Tap Water Quality Report for San Mateo, California
Track your tap water quality with EPA-verified data on contaminants, violations, and health guidelines, updated quarterly from official water system monitoring results.
San Mateo, California tap water has 516 total contaminants, with 20 being above EPA standards and 297 being above InTheTap suggested standards. There are 0 active violations. The primary water source is not specified, serving 0 residents.
Water Systems (27)
27 water systems serve San Mateo, California. 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).