Public water system · MT0000266
ActiveLakeside Water System
At a glance
Lakeside Water System (PWSID MT0000266) is an active community water system in Flathead County, Montana. It reports serving 1,225 people through 512 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 7 violations for this system; 1 is health-based, and the most recent began in September 2012.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,225
Service connections
512
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Lakeside Water System compare with other water systems in Flathead County?
By EPA's size categories, Lakeside Water System is a small system (501 to 3,300 people). Flathead County has 327 active public water systems. Its population served is about 3.8 times the county average of 324 people per system, and accounts for 1.2% of the 105,781 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 Lakeside 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 Lakeside Water System?
EPA lists Lakeside Water System 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. 38 of the 327 active systems in Flathead County (12%) are also owned by a local government.
Does Lakeside Water System have drinking water violations?
EPA's records list 7 violations for this system; 1 is health-based, and the most recent began in September 2012. The violations listed here began between January 1993 and September 2012. By type: 6 monitoring and reporting and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Total coliform bacteria (TCR) (3 of them). EPA lists 7 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 |
|---|---|---|---|---|
| 2012-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2004-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1997-01-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1996-09-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1996-01-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1995-08-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1993-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
All 7 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.
Lakeside Water System: frequently asked questions
Who runs Lakeside Water System?
Lakeside Water System (PWSID MT0000266) is a community water system owned by a local government. It is regulated by the MT state drinking water program.
How many people does Lakeside Water System serve?
Lakeside Water System reports serving 1,225 people through 512 service connections in Flathead County, Montana.
Where does Lakeside 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 Lakeside Water System have any drinking water violations?
EPA's records list 7 violations for this system; 1 is health-based, and the most recent began in September 2012. 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 Lakeside 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. EPA's records list 7 violations for this system; 1 is health-based, and the most recent began in September 2012. For current results, consult the system's annual water quality report, EPA ECHO, or the MT state drinking water program.
Where can I find Lakeside Water System's water quality report?
As a community water system, Lakeside 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 Flathead County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Kalispell Public Works | Flathead | 25,000 | Community | Groundwater |
| Whitefish City of | Flathead | 10,418 | Community | Surface water |
| Flathead County Water and Sewer | Flathead | 7,775 | Community | Groundwater |
| Bigfork County Water and Sewer | Flathead | 6,100 | Community | Groundwater |
| Columbia Falls City of | Flathead | 4,450 | Community | Groundwater |
| Ridge Run | Flathead | 3,500 | 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, “Lakeside Water System, PWSID MT0000266, Montana”, https://aquacensus.com/water-systems/montana/lakeside-water-system-mt0000266 (data as of October 1, 2026).