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Tap water quality report

San Joaquin Water Works #2

EPA monitoring tested this supplier for 45 contaminants and detected 10. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

45
contaminants tested
10
detected
310
people served
0
health-based violations
California rankingsLead in CaliforniaPFAS in California
Water source
Ground water
Ownership
Local government
Counties served
San Joaquin

Compliance record

Formal violations the EPA has on file for this supplier. A health-based violation means a contaminant limit or a required treatment was breached; the rest are monitoring or reporting failures — still violations, but not a measured health risk.

0
health-based violations
4
violations on file
0
still open
ViolationTypeStatusPeriod
Other Monitoring Resolved 2002-07-01
MR Monitoring Resolved 1993-07-01 → 2000-04-04
MR Monitoring Archived 1981-10-01 → 1982-09-30
MR Monitoring Archived 1980-10-30 → 1981-10-29

Other contaminants detected

Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the single worst sample on record — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately.
ContaminantLevel vs EPA limitDetection rateSourcePeriod
Nitrate
2101.8 µg/L 21%
of the EPA limit 10000 µg/L
 14/28 SYR4 2012–2019
1,2-DIBROMO-3-CHLOROPROPANE
0.0400 µg/L 20%
of the EPA limit 0.2000 µg/L
 11/15 SYR4 2012–2018
Lead
0.0 mg/L 0%
of the EPA limit 0.0150 mg/L
 7/7 LCR 2024
Arsenic
5 µg/L 50%
of the EPA limit 10 µg/L
 3/4 SYR4 2012–2017
Barium
124 µg/L 6.2%
of the EPA limit 2000 µg/L
 3/4 SYR4 2012–2017
Fluoride
200 µg/L 5%
of the EPA limit 4000 µg/L
 3/4 SYR4 2012–2017
Chromium
2 µg/L 2%
of the EPA limit 100 µg/L
 1/4 SYR4 2012–2017
Combined Uranium
1.8476 µg/L 6.2%
of the EPA limit 30 µg/L
 1/1 SYR4 2017
Lead
0.9000 µg/L 6%
of the EPA limit 15 µg/L
 1/4 SYR4 2012–2017
Nitrate-Nitrite
1200 µg/L 12%
of the EPA limit 10000 µg/L
 1/3 SYR4 2014–2017
35 contaminants tested, none detected
1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-Trichlorobenzene1,2-Dichloroethane1,2-DichloropropaneAntimony, TotalBenzeneBeryllium, TotalBromodichloromethaneBromoformChlorobenzeneCopperCadmiumCarbon TetrachlorideChloroformDichloromethaneDibromochloromethaneEthylene DibromideEthylbenzeneMercuryNitriteSeleniumStyreneTTHMTetrachloroethyleneThallium, TotalTolueneTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact
MAINTENANCE DIST, SJC UTILITIES
Phone
209-468-3090
Email
cirons@sjgov.org

Frequently asked questions about San Joaquin Water Works #2

Is San Joaquin Water Works #2 tap water safe to drink?

EPA monitoring detected 10 contaminants in San Joaquin Water Works #2's water. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and the utility's annual Consumer Confidence Report for its official compliance status.

What contaminants were detected in San Joaquin Water Works #2's water?

EPA monitoring detected Nitrate, 1,2-DIBROMO-3-CHLOROPROPANE, Lead, Arsenic, Barium, and others. The full list with the level and data source for each is above.

How many people does San Joaquin Water Works #2 serve?

San Joaquin Water Works #2 reports serving 310 people in California, per its EPA record.

Has San Joaquin Water Works #2 had any water quality violations?

The EPA has 4 violations on file for San Joaquin Water Works #2, of which 0 are health-based (a contaminant limit or required treatment was breached) and 0 remain open. The rest are monitoring or reporting failures.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.