Public water system · MT0004507
ActiveArrow Creek Trailer Court
At a glance
Arrow Creek Trailer Court (PWSID MT0004507) is an active community water system in Yellowstone County, Montana. It reports serving 75 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, 2 are health-based, and the most recent began in March 2026.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
75
Service connections
25
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Arrow Creek Trailer Court compare with other water systems in Yellowstone County?
By EPA's size categories, Arrow Creek Trailer Court 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 less than 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 Arrow Creek Trailer Court 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 Arrow Creek Trailer Court?
EPA lists Arrow Creek Trailer Court 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 Arrow Creek Trailer Court have drinking water violations?
Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in March 2026. The violations listed here began between April 2023 and March 2026. By type: 8 monitoring and reporting, 2 public notice, recordkeeping or other, 1 required treatment not met and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Groundwater Rule (6 of them). EPA lists 11 as resolved and 1 as archived. 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. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2026-03-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Unfilt/GWR) · code 31 | Groundwater Rulecode 0700 | No | Archived |
| 2025-10-01 | Required treatment not metTreatment Technique (SWTR and GWR) · code 41 | Groundwater Rulecode 0700 | Yes | Resolved |
| 2025-09-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Unfilt/GWR) · code 31 | Groundwater Rulecode 0700 | No | Resolved |
| 2025-04-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Unfilt/GWR) · code 31 | Groundwater Rulecode 0700 | No | Resolved |
| 2024-12-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Unfilt/GWR) · code 31 | Groundwater Rulecode 0700 | No | Resolved |
| 2024-10-01 | Monitoring and reportingLead Consumer Notice · code 66 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2023-10-01 | Public notice, recordkeeping or otherConsumer Confidence Report Inadequate Reporting · code 72 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2023-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2023-07-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2023-04-01 | Monitoring and reportingInitial, Follow-up, or Routine Source Water M/R · code 56 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2023-04-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Unfilt/GWR) · code 31 | Groundwater Rulecode 0700 | No | Resolved |
| 2023-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitrate-Nitritecode 1038 | Yes | 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.
Arrow Creek Trailer Court: frequently asked questions
Who runs Arrow Creek Trailer Court?
Arrow Creek Trailer Court (PWSID MT0004507) is a community water system privately owned. It is regulated by the MT state drinking water program.
How many people does Arrow Creek Trailer Court serve?
Arrow Creek Trailer Court reports serving 75 people through 25 service connections in Yellowstone County, Montana.
Where does Arrow Creek Trailer Court 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 Arrow Creek Trailer Court 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 March 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 Arrow Creek Trailer Court'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 March 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 Arrow Creek Trailer Court's water quality report?
As a community water system, Arrow Creek Trailer Court 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, “Arrow Creek Trailer Court, PWSID MT0004507, Montana”, https://aquacensus.com/water-systems/montana/arrow-creek-trailer-court-mt0004507 (data as of October 1, 2026).