Public water system · CA3910001
ActiveCalifornia Water Service - Stockton
At a glance
California Water Service - Stockton (PWSID CA3910001) is an active community water system in San Joaquin County, California. It reports serving 176,266 people through 44,359 service connections. Its primary water source is purchased surface water, and EPA lists it as privately owned. EPA's Safe Drinking Water Act records list no violations for this system.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
176,266
Service connections
44,359
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does California Water Service - Stockton compare with other water systems in San Joaquin County?
By EPA's size categories, California Water Service - Stockton is a very large system (more than 100,000 people). San Joaquin County has 302 active public water systems, and California Water Service - Stockton is the 2nd-largest of them by population served. Its population served is about 69 times the county average of 2,571 people per system, and accounts for 23% of the 776,334 people reported by systems filed under the county. Across California, the 7,479 active systems average 5,706 people each. Nationally, the average active community water system reports serving 6,703 people, so California Water Service - Stockton is about 26 times that figure.
What does “community water system” mean?
A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. California has 2,997 active community water systems, 40% of the state's 7,479 active systems. Purchased surface water means the system buys surface water from another public water system rather than drawing its own. 506 California systems (6.8%) list purchased surface water as their primary source.
Who owns and regulates California Water Service - Stockton?
EPA lists California Water Service - Stockton as privately owned. The CA state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 225 of the 302 active systems in San Joaquin County (75%) are also privately owned.
Does California Water Service - Stockton have drinking water violations?
No SDWA violations on record.
EPA's SDWA violation and enforcement data (via EPA ECHO, updated quarterly) lists no violations for California Water Service - Stockton. For the latest compliance status, check EPA ECHO for current compliance history.
California Water Service - Stockton: frequently asked questions
Who runs California Water Service - Stockton?
California Water Service - Stockton (PWSID CA3910001) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does California Water Service - Stockton serve?
California Water Service - Stockton reports serving 176,266 people through 44,359 service connections in San Joaquin County, California.
Where does California Water Service - Stockton get its water?
EPA SDWIS lists this system's primary water source as purchased surface water. Purchased surface water means the system buys surface water from another public water system rather than drawing its own.
Does California Water Service - Stockton have any drinking water violations?
EPA's Safe Drinking Water Act records list no violations for this system.
Is California Water Service - Stockton's water safe to drink?
AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. EPA's Safe Drinking Water Act records list no violations for this system. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find California Water Service - Stockton's water quality report?
As a community water system, California Water Service - Stockton must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1 each year, covering the previous calendar year. The system can provide a copy on request.
Other water systems in San Joaquin County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| City of Stockton | San Joaquin | 191,302 | Community | Surface water |
| Tracy, City of | San Joaquin | 96,609 | Community | Surface water |
| Manteca, City of | San Joaquin | 84,928 | Community | Purchased surface water |
| Lodi, City of | San Joaquin | 68,272 | Community | Surface water |
| City of Lathrop | San Joaquin | 35,080 | Community | Purchased surface water |
| City of Mountain House | San Joaquin | 24,948 | Community | Surface water |
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About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “California Water Service - Stockton, PWSID CA3910001, California”, https://aquacensus.com/water-systems/california/california-water-service-stockton-ca3910001 (data as of October 1, 2026).