Public water system · IA1203026
ActiveAllison Water Supply
At a glance
Allison Water Supply (PWSID IA1203026) is an active community water system in Butler County, Iowa. It reports serving 966 people through 481 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 3 violations for this system; none is health-based, and the most recent began in June 2017.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
966
Service connections
481
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Allison Water Supply compare with other water systems in Butler County?
By EPA's size categories, Allison Water Supply is a small system (501 to 3,300 people). Butler County has 16 active public water systems, and Allison Water Supply is the 6th-largest of them by population served. Its population served is about 65% above the county average of 586 people per system, and accounts for 10% of the 9,368 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 Allison Water 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. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 1,502 Iowa systems (82%) list groundwater as their primary source.
Who owns and regulates Allison Water Supply?
EPA lists Allison Water 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. 9 of the 16 active systems in Butler County (56%) are also owned by a local government.
Does Allison Water Supply have drinking water violations?
EPA's records list 3 violations for this system; none is health-based, and the most recent began in June 2017. The violations listed here began between June 2000 and June 2017. By type: 2 monitoring and reporting and 1 monitoring. The contaminant or rule involved most often is Total coliform bacteria (TCR) (2 of them). EPA lists 3 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 |
|---|---|---|---|---|
| 2017-06-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2001-12-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2000-06-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
All 3 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.
Allison Water Supply: frequently asked questions
Who runs Allison Water Supply?
Allison Water Supply (PWSID IA1203026) is a community water system owned by a local government. It is regulated by the IA state drinking water program.
How many people does Allison Water Supply serve?
Allison Water Supply reports serving 966 people through 481 service connections in Butler County, Iowa.
Where does Allison Water Supply 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 Allison Water Supply have any drinking water violations?
EPA's records list 3 violations for this system; none is health-based, and the most recent began in June 2017. 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 Allison Water 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 3 violations for this system; none is health-based, and the most recent began in June 2017. For current results, consult the system's annual water quality report, EPA ECHO, or the IA state drinking water program.
Where can I find Allison Water Supply's water quality report?
As a community water system, Allison Water 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 Butler County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Parkersburg Water Supply | Butler | 2,019 | Community | Groundwater |
| Shell Rock Muni Water Supp | Butler | 1,269 | Community | Groundwater |
| Clarksville Water Supply | Butler | 1,254 | Community | Groundwater |
| Aplington Water Supply | Butler | 1,126 | Community | Groundwater |
| Greene Muni Water Supply | Butler | 994 | Community | Groundwater |
| Dumont Water Supply | Butler | 635 | 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, “Allison Water Supply, PWSID IA1203026, Iowa”, https://aquacensus.com/water-systems/iowa/allison-water-supply-ia1203026 (data as of October 1, 2026).