SAN JOSE, California Tap Water Quality

3,387,313 people served · 65 water systems

Fair

SAN JOSE, California is a major metropolitan area with 3,387,313 residents served by 65 distinct public water systems. Water service covers ZIP codes 95106, 95112, 95113, 95118, 95119, 95120, and 6 more.

SAN JOSE has documented several EPA health-based violations in the last five years. Residents may want to review which contaminants triggered the exceedances and consider point-of-use filtration for sensitive uses.

EPA reporting identifies Lead and Coliform Bacteria among the regulated contaminants associated with SAN JOSE's recent health-based violations. Each contaminant has different sources, health implications, and recommended mitigation steps — links to the full EPA reference for each are listed alongside the violation history below.

Last updated: 2026-05-18 · Source: EPA SDWIS

Location

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Centered on ZIP-code centroids of water systems serving this city.

ZIP Codes Served

95106 95112 95113 95118 95119 95120 95128 95135 95157 95159 95161 95173

Health-Based Violations (Last 5 Years)

EPA Maximum Contaminant Level exceedances reported by water systems serving SAN JOSE. Each entry explains the contaminant, the health risk, and recommended precautions, and links to a full guide.

Leadchemical

EPA Code 5200 · Treatment Technique Violation

violations

EPA Limit

0.015 mg/L

Last Reading

—

First Reported

Oct 2024

Most Recent

Oct 2024

What this violation means

Lead is a potent neurotoxin with no safe exposure level. In drinking water it primarily enters via corroded lead service lines, lead-soldered copper pipes, and brass fixtures. Children under 6 and pregnant women face the highest risk because lead disrupts developing nervous and skeletal systems.

Recommended precautions

→Run cold tap water 30–120 seconds before drinking or cooking, especially after the tap has been unused for hours.
→Never cook with hot tap water — heat increases lead leaching from pipes.
→Use an NSF/ANSI 53 certified filter for lead removal (carbon block or reverse osmosis).
→If you have children, get blood lead levels tested by your pediatrician.

Read the complete guide to Lead

Coliform Bacteriamicrobial

EPA Code 0200 · Treatment Technique Violation

violations

EPA Limit

0 per 100 mL presence/absence

Last Reading

—

First Reported

Jun 2023

Most Recent

Jun 2023

What this violation means

Total coliform bacteria are themselves usually harmless, but their presence signals that the water distribution system has a vulnerability — typically a cracked pipe, loss of pressure, or back-siphonage — that could allow disease-causing pathogens to enter. Repeated coliform-positive samples trigger mandatory utility investigation.

Recommended precautions

→If your utility issues a boil-water advisory, boil all drinking and cooking water for at least one minute.
→Use bottled water until the advisory is lifted.
→Ice from icemakers and beverages made before the advisory should be discarded.
→UV light and chlorination both kill coliform bacteria — most home filters do not.

Read the complete guide to Coliform Bacteria

Source: EPA Safe Drinking Water Information System (SDWIS). Health-based violations only. Older violations may have been resolved; check your utility's most recent Consumer Confidence Report for current status.

Water Systems Serving SAN JOSE

MT. PLEASANT WATER USERS ASSOCIATION

PWSID: CA4300563

300 served

LAKE SAN ANTONIO MHP WS

PWSID: CA2701906

84 served

MISSION OAKS MOBILE HOME PARK

PWSID: CA3510006

550 served

GREAT OAKS WC INC

PWSID: CA4310022

110,088 served

KENNON WATER COMPANY

PWSID: CA4300521

142 served

1 violation

ROSEVIEW HEIGHTS MUTUAL WATER COMPANY

PWSID: CA4300562

148 served

1 violation

BELLA LAGO MOBILE HOME PARK

PWSID: CA1700610

152 served

1 violation

CITY OF SAN JOSE - NSJ/ALVISO

PWSID: CA4310019

45,559 served

CITY OF SAN JOSE - EVG/EDV/COY

PWSID: CA4310020

101,265 served

CWS - UPPER BODFISH WATER SYSTEM

PWSID: CA1510026

307 served

BAKERSFIELD, CITY OF

PWSID: CA1510031

160,144 served

CWS - KERNVILLE

PWSID: CA1510033

2,572 served

CWS SOUTHLAKE SYSTEM

PWSID: CA1510039

1,112 served

CWS-ONYX WATER SYSTEM

PWSID: CA1510043

284 served

CWS - LAKELAND

PWSID: CA1510049

294 served

CWS - NORTH GARDEN

PWSID: CA1510055

22,762 served

CWS - LOWER BODFISH WATER SYSTEM

PWSID: CA1510056

736 served

LUCERNE WATER CO. - CAL WATER SERVICE

PWSID: CA1710005

2,129 served

CWS - BAKERSFIELD

PWSID: CA1510003

267,881 served

CWS - FREMONT VALLEY

PWSID: CA1500333

167 served

CWS-GRAND OAKS WATER SYSTEM

PWSID: CA1500374

122 served

CWS-SPLIT MOUNTAIN WATER SYSTEM

PWSID: CA1500407

226 served

CALIFORNIA WATER SERVICE CO.-TRAVIS AFB

PWSID: CA4810701

18,111 served

ARMSTRONG VALLEY-CAL WATER SERVICE (PUC)

PWSID: CA4910018

473 served

CALIFORNIA WATER SERVICE CO - WESTLAKE

PWSID: CA5610016

19,533 served

CAL-WATER SERVICE CO.-MARYSVILLE

PWSID: CA5810001

12,419 served

CWS - VISALIA

PWSID: CA5410016

148,496 served

CWS - MULLEN WATER COMPANY

PWSID: CA5400935

138 served

CWS - TULCO WATER COMPANY

PWSID: CA5410041

716 served

TESORO VIEJO MASTER MWC, INC.

PWSID: CA2010017

3,885 served

COAST SPRINGS - CAL. WATER SERVICE (PUC)

PWSID: CA2110007

388 served

CALIFORNIA WATER SERVICE CO-LAKE HUGHES

PWSID: CA1910242

929 served

CALIFORNIA WATER SERVICE CO-LEONA VALLEY

PWSID: CA1910243

878 served

CALIFORNIA WATER SERVICE CO. - PALOS VER

PWSID: CA1910104

71,452 served

CALIFORNIA WATER SERVICE CO. - HERM/REDO

PWSID: CA1910134

96,853 served

CALIFORNIA WATER SERVICE CO.-LANCASTER

PWSID: CA1910010

1,387 served

CALIFORNIA WATER SERVICE - BEAR GULCH

PWSID: CA4110006

61,431 served

CALIFORNIA WATER SERVICE - SAN CARLOS

PWSID: CA4110007

35,344 served

CALIFORNIA WATER SERVICE - SAN MATEO

PWSID: CA4110008

102,348 served

CALIFORNIA WATER SERVICE-S SAN FRANCISCO

PWSID: CA4110009

64,146 served

CALIFORNIA WATER SERVICE - STOCKTON

PWSID: CA3910001

176,266 served

CWSC LOS ALTOS SUBURBAN

PWSID: CA4310001

69,973 served

CALIFORNIA WATER SERVICE CO. - DIXON

PWSID: CA4810002

10,623 served

NOEL HEIGHTS-CAL WATER SERVICE (PUC)

PWSID: CA4900785

79 served

RANCHO DEL PARADISO-CAL WATER SVC (PUC)

PWSID: CA4900514

94 served

HAWKINS WATER CO-CAL WATER SERVICE (PUC)

PWSID: CA4900546

81 served

CAL-WATER SERVICE CO.-HAMILTON CITY

PWSID: CA1110002

1,799 served

CAL-WATER SERVICE CO.-WILLOWS

PWSID: CA1110003

7,240 served

CWS - SELMA

PWSID: CA1010024

26,517 served

CWSC KING CITY

PWSID: CA2710009

16,334 served

CWSC SALINAS

PWSID: CA2710010

123,679 served

CWSC SALINAS HILLS

PWSID: CA2710012

5,293 served

CWSC LAS LOMAS

PWSID: CA2710013

2,084 served

CWSC OAK HILLS

PWSID: CA2710019

3,161 served

COMMERCE-CITY, WATER DEPT.

PWSID: CA1910050

4,205 served

HAWTHORNE-CITY WATER DEPT.

PWSID: CA1910047

44,718 served

CALIFORNIA WATER SERVICE CO. - DOMINGUEZ

PWSID: CA1910033

143,996 served

CALIFORNIA WATER SERVICE CO. - ELA

PWSID: CA1910036

152,474 served

CAL-WATER SERVICE CO.-CHICO

PWSID: CA0410002

114,925 served

CAL-WATER SERVICE CO.-OROVILLE

PWSID: CA0410005

11,106 served

CALIFORNIA WATER SERVICE - LIVERMORE

PWSID: CA0110003

60,414 served

SANTA CLARA VALLEY WATER DISTRICT

PWSID: CA4310027

0 served

CITY OF CUPERTINO

PWSID: CA4310018

16,336 served

SAN JOSE WATER

PWSID: CA4310011

1,039,920 served

2 violations

ABORN HEIGHTS WATER MUTUAL ASSOCIATION

PWSID: CA4300792

45 served

What Can You Do?

✅ Request your utility's annual Consumer Confidence Report (CCR) — required by law.
✅ Use an NSF-certified water filter if violations involve lead, arsenic, or PFAS.
✅ Run cold water for 30 seconds before drinking if you have older plumbing (reduces lead).
✅ Check back monthly — we update data from the EPA every 30 days.

About this data

This overview reflects EPA SDWIS data published as of 2026-05-18. It covers active Community Water Systems (CWS) that exceeded federal Maximum Contaminant Levels during the past five-year EPA reporting window. For up-to-the-minute information, request a current Consumer Confidence Report from your utility, or review the EPA's public dashboard.

Frequently Asked Questions

Is SAN JOSE, California tap water safe to drink?▼

This city's water had several EPA violations in the last 5 years.

How many EPA violations does SAN JOSE have?▼

SAN JOSE has 5 EPA health-based water violations in the last 5 years across 65 water systems serving 3,387,313 people.

What contaminants have been found in SAN JOSE water?▼

The following EPA-regulated contaminants have been detected: 5200, 0200. View details about each contaminant, health effects, and recommended precautions above in the violations table.

Should I use a water filter in SAN JOSE?▼

Using an NSF-certified water filter is recommended if your area has violations involving lead, arsenic, or PFAS. For other contaminants, consult your local water utility. Check the annual Consumer Confidence Report (CCR) for detailed guidance.

What should I do if there are violations in SAN JOSE?▼

Request your water utility's annual Consumer Confidence Report (CCR), which is required by the EPA. Follow the utility's guidance on boil water advisories. Run cold water for 30 seconds before drinking if you have older plumbing. Use an NSF-certified filter if needed based on your water system's violations.