A metal underground waterpipe used as part of the grounding electrode system shall be in direct contact with the earth for a minimum of how many feet?

For a metal underground waterpipe to be effective as part of the grounding electrode system, it is essential that it is in direct contact with the earth for a minimum of 6 feet. This requirement ensures that the grounding system has a reliable and adequate path to dissipate electrical energy into the ground, providing safety from electrical faults.

The minimum distance of 6 feet allows the metal pipe to establish a good electrical connection with the earth, accommodating variations in soil conductivity and ensuring a consistent ground reference. The grounded system plays a critical role in protecting electrical installations and preventing shock hazards, and is often dictated by regulations and standards.

Choosing a lesser distance would not provide the necessary assurance of effective grounding, while opting for a longer distance isn't required for compliance. This requirement reflects both safety concerns and practical considerations prevalent in electrical code standards.