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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 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.
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.
Found in many California water systems, particularly in Central Valley and Los Angeles areas. Linked to industrial contamination and natural geological sources.
Agricultural runoff causes elevated nitrate levels in Central Valley groundwater. Particularly concerning for small rural water systems.
Naturally occurring in groundwater throughout California. More common in rural areas relying on well water.
Found near military bases, airports, and industrial facilities. California has some of the strictest PFAS standards in the nation.
Formed when chlorine reacts with organic matter. More common in systems using surface water and older distribution systems.
California often sets stricter water quality standards than federal EPA requirements. Key state-specific regulations include:
Requires quarterly monitoring for PFAS in public water systems. California has established response levels lower than EPA health advisories.
California set a Maximum Contaminant Level of 10 ppb for hexavalent chromium, though enforcement has been subject to legal challenges.
AB 746 requires testing for lead in drinking water at schools and childcare facilities, with remediation required for elevated levels.
Click any city to view detailed water quality report and Consumer Confidence Report
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
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.
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.
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.