Ontario, Wisconsin Water Quality Report
Water quality data for 1 water system serving 554 people.
Water Source
Detected Contaminants
No contaminant data available for this location.
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Compliance & Violations
Active Violations (10)
75
Oct 17, 2024
Violation
Unknown
Violation
Unknown
Violation
Unknown
Violation
Unknown
Violation
Unknown
Violation
Unknown
Violation
Unknown
Violation
Unknown
Violation
Unknown
Resolved Violations (67)
3A
Jul 1, 2025 — Jul 31, 2025
3A
Jul 1, 2025 — Jul 31, 2025
3A
Jul 1, 2025 — Jul 31, 2025
2E
Oct 17, 2024
27
Apr 1, 2009 — Jun 30, 2009
+ 62 more resolved violations
Frequently Asked Questions
Is Ontario tap water safe to drink?
Ontario's water meets all EPA maximum contaminant levels. However, 0 contaminants were detected at various levels. Some residents may prefer additional filtration for peace of mind.
What contaminants are in Ontario tap water?
0 contaminants have been detected in Ontario's water supply across 1 water system. See the full contaminant table above for details.
How can I improve my water quality in Ontario?
Install a water filter rated for the specific contaminants found in Ontario's water. See our filter recommendations above. You can also request your utility's Consumer Confidence Report for the most current test results.
Does Ontario have any water quality violations?
Yes, Ontario currently has 10 active violations. See the violations section above for details.