A85/100
San Jose Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 3,379,980 residents · California
What's In San Jose's Tap Water?
76
Contaminants Tested
0
Exceed EPA Limits
0
Above EPA Goals
EPA Violation History
1
Violation (last 5yr)
0
Unresolved
1
Health-Related
TIER 2Resolved
Failed treatment technique requirements
When: June 1, 2023 – June 30, 2023Rule: Surface Water Treatment RuleEnforcement: Formal — state order issued
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Water Utility Details
CALIFORNIA WATER SERVICE - LIVERMORE
Population Served
60,414
Water Source
Purchased Surface Water
System ID
CA0110003
CAL-WATER SERVICE CO.-OROVILLE
Population Served
11,106
Water Source
Surface Water
System ID
CA0410005
CAL-WATER SERVICE CO.-CHICO
Population Served
114,925
Water Source
Groundwater
System ID
CA0410002
CWS - SELMA
Population Served
26,517
Water Source
Groundwater
System ID
CA1010024
CAL-WATER SERVICE CO.-HAMILTON CITY
Population Served
1,799
Water Source
Groundwater
System ID
CA1110002
CAL-WATER SERVICE CO.-WILLOWS
Population Served
7,240
Water Source
Groundwater
System ID
CA1110003
CWS - BAKERSFIELD
Population Served
267,881
Water Source
Surface Water
System ID
CA1510003
BAKERSFIELD, CITY OF
Population Served
160,144
Water Source
Purchased Surface Water
System ID
CA1510031
CWS - KERNVILLE
Population Served
2,572
Water Source
Surface Water
System ID
CA1510033
CWS SOUTHLAKE SYSTEM
Population Served
1,112
Water Source
Groundwater
System ID
CA1510039
CWS - NORTH GARDEN
Population Served
22,762
Water Source
Surface Water
System ID
CA1510055
LUCERNE WATER CO. - CAL WATER SERVICE
Population Served
2,129
Water Source
Surface Water
System ID
CA1710005
CALIFORNIA WATER SERVICE CO.-LANCASTER
Population Served
1,387
Water Source
Purchased Surface Water
System ID
CA1910010
CALIFORNIA WATER SERVICE CO. - DOMINGUEZ
Population Served
143,996
Water Source
Purchased Surface Water
System ID
CA1910033
CALIFORNIA WATER SERVICE CO. - ELA
Population Served
152,474
Water Source
Purchased Surface Water
System ID
CA1910036
HAWTHORNE-CITY WATER DEPT.
Population Served
44,718
Water Source
Purchased Surface Water
System ID
CA1910047
COMMERCE-CITY, WATER DEPT.
Population Served
4,205
Water Source
Purchased Surface Water
System ID
CA1910050
CALIFORNIA WATER SERVICE CO. - PALOS VER
Population Served
71,452
Water Source
Purchased Surface Water
System ID
CA1910104
CALIFORNIA WATER SERVICE CO. - HERM/REDO
Population Served
96,853
Water Source
Purchased Surface Water
System ID
CA1910134
TESORO VIEJO MASTER MWC, INC.
Population Served
3,885
Water Source
Surface Water
System ID
CA2010017
CWSC KING CITY
Population Served
16,334
Water Source
Groundwater
System ID
CA2710009
CWSC SALINAS
Population Served
123,679
Water Source
Groundwater
System ID
CA2710010
CWSC SALINAS HILLS
Population Served
5,293
Water Source
Groundwater
System ID
CA2710012
CWSC LAS LOMAS
Population Served
2,084
Water Source
Groundwater
System ID
CA2710013
CWSC OAK HILLS
Population Served
3,161
Water Source
Groundwater
System ID
CA2710019
CALIFORNIA WATER SERVICE - STOCKTON
Population Served
176,266
Water Source
Purchased Surface Water
System ID
CA3910001
CALIFORNIA WATER SERVICE - BEAR GULCH
Population Served
61,431
Water Source
Surface Water
System ID
CA4110006
CALIFORNIA WATER SERVICE - SAN CARLOS
Population Served
35,344
Water Source
Purchased Surface Water
System ID
CA4110007
CALIFORNIA WATER SERVICE - SAN MATEO
Population Served
102,348
Water Source
Purchased Surface Water
System ID
CA4110008
CALIFORNIA WATER SERVICE-S SAN FRANCISCO
Population Served
64,146
Water Source
Purchased Surface Water
System ID
CA4110009
CWSC LOS ALTOS SUBURBAN
Population Served
69,973
Water Source
Purchased Surface Water
System ID
CA4310001
SAN JOSE WATER
Population Served
1,039,920
Water Source
Surface Water
System ID
CA4310011
CITY OF CUPERTINO
Population Served
16,336
Water Source
Purchased Surface Water
System ID
CA4310018
CITY OF SAN JOSE - NSJ/ALVISO
Population Served
45,559
Water Source
Purchased Surface Water
System ID
CA4310019
CITY OF SAN JOSE - EVG/EDV/COY
Population Served
101,265
Water Source
Purchased Surface Water
System ID
CA4310020
GREAT OAKS WC INC
Population Served
110,088
Water Source
Groundwater
System ID
CA4310022
CALIFORNIA WATER SERVICE CO. - DIXON
Population Served
10,623
Water Source
Groundwater
System ID
CA4810002
CALIFORNIA WATER SERVICE CO.-TRAVIS AFB
Population Served
18,111
Water Source
Purchased Surface Water
System ID
CA4810701
CWS - VISALIA
Population Served
148,496
Water Source
Groundwater
System ID
CA5410016
CALIFORNIA WATER SERVICE CO - WESTLAKE
Population Served
19,533
Water Source
Purchased Surface Water
System ID
CA5610016
CAL-WATER SERVICE CO.-MARYSVILLE
Population Served
12,419
Water Source
Groundwater
System ID
CA5810001
Frequently Asked Questions About San Jose Water
Is San Jose tap water safe to drink?
San Jose, California tap water receives a grade of A (85/100), which is considered excellent. Out of 80 contaminants tested, 2 exceed EPA maximum contaminant levels (MCLs) and 5 exceed health guidelines (MCLGs). While the water meets federal standards, some residents may still choose to use a filter for additional peace of mind.
What contaminants are in San Jose's water?
Of the 80 contaminants tested in San Jose's water supply, the most notable include Copper (90th percentile), PFOS, Lead (90th percentile), chlorate, 1,4-dioxane. 2 contaminant(s) exceed EPA legal limits (MCLs). 5 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does San Jose have any water quality violations?
Yes, San Jose has 127 EPA violation(s) on record, with the most recent in 2023. Violation types include TT, MON, MCL. 87 of these are health-based violations, which are the most serious category.
Do I need a water filter in San Jose?
Based on EPA data, using a water filter in San Jose is recommended. 2 contaminant(s) exceed legal limits. An NSF-certified filter — such as a reverse osmosis or activated carbon system — can effectively reduce many common contaminants. Choose a filter certified to remove the specific contaminants found in your area.
Where does San Jose's tap water come from?
San Jose's drinking water is sourced from purchased surface water and supplied by CALIFORNIA WATER SERVICE - LIVERMORE and 40 other water system(s). The system serves approximately 3,379,980 people. Surface water sources include rivers, lakes, and reservoirs.
How often is San Jose's water tested?
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 Jose'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.
How does San Jose's water compare to other cities in California?
San Jose's water quality score of 85/100 earns a grade of A, which is considered excellent. This places San Jose among the better-performing water systems in California. Visit our California state page to see how all cities in the state compare.
What should I do if I'm concerned about San Jose's water quality?
If you have concerns about San Jose'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 (CALIFORNIA WATER SERVICE - LIVERMORE) 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.