Public water system · WI1230078
ActiveMonroe Waterworks
At a glance
Monroe Waterworks (PWSID WI1230078) is an active community water system in Green County, Wisconsin. It reports serving 10,780 people through 3,992 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; 5 are health-based, and the most recent began in July 2014.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
10,780
Service connections
3,992
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Monroe Waterworks compare with other water systems in Green County?
By EPA's size categories, Monroe Waterworks is a large system (10,001 to 100,000 people). Green County has 52 active public water systems, and Monroe Waterworks is the largest of them by population served. Its population served is about 20 times the county average of 540 people per system, and accounts for 38% of the 28,087 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 Monroe Waterworks is about 61% above 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 Monroe Waterworks?
EPA lists Monroe Waterworks 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. 11 of the 52 active systems in Green County (21%) are also owned by a local government.
Does Monroe Waterworks have drinking water violations?
EPA's records list 7 violations for this system; 5 are health-based, and the most recent began in July 2014. The violations listed here began between July 1991 and July 2014. By type: 5 contaminant level above the legal limit and 2 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (5 of them). EPA lists 5 as resolved and 2 as archived. 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. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2014-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2014-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2014-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2010-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1998-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1991-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 1991-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
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.
Monroe Waterworks: frequently asked questions
Who runs Monroe Waterworks?
Monroe Waterworks (PWSID WI1230078) is a community water system owned by a local government. It is regulated by the WI state drinking water program.
How many people does Monroe Waterworks serve?
Monroe Waterworks reports serving 10,780 people through 3,992 service connections in Green County, Wisconsin.
Where does Monroe Waterworks 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 Monroe Waterworks have any drinking water violations?
EPA's records list 7 violations for this system; 5 are health-based, and the most recent began in July 2014. 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 Monroe Waterworks' 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; 5 are health-based, and the most recent began in July 2014. For current results, consult the system's annual water quality report, EPA ECHO, or the WI state drinking water program.
Where can I find Monroe Waterworks' water quality report?
As a community water system, Monroe Waterworks 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 Green County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Brodhead Waterworks | Green | 3,216 | Community | Groundwater |
| Belleville Waterworks | Green | 2,712 | Community | Groundwater |
| New Glarus Waterworks | Green | 2,348 | Community | Groundwater |
| Brooklyn Waterworks | Green | 1,524 | Community | Groundwater |
| Monticello Waterworks | Green | 1,217 | Community | Groundwater |
| Albany Waterworks | Green | 1,018 | Community | Groundwater |
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, “Monroe Waterworks, PWSID WI1230078, Wisconsin”, https://aquacensus.com/water-systems/wisconsin/monroe-waterworks-wi1230078 (data as of October 1, 2026).