San Francisco Tap Water Quality: Is It Safe to Drink? (2026 Report)

San Francisco, California tap water receives a grade of D (39/100), which is considered poor. 0 contaminant(s) exceed EPA maximum contaminant levels and 177 violation(s) are on record. Residents should consider using an NSF-certified water filter to reduce contaminant exposure.

Of the 31 contaminants tested in San Francisco's water supply, the most notable include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.

Yes, San Francisco has 177 EPA violation(s) on record, with the most recent in 2025. Violation types include MON, RPT, MR. 20 of these are health-based violations, which are the most serious category.

San Francisco water meets EPA standards, so a filter is not strictly necessary. However, some residents prefer the added security of a water filter. EPA health goals (MCLGs) are stricter than legal limits and are set at levels with zero expected health risk. 1 contaminant(s) exceed these stricter goals.

San Francisco's drinking water is sourced from groundwater and supplied by JOSHUA VALLEY UTILITY COMPANY and 1 other water system(s). The system serves approximately 5,000 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.

Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. San Francisco's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.

San Francisco's water quality score of 39/100 earns a grade of D, which is considered poor. This is a concerning score that suggests significant water quality issues. Visit our California state page to see how all cities in the state compare.

If you have concerns about San Francisco's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (JOSHUA VALLEY UTILITY COMPANY) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.