Public water system · MT0003203
ActiveAntelope County Water and Sewer
At a glance
Antelope County Water and Sewer (PWSID MT0003203) is an active community water system in Sheridan County, Montana. It reports serving 59 people through 36 service connections. Its primary water source is purchased surface water, 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.
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
59
Service connections
36
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Antelope County Water and Sewer compare with other water systems in Sheridan County?
By EPA's size categories, Antelope County Water and Sewer is a very small system (500 people or fewer). Sheridan County has 8 active public water systems, and Antelope County Water and Sewer is the 5th-largest of them by population served. Its population served is well below the county average of 346 people per system, and accounts for 2.1% of the 2,764 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 Antelope County Water and Sewer 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. Purchased surface water means the system buys surface water from another public water system rather than drawing its own. 212 Montana systems (8.9%) list purchased surface water as their primary source.
Who owns and regulates Antelope County Water and Sewer?
EPA lists Antelope County Water and Sewer 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. 5 of the 8 active systems in Sheridan County (63%) are also owned by a local government.
Does Antelope County Water and Sewer 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 August 2019 and December 2025. By type: 6 monitoring, 4 monitoring and reporting and 2 public notice, recordkeeping or other. The contaminant or rule involved most often is Revised Total Coliform Rule (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 |
|---|---|---|---|---|
| 2025-12-01 | 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 |
| 2023-06-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2021-12-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2021-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | 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 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2019-09-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2019-08-31 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2019-08-31 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | 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.
Antelope County Water and Sewer: frequently asked questions
Who runs Antelope County Water and Sewer?
Antelope County Water and Sewer (PWSID MT0003203) is a community water system owned by a local government. It is regulated by the MT state drinking water program.
How many people does Antelope County Water and Sewer serve?
Antelope County Water and Sewer reports serving 59 people through 36 service connections in Sheridan County, Montana.
Where does Antelope County Water and Sewer get its water?
EPA SDWIS lists this system's primary water source as purchased surface water. Purchased surface water means the system buys surface water from another public water system rather than drawing its own.
Does Antelope County Water and Sewer 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 Antelope County Water and Sewer'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 the system's annual water quality report, EPA ECHO, or the MT state drinking water program.
Where can I find Antelope County Water and Sewer's water quality report?
As a community water system, Antelope County Water and Sewer 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 Sheridan County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Plentywood Water Department | Sheridan | 1,700 | Community | Purchased surface water |
| Medicine Lake Town of | Sheridan | 600 | Community | Purchased surface water |
| Westby Town of | Sheridan | 172 | Community | Purchased surface water |
| Outlook County Sewer and Water | Sheridan | 96 | Community | Groundwater |
| Brush Lake State Park | Sheridan | 58 | Transient non-community | Purchased surface water |
| Sunset Camping LLC | Sheridan | 42 | Transient non-community | Purchased surface water |
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, “Antelope County Water and Sewer, PWSID MT0003203, Montana”, https://aquacensus.com/water-systems/montana/antelope-county-water-and-sewer-mt0003203 (data as of October 1, 2026).