Water Quality in Clearlake Oaks, CA: No Violations — Grade C
Grade C · Score 60/100 · 1 water system · Updated 2026-05-03
Clearlake Oaks's water has moderate compliance issues. Residents in affected areas should consider filtration.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
Check EPA compliance data for Clearlake Oaks, CA and you find zero violations across 1 water system — no MCL exceedances, no monitoring schedule failures, no public health notices, no enforcement orders, and no outstanding compliance actions of any kind documented in the federal Safe Drinking Water Information System.
Water Quality by ZIP Code in Clearlake Oaks
Water quality varies across Clearlake Oaks's 1 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 95423 | C | 60 | 0 | 0 | View report → |
Water Quality Overview
Clearlake Oaks, California receives a water quality grade of C with an overall score of 60 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
No EPA violations have been recorded for the 1 water system serving Clearlake Oaks. This is a positive indicator, though it does not guarantee the absence of all contaminants — some substances (like PFAS) are not yet fully regulated.
What Grade C Means
A grade of C indicates moderate compliance issues. Clearlake Oaks's water systems have some violations that warrant attention. While the water may still be safe for most people, residents in affected ZIP codes should consider additional testing or filtration.
Lead Levels
Lead testing data for Clearlake Oaks is currently being collected. The EPA requires all community water systems to test for lead under the Lead and Copper Rule.
With 65% of homes built before 1986, Clearlake Oaks 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 Clearlake Oaks
Clearlake Oaks is served by 1 community water system regulated under the Safe Drinking Water Act. These systems collectively serve approximately 300 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
How to Check Your Water in Clearlake Oaks
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
Clearlake Oaks vs. Nearby California Cities
How Clearlake Oaks's water quality compares to similar cities in California:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Clearlake Oaks | C | 0 | 1 | 300 |
| Fairfax | C | 0 | 1 | 300 |
| Glenhaven | A | 0 | 1 | 300 |
| Greenbrae | B | 1 | 1 | 300 |
Common Questions About Clearlake Oaks Water
These are the most common questions residents search for about water quality in Clearlake Oaks, California:
Is Clearlake Oaks water hard or soft? Water hardness varies by source. Clearlake Oaks's 1 water system uses a single source. Check your ZIP code report for specific hardness data.
Can I drink Clearlake Oaks tap water? Clearlake Oaks's water receives a grade of C (60/100). No health-based violations have been recorded, but home testing is always recommended.
What is the best water filter for Clearlake Oaks? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Clearlake Oaks vs. California Average
Understanding how Clearlake Oaks 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 Clearlake Oaks.
ZIP Codes in Clearlake Oaks
Clearlake Oaks spans 1 ZIP code. 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.