Public water system · MT0002121
ActiveNorth Davis Duplexes 421
At a glance
North Davis Duplexes 421 (PWSID MT0002121) is an active community water system in Missoula County, Montana. It reports serving 33 people through 13 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, 4 are health-based, and the most recent began in May 2016.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
33
Service connections
13
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does North Davis Duplexes 421 compare with other water systems in Missoula County?
By EPA's size categories, North Davis Duplexes 421 is a very small system (500 people or fewer). Missoula County has 244 active public water systems. Its population served is well below the county average of 576 people per system, and accounts for less than 0.1% of the 140,505 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 North Davis Duplexes 421 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 North Davis Duplexes 421?
EPA lists North Davis Duplexes 421 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. 201 of the 244 active systems in Missoula County (82%) are also privately owned.
Does North Davis Duplexes 421 have drinking water violations?
Of the 12 most recent violations in EPA's records, 4 are health-based, and the most recent began in May 2016. The violations listed here began between January 2002 and May 2016. By type: 7 monitoring and reporting, 4 contaminant level above the legal limit and 1 public notice, recordkeeping or other. The contaminant or rule involved most often is Total coliform bacteria (TCR) (5 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 |
|---|---|---|---|---|
| 2016-05-27 | Monitoring and reportingMonitoring, Source Water (GWR) · code 34 | E. colicode 3014 | No | Resolved |
| 2009-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2008-06-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Acute (TCR) · code 21 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2007-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2007-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2006-07-01 | Monitoring and reportingMonitoring, Repeat Major (TCR) · code 25 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2006-06-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2005-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Inadequate Reporting · code 72 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2002-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Dichloromethanecode 2964 | No | Resolved |
| 2002-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Pentachlorophenolcode 2326 | No | Resolved |
| 2002-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Tetrachloroethylenecode 2987 | No | Resolved |
| 2002-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Ethylbenzenecode 2992 | 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.
North Davis Duplexes 421: frequently asked questions
Who runs North Davis Duplexes 421?
North Davis Duplexes 421 (PWSID MT0002121) is a community water system privately owned. It is regulated by the MT state drinking water program.
How many people does North Davis Duplexes 421 serve?
North Davis Duplexes 421 reports serving 33 people through 13 service connections in Missoula County, Montana.
Where does North Davis Duplexes 421 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 North Davis Duplexes 421 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 May 2016. 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 North Davis Duplexes 421'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 May 2016. For current results, consult the system's annual water quality report, EPA ECHO, or the MT state drinking water program.
Where can I find North Davis Duplexes 421's water quality report?
As a community water system, North Davis Duplexes 421 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 Missoula County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Missoula Water | Missoula | 68,200 | Community | Groundwater |
| University of Montana | Missoula | 15,000 | Non-transient non-community | Purchased groundwater |
| Lolo Water and Sewer Dist | Missoula | 3,315 | Community | Groundwater |
| Town Pump Bonner 1 | Missoula | 2,460 | Non-transient non-community | Groundwater |
| Clearwater Junction Rest Area | Missoula | 2,002 | Transient non-community | Groundwater |
| Seeley Lake Water District | Missoula | 1,575 | Community | Surface water |
Related pages
Working with water-system records? Pro adds alerts, change history and CSV export ($49/mo); Enterprise adds full national files, the API and an MCP server for AI tools.
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, “North Davis Duplexes 421, PWSID MT0002121, Montana”, https://aquacensus.com/water-systems/montana/north-davis-duplexes-421-mt0002121 (data as of October 1, 2026).