Los Angeles, California Water Quality Report
Population: 3,979,576 | Last Updated: 1/14/2024
Overall Water Quality Grade
Based on compliance rates, contaminant levels, and treatment effectiveness
Water Sources
Los Angeles receives its drinking water from multiple sources:
Los Angeles Aqueduct
30%Surface Water
Water from the Eastern Sierra Nevada mountains via the historic LA Aqueduct
State Water Project
35%Surface Water
Northern California water delivered via the California Aqueduct
Colorado River Aqueduct
25%Surface Water
Water from the Colorado River imported from eastern sources
Local Groundwater
10%Groundwater
Groundwater from the San Fernando Valley and other local basins
Detected Contaminants
All contaminants listed below are within legal limits, but some may exceed health guidelines.
| Contaminant | Detected Level | Legal Limit | Health Goal | Status | Trend |
|---|---|---|---|---|---|
| Chromium-6 | 1.8 ppb | 10 ppb | 0.02 ppb | Above Health Goal | ↓ improving |
| Lead | 4.5 ppb | 15 ppb | 0 ppb | Below Legal Limit | → stable |
| Total Trihalomethanes (TTHMs) | 52 ppb | 80 ppb | 0 ppb | Below Legal Limit | ↓ improving |
| Arsenic | 2.1 ppb | 10 ppb | 0.004 ppb | Above Health Goal | → stable |
| Perchlorate | 3.2 ppb | 6 ppb | 1 ppb | Above Health Goal | ↓ improving |
Comparison with California State Average
Lead Compliance
2.0 points above state average
Bacterial Compliance
1.0 points above state average
Chemical Compliance
2.0 points above state average
Overall Score
2.0 points above state average
Water Quality Trends
Overall water quality score over the past 5 years
Water quality has improved by 4.0 points since 2019
Contamination History
Chromium-6 Detection
Higher than recommended levels of hexavalent chromium (Chromium-6) found in some water sources
Resolution:
Enhanced treatment processes implemented, ongoing monitoring and blending strategies
San Fernando Valley Groundwater Contamination
Industrial pollutants including TCE and PCE found in some groundwater wells
Resolution:
Affected wells taken offline, treatment systems installed, alternative sources utilized
PFAS Detection
Per- and polyfluoroalkyl substances (PFAS) detected in some local groundwater sources
Resolution:
Wellhead treatment systems installed, water blending optimization implemented
Frequently Asked Questions - Los Angeles Water Quality
Is Los Angeles tap water safe to drink?
Yes, LA tap water meets all federal and state drinking water standards. The Los Angeles Department of Water and Power conducts over 300,000 water quality tests annually to ensure safety and quality.
Why is LA water so hard?
LA receives water from multiple sources, including the Colorado River and State Water Project, which naturally contain higher mineral content. The water hardness averages 145 mg/L (moderately hard), which is safe but may leave mineral deposits on fixtures.
What is being done about Chromium-6?
LADWP has invested over $70 million in wellhead treatment systems to remove Chromium-6. While levels are below the legal limit, the utility continues to reduce concentrations through treatment and source blending.
Should I use a water filter in Los Angeles?
While LA tap water is safe to drink, some residents choose to use filters to reduce mineral content, improve taste, or further reduce contaminants to below health goal levels. NSF-certified filters for specific contaminants are recommended if filtering.
Where does LA get its water?
LA imports about 85% of its water from the Eastern Sierra Nevada (LA Aqueduct), Northern California (State Water Project), and the Colorado River. About 10-15% comes from local groundwater sources in the San Fernando Valley and other basins.
Nearby Water Utilities
Compare water quality in nearby cities:
Pasadena, CA
Glendale, CA
Long Beach, CA
Santa Monica, CA
Utility Information
Water Provider
Los Angeles Department of Water and Power (LADWP)
Contact Information
Customer Service: (800) 342-5397
Emergency: (800) 342-5397
Data Disclaimer
This water quality report is compiled from publicly available data and annual water quality reports. For the most current information, please contact your local water utility or visit their official website. Last updated: 1/14/2024.