San Diego, California Water Quality Report
Population: 1,386,932 | Last Updated: 1/14/2024
Overall Water Quality Grade
Based on compliance rates, contaminant levels, and treatment effectiveness
Water Sources
San Diego receives its drinking water from multiple sources:
Colorado River (via Metropolitan Water District)
50%Surface Water
Imported water from the Colorado River via aqueduct system
State Water Project (Northern California)
35%Surface Water
Water from Northern California reservoirs via the California Aqueduct
Local Sources (Reservoirs & Groundwater)
15%Mixed
Local reservoirs in San Diego County and groundwater sources
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 | 2.1 ppb | 10 ppb | 0.02 ppb | Above Health Goal | → stable |
| Total Trihalomethanes (TTHMs) | 56 ppb | 80 ppb | 0 ppb | Below Legal Limit | → stable |
| Lead | 3.9 ppb | 15 ppb | 0 ppb | Below Legal Limit | → stable |
| Arsenic | 1.8 ppb | 10 ppb | 0.004 ppb | Above Health Goal | → stable |
| 1,2,3-Trichloropropane | 0.008 ppb | 0.005 ppb | 0.0007 ppb | Above Legal Limit | ↓ improving |
Comparison with California State Average
Lead Compliance
2.0 points above state average
Bacterial Compliance
Chemical Compliance
2.0 points below state average
Overall Score
Water Quality Trends
Overall water quality score over the past 5 years
Water quality has improved by 3.0 points since 2019
Contamination History
1,2,3-TCP Exceedance
Toxic solvent 1,2,3-trichloropropane exceeded state limit in some groundwater wells
Resolution:
Affected wells taken offline, treatment systems installed, blending strategies implemented
PFAS Detection
Per- and polyfluoroalkyl substances detected in some local groundwater sources
Resolution:
Enhanced monitoring, wellhead treatment systems planned, increased reliance on imported water
Frequently Asked Questions - San Diego Water Quality
Is San Diego tap water safe to drink?
Yes, San Diego's tap water meets all federal and state drinking water standards. The City of San Diego conducts over 120,000 water quality tests annually and operates multiple advanced treatment facilities.
Why is San Diego water hard?
San Diego's water hardness (averaging 155 mg/L) comes from natural minerals in the Colorado River and State Water Project sources. Hard water is safe to drink and provides beneficial minerals, though it may cause mineral deposits.
What is 1,2,3-TCP and should I be concerned?
1,2,3-TCP is a toxic solvent that contaminated some local groundwater. San Diego has taken affected wells offline and installed treatment systems. Most residents receive blended water that meets state limits. The city is working to fully eliminate this contaminant.
Where does San Diego get its water?
San Diego imports about 85% of its water from the Colorado River and Northern California via large aqueduct systems. About 15% comes from local sources including reservoirs and groundwater. The city is investing in water recycling and desalination for future reliability.
Is San Diego building a desalination plant?
The Carlsbad Desalination Plant (opened 2015) provides about 10% of San Diego County's water supply. This seawater desalination facility produces drought-proof water and represents one of the region's diverse water supply strategies.
Nearby Water Utilities
Compare water quality in nearby cities:
Chula Vista, CA
Oceanside, CA
Carlsbad, CA
El Cajon, CA
Utility Information
Water Provider
City of San Diego Public Utilities Department
Contact Information
Customer Service: 619-515-3500
Emergency: 619-515-3525
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.