Mason City, Illinois Water Quality Report
Water quality data for 1 water system serving 2,558 people.
Water Source
Detected Contaminants
No contaminant data available for this location.
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Compliance & Violations
Active Violations (2)
4H
Jul 2, 2025
4H
Jul 2, 2025
Resolved Violations (89)
02
Jul 1, 2009 — Sep 30, 2009
02
Jul 1, 2009 — Sep 30, 2009
02
Jul 1, 2009 — Sep 30, 2009
02
Jul 1, 2009 — Sep 30, 2009
02
Apr 1, 2009 — Jun 30, 2009
+ 84 more resolved violations
Frequently Asked Questions
Is Mason City tap water safe to drink?
Mason City'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 Mason City tap water?
0 contaminants have been detected in Mason City's water supply across 1 water system. See the full contaminant table above for details.
How can I improve my water quality in Mason City?
Install a water filter rated for the specific contaminants found in Mason City's water. See our filter recommendations above. You can also request your utility's Consumer Confidence Report for the most current test results.
Does Mason City have any water quality violations?
Yes, Mason City currently has 2 active violations. See the violations section above for details.