Public water system · CA0706029
ActiveExcelsior Middle School
At a glance
Excelsior Middle School (PWSID CA0706029) is an active non-transient non-community water system in Contra Costa County, California. It reports serving 600 people through 2 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 3 violations for this system; none is health-based, and the most recent began in October 2017.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
600
Service connections
2
Primary source
GW
Groundwater
System type
NTNCWS
Non-transient non-community water system
System record
How does Excelsior Middle School compare with other water systems in Contra Costa County?
By EPA's size categories, Excelsior Middle School is a small system (501 to 3,300 people). 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 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 Excelsior Middle School is about 40% above 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 Excelsior Middle School?
EPA lists Excelsior Middle 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 Excelsior Middle School have drinking water violations?
EPA's records list 3 violations for this system; none is health-based, and the most recent began in October 2017. The violations listed here began between May 1983 and October 2017. By type: 2 monitoring and reporting and 1 public notice, recordkeeping or other. The contaminants or rules involved are Lead and Copper Rule and Arsenic. EPA lists 2 as resolved and 1 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 |
|---|---|---|---|---|
| 2017-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2012-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Arseniccode 1005 | No | Resolved |
| 1983-05-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
All 3 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.
Excelsior Middle School: frequently asked questions
Who runs Excelsior Middle School?
Excelsior Middle School (PWSID CA0706029) 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 Excelsior Middle School serve?
Excelsior Middle School reports serving 600 people through 2 service connections in Contra Costa County, California.
Where does Excelsior Middle 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 Excelsior Middle School have any drinking water violations?
EPA's records list 3 violations for this system; none is health-based, and the most recent began in October 2017. 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 Excelsior Middle 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. EPA's records list 3 violations for this system; none is health-based, and the most recent began in October 2017. For current results, consult EPA ECHO, or the CA state drinking water program.
Where can I find Excelsior Middle School's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Excelsior Middle 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, “Excelsior Middle School, PWSID CA0706029, California”, https://aquacensus.com/water-systems/california/excelsior-middle-school-ca0706029 (data as of October 1, 2026).