Public water system · CA5000249
ActiveStanislaus Union School Dist
At a glance
Stanislaus Union School Dist (PWSID CA5000249) is an active non-transient non-community water system in Stanislaus County, California. It reports serving 390 people through 5 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 9 violations for this system; 2 are health-based, and the most recent began in July 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
390
Service connections
5
Primary source
GW
Groundwater
System type
NTNCWS
Non-transient non-community water system
System record
How does Stanislaus Union School Dist compare with other water systems in Stanislaus County?
By EPA's size categories, Stanislaus Union School Dist is a very small system (500 people or fewer). Stanislaus County has 191 active public water systems. Its population served is well below the county average of 2,684 people per system, and accounts for less than 0.1% of the 512,656 people reported by systems filed under the county. Across California, the 7,479 active systems average 5,706 people each. Nationally, the average active non-transient non-community water system reports serving 430 people, so Stanislaus Union School Dist is roughly in line with that figure.
What does “non-transient non-community water system” mean?
A non-transient non-community water system regularly serves at least 25 of the same people for more than six months a year, but not where they live. Schools, factories, office buildings and hospitals with their own supply are typical examples. California has 1,466 active non-transient non-community water systems, 20% 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 Stanislaus Union School Dist?
EPA lists Stanislaus Union School Dist 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. 57 of the 191 active systems in Stanislaus County (30%) are also owned by a local government.
Does Stanislaus Union School Dist have drinking water violations?
EPA's records list 9 violations for this system; 2 are health-based, and the most recent began in July 2025. The violations listed here began between October 1982 and July 2025. By type: 5 monitoring and reporting, 2 contaminant level above the legal limit and 2 public notice, recordkeeping or other. The contaminant or rule involved most often is Total coliform bacteria (TCR) (4 of them). EPA lists 4 as resolved, 3 as archived and 2 as unaddressed. 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. Unaddressed means the violation is not resolved or archived and is not yet covered by formal enforcement.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2025-07-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Unaddressed |
| 2023-08-01 | Monitoring and reportingWater Quality Parameter M/R · code 53 | Lead and Copper Rulecode 5000 | No | Archived |
| 2019-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Unaddressed |
| 2006-12-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2002-11-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2002-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Acute (TCR) · code 21 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1997-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1983-04-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1982-10-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
All 9 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.
Stanislaus Union School Dist: frequently asked questions
Who runs Stanislaus Union School Dist?
Stanislaus Union School Dist (PWSID CA5000249) is a non-transient non-community water system owned by a local government. It is regulated by the CA state drinking water program.
How many people does Stanislaus Union School Dist serve?
Stanislaus Union School Dist reports serving 390 people through 5 service connections in Stanislaus County, California.
Where does Stanislaus Union School Dist 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 Stanislaus Union School Dist have any drinking water violations?
EPA's records list 9 violations for this system; 2 are health-based, and the most recent began in July 2025. 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 Stanislaus Union School Dist'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 records list 9 violations for this system; 2 are health-based, and the most recent began in July 2025. For current results, consult EPA ECHO, or the CA state drinking water program.
Where can I find Stanislaus Union School Dist's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Stanislaus Union School Dist is a non-transient non-community water system, so it is not required to publish one; like every public water system, it must notify the people it serves about violations under EPA's public notification rules.
Other water systems in Stanislaus County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Modesto, City of | Stanislaus | 218,771 | Community | Purchased surface water |
| Turlock, City of | Stanislaus | 72,682 | Community | Purchased surface water |
| Ceres, City of | Stanislaus | 54,513 | Community | Purchased surface water |
| Patterson, City of | Stanislaus | 24,977 | Community | Groundwater |
| Riverbank, City of | Stanislaus | 24,834 | Community | Groundwater |
| Oakdale, City of | Stanislaus | 23,235 | Community | Groundwater |
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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, “Stanislaus Union School Dist, PWSID CA5000249, California”, https://aquacensus.com/water-systems/california/stanislaus-union-school-dist-ca5000249 (data as of October 1, 2026).