Water Quality in Cotati, CA: 2 Violations Recorded for Mapped Water Systems
4 water systems · 1 directly mapped ZIP records
Available EPA records report 2 violations across 1 directly mapped ZIP records with known counts for Cotati. This is compliance evidence, not a property-level tap-water verdict.
Data: EPA Safe Drinking Water Information System (SDWIS)
Water Quality by ZIP Code in Cotati
This table shows typed EPA water evidence only. Missing violation counts are displayed as N/A, not zero.
| ZIP Code | Violations | Health | |
|---|---|---|---|
| 94931 | 2 | 0 | View report → |
Water Quality Overview
Cotati, California has directly mapped EPA water-system data for 1 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 2 violations (all classified as monitoring/reporting type in the available record) across 1 directly mapped ZIP record with reported counts.
Lead Levels
The average of the reported 90th-percentile lead results across the ZIP codes of Cotati is reported as 0 mg/L (a reported 0 is not proof of no lead; check the source record for its reporting limit); the EPA action level of 0.015 mg/L applies to a water system's own 90th-percentile result and is not a safety threshold (EPA's health goal for lead is zero). No exceedances appear among the 1 ZIP records with known lead status.
With 63% of homes built before 1986, Cotati 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 Cotati
Cotati is served by 4 community water systems regulated under the Safe Drinking Water Act. About 9,320 people live in the area (1 ZIP code, Census); this is not the systems' reported service population.
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
EPA records list 3 enforcement actions against water systems serving Cotati. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Cotati
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
Contaminants Detected in Cotati Water Systems
The following contaminants have been detected or caused violations across Cotati's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Barium | Inorganic | 2 mg/L | 1 | 1 | No |
The standard column shows the EPA Maximum Contaminant Level (MCL) except for lead and copper, whose value is an action level that triggers corrective steps and is not an MCL. Health-based violations are MCL, MRDL and treatment-technique violations.
EPA Enforcement History
The EPA and state regulators have taken 3 enforcement actions against water systems serving Cotati. Recent actions:
| Date | Action Type |
|---|---|
| 2024-03-08 | State Order Extension |
| 2021-09-10 | State Filed Suit |
| 2021-09-08 | State Filed Suit |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2024-03-08.
Cotati vs. Nearby California Cities
How Cotati's water quality compares to similar cities in California:
| City | Direct EPA ZIPs | Violations | Systems | Population |
|---|---|---|---|---|
| Cotati | 1 | 2 | 4 | 9,320 |
| Mentone | 1 | 5 | 2 | 9,394 |
| Coloma | 1 | 1 | 1 | 9,434 |
| Penn Valley | 1 | 0 | 2 | 9,448 |
Common Questions About Cotati Water
These are the most common questions residents search for about water quality in Cotati, California:
Is Cotati water hard or soft? Water hardness varies by source. Cotati's 4 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Cotati tap water? City-level EPA records cannot determine safety at a specific tap. No health-based violations are recorded across 1 directly mapped ZIP records with known counts, but this is not a property-level safety guarantee.
What is the best water filter for Cotati? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Cotati vs. California Average
Understanding how Cotati 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 Cotati.
ZIP Codes in Cotati
Cotati spans 1 ZIP code. EPA water-system coverage is available for 1 directly mapped ZIP code. 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.