San Francisco
Is San Francisco tap water safe to drink?
Mostly yes — San Francisco scores 96/100. This report aggregates EPA drinking water data across 4 local systems in San Francisco. We found 256 total violations (22 unresolved).
Real-Time Environment
Live: 10:15 AM☀️ No active precipitation. Rainfall can impact surface water turbidity and pollutant runoff in San Francisco.
Water Quality Impact
🛡️ Home Water Treatment Needs
Should you invest in filtration or softening for your home in San Francisco?
Expert Advice
Your water quality is excellent. Standard filtration is optional but can further enhance taste.
Buying a Filter?
Filter requirements and certified reduction benchmarks for San Francisco tap water.
Baby Formula Safety
Infant formula preparation risks, nitrate levels, and lead pipe guidance in San Francisco.
Homebuyer's Perspective
Evaluating water infrastructure in San Francisco protects plumbing and helps estimate water heater longevity. The high safety score (96/100) suggests lower risk for plumbing corrosion and appliance scaling.
Health & Family Safety
Residents should monitor Lead (90th percentile) levels. Pregnant women and families with young children should consult the specific EPA health goals listed below.
View Health Risk Glossary →Compliance Record for San Francisco
Based on EPA SDWIS violation records and contaminant test results for all water systems serving San Francisco.
Frequently Asked Questions
Is San Francisco tap water safe to drink?
Mostly yes — San Francisco scores 96/100.
How many water systems serve San Francisco?
San Francisco is served by 4 public water systems in our latest EPA-backed dataset.
How can I check water quality for my exact address in San Francisco?
Use the WaterQ search tool to look up your ZIP code and view nearby systems, contaminant levels, and recent violations for San Francisco.
What is the water quality score for San Francisco?
The water quality score for San Francisco is 96 out of 100, based on EPA contaminant data, violation history, and testing results across the 4 systems serving the city.
What are the top contaminants in San Francisco?
The top contaminants detected in San Francisco include Lead (90th percentile). View detailed information on our contaminants page.
San Francisco Water Quality Summary
San Francisco, CA receives a water quality score of 96/100 (Grade A) based on EPA Safe Drinking Water Information System (SDWIS) compliance data for 4 public water systems serving the area.
San Francisco's water quality is above the national average, with strong compliance records and low contaminant levels. Residents generally receive clean, safe tap water that meets EPA standards.
San Francisco's score of 96 is 7 points above the California state average of 89, and above the nationwide average of roughly 78/100 across all U.S. states.
For households and homebuyers in this large West Coast city, the water supply across San Francisco, California's multiple distribution networks maintains an exemplary rating for safety and quality. This consistently high compliance maintains reliable compliance, particularly when considering the broader regional context of Central Valley agriculture, varied geology, and the typical environmental demands of large urban centers. The strength of these local systems suggests robust treatment and infrastructure capable of delivering reliable tap water throughout the community.
Water quality data is sourced from the U.S. EPA SDWIS database and updated quarterly. Learn about our scoring methodology → Read our California water quality rankings report →
Key Contaminants
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Water Systems Serving San Francisco (4)
Check Your Specific Address
Water quality can vary by neighborhood in San Francisco.
Related
Quick compare in California
Compare San Francisco water quality: View all states · Contaminant library · How we score water quality