Public water system · WI2460112

Active

Mequon Water Utility

At a glance

Mequon Water Utility (PWSID WI2460112) is an active community water system in Ozaukee County, Wisconsin. It reports serving 11,152 people through 504 service connections. Its primary water source is purchased surface water, 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 May 2020.

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

Population served

11,152

Service connections

504

Primary source

SWP

Purchased surface water

System type

CWS

Community water system

System record

PWSIDWI2460112

System typeCommunity water system

Activity statusActive

Population served11,152

Service connections504

Primary water sourcePurchased surface water

Owner typeLocal government

Primacy agencyWI state drinking water program

City servedMequon

StateWisconsin

ZIP—

CountyOzaukee County

How does Mequon Water Utility compare with other water systems in Ozaukee County?

By EPA's size categories, Mequon Water Utility is a large system (10,001 to 100,000 people). Ozaukee County has 249 active public water systems, and Mequon Water Utility is the 4th-largest of them by population served. Its population served is about 30 times the county average of 371 people per system, and accounts for 12% 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 Mequon Water Utility is about 66% 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. Purchased surface water means the system buys surface water from another public water system rather than drawing its own. 43 Wisconsin systems (0.4%) list purchased surface water as their primary source.

Who owns and regulates Mequon Water Utility?

EPA lists Mequon Water Utility 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 Mequon Water Utility have drinking water violations?

Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in May 2020. The violations listed here began between October 1997 and May 2020. By type: 6 monitoring and reporting, 3 contaminant level above the legal limit, 2 public notice, recordkeeping or other and 1 monitoring. The contaminant or rule involved most often is Total coliform bacteria (TCR) (3 of them). EPA lists 12 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
2020-05-01	MonitoringMonitoring, Routine (RTCR) · code 3A	Revised Total Coliform Rulecode 8000	No	Resolved
2018-10-01	Public notice, recordkeeping or otherConsumer Confidence Report Inadequate Reporting · code 72	Consumer Confidence Rulecode 7000	No	Resolved
2014-01-01	Monitoring and reportingMonitoring and Reporting (DBP) · code 27	Haloacetic acids (HAA5)code 2456	No	Resolved
2014-01-01	Monitoring and reportingMonitoring and Reporting (DBP) · code 27	Total trihalomethanes (TTHM)code 2950	No	Resolved
2010-01-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01	Nickelcode 1036	Yes	Resolved
2002-06-01	Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24	Total coliform bacteria (TCR)code 3100	No	Resolved
2001-04-01	Monitoring and reportingMonitoring, Regular · code 03	Nitratecode 1040	No	Resolved
2000-07-11	Monitoring and reportingMonitoring, Check/Repeat/Confirmation · code 04	Fluoridecode 1025	No	Resolved
2000-07-01	Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71	Consumer Confidence Rulecode 7000	No	Resolved
1999-01-01	Monitoring and reportingMonitoring, Regular · code 03	Chromiumcode 1020	No	Resolved
1998-08-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22	Total coliform bacteria (TCR)code 3100	Yes	Resolved
1997-10-01	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.

Mequon Water Utility: frequently asked questions

Who runs Mequon Water Utility?

Mequon Water Utility (PWSID WI2460112) is a community water system owned by a local government. It is regulated by the WI state drinking water program.

How many people does Mequon Water Utility serve?

Mequon Water Utility reports serving 11,152 people through 504 service connections in Ozaukee County, Wisconsin.

Where does Mequon Water Utility get its water?

EPA SDWIS lists this system's primary water source as purchased surface water. Purchased surface water means the system buys surface water from another public water system rather than drawing its own.

Does Mequon Water Utility 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 May 2020. 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 Mequon Water Utility's 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 May 2020. For current results, consult the system's annual water quality report, EPA ECHO, or the WI state drinking water program.

Where can I find Mequon Water Utility's water quality report?

As a community water system, Mequon Water Utility 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
Grafton Waterworks	Ozaukee	12,269	Community	Groundwater
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, “Mequon Water Utility, PWSID WI2460112, Wisconsin”, https://aquacensus.com/water-systems/wisconsin/mequon-water-utility-wi2460112 (data as of October 1, 2026).