Public water system · CA0706028
ActiveKnightsen Elementary School
At a glance
Knightsen Elementary School (PWSID CA0706028) is an active non-transient non-community water system in Contra Costa County, California. It reports serving 350 people through 4 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 October 2016.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
350
Service connections
4
Primary source
GW
Groundwater
System type
NTNCWS
Non-transient non-community water system
System record
How does Knightsen Elementary School compare with other water systems in Contra Costa County?
By EPA's size categories, Knightsen Elementary School is a very small system (500 people or fewer). Contra Costa County has 84 active public water systems. Its population served is well below the county average of 6,726 people per system, and accounts for less than 0.1% of the 564,952 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 Knightsen Elementary School is about 19% 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 Knightsen Elementary School?
EPA lists Knightsen Elementary School 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. 25 of the 84 active systems in Contra Costa County (30%) are also owned by a local government.
Does Knightsen Elementary School have drinking water violations?
Of the 12 most recent violations in EPA's records, 12 are health-based, and the most recent began in October 2016. The violations listed here began between January 2014 and October 2016. 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 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 |
|---|---|---|---|---|
| 2016-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2016-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2016-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2016-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2015-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2015-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2015-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2015-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2014-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2014-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2014-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2014-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
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.
Knightsen Elementary School: frequently asked questions
Who runs Knightsen Elementary School?
Knightsen Elementary School (PWSID CA0706028) 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 Knightsen Elementary School serve?
Knightsen Elementary School reports serving 350 people through 4 service connections in Contra Costa County, California.
Where does Knightsen Elementary School 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 Knightsen Elementary School 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 October 2016. 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 Knightsen Elementary School'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 October 2016. For current results, consult EPA ECHO, or the CA state drinking water program.
Where can I find Knightsen Elementary School's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Knightsen Elementary School 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 Contra Costa County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Contra Costa Water District | Contra Costa | 198,000 | Community | Surface water |
| City of Antioch | Contra Costa | 115,074 | Community | Surface water |
| Brentwood | Contra Costa | 64,513 | Community | Purchased surface water |
| City of Pittsburg | Contra Costa | 62,500 | Community | Purchased surface water |
| Diablo Water District | Contra Costa | 43,357 | Community | Purchased surface water |
| City of Martinez | Contra Costa | 30,997 | 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, “Knightsen Elementary School, PWSID CA0706028, California”, https://aquacensus.com/water-systems/california/knightsen-elementary-school-ca0706028 (data as of October 1, 2026).