Public water system · MT0002385
ActiveBig Sky County Water and Sewer Dist 363
At a glance
Big Sky County Water and Sewer Dist 363 (PWSID MT0002385) is an active community water system in Madison County, Montana. It reports serving 4,132 people through 2,599 service connections. 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, one is health-based, and the most recent began in April 2025.
This page covers its drinking water system only; sewer and wastewater service are not part of EPA's drinking water records.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
4,132
Service connections
2,599
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Big Sky County Water and Sewer Dist 363 compare with other water systems in Madison County?
By EPA's size categories, Big Sky County Water and Sewer Dist 363 is a medium system (3,301 to 10,000 people). Madison County has 45 active public water systems, and Big Sky County Water and Sewer Dist 363 is the largest of them by population served. Its population served is about 13 times the county average of 320 people per system, and accounts for 29% 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 community water system reports serving 6,703 people, so Big Sky County Water and Sewer Dist 363 is about 38% 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 Big Sky County Water and Sewer Dist 363?
EPA lists Big Sky County Water and Sewer Dist 363 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 Big Sky County Water and Sewer Dist 363 have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in April 2025. The violations listed here began between January 2009 and April 2025. By type: 9 monitoring and reporting, 2 public notice, recordkeeping or other and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Nitrate-Nitrite (6 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 |
|---|---|---|---|---|
| 2025-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitrate-Nitritecode 1038 | No | Resolved |
| 2020-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Asbestoscode 1094 | No | Resolved |
| 2014-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2014-01-01 | Monitoring and reportingLead Consumer Notice · code 66 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2012-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitrate-Nitritecode 1038 | No | Resolved |
| 2012-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2011-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Asbestoscode 1094 | No | Resolved |
| 2009-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitrate-Nitritecode 1038 | No | Resolved |
| 2009-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitrate-Nitritecode 1038 | No | Resolved |
| 2009-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitrate-Nitritecode 1038 | No | Resolved |
| 2009-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitrate-Nitritecode 1038 | 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.
Big Sky County Water and Sewer Dist 363: frequently asked questions
Who runs Big Sky County Water and Sewer Dist 363?
Big Sky County Water and Sewer Dist 363 (PWSID MT0002385) is a community water system owned by a local government. It is regulated by the MT state drinking water program.
How many people does Big Sky County Water and Sewer Dist 363 serve?
Big Sky County Water and Sewer Dist 363 reports serving 4,132 people through 2,599 service connections in Madison County, Montana.
Where does Big Sky County Water and Sewer Dist 363 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 Big Sky County Water and Sewer Dist 363 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 April 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 Big Sky County Water and Sewer Dist 363'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 April 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the MT state drinking water program.
Where can I find Big Sky County Water and Sewer Dist 363's water quality report?
As a community water system, Big Sky County Water and Sewer Dist 363 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 Madison County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| 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 |
| Ennis S Raynolds Pass Rest Area | Madison | 500 | Transient non-community | Groundwater |
Related pages
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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, “Big Sky County Water and Sewer Dist 363, PWSID MT0002385, Montana”, https://aquacensus.com/water-systems/montana/big-sky-county-water-and-sewer-dist-363-mt0002385 (data as of October 1, 2026).