Public water system · MT0001085
ActiveLone Rock School District No 13
At a glance
Lone Rock School District No 13 (PWSID MT0001085) is an active non-transient non-community water system in Ravalli County, Montana. It reports serving 280 people through 2 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 July 2015.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
280
Service connections
2
Primary source
GW
Groundwater
System type
NTNCWS
Non-transient non-community water system
System record
How does Lone Rock School District No 13 compare with other water systems in Ravalli County?
By EPA's size categories, Lone Rock School District No 13 is a very small system (500 people or fewer). Ravalli County has 130 active public water systems. Its population served is about 18% above the county average of 237 people per system, and accounts for 0.9% of the 30,805 people reported by systems filed under the county. Across Montana, the 2,378 active systems average 489 people each. Nationally, the average active non-transient non-community water system reports serving 430 people, so Lone Rock School District No 13 is about 35% below that figure.
What does “non-transient non-community water system” mean?
A non-transient non-community water system regularly serves at least 25 of the same people for more than six months a year, but not where they live. Schools, factories, office buildings and hospitals with their own supply are typical examples. Montana has 319 active non-transient non-community water systems, 13% 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 Lone Rock School District No 13?
EPA lists Lone Rock School District No 13 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. 112 of the 130 active systems in Ravalli County (86%) are also privately owned.
Does Lone Rock School District No 13 have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in July 2015. The violations listed here began between January 2002 and July 2015. By type: 12 monitoring and reporting. The contaminants or rules involved are Total coliform bacteria (TCR), Nitrate-Nitrite, Ethylbenzene and Tetrachloroethylene. 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 |
|---|---|---|---|---|
| 2015-07-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2006-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitrate-Nitritecode 1038 | No | Resolved |
| 2002-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Ethylbenzenecode 2992 | No | Resolved |
| 2002-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Tetrachloroethylenecode 2987 | No | Resolved |
| 2002-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Carbon tetrachloridecode 2982 | No | Resolved |
| 2002-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2-Dichloropropanecode 2983 | No | Resolved |
| 2002-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1,2-Trichloroethanecode 2985 | No | Resolved |
| 2002-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Trichloroethylenecode 2984 | No | Resolved |
| 2002-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Styrenecode 2996 | No | Resolved |
| 2002-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Chlorobenzenecode 2989 | No | Resolved |
| 2002-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Toluenecode 2991 | No | Resolved |
| 2002-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1,1-Trichloroethanecode 2981 | 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.
Lone Rock School District No 13: frequently asked questions
Who runs Lone Rock School District No 13?
Lone Rock School District No 13 (PWSID MT0001085) is a non-transient non-community water system privately owned. It is regulated by the MT state drinking water program.
How many people does Lone Rock School District No 13 serve?
Lone Rock School District No 13 reports serving 280 people through 2 service connections in Ravalli County, Montana.
Where does Lone Rock School District No 13 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 Lone Rock School District No 13 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 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 Lone Rock School District No 13'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 July 2015. For current results, consult EPA ECHO, or the MT state drinking water program.
Where can I find Lone Rock School District No 13's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Lone Rock School District No 13 is a non-transient non-community water system, so it is not required to publish one; like every public water system, it must notify the people it serves about violations under EPA's public notification rules.
Other water systems in Ravalli County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Hamilton City of | Ravalli | 5,660 | Community | Groundwater |
| Stevensville Town of | Ravalli | 2,090 | Community | Groundwater |
| Super One Food Store | Ravalli | 1,769 | Non-transient non-community | Groundwater |
| Town Pump Woodside 1 | Ravalli | 1,198 | Transient non-community | Groundwater |
| Town Pump Florence 1 | Ravalli | 1,092 | Transient non-community | Groundwater |
| Florence Carlton School | Ravalli | 1,025 | Non-transient non-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, “Lone Rock School District No 13, PWSID MT0001085, Montana”, https://aquacensus.com/water-systems/montana/lone-rock-school-district-no-13-mt0001085 (data as of October 1, 2026).