Tap Water Quality Report for O Fallon, Illinois
Track your tap water quality with EPA-verified data on contaminants, violations, and health guidelines, updated quarterly from official water system monitoring results.
O Fallon, Illinois tap water has 63 total contaminants, with 0 being above EPA standards and 38 being above InTheTap suggested standards. There are 0 active violations. The primary water source is not specified, serving 0 residents.
Water Systems (2)
2 water systems serve O Fallon, Illinois. Select one or more to filter the data below.
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Water Quality Analysis
Comprehensive analysis of your water quality, showing both detected contaminants and violations history. Note that exceeding EPA contaminant levels in a single test doesn't always constitute a violation, as violations typically require sustained exceedances or failure to follow required treatment protocols.
Water Analysis
View detected contaminants and concentration levels for your water system(s).