Sometimes you can take a couple willow sticks and hold them in your hand and they will point down when you are near them are a couple of bronge rods. Best to get a pipe locateing co. and find them.
I would not recommend using dowsing (witching) rods. At least I wouldn’t recommend wasting money to pay a dowser…You can try using a metal detector if the pipe is not buried too deep (and is not plastic…). If that doesn’t work, you will have to excavate the pipe back from the house to the well. You can still use the metal detector for treasure hunting, which can be an enjoyable and very rarely profitable hobby.