Water quality · CA

California Water Quality (2026)

Mixed surface and groundwater across regions; chromium-6, nitrate and arsenic are recurring concerns, particularly in Central Valley agricultural areas.

Our California coverage focuses on the 5 metros below: Fresno, Los Angeles, Sacramento, San Diego, San Francisco. Each city page lists the utility's water source, hardness in grains per gallon, any contaminants flagged above EWG's stricter health guideline, and the whole-house system type that matches that specific profile, not a generic recommendation copied across the state.

If your California city is not in the list yet, the nearest covered metro is usually a reasonable proxy: regional source water and treatment plants are typically shared across nearby municipalities. Private wells in California are a different story and need a mail-in lab panel, the utility CCR will not apply.

Sources: EWG Tap Water Database