Kern County Water Quality: 356 Violations (CA)
87 water systems · 102 ZIP codes · Grade C · Updated 2026-06-04
Data: EPA Safe Drinking Water Information System (SDWIS), EPA ECHO Last verified: 2026-06-04
Violation Trend
EPA violations across water systems in Kern County.
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Find the Right Filter →Water Quality Overview
Kern County has 87 community water systems serving approximately 53,309,253 people across 102 ZIP codes. These systems have accumulated 356 EPA violations, including 283 health-based violations.
Health-based violations account for 79% of all violations in Kern County. These violations indicate contaminant levels that may pose direct risks to human health.
Violation Breakdown
| Violation Type | Count | Percentage |
|---|---|---|
| Health-based | 283 | 79.5% |
| Monitoring/Reporting | 73 | 20.5% |
| Total | 356 | 100% |
Health-based violations indicate contaminant levels exceeding EPA Maximum Contaminant Levels (MCLs). Monitoring violations indicate failures to test or report.
Cities with Most Violations
| Rank | City | Violations | Health-Based | ZIP Codes | Population |
|---|---|---|---|---|---|
| 1 | Bakersfield | 120 | 96 | 24 | 9,344,491 |
| 2 | Weldon | 48 | 46 | 1 | 1,526 |
| 3 | Mojave | 36 | 36 | 2 | 41,419 |
| 4 | Rosamond | 30 | 29 | 1 | 21,984 |
| 5 | Wofford Heights | 25 | 25 | 1 | 338 |
| 6 | Lake Isabella | 24 | 9 | 1 | 3,494 |
| 7 | Edison | 15 | 14 | 1 | 300,836 |
| 8 | Lebec | 12 | 10 | 1 | 44,546 |
| 9 | Tehachapi | 10 | 4 | 2 | 64,892 |
| 10 | Woody | 7 | 5 | 1 | 26 |
Violation Trend
Year-by-year EPA violations across water systems in Kern County:
| Year | Total | Health-Based |
|---|---|---|
| 2021 | 15 | 15 |
| 2022 | 128 | 128 |
| 2023 | 209 | 209 |
| 2024 | 297 | 297 |
| 2025 | 136 | 136 |
Most Common Contaminants
| Contaminant | Category | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|
| Combined Radium | Radionuclides | 64 | 4 | Yes |
| Barium | Inorganic | 54 | 4 | Yes |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 53 | 28 | Yes |
| Lead | Inorganic | 52 | 7 | Yes |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 48 | 24 | Yes |
| Stage 2 DBP Rule | Treatment Technique | 33 | 12 | Yes |
| Stage 1 DBP Rule | Treatment Technique | 31 | 29 | No |
| Surface Water Treatment Rule | Treatment Technique | 10 | 4 | No |
| Nickel | Inorganic | 2 | 1 | Yes |
Understanding Water Quality Scores
Each ZIP code in Kern County receives a safety score from 0-100 based on EPA compliance data. Scores factor in the number and severity of violations, with health-based violations weighted more heavily than monitoring failures. Resolved violations (where the system returned to compliance) receive reduced weight in the scoring.
The county-level grade (C) represents the average across all 102 ZIP codes. Individual ZIP codes may vary significantly — a county with a B grade may contain both A-rated and D-rated areas.
Water Systems in Kern County
Kern County is served by 87 community water systems, averaging 0.9 systems per ZIP code. Each system is independently regulated and tested by the EPA. Larger systems serving more people typically have more extensive monitoring requirements.
Water systems in Kern County source water from a mix of surface water (rivers, reservoirs) and groundwater (wells, aquifers). Source type affects which contaminants are most likely to be detected.
How to Check Your Water in Kern County
Enter your ZIP code on ZipCheckup for detailed water system data including contaminant levels, violation history, and safety scores
Request your CCR — every water utility must provide an annual Consumer Confidence Report
Get a home test — certified kits ($20-$50) or professional lab tests ($150-$400) can detect contaminants not covered by routine testing
Consider filtration — NSF-certified filters can address specific contaminants found in your area
Check for lead — homes built before 1986 should test for lead regardless of utility compliance
EPA Enforcement
The EPA and state regulators have taken 307 enforcement actions against water systems in Kern County. Enforcement actions range from compliance assistance and administrative orders to formal penalties. Systems under enforcement are required to remediate violations and may face ongoing monitoring requirements.
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Enforcement: EPA ECHO
Updated daily.
Water Quality Map: Kern County, CA
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Water Quality by ZIP Code in Kern County
Water quality varies across Kern County's 102 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | City | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|---|
| 93283 | Weldon | C | 55 | 48 | 46 | View → |
| 93560 | Rosamond | F | 28 | 30 | 29 | View → |
| 93285 | Wofford Heights | C | 58 | 25 | 25 | View → |
| 93240 | Lake Isabella | C | 59 | 24 | 9 | View → |
| 93501 | Mojave | C | 58 | 18 | 18 | View → |
| 93502 | Mojave | D | 50 | 18 | 18 | View → |
| 93220 | Edison | F | 39 | 15 | 14 | View → |
| 93243 | Lebec | C | 58 | 12 | 10 | View → |
| 93287 | Woody | F | 32 | 7 | 5 | View → |
| 93527 | Inyokern | B | 78 | 6 | 1 | View → |
| 93205 | Bodfish | B | 78 | 5 | 2 | View → |
| 93304 | Bakersfield | B | 76 | 5 | 4 | View → |
| 93305 | Bakersfield | B | 76 | 5 | 4 | View → |
| 93306 | Bakersfield | B | 76 | 5 | 4 | View → |
| 93308 | Bakersfield | B | 76 | 5 | 4 | View → |
| 93309 | Bakersfield | B | 76 | 5 | 4 | View → |
| 93311 | Bakersfield | B | 76 | 5 | 4 | View → |
| 93312 | Bakersfield | B | 76 | 5 | 4 | View → |
| 93314 | Bakersfield | B | 76 | 5 | 4 | View → |
| 93389 | Bakersfield | B | 76 | 5 | 4 | View → |
What are EPA health violations?
Health-based violations mean a contaminant was detected above the EPA's Maximum Contaminant Level (MCL) — the legal limit designed to protect human health. Kern County has 283 such violations. Not all violations cause illness, but repeated exceedances increase risk, especially for children and immunocompromised individuals.
What is a water quality grade?
ZipCheckup grades water systems from A to F based on EPA violation history, contaminant levels, and system compliance. Grade A means few or no violations; Grade F indicates persistent or serious issues. Kern County's overall grade is C.
Not sure if your water needs a filter?
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Find the Right Filter →Frequently Asked Questions
Is the tap water safe in Kern County, California?
Kern County has 87 community water systems with 356 recorded EPA violations, including 283 health-based. Water quality varies by ZIP code — check your specific location for detailed results.
How many water violations does Kern County have?
Kern County has 356 total EPA violations across 102 ZIP codes. 283 are health-based violations indicating contaminant levels potentially harmful to health.
Which city in Kern County has the most water violations?
Bakersfield has the most violations in Kern County with 120 recorded EPA violations across 24 ZIP codes.
What contaminants are found in Kern County water?
Kern County water systems are monitored for over 90 EPA-regulated contaminants including lead, copper, nitrates, disinfection byproducts, and bacteria. Check your ZIP code for contaminant-specific data.
How can I test my water in Kern County?
Contact your local water utility for free or low-cost testing. You can also use a certified home test kit ($20-$50) or hire a certified lab ($150-$400).