Lead Detection in Residential Water Lines

Introduction

This project addresses the increasingly critical problem of lead contamination in residential water systems. Large portions of North America, especially older neighborhoods, still rely on aging service lines that may leach toxic lead into drinking water. Our objective was to design an accessible, low-cost, and user-friendly method for everyday residents to detect potential lead presence without requiring specialized equipment.

What did we do?

C-Sketch

conceptual designs exploring early ideas for user interaction and device geometry

A radar-based detection test

using Arduino sensors (experimentally tested but ultimately deemed infeasible)

A functional lead detection stick

using treated cotton swabs for color-change testing

CAD models

to visualize structures, ergonomics and material layout

Why?

Detecting lead at its source is both urgent and necessary. The EPA’s Lead and Copper Rule sets an action threshold of 15 ppb, meaning reliable detection is essential for public safety. Residents need a testing method that is inexpensive, intuitive, and accurate enough to indicate the presence of harmful concentrations.

Our objectives:

Affordable for homeowners

Easy to use with minimal instructions

Fast to interpret through visible color change

Safe and portable

How did we do it?

Early Concept Exploration

We began with creative, open-format C-Sketch brainstorming to visualize how a user might sample water, apply a chemical agent, and interpret results.

Early hand-drawn concepts exploring device shape, housing, replaceable heads, and flow of user interaction.

Arduino radar prototype connected to a PIR and LCD output during feasibility testing. Result: lead detection was not reliable, so the concept was discontinued.

Radar Detection Test

We experimented with an Arduino-based approach to detect metal pipes underground. Although the setup successfully demonstrated sensor behavior, it failed to reliably differentiate lead from other metals, and required too many assumptions and calibrations.

Lead Detection Stick Prototype

CAD model capturing the internal housing for the swab head and standardized grip for user comfort

Our strongest direction became the chemical testing stick, using sodium rhodizonate—a compound known to react visibly with lead ions.

We designed a stainless-steel handle that:

Holds a replaceable cotton swab head

Allows clean and controlled dipping

Uses a compact hinged case for water samples

Initial field test of the chemical reaction using a treated cotton swab inserted into the reusable applicator.

Through iterative development, our team evolved from broad, ambitious detection technologies to a simple, effective household tool. Our final concept offers a low-cost, accessible method for residents to detect potential lead contamination independently—supporting public health and environmental safety.