404.12 Minimum burial depth.
FGC § 404.12
Underground piping systems shall be installed a minimum depth of 24 inches (609.6 mm) below grade, measured to the top of the pipe. Exception: Burial depth less than 24 inches (609.6 mm) is permissible when the underground piping system is protected by steel protective plates not less than 1/4-inch thick (6.36 mm) and with joints tack welded and overlapped a minimum of 3 inches (76.2 mm). The pipe shall be not less than 4 inches (101.6 mm) below the protective steel plate.













