To be classified as a grounding electrode, how long must a metal water pipe be in contact with the earth?

The classification of a metal water pipe as a grounding electrode requires it to be in contact with the earth for an adequate length to ensure it can effectively dissipate electrical energy and provide a safe pathway for fault currents. The National Electrical Code (NEC) specifies that a metal water pipe must be at least 10 feet in length for it to be considered a proper grounding electrode. This length ensures that the pipe can effectively serve its purpose by providing a reliable and low-resistance path to the ground, thus enhancing electrical safety and reducing the risk of shock hazards. The requirement for a 10-foot contact distance is based on standardized practices that consider soil resistivity and the importance of grounding in electrical installations.