Public water system · IA8340099
ActiveIrwin Municipal Supply
At a glance
Irwin Municipal Supply (PWSID IA8340099) is an active community water system in Shelby County, Iowa. It reports serving 313 people through 177 service connections. Its primary water source is purchased groundwater, and EPA lists it as owned by a local government. EPA's records list 10 violations for this system; none is health-based, and the most recent began in November 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
313
Service connections
177
Primary source
GWP
Purchased groundwater
System type
CWS
Community water system
System record
How does Irwin Municipal Supply compare with other water systems in Shelby County?
By EPA's size categories, Irwin Municipal Supply is a very small system (500 people or fewer). Shelby County has 8 active public water systems, and Irwin Municipal Supply is the 5th-largest of them by population served. Its population served is well below the county average of 976 people per system, and accounts for 4% of the 7,809 people reported by systems filed under the county. Across Iowa, the 1,828 active systems average 1,718 people each. Nationally, the average active community water system reports serving 6,703 people, so Irwin Municipal Supply 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. Iowa has 1,084 active community water systems, 59% of the state's 1,828 active systems. Purchased groundwater means the system buys groundwater from another public water system rather than drawing its own. 156 Iowa systems (8.5%) list purchased groundwater as their primary source.
Who owns and regulates Irwin Municipal Supply?
EPA lists Irwin Municipal Supply as owned by a local government. The IA state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 8 of the 8 active systems in Shelby County (100%) are also owned by a local government.
Does Irwin Municipal Supply have drinking water violations?
EPA's records list 10 violations for this system; none is health-based, and the most recent began in November 2025. The violations listed here began between June 1992 and November 2025. By type: 6 monitoring and 4 monitoring and reporting. The contaminant or rule involved most often is Revised Total Coliform Rule (6 of them). EPA lists 10 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 |
|---|---|---|---|---|
| 2025-11-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2025-05-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2024-12-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2024-10-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2023-12-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2022-07-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2000-01-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1994-02-01 | 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 |
| 1992-06-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
All 10 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.
Irwin Municipal Supply: frequently asked questions
Who runs Irwin Municipal Supply?
Irwin Municipal Supply (PWSID IA8340099) is a community water system owned by a local government. It is regulated by the IA state drinking water program.
How many people does Irwin Municipal Supply serve?
Irwin Municipal Supply reports serving 313 people through 177 service connections in Shelby County, Iowa.
Where does Irwin Municipal Supply get its water?
EPA SDWIS lists this system's primary water source as purchased groundwater. Purchased groundwater means the system buys groundwater from another public water system rather than drawing its own.
Does Irwin Municipal Supply have any drinking water violations?
EPA's records list 10 violations for this system; none is health-based, and the most recent began in November 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 Irwin Municipal Supply'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 10 violations for this system; none is health-based, and the most recent began in November 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the IA state drinking water program.
Where can I find Irwin Municipal Supply's water quality report?
As a community water system, Irwin Municipal Supply 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 Shelby County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Harlan Municipal Utilities | Shelby | 5,067 | Community | Groundwater |
| Shelby Water Supply | Shelby | 727 | Community | Groundwater |
| Elk Horn Muni Water Works | Shelby | 631 | Community | Groundwater |
| Earling Water Supply | Shelby | 397 | Community | Purchased groundwater |
| Defiance Water Department | Shelby | 250 | Community | Groundwater |
| Panama Water Works | Shelby | 235 | Community | Purchased 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, “Irwin Municipal Supply, PWSID IA8340099, Iowa”, https://aquacensus.com/water-systems/iowa/irwin-municipal-supply-ia8340099 (data as of October 1, 2026).