Independent grades from EPA data — 20,609 ZIP codes analyzed
What's in your tap water?
Enter your ZIP code and get an instant A–F grade for your local water quality.
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ZIP codes graded
Contaminants tracked
EPA violations analyzed
States & territories
Lowest-Graded Water Systems
These cities scored lowest in our analysis of EPA violation and contaminant data
Highest-Graded Water Systems
The cleanest report cards in the country, according to EPA data
How TapWaterGrade Works
From raw EPA records to a grade you can act on
We Gather Data
EPA ECHO database, Envirofacts API, and Safe Drinking Water Act violations
We Analyze
Process contaminants, violations, severity, and compliance data
We Grade
Apply consistent A–F grading based on water quality metrics
You Search
Look up your ZIP code to see your local water quality grade
Check your water now
It takes 5 seconds. Enter your ZIP code and see exactly what's in your tap water.