Safe
California, United States
Is Tap Water Safe to Drink in San Francisco?
Yes, tap water in San Francisco is safe to drink and is considered among the purest municipal water in the country, sourced almost entirely from the protected Hetch Hetchy Reservoir in Yosemite National Park.
Hardness
Very soft
pH
8.5–9.0 (adjusted for corrosion control)
TDS
ranges 30–50 ppm
EPA Status
Compliant
Water Source
The San Francisco Public Utilities Commission (SFPUC) draws roughly 85% of its supply from the Hetch Hetchy Reservoir, fed by Sierra Nevada snowmelt in a protected watershed, requiring minimal treatment.
EPA Compliance Status
Meets all federal Safe Drinking Water Act standards; operates under an EPA filtration avoidance determination due to exceptional source water quality.
Notable Contaminants & Context
- •No significant source-water concerns given the protected high-Sierra watershed
- •Some older buildings have legacy plumbing; SFPUC adjusts water chemistry for corrosion control
How It Compares
Hetch Hetchy water is regularly cited as some of the cleanest source water of any major U.S. city, requiring far less treatment than river- or lake-sourced systems.
Tips
- •San Francisco tap water is genuinely excellent straight from the tap
- •SFPUC publishes detailed water quality data by neighborhood
- •No need to buy bottled water in the city