A | 4 | 2 | Yes |
| Surface Water Treatment Rule | Treatment Technique | N/A | 2 | 2 | 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 San Ramon:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2023 | 8 | 8 |
| 2024 | 8 | 8 |
| 2025 | 4 | 4 |
Violations have decreased from 8 in 2023 to 4 in 2025, indicating improving compliance.
EPA Enforcement History
The EPA and state regulators have taken 4 enforcement actions against water systems serving San Ramon. Recent actions:
| Date | Action Type |
|---|---|
| 2025-08-20 | State Filed Suit |
| 2024-05-26 | State Informal Action |
| 2022-10-10 | State Order Extension |
| 2021-10-21 | State Filed Suit |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-08-20.
San Ramon vs. Nearby California Cities
How San Ramon's water quality compares to similar cities in California:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| San Ramon | C | 32 | 2 | 160 |
| Auberry | B | 1 | 2 | 160 |
| Browns Valley | C | 0 | 1 | 160 |
| Caspar | C | 0 | 1 | 160 |
Common Questions About San Ramon Water
These are the most common questions residents search for about water quality in San Ramon, California:
Is San Ramon water hard or soft? Water hardness varies by source. San Ramon's 2 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink San Ramon tap water? San Ramon's water receives a grade of C (66/100). There are 20 health-based violations — consider filtration.
What is the best water filter for San Ramon? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
San Ramon vs. California Average
Understanding how San Ramon 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 Ramon.
ZIP Codes in San Ramon
San Ramon spans 2 ZIP codes. The ZIP with the lowest water quality score is 94582. 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.