Water Quality in Mendocino, CA: 5 Violations — Grade A
Grade A · Score 85/100 · 5 water systems · Updated 2026-05-03
Mendocino's water meets all EPA standards with no health-based violations.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
Available EPA records for Mendocino, CA: 5 water compliance violations tied to local public water systems.
Water Quality by ZIP Code in Mendocino
Water quality varies across Mendocino's 1 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 95460 | A | 85 | 5 | 5 | View report → |
Violation Trend
EPA violations recorded for water systems serving Mendocino.
Water Quality Overview
Mendocino, California receives a water quality grade of A with an overall score of 85 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
The 5 water systems serving Mendocino have accumulated 5 EPA violations, including 5 health-based violations. These violations are tracked across 1 ZIP codes serving approximately 423 people.
What Grade A Means
A grade of A indicates excellent compliance with EPA drinking water standards. Mendocino's water systems have maintained strong performance in both contaminant monitoring and regulatory compliance.
Lead Levels
The average 90th percentile lead level across Mendocino water systems is 0.0069 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
With 55% of homes built before 1986, Mendocino 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 Mendocino
Mendocino is served by 5 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 423 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 3 enforcement actions against water systems serving Mendocino. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Mendocino
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 Mendocino Water Systems
The following contaminants have been detected or caused violations across Mendocino's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 0.06 mg/L | 5 | 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 Mendocino:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2021 | 3 | 3 |
| 2023 | 1 | 1 |
Violations have decreased from 3 in 2021 to 1 in 2023, indicating improving compliance.
EPA Enforcement History
The EPA and state regulators have taken 3 enforcement actions against water systems serving Mendocino. Recent actions:
| Date | Action Type |
|---|---|
| 2024-02-07 | State Order Extension |
| 2023-09-05 | State Filed Suit |
| 2021-06-21 | State Filed Suit |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2024-02-07.
Mendocino vs. Nearby California Cities
How Mendocino's water quality compares to similar cities in California:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Mendocino | A | 5 | 5 | 423 |
| San Leandro | C | 0 | 1 | 420 |
| San Lorenzo | B | 0 | 1 | 420 |
| Death Valley | B | 2 | 3 | 413 |
Common Questions About Mendocino Water
These are the most common questions residents search for about water quality in Mendocino, California:
Is Mendocino water hard or soft? Water hardness varies by source. Mendocino's 5 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Mendocino tap water? Mendocino's water receives a grade of A (85/100). There are 5 health-based violations — consider filtration.
What is the best water filter for Mendocino? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Mendocino vs. California Average
Understanding how Mendocino 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 Mendocino.
ZIP Codes in Mendocino
Mendocino spans 1 ZIP code. The ZIP with the lowest water quality score is 95460. 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.
Frequently Asked Questions
Your Water is Safe — Here's How to Keep It That Way
Grade A is excellent news. Here's what proactive homeowners do to maintain water quality:
Annual Water Testing
EPA recommends annual testing even with clean water. Home test kits: $20-$50. Catches changes before they become problems.
Maintenance Filtration
A basic carbon filter removes chlorine taste and catches emerging contaminants like PFAS that aren't yet fully regulated.
Plumbing Check
Even safe city water picks up lead from home pipes. If your home was built before 1986, a one-time pipe inspection is recommended.