California Water Quality Reports
Comprehensive water quality reports for major cities in California. Access Consumer Confidence Reports, contaminant data, EPA compliance information, and historical trends for water systems across the state.
California Water Quality Overview
Water Sources
California relies on a diverse mix of water sources including the Colorado River, State Water Project from Northern California, local groundwater basins, and surface water from rivers and reservoirs. Southern California imports most of its water, while Northern California uses more local sources.
Treatment Infrastructure
Major metropolitan areas use advanced treatment including filtration, ozonation, and UV disinfection. Smaller systems typically use conventional filtration and chlorination. Many systems have upgraded treatment in recent years to address emerging contaminants.
Key Statistics
Common Contaminants in California
Hexavalent Chromium (Chromium-6)
Found in many California water systems, particularly in Central Valley and Los Angeles areas. Linked to industrial contamination and natural geological sources.
Nitrates
Agricultural runoff causes elevated nitrate levels in Central Valley groundwater. Particularly concerning for small rural water systems.
Arsenic
Naturally occurring in groundwater throughout California. More common in rural areas relying on well water.
PFAS (Forever Chemicals)
Found near military bases, airports, and industrial facilities. California has some of the strictest PFAS standards in the nation.
Disinfection Byproducts (TTHMs/HAA5)
Formed when chlorine reacts with organic matter. More common in systems using surface water and older distribution systems.
California-Specific Regulations
California often sets stricter water quality standards than federal EPA requirements. Key state-specific regulations include:
AB 685 (PFAS Monitoring)
Requires quarterly monitoring for PFAS in public water systems. California has established response levels lower than EPA health advisories.
Chromium-6 Standards
California set a Maximum Contaminant Level of 10 ppb for hexavalent chromium, though enforcement has been subject to legal challenges.
Lead in Schools
AB 746 requires testing for lead in drinking water at schools and childcare facilities, with remediation required for elevated levels.
Top 10 Cities - Water Quality Reports
Click any city to view detailed water quality report and Consumer Confidence Report
Historical Water Quality Trends
2020-2024 Improvements
- Significant reduction in PFAS contamination through advanced treatment upgrades
- Decreased nitrate violations in Central Valley through wellhead treatment
- Improved chromium-6 monitoring and public reporting
- Enhanced lead testing at schools and childcare facilities
Ongoing Challenges
- Small disadvantaged communities still struggle with arsenic and nitrate contamination
- Aging infrastructure in some urban areas contributes to lead exposure
- Drought conditions can concentrate contaminants in water supplies
- Emerging contaminants like microplastics require new monitoring approaches
California Water Quality Agency Contact
California State Water Resources Control Board
Division of Drinking Water
P.O. Box 100
Sacramento, CA 95812-0100
Contact Information
Phone: (916) 449-5577
Email: dwsap@waterboards.ca.gov
Website: waterboards.ca.gov/drinking_water
EPA Region 9 (Pacific Southwest)
75 Hawthorne Street, San Francisco, CA 94105
Phone: (415) 947-8000 | Toll-free: (866) 372-9378
Frequently Asked Questions
How do I find my California city water quality report?
Select your city from the list above to view its detailed water quality report. Each report includes contaminant levels, source water information, treatment methods, and links to official Consumer Confidence Reports from your local water utility.
What are common water quality issues in California?
California water systems commonly monitor for arsenic, nitrates, disinfection byproducts (TTHMs and HAA5), PFAS (forever chemicals), and hexavalent chromium. Specific contaminants vary by region depending on agricultural activity, industrial presence, and natural geology.
Who regulates water quality in California?
Water quality in California is regulated by the California State Water Resources Control Board's Division of Drinking Water, working in conjunction with the federal EPA. The state sets standards that often exceed federal EPA requirements.