Water Quality in Walnut Creek, CA: No Violations - Grade N/A
2 water systems · 4 directly mapped ZIP records
Available EPA records report no violations across 4 directly mapped ZIP records with known counts for Walnut Creek. This does not cover unavailable records or guarantee a specific tap is contaminant-free.
Data: EPA Safe Drinking Water Information System (SDWIS)
Water Quality by ZIP Code in Walnut Creek
This table shows typed EPA water evidence only. Missing violation counts are displayed as N/A, not zero.
| ZIP Code | Violations | Health | |
|---|---|---|---|
| 94595 | 0 | 0 | View report → |
| 94596 | 0 | 0 | View report → |
| 94597 | 0 | 0 | View report → |
| 94598 | 0 | 0 | View report → |
Water Quality Overview
Walnut Creek, California has directly mapped EPA water-system data for 4 ZIP codes. This page reports typed compliance facts and does not relabel the multi-source Home Safety Score as a drinking-water grade.
The available EPA records report no violations across 4 directly mapped ZIP records with reported counts for Walnut Creek. This does not guarantee the absence of contaminants.
Lead Levels
The average 90th percentile lead level across Walnut Creek water systems is 0.0023 mg/L - within EPA limits. No exceedances appear among the 4 ZIP records with known lead status.
With 75% of homes built before 1986, Walnut Creek 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.
Water Systems Serving Walnut Creek
Walnut Creek is served by 2 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 91,171 people across 4 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
How to Check Your Water in Walnut Creek
Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels and violation history
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
Walnut Creek vs. Nearby California Cities
How Walnut Creek's water quality compares to similar cities in California:
| City | Direct EPA ZIPs | Violations | Systems | Population |
|---|---|---|---|---|
| Walnut Creek | 4 | 0 | 2 | 91,171 |
| South Gate | 1 | 2 | 5 | 91,719 |
| Westminster | 1 | 1 | 5 | 90,140 |
| Napa | 2 | 2 | 5 | 92,380 |
Water Quality by ZIP Code in Walnut Creek
EPA coverage and recorded violations can differ across Walnut Creek's ZIP codes. Missing counts are shown as unavailable, not zero:
Common Questions About Walnut Creek Water
These are the most common questions residents search for about water quality in Walnut Creek, California:
Is Walnut Creek water hard or soft? Water hardness varies by source. Walnut Creek's 2 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Walnut Creek tap water? City-level EPA records cannot determine safety at a specific tap. No health-based violations are recorded across 4 directly mapped ZIP records with known counts, but this is not a property-level safety guarantee.
What is the best water filter for Walnut Creek? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Walnut Creek vs. California Average
Understanding how Walnut Creek 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 Walnut Creek.
ZIP Codes in Walnut Creek
Walnut Creek spans 4 ZIP codes. EPA water-system coverage is available for 4 directly mapped ZIP codes. 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
Source reporting periods vary. See each cited source for its publication schedule.