1. Locate your water service line. A portion of the service line can usually be found by looking at the piping that comes through the exterior wall inside your basement. 2. If the water service line is white, blue, or black the material is likely Plastic or PVC. 3. If the service line is grey and metallic, use a magnet to test its material. If the magnet sticks to the pipe, then it is a galvanized steel line. If the magnet does not stick to the pipe then it’s possibly a lead line. 4. Take a coin or a penny and firmly scratch the line. A steel line is very hard to scratch but a lead line can be easily scratched and will leave a shiny silver color.