Public water system · MT0005118
ActiveStill River Estates Subdivision
At a glance
Still River Estates Subdivision (PWSID MT0005118) is an active community water system in Yellowstone County, Montana. It reports serving 188 people through 25 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, none is health-based, and the most recent began in May 2026.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
188
Service connections
25
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Still River Estates Subdivision compare with other water systems in Yellowstone County?
By EPA's size categories, Still River Estates Subdivision is a very small system (500 people or fewer). Yellowstone County has 119 active public water systems. Its population served is well below the county average of 1,422 people per system, and accounts for 0.1% of the 169,240 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 Still River Estates 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 Still River Estates Subdivision?
EPA lists Still River Estates 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. 97 of the 119 active systems in Yellowstone County (82%) are also privately owned.
Does Still River Estates Subdivision have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in May 2026. The violations listed here began between January 2025 and May 2026. By type: 12 monitoring and reporting. The contaminants or rules involved are Nitrate-Nitrite, Dichloromethane, Styrene and cis-1,2-Dichloroethylene. 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 |
|---|---|---|---|---|
| 2026-05-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitrate-Nitritecode 1038 | No | Resolved |
| 2025-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Dichloromethanecode 2964 | No | Resolved |
| 2025-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Styrenecode 2996 | No | Resolved |
| 2025-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | cis-1,2-Dichloroethylenecode 2380 | No | Resolved |
| 2025-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2,4-Trichlorobenzenecode 2378 | No | Resolved |
| 2025-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | p-Dichlorobenzenecode 2969 | No | Resolved |
| 2025-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1-Dichloroethylenecode 2977 | No | Resolved |
| 2025-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Vinyl chloridecode 2976 | No | Resolved |
| 2025-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Xylenes, Totalcode 2955 | No | Resolved |
| 2025-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Benzenecode 2990 | No | Resolved |
| 2025-01-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2025-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | o-Dichlorobenzenecode 2968 | 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.
Still River Estates Subdivision: frequently asked questions
Who runs Still River Estates Subdivision?
Still River Estates Subdivision (PWSID MT0005118) is a community water system privately owned. It is regulated by the MT state drinking water program.
How many people does Still River Estates Subdivision serve?
Still River Estates Subdivision reports serving 188 people through 25 service connections in Yellowstone County, Montana.
Where does Still River Estates 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 Still River Estates Subdivision 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 May 2026. 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 Still River Estates 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, none is health-based, and the most recent began in May 2026. For current results, consult the system's annual water quality report, EPA ECHO, or the MT state drinking water program.
Where can I find Still River Estates Subdivision's water quality report?
As a community water system, Still River Estates 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 Yellowstone County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Billings City of | Yellowstone | 114,000 | Community | Surface water |
| Billings Heights Co Water Dist of | Yellowstone | 12,000 | Community | Purchased surface water |
| Laurel Municipal Water System | Yellowstone | 6,339 | Community | Surface water |
| Lockwood Water and Sewer District | Yellowstone | 5,900 | Community | Surface water |
| Rocky Mountain College | Yellowstone | 5,700 | Non-transient non-community | Purchased surface water |
| Montana State University Billings | Yellowstone | 2,999 | Non-transient non-community | Purchased surface water |
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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, “Still River Estates Subdivision, PWSID MT0005118, Montana”, https://aquacensus.com/water-systems/montana/still-river-estates-subdivision-mt0005118 (data as of October 1, 2026).