Public water system · MT0004263
ActiveHardin Subdivision
At a glance
Hardin Subdivision (PWSID MT0004263) is an active community water system in Gallatin County, Montana. It reports serving 28 people through 11 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, one is health-based, and the most recent began in July 2015.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
28
Service connections
11
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Hardin Subdivision compare with other water systems in Gallatin County?
By EPA's size categories, Hardin Subdivision 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 community water system reports serving 6,703 people, so Hardin Subdivision is well below that figure.
What does “community water system” mean?
A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. Montana has 853 active community water systems, 36% 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 Hardin Subdivision?
EPA lists Hardin Subdivision 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 Hardin Subdivision have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in July 2015. The violations listed here began between January 2006 and July 2015. By type: 11 monitoring and reporting and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Lead and Copper Rule (2 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 |
|---|---|---|---|---|
| 2015-07-22 | Monitoring and reportingMonitoring, Source Water (GWR) · code 34 | E. colicode 3014 | No | Resolved |
| 2015-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2007-01-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2006-07-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2006-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1,1-Trichloroethanecode 2981 | No | Resolved |
| 2006-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Carbon tetrachloridecode 2982 | No | Resolved |
| 2006-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Toluenecode 2991 | No | Resolved |
| 2006-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2,4-Trichlorobenzenecode 2378 | No | Resolved |
| 2006-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1-Dichloroethylenecode 2977 | No | Resolved |
| 2006-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Tetrachloroethylenecode 2987 | No | Resolved |
| 2006-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Chlorobenzenecode 2989 | No | Resolved |
| 2006-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1,2-Trichloroethanecode 2985 | 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.
Hardin Subdivision: frequently asked questions
Who runs Hardin Subdivision?
Hardin Subdivision (PWSID MT0004263) is a community water system privately owned. It is regulated by the MT state drinking water program.
How many people does Hardin Subdivision serve?
Hardin Subdivision reports serving 28 people through 11 service connections in Gallatin County, Montana.
Where does Hardin Subdivision 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 Hardin Subdivision have any drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in July 2015. 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 Hardin Subdivision'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, one is health-based, and the most recent began in July 2015. For current results, consult the system's annual water quality report, EPA ECHO, or the MT state drinking water program.
Where can I find Hardin Subdivision's water quality report?
As a community water system, Hardin Subdivision must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1 each year, covering the previous calendar year. The system can provide a copy on request.
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, “Hardin Subdivision, PWSID MT0004263, Montana”, https://aquacensus.com/water-systems/montana/hardin-subdivision-mt0004263 (data as of October 1, 2026).