I built TapGrade so anyone can get a clear read on their tap water by typing in a ZIP code.
TapGrade takes official EPA violation data and turns it into a simple A-F grade for any community water system in the country. Drinking water reports exist, but they are long, technical, and easy to ignore. I wanted a single, honest letter grade you could get in seconds, with the reasoning behind it.
Overview
TapGrade started from a question almost everyone has asked at some point: is my tap water actually safe? The honest answer is usually available in EPA data, but it is spread across violation records and dense annual reports that are effectively unreadable for a normal person.
So I built the app to collapse all of that into one letter grade. It looks at the last decade of health-based violations, weighs recent and unresolved issues more heavily, and then, crucially, shows its work so the grade does not feel like a black box.
From there you can go as deep as you want. The free version gives you the grade, the top contaminants, and a trend line, while premium opens up the full violation history, Lead and Copper sampling, enforcement actions, filter recommendations, and saved locations with alerts. Everything stays on device, with no account required.
At a glance
Audience: Renters, homebuyers, parents, and anyone who has ever wondered whether their tap water is actually safe and wanted a straight answer.
Built with: SwiftUI, iOS, EPA Data
Project type: iPhone app
Key features
- Enter any US ZIP code and get an instant A-F grade for the local water system.
- See exactly why the grade landed where it did, with each deduction explained.
- Review the contaminants behind violations and how they compare to EPA limits.
- Track a five-year grade trend and, with premium, full violation and Lead and Copper history.
- Save multiple locations and get alerts when new violations appear, with no subscription.
Highlights
Turns ten years of official EPA violation data into a single A-F grade for any ZIP code.
Explains every grade deduction in plain English instead of regulatory jargon.
Breaks down contaminants, trends, and Lead and Copper results for the curious.
How it is built
I built TapGrade as a native SwiftUI app on top of public EPA data. It weighs the last ten years of health-based violations, leans on more recent issues, flags unresolved problems, and explains every deduction in plain language, all on device.
Why it matters
Water quality data is public, but it is buried in annual reports and regulatory databases that most people never open. TapGrade reduces that to a grade you can actually act on, then lets you dig into the specifics if you want them.