Public water system · WI6560137
ActiveSomerset Waterworks
At a glance
Somerset Waterworks (PWSID WI6560137) is an active community water system in St. Croix County, Wisconsin. It reports serving 3,334 people through 1,173 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in July 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
3,334
Service connections
1,173
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Somerset Waterworks compare with other water systems in St. Croix County?
By EPA's size categories, Somerset Waterworks is a medium system (3,301 to 10,000 people). St. Croix County has 165 active public water systems, and Somerset Waterworks is the 4th-largest of them by population served. Its population served is about 9.6 times the county average of 349 people per system, and accounts for 5.8% of the 57,590 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 Somerset Waterworks is about half of 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 Somerset Waterworks?
EPA lists Somerset 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. 21 of the 165 active systems in St. Croix County (13%) are also owned by a local government.
Does Somerset Waterworks have drinking water violations?
Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in July 2025. The violations listed here began between November 2011 and July 2025. By type: 5 monitoring and reporting, 2 reporting, 2 public notice, recordkeeping or other, 2 contaminant level above the legal limit and 1 required treatment not met. The contaminant or rule involved most often is Lead and Copper Rule Revisions (3 of them). EPA lists 10 as resolved and 2 as unaddressed. 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. Unaddressed means the violation is not resolved or archived and is not yet covered by formal enforcement.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2025-07-02 | ReportingNotification, Known or Potential LSL · code 4H | Lead and Copper Rule Revisionscode 5200 | No | Resolved |
| 2024-10-17 | Required treatment not metLSL Inventory · code 2E | Lead and Copper Rule Revisionscode 5200 | Yes | Resolved |
| 2024-10-17 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Unaddressed |
| 2024-10-17 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Unaddressed |
| 2024-10-17 | ReportingLSL Reporting · code 4G | Lead and Copper Rule Revisionscode 5200 | No | Resolved |
| 2024-01-01 | Monitoring and reportingLead Consumer Notice · code 66 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2018-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2018-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2015-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2015-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2011-12-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2011-11-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
The 12 most recent 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.
Somerset Waterworks: frequently asked questions
Who runs Somerset Waterworks?
Somerset Waterworks (PWSID WI6560137) is a community water system owned by a local government. It is regulated by the WI state drinking water program.
How many people does Somerset Waterworks serve?
Somerset Waterworks reports serving 3,334 people through 1,173 service connections in St. Croix County, Wisconsin.
Where does Somerset 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 Somerset Waterworks have any drinking water violations?
Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in July 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 Somerset 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. Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in July 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 Somerset Waterworks' water quality report?
As a community water system, Somerset 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 St. Croix County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Hudson Waterworks | St. Croix | 18,558 | Community | Groundwater |
| New Richmond Waterworks | St. Croix | 10,824 | Community | Groundwater |
| Baldwin Waterworks | St. Croix | 4,440 | Community | Groundwater |
| Hammond Waterworks | St. Croix | 1,884 | Community | Groundwater |
| Roberts Waterworks | St. Croix | 1,872 | Community | Groundwater |
| Woodville Waterworks | St. Croix | 1,386 | 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, “Somerset Waterworks, PWSID WI6560137, Wisconsin”, https://aquacensus.com/water-systems/wisconsin/somerset-waterworks-wi6560137 (data as of October 1, 2026).