Every drop of clean water is precious. Unfortunately, 30—50% of water is lost through aging infrastructure. And lost water equals lost revenue to the water service supplier. Water is lost through leaks and cracks in pipes and their fittings. Since most infrastructure is underground, it is virtually impossible to visually determine the location of these leaks unless the water has reached the surface (causing ponding and sink holes, structural damage, buckling pavement, etc.), and the exact location may be indeterminate. Leak detection requires special technologies that allow inspectors to precisely determine the location and severity of pipeline leaks. This is a field that continues to grow and advance by utilizing both established technology and by adopting emerging methods.