Is ONTARIO WATERWORKS required to publish a Consumer Confidence Report?

Yes. ONTARIO WATERWORKS is a community water system, and federal rules (40 CFR 141 Subpart O) require every community water system to publish a Consumer Confidence Report each year.

When is ONTARIO WATERWORKS’s next Consumer Confidence Report due?

ONTARIO WATERWORKS’s next Consumer Confidence Report is due by July 1, 2027. The report covers calendar year 2026.

What is a Consumer Confidence Report?

A Consumer Confidence Report (CCR) is the annual drinking water quality report that community water systems must provide to the people they serve. It lists the contaminants detected in the system’s water during the year, where the water comes from, and how the results compare with federal limits. EPA’s revised CCR rule takes effect January 1, 2027, and the first reports in the new format are due July 1, 2027.

Ontario, WI · Vernon County

ONTARIO WATERWORKS Water System

Consumer Confidence Report status

ONTARIO WATERWORKS must publish a Consumer Confidence Report — the annual drinking water quality report covering calendar year 2026 — by July 1, 2027.

As of August 1, 2026, EPA's federal records show no open violations for ONTARIO WATERWORKS.

Data sourced from the EPA ECHO database (SDWA bulk download), last refreshed August 1, 2026. This is a record-keeping and public-information tool — it does not replace Wisconsin’s official records. Always confirm current status with Wisconsin before making decisions based on this information.

System facts

System ID (PWSID): WI6630259
System type: Community Water System
Population served: 554
Service connections: 241
Ownership: local government
Water source: groundwater (wells)

ONTARIO WATERWORKS is one of 333 community water systems in Wisconsin in the 501 to 3,300 people size category, serving 554 people from groundwater.

As of August 1, 2026, its federal record holds 4 entries between 1993 and 2025, all of which EPA lists as closed.

Of the 4, 1 are monitoring and reporting requirements — the category that accounts for about four in five of all violations in EPA's national dataset — rather than findings about the water itself. The record involves the Total Coliform Rules and the Stage 2 Disinfectants and Disinfection Byproducts Rule.

Violation history

Monitoring and Reporting (DBP)
—
TTHM
January 1, 2025 – December 31, 2025
Archived
Maximum Contaminant Level Violation, Monthly (TCR)
Health-based
Coliform (TCR)
August 1, 1994 – August 31, 1994
Resolved
Maximum Contaminant Level Violation, Monthly (TCR)
Health-based
Coliform (TCR)
August 1, 1993 – August 31, 1993
Resolved
Maximum Contaminant Level Violation, Monthly (TCR)
Health-based
Coliform (TCR)
May 1, 1993 – May 31, 1993
Resolved

Archived closed in EPA's records (typically due to age or a data correction)Resolved addressed and confirmed by the state

Period	Violation	Contaminant / rule	Health-based	Status
January 1, 2025 – December 31, 2025	Monitoring and Reporting (DBP)	TTHM	—	Archived
August 1, 1994 – August 31, 1994	Maximum Contaminant Level Violation, Monthly (TCR)	Coliform (TCR)	Health-based	Resolved
August 1, 1993 – August 31, 1993	Maximum Contaminant Level Violation, Monthly (TCR)	Coliform (TCR)	Health-based	Resolved
May 1, 1993 – May 31, 1993	Maximum Contaminant Level Violation, Monthly (TCR)	Coliform (TCR)	Health-based	Resolved

Archived closed in EPA's records (typically due to age or a data correction)Resolved addressed and confirmed by the state

Enforcement actions

October 28, 2025State Public Notification requested33 linked violations
June 21, 2006State Public Notification received87 linked violations
September 13, 1994State Public Notification received1 linked violation
September 2, 1994State Compliance achieved1 linked violation
August 29, 1994State Public Notification requested1 linked violation
August 29, 1994State Violation/Reminder Notice1 linked violation
January 6, 1994State Compliance achieved1 linked violation
December 22, 1993State Public Notification received1 linked violation
December 6, 1993State Site Visit for enforcement purposes1 linked violation
November 18, 1993State Technical Assistance Visit1 linked violation
October 26, 1993State Public Notification requested1 linked violation
October 26, 1993State Violation/Reminder Notice1 linked violation
October 20, 1993State Public Notification received1 linked violation
September 10, 1993State Public Notification received1 linked violation
September 10, 1993State Compliance achieved1 linked violation
September 3, 1993State Violation/Reminder Notice1 linked violation
September 3, 1993State Public Notification requested1 linked violation
July 19, 1993State Public Notification received1 linked violation
June 23, 1993State Public Notification received1 linked violation
June 4, 1993State Compliance achieved1 linked violation
May 27, 1993State Public Notification requested1 linked violation
May 27, 1993State Violation/Reminder Notice1 linked violation

Common questions

Is ONTARIO WATERWORKS required to publish a Consumer Confidence Report?: Yes. ONTARIO WATERWORKS is a community water system, and federal rules (40 CFR 141 Subpart O) require every community water system to publish a Consumer Confidence Report each year.
When is ONTARIO WATERWORKS’s next Consumer Confidence Report due?: ONTARIO WATERWORKS’s next Consumer Confidence Report is due by July 1, 2027. The report covers calendar year 2026.
Does ONTARIO WATERWORKS have any open drinking water violations on record?: As of August 1, 2026, EPA's federal records show no open violations for ONTARIO WATERWORKS.
What is a Consumer Confidence Report?: A Consumer Confidence Report (CCR) is the annual drinking water quality report that community water systems must provide to the people they serve. It lists the contaminants detected in the system’s water during the year, where the water comes from, and how the results compare with federal limits. EPA’s revised CCR rule takes effect January 1, 2027, and the first reports in the new format are due July 1, 2027.

Contact

ONTARIO VILLAGE CLERK/TERRI TAYLOR

Phone not on record

Ontario, WI 54651