Public water system · CA3910002
ActiveSan Joaquin County - Colonial Heights
At a glance
San Joaquin County - Colonial Heights (PWSID CA3910002) is an active community water system in San Joaquin County, California. It reports serving 1,841 people through 559 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. EPA's records list one violation for this system; it is not health-based, and the most recent began in July 1993.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,841
Service connections
559
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does San Joaquin County - Colonial Heights compare with other water systems in San Joaquin County?
By EPA's size categories, San Joaquin County - Colonial Heights is a small system (501 to 3,300 people). San Joaquin County has 302 active public water systems. Its population served is about 28% below the county average of 2,571 people per system, and accounts for 0.2% 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 San Joaquin County - Colonial Heights is well below 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 San Joaquin County - Colonial Heights?
EPA lists San Joaquin County - Colonial Heights as owned by a local government. 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. 69 of the 302 active systems in San Joaquin County (23%) are also owned by a local government.
Does San Joaquin County - Colonial Heights have drinking water violations?
EPA's records list one violation for this system; it is not health-based, and the most recent began in July 1993. By type: 1 monitoring and reporting. The contaminant or rule involved is Lead and Copper Rule. EPA lists 1 as resolved. Resolved means at least one resolving action is on record: the system returned to compliance, the rule no longer applies, or no further action was needed.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 1993-07-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
The one violation in EPA's records.Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.
San Joaquin County - Colonial Heights: frequently asked questions
Who runs San Joaquin County - Colonial Heights?
San Joaquin County - Colonial Heights (PWSID CA3910002) is a community water system owned by a local government. It is regulated by the CA state drinking water program.
How many people does San Joaquin County - Colonial Heights serve?
San Joaquin County - Colonial Heights reports serving 1,841 people through 559 service connections in San Joaquin County, California.
Where does San Joaquin County - Colonial Heights 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 San Joaquin County - Colonial Heights have any drinking water violations?
EPA's records list one violation for this system; it is not health-based, and the most recent began in July 1993. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.
Is San Joaquin County - Colonial Heights' 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 records list one violation for this system; it is not health-based, and the most recent began in July 1993. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find San Joaquin County - Colonial Heights' water quality report?
As a community water system, San Joaquin County - Colonial Heights 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 |
| California Water Service - Stockton | San Joaquin | 176,266 | Community | Purchased 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 |
Related pages
Working with water-system records? Pro adds alerts, change history and CSV export ($49/mo); Enterprise adds full national files, the API and an MCP server for AI tools.
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, “San Joaquin County - Colonial Heights, PWSID CA3910002, California”, https://aquacensus.com/water-systems/california/san-joaquin-county-colonial-heights-ca3910002 (data as of October 1, 2026).