Public water system · MT0000046
ActiveRyan Dam Water System
At a glance
Ryan Dam Water System (PWSID MT0000046) is an active community water system in Cascade County, Montana. It reports serving 230 people through 14 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, one is health-based, and the most recent began in May 2023.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
230
Service connections
14
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Ryan Dam Water System compare with other water systems in Cascade County?
By EPA's size categories, Ryan Dam Water System is a very small system (500 people or fewer). Cascade County has 98 active public water systems. Its population served is well below the county average of 985 people per system, and accounts for 0.2% of the 96,513 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 Ryan Dam Water System 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 Ryan Dam Water System?
EPA lists Ryan Dam Water System 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. 73 of the 98 active systems in Cascade County (74%) are also privately owned.
Does Ryan Dam Water System have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in May 2023. The violations listed here began between December 2008 and May 2023. By type: 10 monitoring and reporting, 1 required treatment not met and 1 public notice, recordkeeping or other. The contaminant or rule involved most often is Lead and Copper Rule (3 of them). EPA lists 10 as resolved and 2 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 |
|---|---|---|---|---|
| 2023-05-24 | Required treatment not metTreatment Technique, Level 1 Assessment (RTCR) · code 2A | Revised Total Coliform Rulecode 8000 | Yes | Resolved |
| 2023-04-20 | Monitoring and reportingMonitoring, Source Water (GWR) · code 34 | E. colicode 3014 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Archived |
| 2023-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Archived |
| 2019-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2019-07-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Unfilt/GWR) · code 31 | Groundwater Rulecode 0700 | No | Resolved |
| 2018-07-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Unfilt/GWR) · code 31 | Groundwater Rulecode 0700 | No | Resolved |
| 2012-10-01 | Monitoring and reportingLead Consumer Notice · code 66 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2011-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Asbestoscode 1094 | No | Resolved |
| 2011-01-01 | Monitoring and reportingWater Quality Parameter M/R · code 53 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2011-01-01 | Monitoring and reportingWater Quality Parameter M/R · code 53 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2008-12-01 | Monitoring and reportingMonitoring, Repeat Major (TCR) · code 25 | Total coliform bacteria (TCR)code 3100 | 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.
Ryan Dam Water System: frequently asked questions
Who runs Ryan Dam Water System?
Ryan Dam Water System (PWSID MT0000046) is a community water system privately owned. It is regulated by the MT state drinking water program.
How many people does Ryan Dam Water System serve?
Ryan Dam Water System reports serving 230 people through 14 service connections in Cascade County, Montana.
Where does Ryan Dam Water System 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 Ryan Dam Water System 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 May 2023. 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 Ryan Dam Water System'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 May 2023. For current results, consult the system's annual water quality report, EPA ECHO, or the MT state drinking water program.
Where can I find Ryan Dam Water System's water quality report?
As a community water system, Ryan Dam Water System 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 Cascade County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Great Falls City of | Cascade | 60,000 | Community | Surface water |
| Malmstrom Air Force Base | Cascade | 8,850 | Community | Purchased surface water |
| Source Giant Springs Inc. | Cascade | 3,007 | Non-transient non-community | Groundwater |
| Montana Expo Park Cascade County | Cascade | 2,510 | Transient non-community | Purchased surface water |
| Sun Prairie Village County | Cascade | 1,800 | Community | Groundwater |
| University of Providence | Cascade | 1,472 | 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, “Ryan Dam Water System, PWSID MT0000046, Montana”, https://aquacensus.com/water-systems/montana/ryan-dam-water-system-mt0000046 (data as of October 1, 2026).