Water Quality in Lake Isabella, CA: 24 Violations — Grade C
Grade C · Score 59/100 · 5 water systems · Updated 2026-05-03
Lake Isabella'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
According to EPA filings, Lake Isabella, CA has 24 water compliance violations on record — sourced from SDWIS, the federal database that tracks reportable events for every registered public water system in the state.
Water Quality by ZIP Code in Lake Isabella
Water quality varies across Lake Isabella's 1 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 93240 | C | 59 | 24 | 9 | View report → |
Violation Trend
EPA violations recorded for water systems serving Lake Isabella.
Water Quality Overview
Lake Isabella, California receives a water quality grade of C with an overall score of 59 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
The 5 water systems serving Lake Isabella have accumulated 24 EPA violations, including 9 health-based violations. These violations are tracked across 1 ZIP codes serving approximately 494 people.
What Grade C Means
A grade of C indicates moderate compliance issues. Lake Isabella'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
The average 90th percentile lead level across Lake Isabella water systems is 0.0010 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
With 83% of homes built before 1986, Lake Isabella 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.
Radon Risk
Lake Isabella is in EPA Radon Zone 2 (Moderate risk). Testing is recommended, especially for homes with basements or ground-level living spaces.
Water Systems Serving Lake Isabella
Lake Isabella is served by 5 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 494 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 10 enforcement actions against water systems serving Lake Isabella. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Lake Isabella
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 Lake Isabella Water Systems
The following contaminants have been detected or caused violations across Lake Isabella's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Lead | Inorganic | 0.015 mg/L | 7 | 1 | Yes |
| Stage 2 DBP Rule | Treatment Technique | N/A | 6 | 1 | Yes |
| Surface Water Treatment Rule | Treatment Technique | N/A | 5 | 1 | No |
| Stage 1 DBP Rule | Treatment Technique | N/A | 3 | 1 | No |
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 Lake Isabella:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2023 | 1 | 1 |
| 2024 | 11 | 11 |
| 2025 | 3 | 3 |
Violations have increased from 1 in 2023 to 3 in 2025. This trend warrants monitoring.
EPA Enforcement History
The EPA and state regulators have taken 10 enforcement actions against water systems serving Lake Isabella. Recent actions:
| Date | Action Type |
|---|---|
| 2025-08-26 | State Order Extension |
| 2025-06-02 | State Filed Suit |
| 2024-12-31 | State Filed Suit |
| 2024-08-27 | State Filed Suit |
| 2024-05-17 | State Filed Suit |
| 2024-01-12 | State Order Extension |
| 2023-11-03 | State Filed Suit |
| 2023-09-26 | State Order Extension |
| 2023-07-10 | State Filed Suit |
| 2023-06-30 | State Order Extension |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-08-26.
Lake Isabella vs. Nearby California Cities
How Lake Isabella's water quality compares to similar cities in California:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Lake Isabella | C | 24 | 5 | 494 |
| Miranda | A | 0 | 1 | 492 |
| Ahwahnee | D | 0 | 1 | 498 |
| Fish Camp | D | 0 | 1 | 498 |
Common Questions About Lake Isabella Water
These are the most common questions residents search for about water quality in Lake Isabella, California:
Is Lake Isabella water hard or soft? Water hardness varies by source. Lake Isabella's 5 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Lake Isabella tap water? Lake Isabella's water receives a grade of C (59/100). There are 9 health-based violations — consider filtration.
What is the best water filter for Lake Isabella? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Lake Isabella vs. California Average
Understanding how Lake Isabella 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 Lake Isabella.
ZIP Codes in Lake Isabella
Lake Isabella spans 1 ZIP code. The ZIP with the lowest water quality score is 93240. 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.