Public water system · WI6420069
ActiveOakdale Waterworks
At a glance
Oakdale Waterworks (PWSID WI6420069) is an active community water system in Monroe County, Wisconsin. It reports serving 317 people through 140 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 4 violations for this system; 3 are health-based, and the most recent began in November 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
317
Service connections
140
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Oakdale Waterworks compare with other water systems in Monroe County?
By EPA's size categories, Oakdale Waterworks is a very small system (500 people or fewer). Monroe County has 102 active public water systems. Its population served is about 18% below the county average of 385 people per system, and accounts for 0.8% of the 39,274 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 Oakdale Waterworks 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. 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 Oakdale Waterworks?
EPA lists Oakdale 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. 14 of the 102 active systems in Monroe County (14%) are also owned by a local government.
Does Oakdale Waterworks have drinking water violations?
EPA's records list 4 violations for this system; 3 are health-based, and the most recent began in November 2025. The violations listed here began between September 1997 and November 2025. By type: 2 contaminant level above the legal limit, 1 monitoring and 1 required treatment not met. The contaminant or rule involved most often is Total coliform bacteria (TCR) (2 of them). EPA lists 4 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 |
| 2025-08-02 | Required treatment not metTreatment Technique No Certif. Operator · code 12 | Stage 1 Disinfectants and Disinfection Byproducts Rulecode 0400 | Yes | Resolved |
| 1998-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1997-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
All 4 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.
Oakdale Waterworks: frequently asked questions
Who runs Oakdale Waterworks?
Oakdale Waterworks (PWSID WI6420069) is a community water system owned by a local government. It is regulated by the WI state drinking water program.
How many people does Oakdale Waterworks serve?
Oakdale Waterworks reports serving 317 people through 140 service connections in Monroe County, Wisconsin.
Where does Oakdale 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 Oakdale Waterworks have any drinking water violations?
EPA's records list 4 violations for this system; 3 are 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 Oakdale 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 4 violations for this system; 3 are 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 WI state drinking water program.
Where can I find Oakdale Waterworks' water quality report?
As a community water system, Oakdale 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 Monroe County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Sparta Waterworks | Monroe | 10,025 | Community | Groundwater |
| Fort Mccoy North Post | Monroe | 10,000 | Community | Groundwater |
| Tomah Waterworks | Monroe | 9,192 | Community | Groundwater |
| Cashton Waterworks | Monroe | 1,120 | Community | Groundwater |
| Brookwood High School | Monroe | 700 | Non-transient non-community | Groundwater |
| Norwalk Waterworks | Monroe | 653 | 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, “Oakdale Waterworks, PWSID WI6420069, Wisconsin”, https://aquacensus.com/water-systems/wisconsin/oakdale-waterworks-wi6420069 (data as of October 1, 2026).