Public water system · CA1200546
ActiveCasterlin School
At a glance
Casterlin School (PWSID CA1200546) is an active non-transient non-community water system in Humboldt County, California. It reports serving 50 people through 1 service connection. 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, 3 are health-based, and the most recent began in October 2024.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
50
Service connections
1
Primary source
GW
Groundwater
System type
NTNCWS
Non-transient non-community water system
System record
How does Casterlin School compare with other water systems in Humboldt County?
By EPA's size categories, Casterlin School is a very small system (500 people or fewer). Humboldt County has 90 active public water systems. Its population served is well below the county average of 1,486 people per system, and accounts for less than 0.1% of the 133,779 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 Casterlin School is well 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 Casterlin School?
EPA lists Casterlin 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. 33 of the 90 active systems in Humboldt County (37%) are also owned by a local government.
Does Casterlin School have drinking water violations?
Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in October 2024. The violations listed here began between July 1984 and October 2024. By type: 4 public notice, recordkeeping or other, 3 required treatment not met, 3 monitoring and reporting, 1 reporting and 1 monitoring. The contaminant or rule involved most often is Lead and Copper Rule Revisions (2 of them). EPA lists 7 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 |
|---|---|---|---|---|
| 2024-10-17 | Required treatment not metLSL Inventory · code 2E | Lead and Copper Rule Revisionscode 5200 | Yes | Unaddressed |
| 2024-10-17 | ReportingLSL Reporting · code 4G | Lead and Copper Rule Revisionscode 5200 | No | Unaddressed |
| 2022-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2019-01-01 | Required treatment not metTreatment Technique No Certif. Operator · code 12 | Stage 1 Disinfectants and Disinfection Byproducts Rulecode 0400 | Yes | Resolved |
| 2018-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2018-06-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2006-12-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1993-12-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1993-06-01 | Required treatment not metTreatment Technique (SWTR and GWR) · code 41 | Surface Water Treatment Rulecode 0200 | Yes | Resolved |
| 1984-09-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-08-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-07-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | 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.
Casterlin School: frequently asked questions
Who runs Casterlin School?
Casterlin School (PWSID CA1200546) 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 Casterlin School serve?
Casterlin School reports serving 50 people through 1 service connection in Humboldt County, California.
Where does Casterlin 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 Casterlin School have any drinking water violations?
Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in October 2024. 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 Casterlin 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, 3 are health-based, and the most recent began in October 2024. For current results, consult EPA ECHO, or the CA state drinking water program.
Where can I find Casterlin School's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Casterlin 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 Humboldt County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Eureka, City of | Humboldt | 27,078 | Community | Purchased groundwater |
| Arcata, City of | Humboldt | 20,875 | Community | Purchased groundwater |
| Humboldt C.S.D. | Humboldt | 19,807 | Community | Groundwater |
| Mckinleyville C.S.D. | Humboldt | 16,900 | Community | Purchased groundwater |
| Fortuna, City of | Humboldt | 12,133 | Community | Groundwater |
| Rio Dell, City of | Humboldt | 3,300 | 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, “Casterlin School, PWSID CA1200546, California”, https://aquacensus.com/water-systems/california/casterlin-school-ca1200546 (data as of October 1, 2026).