Public water system · WI2460111
ActiveGrafton Waterworks
At a glance
Grafton Waterworks (PWSID WI2460111) is an active community water system in Ozaukee County, Wisconsin. It reports serving 12,269 people through 4,544 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, none is health-based, and the most recent began in January 2008.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
12,269
Service connections
4,544
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Grafton Waterworks compare with other water systems in Ozaukee County?
By EPA's size categories, Grafton Waterworks is a large system (10,001 to 100,000 people). Ozaukee County has 249 active public water systems, and Grafton Waterworks is the 3rd-largest of them by population served. Its population served is about 33 times the county average of 371 people per system, and accounts for 13% of the 92,392 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 Grafton Waterworks is about 83% 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 Grafton Waterworks?
EPA lists Grafton 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. 24 of the 249 active systems in Ozaukee County (9.6%) are also owned by a local government.
Does Grafton Waterworks have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2008. The violations listed here began between January 2004 and January 2008. By type: 11 monitoring and reporting and 1 public notice, recordkeeping or other. The contaminants or rules involved are Haloacetic acids (HAA5), Total trihalomethanes (TTHM), Total coliform bacteria (TCR) and Public Notice. EPA lists 8 as archived and 4 as resolved. 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. 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 |
|---|---|---|---|---|
| 2008-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2008-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2006-11-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2004-04-01 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2004-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Xylenes, Totalcode 2955 | No | Archived |
| 2004-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Dichloromethanecode 2964 | No | Archived |
| 2004-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | o-Dichlorobenzenecode 2968 | No | Archived |
| 2004-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Chlorobenzenecode 2989 | No | Archived |
| 2004-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2,4-Trichlorobenzenecode 2378 | No | Archived |
| 2004-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Tetrachloroethylenecode 2987 | No | Archived |
| 2004-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Benzenecode 2990 | No | Archived |
| 2004-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Toluenecode 2991 | No | Archived |
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.
Grafton Waterworks: frequently asked questions
Who runs Grafton Waterworks?
Grafton Waterworks (PWSID WI2460111) is a community water system owned by a local government. It is regulated by the WI state drinking water program.
How many people does Grafton Waterworks serve?
Grafton Waterworks reports serving 12,269 people through 4,544 service connections in Ozaukee County, Wisconsin.
Where does Grafton 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 Grafton Waterworks have any drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2008. 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 Grafton 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, none is health-based, and the most recent began in January 2008. For current results, consult the system's annual water quality report, EPA ECHO, or the WI state drinking water program.
Where can I find Grafton Waterworks' water quality report?
As a community water system, Grafton 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 Ozaukee County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Port Washington Waterworks | Ozaukee | 12,853 | Community | Surface water |
| Cedarburg L & W Commission | Ozaukee | 12,500 | Community | Groundwater |
| Mequon Water Utility | Ozaukee | 11,152 | Community | Purchased surface water |
| Saukville Waterworks | Ozaukee | 4,268 | Community | Groundwater |
| Belgium Waterworks | Ozaukee | 2,493 | Community | Groundwater |
| Fredonia Waterworks | Ozaukee | 2,279 | 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, “Grafton Waterworks, PWSID WI2460111, Wisconsin”, https://aquacensus.com/water-systems/wisconsin/grafton-waterworks-wi2460111 (data as of October 1, 2026).