Drinking Water Systems in Ontario, Wisconsin
2 water systems are reported for this city, with a combined service population of 1,108. The systems have 2 EPA violation records in the five-year period ending June 30, 2026.
Water Systems Serving Ontario
ONTARIO WATERWORKS
554 served6 historical records1 recent
B
ONTARIO WATERWORKS
554 served6 historical records1 recent
B
EPA Contaminant Categories in Historical Violation Records
Coliform (TCR)8 records
Total Trihalomethanes (TTHMs)2 records
Category counts aggregate historical compliance records across listed systems. They do not show current concentrations or household test results.