Public water system · MT0001740
ActiveSt Ignatius Town of
At a glance
Town of St Ignatius (PWSID MT0001740) is an active community water system in Lake County, Montana. It reports serving 700 people through 291 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in September 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
700
Service connections
291
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Town of St Ignatius compare with other water systems in Lake County?
By EPA's size categories, Town of St Ignatius is a small system (501 to 3,300 people). Lake County has 90 active public water systems, and Town of St Ignatius is the 4th-largest of them by population served. Its population served is about 3.2 times the county average of 220 people per system, and accounts for 3.5% of the 19,829 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 Town of St Ignatius 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 Town of St Ignatius?
EPA lists Town of St Ignatius 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. 9 of the 90 active systems in Lake County (10%) are also owned by a local government.
Does Town of St Ignatius have drinking water violations?
Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in September 2025. The violations listed here began between January 2016 and September 2025. By type: 10 monitoring and reporting and 2 required treatment not met. The contaminant or rule involved most often is Groundwater Rule (4 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 |
|---|---|---|---|---|
| 2025-09-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Unfilt/GWR) · code 31 | Groundwater Rulecode 0700 | No | Resolved |
| 2024-07-17 | Monitoring and reportingMonitoring, Source Water (GWR) · code 34 | E. colicode 3014 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitrate-Nitritecode 1038 | No | Resolved |
| 2022-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2020-07-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Unfilt/GWR) · code 31 | Groundwater Rulecode 0700 | No | Resolved |
| 2019-09-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2019-09-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2016-10-01 | Required treatment not metTreatment Technique (SWTR and GWR) · code 41 | Groundwater Rulecode 0700 | Yes | Resolved |
| 2016-03-01 | Required treatment not metTreatment Technique (SWTR and GWR) · code 41 | Groundwater Rulecode 0700 | Yes | Resolved |
| 2016-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Di(2-ethylhexyl) phthalatecode 2039 | No | Resolved |
| 2016-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Oxamylcode 2036 | No | Resolved |
| 2016-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Picloramcode 2040 | 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.
Town of St Ignatius: frequently asked questions
Who runs Town of St Ignatius?
Town of St Ignatius (PWSID MT0001740) is a community water system owned by a local government. It is regulated by the MT state drinking water program.
How many people does Town of St Ignatius serve?
Town of St Ignatius reports serving 700 people through 291 service connections in Lake County, Montana.
Where does Town of St Ignatius 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 Town of St Ignatius 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 September 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 Town of St Ignatius' 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 September 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 Town of St Ignatius' water quality report?
As a community water system, Town of St Ignatius 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 Lake County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Polson City of | Lake | 5,300 | Community | Groundwater |
| Ronan City of | Lake | 2,483 | Community | Surface water |
| Pablo Lake County Water and Sewer Dist | Lake | 2,175 | Community | Groundwater |
| Woods Bay Water and Sewer District | Lake | 685 | Community | Groundwater |
| Wilson Foods | Lake | 600 | Transient non-community | Groundwater |
| Consolidated Charlo Lake Co W and S Dist | Lake | 450 | 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, “St Ignatius Town of, PWSID MT0001740, Montana”, https://aquacensus.com/water-systems/montana/st-ignatius-town-of-mt0001740 (data as of October 1, 2026).