San Jose
Is San Jose tap water safe to drink?
Mostly yes — San Jose scores 96/100. This report aggregates EPA drinking water data across 44 local systems in San Jose. We found 393 total violations (77 unresolved).
Real-Time Environment
Live: 05:45 PM☀️ No active precipitation. Rainfall can impact surface water turbidity and pollutant runoff in San Jose.
Water Quality Impact
🛡️ Home Water Treatment Needs
Should you invest in filtration or softening for your home in San Jose?
Expert Advice
Your water quality is excellent. Standard filtration is optional but can further enhance taste.
Buying a Filter?
Wondering if San Jose tap water needs filtering? We break it down.
Baby Formula Safety
Mixing baby formula with San Jose tap water? Read this first.
Homebuyer's Perspective
If you're house-hunting in San Jose, water quality belongs on your due-diligence checklist alongside schools and crime data. The high safety score (96/100) suggests lower risk for plumbing corrosion and appliance scaling.
Health & Family Safety
Residents should monitor Copper (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 Jose
Based on EPA SDWIS violation records and contaminant test results for all water systems serving San Jose.
Frequently Asked Questions
Is San Jose tap water safe to drink?
Mostly yes — San Jose scores 96/100.
How many water systems serve San Jose?
San Jose is served by 44 public water systems in our latest EPA-backed dataset.
How can I check water quality for my exact address in San Jose?
Use the WaterQ search tool to look up your ZIP code and view nearby systems, contaminant levels, and recent violations for San Jose.
What is the water quality score for San Jose?
The water quality score for San Jose is 96 out of 100, based on EPA contaminant data, violation history, and testing results across the 44 systems serving the city.
What are the top contaminants in San Jose?
The top contaminants detected in San Jose include Copper (90th percentile), Lead (90th percentile). View detailed information on our contaminants page.
San Jose Water Quality Summary
San Jose, CA receives a water quality score of 96/100 (Grade A) based on EPA Safe Drinking Water Information System (SDWIS) compliance data for 44 public water systems serving the area.
San Jose'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 Jose'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 residents and homebuyers in this major metro area, San Jose's drinking water consistently achieves excellent ratings that reflect a strong standard of safety. Because the city lies in a West Coast region characterized by varied geology, large urban centers, and nearby Central Valley agriculture, local water quality is managed through dozens of distinct water systems. This multi-system setup helps buffer the community against regional environmental and geological variations, providing peace of mind and highly rated tap water across the metropolitan expanse of California.
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 Jose (44)
Great Oaks Wc Inc
ACity Of San Jose - Nsj/Alviso
ACity Of San Jose - Evg/Edv/Coy
AO'Connor Hospital
BCws - Bakersfield
ALucerne Water Co. - Cal Water Service
ABakersfield, City Of
ACws - Kernville
ACws Southlake System
ACws - North Garden
ACal-Water Service Co.-Hamilton City
ACal-Water Service Co.-Willows
ACws - Selma
ACwsc Salinas Hills
ACwsc Las Lomas
ACwsc Oak Hills
ACwsc King City
ACwsc Salinas
ACalifornia Water Service Co.-Lancaster
ACalifornia Water Service Co. - Palos Ver
ACalifornia Water Service Co. - Herm/Redo
ACalifornia Water Service - Bear Gulch
ACalifornia Water Service - San Carlos
ACalifornia Water Service - San Mateo
ACalifornia Water Service-S San Francisco
ACalifornia Water Service - Stockton
ACwsc Los Altos Suburban
ACalifornia Water Service Co. - Dixon
ACalifornia Water Service Co.-Travis Afb
ACalifornia Water Service Co - Westlake
ACal-Water Service Co.-Marysville
ACws - Visalia
ATesoro Viejo Master Mwc, Inc.
AWestern Digital Technologies, Inc.
ASanta Clara Valley Medical Center
AHawthorne-City Water Dept.
ACommerce-City, Water Dept.
ACalifornia Water Service Co. - Dominguez
BCalifornia Water Service Co. - Ela
ACal-Water Service Co.-Chico
ACal-Water Service Co.-Oroville
ACalifornia Water Service - Livermore
ASan Jose Water
ACity Of Cupertino
ACheck Your Specific Address
Water quality can vary by neighborhood in San Jose.
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