Public water system · WI1540127
ActiveJanesville Water Utility
At a glance
Janesville Water Utility (PWSID WI1540127) is an active community water system in Rock County, Wisconsin. It reports serving 64,415 people through 23,857 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 2 violations for this system; 1 is health-based, and the most recent began in April 2016.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
64,415
Service connections
23,857
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Janesville Water Utility compare with other water systems in Rock County?
By EPA's size categories, Janesville Water Utility is a large system (10,001 to 100,000 people). Rock County has 156 active public water systems, and Janesville Water Utility is the largest of them by population served. Its population served is about 68 times the county average of 952 people per system, and accounts for 43% of the 148,563 people reported by systems filed under the county. Across Wisconsin, the 11,056 active systems average 469 people each. Nationally, the average active community water system reports serving 6,703 people, so Janesville Water Utility is about 9.6 times 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. Wisconsin has 1,053 active community water systems, 9.5% of the state's 11,056 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 10,978 Wisconsin systems (99%) list groundwater as their primary source.
Who owns and regulates Janesville Water Utility?
EPA lists Janesville Water Utility as owned by a local government. The WI state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 27 of the 156 active systems in Rock County (17%) are also owned by a local government.
Does Janesville Water Utility have drinking water violations?
EPA's records list 2 violations for this system; 1 is health-based, and the most recent began in April 2016. The violations listed here began between December 2002 and April 2016. By type: 1 monitoring and 1 contaminant level above the legal limit. The contaminants or rules involved are Revised Total Coliform Rule and Total coliform bacteria (TCR). EPA lists 2 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 |
|---|---|---|---|---|
| 2016-04-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2002-12-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
All 2 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.
Janesville Water Utility: frequently asked questions
Who runs Janesville Water Utility?
Janesville Water Utility (PWSID WI1540127) is a community water system owned by a local government. It is regulated by the WI state drinking water program.
How many people does Janesville Water Utility serve?
Janesville Water Utility reports serving 64,415 people through 23,857 service connections in Rock County, Wisconsin.
Where does Janesville Water Utility 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 Janesville Water Utility have any drinking water violations?
EPA's records list 2 violations for this system; 1 is health-based, and the most recent began in April 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 Janesville Water Utility'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 2 violations for this system; 1 is health-based, and the most recent began in April 2016. For current results, consult the system's annual water quality report, EPA ECHO, or the WI state drinking water program.
Where can I find Janesville Water Utility's water quality report?
As a community water system, Janesville Water Utility 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 Rock County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Beloit City of | Rock | 36,677 | Community | Groundwater |
| Evansville Waterworks | Rock | 5,703 | Community | Groundwater |
| Milton Waterworks | Rock | 5,588 | Community | Groundwater |
| Edgerton Waterworks | Rock | 5,512 | Community | Groundwater |
| Wi Dot Rest Area 22 Turtle | Rock | 3,005 | Transient non-community | Groundwater |
| Wi Dot Rest Area 17 Milton | Rock | 2,503 | 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, “Janesville Water Utility, PWSID WI1540127, Wisconsin”, https://aquacensus.com/water-systems/wisconsin/janesville-water-utility-wi1540127 (data as of October 1, 2026).