Water Quality in Oakley, CA: 29 Violations — Grade D
Grade D · Score 53/100 · 5 water systems · Updated 2026-05-03
Oakley's water has significant violations. Water testing and filtration are recommended.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
Water systems in Oakley, CA have accumulated 29 EPA violations across the full compliance record — a dataset that captures reportable health-based exceedances, monitoring lapses, and enforcement actions filed with the federal Safe Drinking Water Information System.
Water Quality by ZIP Code in Oakley
Water quality varies across Oakley's 1 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 94561 | D | 53 | 29 | 29 | View report → |
Violation Trend
EPA violations recorded for water systems serving Oakley.
Water Quality Overview
Oakley, California 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).
The 5 water systems serving Oakley have accumulated 29 EPA violations, including 29 health-based violations. These violations are tracked across 1 ZIP codes serving approximately 44,450 people.
What Grade D Means
A grade of D indicates significant compliance issues. Oakley'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 Oakley water systems is 0.0019 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
Radon Risk
Oakley is in EPA Radon Zone 2 (Moderate risk). Testing is recommended, especially for homes with basements or ground-level living spaces.
Water Systems Serving Oakley
Oakley is served by 5 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 44,450 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 2 enforcement actions against water systems serving Oakley. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Oakley
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 Oakley Water Systems
The following contaminants have been detected or caused violations across Oakley's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Barium | Inorganic | 2 mg/L | 29 | 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 Oakley:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2023 | 5 | 5 |
| 2024 | 10 | 10 |
Violations have increased from 5 in 2023 to 10 in 2024. This trend warrants monitoring.
EPA Enforcement History
The EPA and state regulators have taken 2 enforcement actions against water systems serving Oakley. Recent actions:
| Date | Action Type |
|---|---|
| 2021-12-10 | State Filed Suit |
| 2021-02-26 | State Filed Suit |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2021-12-10.
Oakley vs. Nearby California Cities
How Oakley's water quality compares to similar cities in California:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Oakley | D | 29 | 5 | 44,450 |
| Desert Hot Springs | B | 2 | 3 | 44,400 |
| Elk Grove | C | 0 | 3 | 43,906 |
| Coachella | B | 2 | 1 | 43,590 |
Common Questions About Oakley Water
These are the most common questions residents search for about water quality in Oakley, California:
Is Oakley water hard or soft? Water hardness varies by source. Oakley's 5 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Oakley tap water? Oakley's water receives a grade of D (53/100). There are 29 health-based violations — consider filtration.
What is the best water filter for Oakley? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Oakley vs. California Average
Understanding how Oakley 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 Oakley.
ZIP Codes in Oakley
Oakley spans 1 ZIP code. The ZIP with the lowest water quality score is 94561. 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.