Public water system · WI2650060
ActiveWilliams Bay Waterworks
At a glance
Williams Bay Waterworks (PWSID WI2650060) is an active community water system in Walworth County, Wisconsin. It reports serving 2,601 people through 963 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, one is health-based, and the most recent began in September 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
2,601
Service connections
963
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Williams Bay Waterworks compare with other water systems in Walworth County?
By EPA's size categories, Williams Bay Waterworks is a small system (501 to 3,300 people). Walworth County has 252 active public water systems. Its population served is about 6.9 times the county average of 380 people per system, and accounts for 2.7% of the 95,693 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 Williams Bay Waterworks is about 61% 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 Williams Bay Waterworks?
EPA lists Williams Bay 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. 29 of the 252 active systems in Walworth County (12%) are also owned by a local government.
Does Williams Bay Waterworks have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in September 2025. The violations listed here began between October 2012 and September 2025. By type: 7 monitoring and reporting, 4 public notice, recordkeeping or other and 1 required treatment not met. The contaminant or rule involved most often is Lead and Copper Rule (4 of them). EPA lists 9 as resolved, 2 as archived and 1 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. 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. 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 |
|---|---|---|---|---|
| 2025-09-11 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2025-07-01 | Required treatment not metPublic Education · code 65 | Lead and Copper Rulecode 5000 | Yes | Resolved |
| 2025-01-01 | Monitoring and reportingWater Quality Parameter M/R · code 53 | Lead and Copper Rulecode 5000 | No | Archived |
| 2025-01-01 | Monitoring and reportingWater Quality Parameter M/R · code 53 | Lead and Copper Rulecode 5000 | No | Archived |
| 2025-01-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Unaddressed |
| 2021-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2021-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Inadequate Reporting · code 72 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2020-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2012-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2012-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitritecode 1041 | No | Resolved |
| 2012-10-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2012-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | 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.
Williams Bay Waterworks: frequently asked questions
Who runs Williams Bay Waterworks?
Williams Bay Waterworks (PWSID WI2650060) is a community water system owned by a local government. It is regulated by the WI state drinking water program.
How many people does Williams Bay Waterworks serve?
Williams Bay Waterworks reports serving 2,601 people through 963 service connections in Walworth County, Wisconsin.
Where does Williams Bay 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 Williams Bay Waterworks have any drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in September 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 Williams Bay 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, one is health-based, and the most recent began in September 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 Williams Bay Waterworks' water quality report?
As a community water system, Williams Bay 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 Walworth County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Whitewater Waterworks | Walworth | 14,000 | Community | Groundwater |
| Elkhorn Waterworks | Walworth | 10,317 | Community | Groundwater |
| Delavan Waterworks | Walworth | 9,028 | Community | Groundwater |
| Lake Geneva Utility Commission | Walworth | 7,107 | Community | Groundwater |
| East Troy Waterworks | Walworth | 5,054 | Community | Groundwater |
| Bloomfield, Village of | Walworth | 4,071 | 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, “Williams Bay Waterworks, PWSID WI2650060, Wisconsin”, https://aquacensus.com/water-systems/wisconsin/williams-bay-waterworks-wi2650060 (data as of October 1, 2026).