Public water system · MT0003790
ActiveHarrison School District No 23
At a glance
Harrison School District No 23 (PWSID MT0003790) is an active non-transient non-community water system in Madison County, Montana. It reports serving 100 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, none is health-based, and the most recent began in December 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
100
Service connections
1
Primary source
GW
Groundwater
System type
NTNCWS
Non-transient non-community water system
System record
How does Harrison School District No 23 compare with other water systems in Madison County?
By EPA's size categories, Harrison School District No 23 is a very small system (500 people or fewer). Madison County has 45 active public water systems. Its population served is well below the county average of 320 people per system, and accounts for 0.7% of the 14,392 people reported by systems filed under the county. Across Montana, the 2,378 active systems average 489 people each. Nationally, the average active non-transient non-community water system reports serving 430 people, so Harrison School District No 23 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. Montana has 319 active non-transient non-community water systems, 13% of the state's 2,378 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 1,994 Montana systems (84%) list groundwater as their primary source.
Who owns and regulates Harrison School District No 23?
EPA lists Harrison School District No 23 as owned by a local government. The MT state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 7 of the 45 active systems in Madison County (16%) are also owned by a local government.
Does Harrison School District No 23 have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in December 2025. The violations listed here began between December 2021 and December 2025. By type: 10 monitoring and 2 monitoring and reporting. The contaminant or rule involved most often is Revised Total Coliform Rule (10 of them). EPA lists 11 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 |
|---|---|---|---|---|
| 2025-12-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2025-08-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2024-12-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2024-11-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Archived |
| 2024-08-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2024-07-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2024-06-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2024-04-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitrate-Nitritecode 1038 | No | Resolved |
| 2023-08-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2022-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2021-12-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | 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.
Harrison School District No 23: frequently asked questions
Who runs Harrison School District No 23?
Harrison School District No 23 (PWSID MT0003790) is a non-transient non-community water system owned by a local government. It is regulated by the MT state drinking water program.
How many people does Harrison School District No 23 serve?
Harrison School District No 23 reports serving 100 people through 1 service connection in Madison County, Montana.
Where does Harrison School District No 23 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 Harrison School District No 23 have any drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in December 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 Harrison School District No 23'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, none is health-based, and the most recent began in December 2025. For current results, consult EPA ECHO, or the MT state drinking water program.
Where can I find Harrison School District No 23's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Harrison School District No 23 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 Madison County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Big Sky County Water and Sewer Dist 363 | Madison | 4,132 | Community | Groundwater |
| Virginia City Water Dept | Madison | 1,500 | Community | Groundwater |
| Ennis Town of | Madison | 1,400 | Community | Groundwater |
| Sheridan Town of | Madison | 632 | Community | Groundwater |
| Nevada City | Madison | 621 | Transient non-community | Groundwater |
| Earthquake Lake Visitor Center | Madison | 503 | Transient non-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, “Harrison School District No 23, PWSID MT0003790, Montana”, https://aquacensus.com/water-systems/montana/harrison-school-district-no-23-mt0003790 (data as of October 1, 2026).