Public water system · MT0000274
ActiveLibby City of
At a glance
City of Libby (PWSID MT0000274) is an active community water system in Lincoln County, Montana. It reports serving 4,892 people through 1,957 service connections. Its primary water source is surface water, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 4 are health-based, and the most recent began in December 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
4,892
Service connections
1,957
Primary source
SW
Surface water
System type
CWS
Community water system
System record
How does City of Libby compare with other water systems in Lincoln County?
By EPA's size categories, City of Libby is a medium system (3,301 to 10,000 people). Lincoln County has 92 active public water systems, and City of Libby is the largest of them by population served. Its population served is about 23 times the county average of 212 people per system, and accounts for 25% of the 19,484 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 City of Libby is about 27% 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. Surface water means the system draws its water from rivers, lakes, streams or reservoirs. 60 Montana systems (2.5%) list surface water as their primary source.
Who owns and regulates City of Libby?
EPA lists City of Libby 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. 11 of the 92 active systems in Lincoln County (12%) are also owned by a local government.
Does City of Libby have drinking water violations?
Of the 12 most recent violations in EPA's records, 4 are health-based, and the most recent began in December 2025. The violations listed here began between January 2021 and December 2025. By type: 8 monitoring and reporting and 4 required treatment not met. The contaminant or rule involved most often is Interim Enhanced Surface Water Treatment Rule (3 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 |
|---|---|---|---|---|
| 2025-12-01 | Required treatment not metMonthly Turbidity Exceed (Enhanced SWTR) · code 44 | Interim Enhanced Surface Water Treatment Rulecode 0300 | Yes | Resolved |
| 2022-03-01 | Required treatment not metMonthly Turbidity Exceed (Enhanced SWTR) · code 44 | Interim Enhanced Surface Water Treatment Rulecode 0300 | Yes | Resolved |
| 2022-03-01 | Required treatment not metTreatment Technique (SWTR and GWR) · code 41 | Long Term 2 Enhanced Surface Water Treatment Rulecode 0800 | Yes | Resolved |
| 2021-10-01 | Required treatment not metMonthly Turbidity Exceed (Enhanced SWTR) · code 44 | Interim Enhanced Surface Water Treatment Rulecode 0300 | Yes | Resolved |
| 2021-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Styrenecode 2996 | No | Resolved |
| 2021-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2,4-Trichlorobenzenecode 2378 | No | Resolved |
| 2021-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1-Dichloroethylenecode 2977 | No | Resolved |
| 2021-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Trichloroethylenecode 2984 | No | Resolved |
| 2021-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Dichloromethanecode 2964 | No | Resolved |
| 2021-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | cis-1,2-Dichloroethylenecode 2380 | No | Resolved |
| 2021-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Benzenecode 2990 | No | Resolved |
| 2021-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Tetrachloroethylenecode 2987 | 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.
City of Libby: frequently asked questions
Who runs City of Libby?
City of Libby (PWSID MT0000274) is a community water system owned by a local government. It is regulated by the MT state drinking water program.
How many people does City of Libby serve?
City of Libby reports serving 4,892 people through 1,957 service connections in Lincoln County, Montana.
Where does City of Libby get its water?
EPA SDWIS lists this system's primary water source as surface water. Surface water means the system draws its water from rivers, lakes, streams or reservoirs.
Does City of Libby have any drinking water violations?
Of the 12 most recent violations in EPA's records, 4 are health-based, and the most recent began in December 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 City of Libby'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, 4 are health-based, and the most recent began in December 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 City of Libby's water quality report?
As a community water system, City of Libby 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 Lincoln County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Troy City of | Lincoln | 2,100 | Community | Groundwater |
| Eureka Town of | Lincoln | 1,995 | Community | Surface water |
| Bears Country Store | Lincoln | 805 | Transient non-community | Groundwater |
| Fortine Mercantile | Lincoln | 504 | Transient non-community | Groundwater |
| Indian Springs Ranch Sub | Lincoln | 455 | Community | Groundwater |
| Wilderness Club the | Lincoln | 440 | 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, “Libby City of, PWSID MT0000274, Montana”, https://aquacensus.com/water-systems/montana/libby-city-of-mt0000274 (data as of October 1, 2026).