Water Quality in Moraga, CA: 54 Violations — Grade D
Grade D · Score 48/100 · 2 water systems · Updated 2026-05-03
Moraga's water has significant violations. Water testing and filtration are recommended.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
The compliance history for Moraga, CA includes 54 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 Moraga
Water quality varies across Moraga's 3 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 94570 | D | 45 | 18 | 14 | View report → |
| 94575 | D | 45 | 18 | 14 | View report → |
| 94556 | C | 66 | 18 | 14 | View report → |
Violation Trend
EPA violations recorded for water systems serving Moraga.
Water Quality Overview
Moraga, California receives a water quality grade of D with an overall score of 48 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
The 2 water systems serving Moraga have accumulated 54 EPA violations, including 42 health-based violations. These violations are tracked across 3 ZIP codes serving approximately 185 people.
What Grade D Means
A grade of D indicates significant compliance issues. Moraga'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
The average 90th percentile lead level across Moraga water systems is 0.0065 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
With 85% of homes built before 1986, Moraga 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
Moraga is in EPA Radon Zone 2 (Moderate risk). Testing is recommended, especially for homes with basements or ground-level living spaces.
Water Systems Serving Moraga
Moraga is served by 2 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 185 people across 3 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 12 enforcement actions against water systems serving Moraga. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Moraga
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 Moraga Water Systems
The following contaminants have been detected or caused violations across Moraga's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Barium | Inorganic | 2 mg/L | 36 | 3 | Yes |
| Stage 2 DBP Rule | Treatment Technique | N/A | 12 | 3 | Yes |
| Stage 1 DBP Rule | Treatment Technique | N/A | 3 | 3 | 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 Moraga:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2021 | 9 | 9 |
| 2022 | 12 | 12 |
| 2023 | 12 | 12 |
| 2024 | 6 | 6 |
Violations have decreased from 9 in 2021 to 6 in 2024, indicating improving compliance.
EPA Enforcement History
The EPA and state regulators have taken 4 enforcement actions against water systems serving Moraga. Recent actions:
| Date | Action Type |
|---|---|
| 2024-01-08 | State Order Extension |
| 2023-12-15 | State Filed Suit |
| 2023-09-04 | State Filed Suit |
| 2021-04-09 | State Filed Suit |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2024-01-08.
Moraga vs. Nearby California Cities
How Moraga's water quality compares to similar cities in California:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Moraga | D | 54 | 2 | 185 |
| Alderpoint | A | 1 | 1 | 185 |
| Dana Point | B | 9 | 1 | 185 |
| Mad River | C | 0 | 1 | 185 |
Water Quality by ZIP Code in Moraga
Water quality varies across Moraga's ZIP codes. The table below shows the worst-scoring and best-scoring areas:
Water quality scores in Moraga range from 45 to 66 — a spread of 21 points. This variation means your specific ZIP code matters significantly.
Common Questions About Moraga Water
These are the most common questions residents search for about water quality in Moraga, California:
Is Moraga water hard or soft? Water hardness varies by source. Moraga's 2 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Moraga tap water? Moraga's water receives a grade of D (48/100). There are 42 health-based violations — consider filtration.
What is the best water filter for Moraga? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Moraga vs. California Average
Understanding how Moraga 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 Moraga.
ZIP Codes in Moraga
Moraga spans 3 ZIP codes. The ZIP with the lowest water quality score is 94556. 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.