Public water system · CA3901113
ActiveWalnut Acres
At a glance
Walnut Acres (PWSID CA3901113) is an active community water system in San Joaquin County, California. It reports serving 106 people through 32 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 5 violations for this system; none is health-based, and the most recent began in September 2014.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
106
Service connections
32
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Walnut Acres compare with other water systems in San Joaquin County?
By EPA's size categories, Walnut Acres is a very small system (500 people or fewer). San Joaquin County has 302 active public water systems. Its population served is well below the county average of 2,571 people per system, and accounts for less than 0.1% 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 Walnut Acres 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. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 6,179 California systems (83%) list groundwater as their primary source.
Who owns and regulates Walnut Acres?
EPA lists Walnut Acres 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 Walnut Acres have drinking water violations?
EPA's records list 5 violations for this system; none is health-based, and the most recent began in September 2014. The violations listed here began between October 1980 and September 2014. By type: 4 monitoring and reporting and 1 public notice, recordkeeping or other. The contaminant or rule involved most often is Total coliform bacteria (TCR) (2 of them). EPA lists 3 as resolved and 2 as archived. 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. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2014-09-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2003-04-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2002-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 1981-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Archived |
| 1980-10-30 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Archived |
All 5 violations in EPA's records, newest first.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.
Walnut Acres: frequently asked questions
Who runs Walnut Acres?
Walnut Acres (PWSID CA3901113) is a community water system owned by a local government. It is regulated by the CA state drinking water program.
How many people does Walnut Acres serve?
Walnut Acres reports serving 106 people through 32 service connections in San Joaquin County, California.
Where does Walnut Acres get its water?
EPA SDWIS lists this system's primary water source as groundwater. Groundwater means the system draws its water from wells or springs fed by underground aquifers.
Does Walnut Acres have any drinking water violations?
EPA's records list 5 violations for this system; none is health-based, and the most recent began in September 2014. 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 Walnut Acres' 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 5 violations for this system; none is health-based, and the most recent began in September 2014. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Walnut Acres' water quality report?
As a community water system, Walnut Acres 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 |
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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, “Walnut Acres, PWSID CA3901113, California”, https://aquacensus.com/water-systems/california/walnut-acres-ca3901113 (data as of October 1, 2026).