Public water system · WI2684642

Active

Delafield Waterworks

At a glance

Delafield Waterworks (PWSID WI2684642) is an active community water system in Waukesha County, Wisconsin. It reports serving 300 people through 111 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 11 violations for this system; 3 are health-based, and the most recent began in July 2001.

Dataset updated October 2026 . Source: EPA SDWIS/ECHO public records.

Population served

300

Service connections

111

Primary source

Groundwater

System type

CWS

Community water system

System record

PWSIDWI2684642

System typeCommunity water system

Activity statusActive

Population served300

Service connections111

Primary water sourceGroundwater

Owner typeLocal government

Primacy agencyWI state drinking water program

City servedDelafield

StateWisconsin

ZIP—

CountyWaukesha County

How does Delafield Waterworks compare with other water systems in Waukesha County?

By EPA's size categories, Delafield Waterworks is a very small system (500 people or fewer). Waukesha County has 589 active public water systems. Its population served is about half of the county average of 549 people per system, and accounts for less than 0.1% of the 323,265 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 Delafield 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 Delafield Waterworks?

EPA lists Delafield 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. 102 of the 589 active systems in Waukesha County (17%) are also owned by a local government.

Does Delafield Waterworks have drinking water violations?

EPA's records list 11 violations for this system; 3 are health-based, and the most recent began in July 2001. The violations listed here began between January 1995 and July 2001. By type: 7 monitoring and reporting, 3 contaminant level above the legal limit and 1 public notice, recordkeeping or other. The contaminant or rule involved most often is Combined Radium (-226 and -228) (4 of them). EPA lists 11 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
2001-07-01	Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71	Consumer Confidence Rulecode 7000	No	Resolved
2001-01-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Combined Radium (-226 and -228)code 4010	Yes	Resolved
2001-01-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Gross alpha (excluding radon and uranium)code 4000	Yes	Resolved
2000-04-01	Monitoring and reportingMonitoring, Regular · code 03	Radium-228code 4030	No	Resolved
2000-04-01	Monitoring and reportingMonitoring, Regular · code 03	Gross alpha (excluding radon and uranium)code 4000	No	Resolved
2000-04-01	Monitoring and reportingMonitoring, Regular · code 03	Combined Radium (-226 and -228)code 4010	No	Resolved
2000-04-01	Monitoring and reportingMonitoring, Regular · code 03	Radium-226code 4020	No	Resolved
1999-07-20	Monitoring and reportingMonitoring, Check/Repeat/Confirmation · code 04	Combined Radium (-226 and -228)code 4010	No	Resolved
1999-07-20	Monitoring and reportingMonitoring, Check/Repeat/Confirmation · code 04	Gross alpha (excluding radon and uranium)code 4000	No	Resolved
1998-01-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Combined Radium (-226 and -228)code 4010	Yes	Resolved
1995-01-01	Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51	Lead and Copper Rulecode 5000	No	Resolved

All 11 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.

Delafield Waterworks: frequently asked questions

Who runs Delafield Waterworks?

Delafield Waterworks (PWSID WI2684642) is a community water system owned by a local government. It is regulated by the WI state drinking water program.

How many people does Delafield Waterworks serve?

Delafield Waterworks reports serving 300 people through 111 service connections in Waukesha County, Wisconsin.

Where does Delafield 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 Delafield Waterworks have any drinking water violations?

EPA's records list 11 violations for this system; 3 are health-based, and the most recent began in July 2001. 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 Delafield 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 11 violations for this system; 3 are health-based, and the most recent began in July 2001. For current results, consult the system's annual water quality report, EPA ECHO, or the WI state drinking water program.

Where can I find Delafield Waterworks' water quality report?

As a community water system, Delafield 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 Waukesha County

Water system	County	Population served	Type	Source
Waukesha Water Utility	Waukesha	70,718	Community	Purchased surface water
Brookfield Water Utility	Waukesha	29,070	Community	Groundwater
New Berlin Water Utility	Waukesha	27,899	Community	Purchased surface water
Menomonee Falls Ww - Surface Water	Waukesha	23,867	Community	Purchased surface water
Oconomowoc Waterworks	Waukesha	15,805	Community	Groundwater
Sussex Village Hall & Water Utility	Waukesha	11,750	Community	Groundwater

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, “Delafield Waterworks, PWSID WI2684642, Wisconsin”, https://aquacensus.com/water-systems/wisconsin/delafield-waterworks-wi2684642 (data as of October 1, 2026).