Abstract: A method for locating and inspecting underground or other nonvisible, non-electrically conductive pipes. An electrolyte is introduced into the pipe and a time varying electrical signal is applied to the fluid as in a standard prior art method for locating underground pipes, wherein proximity to the pipe is determined by assessing the strength of the electromagnetic field produced thereby. The method also provides for detecting leaks by introducing the electrolyte relatively slowly, to ensure that a pool of the electrolyte accumulates outside the pipe adjacent the leak.