Public water system · CA3701010
ActiveWarner Unified School District
At a glance
Warner Unified School District (PWSID CA3701010) is an active non-transient non-community water system in San Diego County, California. It reports serving 250 people through 15 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 12 are health-based, and the most recent began in April 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
250
Service connections
15
Primary source
GW
Groundwater
System type
NTNCWS
Non-transient non-community water system
System record
How does Warner Unified School District compare with other water systems in San Diego County?
By EPA's size categories, Warner Unified School District is a very small system (500 people or fewer). San Diego County has 191 active public water systems. Its population served is well below the county average of 19,427 people per system, and accounts for less than 0.1% of the 3,710,459 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 Warner Unified School District is about 42% below 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 Warner Unified School District?
EPA lists Warner Unified School District 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. 58 of the 191 active systems in San Diego County (30%) are also owned by a local government.
Does Warner Unified School District have drinking water violations?
Of the 12 most recent violations in EPA's records, 12 are health-based, and the most recent began in April 2025. The violations listed here began between July 2022 and April 2025. By type: 12 contaminant level above the legal limit. The contaminant or rule involved most often is Arsenic (12 of them). EPA lists 12 as archived. 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 |
|---|---|---|---|---|
| 2025-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
| 2025-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
| 2024-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
| 2024-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
| 2024-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
| 2024-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
| 2023-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
| 2023-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
| 2023-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
| 2023-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
| 2022-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
| 2022-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
The 12 most recent 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.
Warner Unified School District: frequently asked questions
Who runs Warner Unified School District?
Warner Unified School District (PWSID CA3701010) 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 Warner Unified School District serve?
Warner Unified School District reports serving 250 people through 15 service connections in San Diego County, California.
Where does Warner Unified School District 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 Warner Unified School District have any drinking water violations?
Of the 12 most recent violations in EPA's records, 12 are health-based, and the most recent began in April 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 Warner Unified School District'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. Of the 12 most recent violations in EPA's records, 12 are health-based, and the most recent began in April 2025. For current results, consult EPA ECHO, or the CA state drinking water program.
Where can I find Warner Unified School District's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Warner Unified School District 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 San Diego County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| San Diego, City of | San Diego | 1,385,379 | Community | Surface water |
| Helix Water District | San Diego | 277,668 | Community | Surface water |
| Otay Water District | San Diego | 238,008 | Community | Purchased surface water |
| Sweetwater Authority | San Diego | 191,282 | Community | Surface water |
| Oceanside, City of | San Diego | 171,483 | Community | Purchased surface water |
| Escondido, City of | San Diego | 137,044 | 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, “Warner Unified School District, PWSID CA3701010, California”, https://aquacensus.com/water-systems/california/warner-unified-school-district-ca3701010 (data as of October 1, 2026).