Public water system · MT0001321
ActiveMountainside Koa
At a glance
Mountainside Koa (PWSID MT0001321) is an active transient non-community water system in Gallatin County, Montana. It reports serving 102 people through 100 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in October 2023.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
102
Service connections
100
Primary source
GW
Groundwater
System type
TNCWS
Transient non-community water system
System record
How does Mountainside Koa compare with other water systems in Gallatin County?
By EPA's size categories, Mountainside Koa is a very small system (500 people or fewer). Gallatin County has 207 active public water systems. Its population served is well below the county average of 713 people per system, and accounts for less than 0.1% of the 147,534 people reported by systems filed under the county. Across Montana, the 2,378 active systems average 489 people each. Nationally, the average active transient non-community water system reports serving 144 people, so Mountainside Koa is about 29% below that figure.
What does “transient non-community water system” mean?
A transient non-community water system serves places where people do not stay long, such as gas stations and campgrounds, and regularly serves at least 25 people a day for at least 60 days a year. Montana has 1,206 active transient non-community water systems, 51% 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 Mountainside Koa?
EPA lists Mountainside Koa as privately owned. 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. 180 of the 207 active systems in Gallatin County (87%) are also privately owned.
Does Mountainside Koa have drinking water violations?
Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in October 2023. The violations listed here began between October 2007 and October 2023. By type: 8 monitoring and reporting, 1 reporting, 1 monitoring, 1 required treatment not met and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Total coliform bacteria (TCR) (8 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 |
|---|---|---|---|---|
| 2023-10-01 | ReportingReport Startup Procedures Cert Form (RTCR) · code 4C | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2019-05-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2018-05-02 | Required treatment not metTreatment Technique Startup Procedures (RTCR) · code 2D | Revised Total Coliform Rulecode 8000 | Yes | Resolved |
| 2015-10-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2012-05-01 | Monitoring and reportingMonitoring, Source Water (GWR) · code 34 | E. colicode 3014 | No | Resolved |
| 2011-10-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2010-10-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2008-10-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2008-09-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2008-06-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2008-04-01 | Monitoring and reportingMonitoring, Repeat Major (TCR) · code 25 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2007-10-01 | Monitoring and reportingMonitoring, Repeat Major (TCR) · code 25 | Total coliform bacteria (TCR)code 3100 | 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.
Mountainside Koa: frequently asked questions
Who runs Mountainside Koa?
Mountainside Koa (PWSID MT0001321) is a transient non-community water system privately owned. It is regulated by the MT state drinking water program.
How many people does Mountainside Koa serve?
Mountainside Koa reports serving 102 people through 100 service connections in Gallatin County, Montana.
Where does Mountainside Koa 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 Mountainside Koa have any drinking water violations?
Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in October 2023. 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 Mountainside Koa'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, 2 are health-based, and the most recent began in October 2023. For current results, consult EPA ECHO, or the MT state drinking water program.
Where can I find Mountainside Koa's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Mountainside Koa is a 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 Gallatin County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Bozeman City of | Gallatin | 56,000 | Community | Surface water |
| Montana State University Bozeman | Gallatin | 19,200 | Non-transient non-community | Purchased surface water |
| Belgrade City of | Gallatin | 10,460 | Community | Groundwater |
| West Yellowstone Town of | Gallatin | 9,899 | Community | Groundwater |
| North Star Zoot Water | Gallatin | 4,323 | Community | Groundwater |
| River Rock County Water and Sewer Dist | Gallatin | 4,200 | 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, “Mountainside Koa, PWSID MT0001321, Montana”, https://aquacensus.com/water-systems/montana/mountainside-koa-mt0001321 (data as of October 1, 2026).