Is Lake Isabella, CA Tap Water Safe to Drink?
Graded D+, with 64 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
50/100
waterverge.com Lake Isabella, CA — Water Quality Report
Lake Isabella's drinking water received a grade of D+ (50 out of 100), indicating poor water quality. The city's 7 water systems serve approximately 594 residents using groundwater.
Lead levels were measured at 1.3 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program.
The system has 373 violations on record, including 162 health-based violations. 64 remain unresolved.
What to know about Lake Isabella's water
Lake Isabella ranks #608 out of 694 cities in California for water quality, placing it among the lowest-rated in the state.
Lake Isabella relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.
As a small community water system, Lake Isabella may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
The system has seen 52 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Lake Isabella, CA water safe to drink?
Lake Isabella's drinking water has significant quality concerns based on EPA testing data. With a grade of D+ (50/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 7 water systems serve approximately 594 residents using groundwater (wells).
Recent water quality updates for Lake Isabella
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Lake Isabella's water quality assessment. Grade: D+ (50/100).
1 health-based. Contaminants: Lead and Copper Rule, Arsenic.
1 health-based. Contaminants: Arsenic.
1 health-based. Contaminants: Arsenic.
Federal disaster declaration (FEMA DR-4750). Hurricane event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-3592). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Lake Isabella's water supply.
Well within EPA limits.
Violation history
Lake Isabella's water system has 373 total violations on record, including 162 health-based violations. 64 remain unresolved. 52 violations were issued in the last 5 years.
Flood & environmental risk
Kern County has experienced 10 federally declared disasters since 1967. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies.
Where does Lake Isabella's water come from?
Lake Isabella's drinking water comes from groundwater (wells), supplied by 7 water systems serving approximately 594 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.
What Lake Isabella residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Lake Isabella's water.
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
Lake Isabella's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Flood & disaster history
Kern County has experienced 10 federally declared disasters since 1967. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 1.3 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Lake Isabella compares by contaminant
Explore where Lake Isabella ranks among all California cities for specific contaminants.
Water source & infrastructure
Where Lake Isabella's water comes from
Lake Isabella's drinking water is drawn from underground aquifers through wells.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.
Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.
The system is operated by private ownership and serves approximately 594 people through 7 water systems.
Water systems serving Lake Isabella
| System Name | PWSID | Population | Source |
|---|---|---|---|
| KERN VALLEY MUTUAL WATER COMPANY | CA1500252 | 132 | GW |
| OAK KNOLLS MUTUAL WATER COMPANY | CA1500465 | 123 | GW |
| CLARK STREET COMMUNITY WELL | CA1502056 | 90 | GW |
| KERNVALE MUTUAL WATER CO | CA1500364 | 75 | GWP |
| HUNGRY GULCH MWC | CA1500436 | 74 | GW |
| FOURTH STREET WATER SYSTEM | CA1500449 | 56 | GW |
| CYPRESS CANYON WATER SYSTEM | CA1502449 | 44 | GW |
How Lake Isabella compares
Full California rankings →Lake Isabella's score of 50/100 is below the average of 57/100 among major California cities. It outscores 5 of 10 nearby cities.
Nearby cities
View California rankings →About Lake Isabella, CA
Wikipedia →Lake Isabella is a census-designated place (CDP) in the southern Sierra Nevada, in Kern County, California, United States. It is named after the Lake Isabella reservoir and located at the lake’s southwestern edge, 6 miles (9.7 km) south of Wofford Heights in the Kern River Valley.
Learn more about your water
Guides and resources related to Lake Isabella's water quality findings.
Explore water quality across Kern
Frequently asked questions
Is Lake Isabella, CA tap water safe to drink?
Lake Isabella's water quality earned a grade of D+ (50/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #608 out of 694 cities tested in California.
What contaminants are in Lake Isabella's water?
Lead was measured at 1.3 ppb (90th percentile). 373 violations are on record.
How is Lake Isabella's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Lake Isabella?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Lake Isabella's water come from?
Lake Isabella's water is sourced from Groundwater. The city has 7 water systems serving approximately 594 residents.
What health violations has Lake Isabella's water system had?
Lake Isabella has 162 health-based violations on record. The most recent violation was recorded in October 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 64 violations remain unresolved.
Is Lake Isabella's groundwater at risk of contamination?
Lake Isabella uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 373 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does Lake Isabella's water compare to other cities?
Lake Isabella ranks #608 out of 694 cities in California (better than 12% of state cities) and #13186 out of 15744 cities nationally (16th percentile). The grade of D+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.