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California Water Service - Stockton

Published drinking-water records and contacts for California Water Service - Stockton. System CA3910001. Review sources and dates; not a real-time water assessment.

System ID
CA3910001
State or territory
CA
Published population served
176266
System type (source code)
CWS

Published records and dates

Missing records here do not mean the provider did not test. Published records are not a real-time assessment of your tap water.

Read the provider’s annual water quality report

Report link listed: 2026-10-05. This is not the report’s sampling date.

Published testing results

Selected recent records are shown below. Different sampling locations and dates are not interchangeable. These excerpts are not a complete testing history.

“<” means below the stated reporting limit, not zero. A reported measurement alone is not a safety verdict. Read an example

EPA UCMR 5 — most recent imported sample per substance
SubstancePublished resultReporting limitSample dateSampling location
11Cl-PF3OUdS< 0.005 µg/L0.005 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
4:2 FTS< 0.003 µg/L0.003 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
6:2 FTS< 0.005 µg/L0.005 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
8:2 FTS< 0.005 µg/L0.005 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
9Cl-PF3ONS< 0.002 µg/L0.002 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
ADONA< 0.003 µg/L0.003 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
HFPO-DA< 0.005 µg/L0.005 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
NEtFOSAA< 0.005 µg/L0.005 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
NFDHA< 0.02 µg/L0.02 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
NMeFOSAA< 0.006 µg/L0.006 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
PFBA< 0.005 µg/L0.005 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
PFBS< 0.003 µg/L0.003 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
PFDA< 0.003 µg/L0.003 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
PFDoA< 0.003 µg/L0.003 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
PFEESA< 0.003 µg/L0.003 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
PFHpA< 0.003 µg/L0.003 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
PFHpS< 0.003 µg/L0.003 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
PFHxA< 0.003 µg/L0.003 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
PFHxS< 0.003 µg/L0.003 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
PFMBA< 0.003 µg/L0.003 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
PFMPA< 0.004 µg/L0.004 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
PFNA< 0.004 µg/L0.004 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
PFOA< 0.004 µg/L0.004 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
PFOS< 0.004 µg/L0.004 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
PFPeA< 0.003 µg/L0.003 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
PFPeS< 0.004 µg/L0.004 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
PFTA< 0.008 µg/L0.008 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
PFTrDA< 0.007 µg/L0.007 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
PFUnA< 0.002 µg/L0.002 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863
lithium< 9 µg/L9 µg/L2026-03-10Well 7-02 (GWRMP) / 3910001863

Download all EPA UCMR 5 records (CSV)

Lead and copper: 90th-percentile summaries

These describe a monitoring period across sampled locations, not the result at your home. How to read the 90th percentile

Eight most recent imported monitoring summaries
SubstancePublished 90th percentileMonitoring periodSource quarter
Lead (PB90) 0 mg/L2022-01-01 – 2024-12-312026Q3
Lead (PB90) 0 mg/L2019-01-01 – 2021-12-312026Q3
Lead (PB90) 0 mg/L2016-01-01 – 2018-12-312026Q3
Lead (PB90) 0 mg/L2013-01-01 – 2015-12-312026Q3
Lead (PB90) 0 mg/L2011-01-01 – 2013-12-312026Q3
Lead (PB90) 0 mg/L2008-01-01 – 2010-12-312026Q3
Lead (PB90) 0.005 mg/L2007-01-01 – 2007-12-312026Q3
Lead (PB90) 0.005 mg/L2004-01-01 – 2004-12-312026Q3
Twelve most recent imported state laboratory records
SubstancePublished resultSample dateLocation / source
1,2,3-TRICHLOROBENZENE< 0.500000000 UG/L2026-07-07WELL 75-01 - TREATED / California DDW laboratory results
N-BUTYLBENZENE< 0.500000000 UG/L2026-07-07WELL 75-01 - TREATED / California DDW laboratory results
PERFLUOROBUTANE SULFONIC ACID (PFBS)< 2.000000000 NG/L2026-07-07WELL 75-01 - TREATED / California DDW laboratory results
PERFLUOROUNDECANOIC ACID (PFUNA)< 2.000000000 NG/L2026-07-07WELL 75-01 - TREATED / California DDW laboratory results
1,1,1-TRICHLOROETHANE< 0.500000000 UG/L2026-07-07WELL 75-01 - TREATED / California DDW laboratory results
PERFLUORODECANOIC ACID (PFDA)< 2.000000000 NG/L2026-07-07WELL 75-01 - TREATED / California DDW laboratory results
PERFLUOROPENTANOIC ACID (PFPEA)< 2.000000000 NG/L2026-07-07WELL 75-01 - TREATED / California DDW laboratory results
STYRENE< 0.500000000 UG/L2026-07-07WELL 75-01 - TREATED / California DDW laboratory results
TRICHLOROFLUOROMETHANE< 5.000000000 UG/L2026-07-07WELL 75-01 - TREATED / California DDW laboratory results
MANGANESE< 10.000000000 UG/L2026-07-07STOCKTON EAST PLANT - TREATED / California DDW laboratory results
PERFLUORODODECANOIC ACID (PFDOA)< 2.000000000 NG/L2026-07-07WELL 75-01 - TREATED / California DDW laboratory results
M-DICHLOROBENZENE< 0.500000000 UG/L2026-07-07WELL 75-01 - TREATED / California DDW laboratory results

State sampling points can include untreated water. Publisher qualifiers and units are retained; consult the full source notes before interpreting a record.

Download state records with source notes (CSV)

Published compliance history

0 imported records. Status is as recorded in the source; historical records are not current advisories. Missing records do not establish that no violations occurred.

Source dates and refresh checks

A refresh check is not a sample date. Publication periods, sample dates and checks are shown separately.

Administrative contact (EPA filing)

James, Sophie: 408-367-8593

An administrative filing contact may not be a customer-service line. Confirm current contact details with the provider.

Official state resources · How to read these records