Why should you avoid using structures for grounding?

• A. They cannot carry current
• B. They are unreliable
• C. Other services may be bonded to them
• D. They are too expensive

Answer: (C)

Using structures for grounding is avoided because other services are often bonded to those structures. When a structure is bonded to multiple utilities (like power, telephone, water, or gas), any grounding current you inject can travel into those bonded networks. That creates unexpected current paths, energizes other buried or nearby services, and can pose shock hazards to workers and the public. Structures are also not a reliable, low-impedance ground point for tracing signals due to coatings, corrosion, and potential differences. For safe, effective grounding, use a dedicated ground connection designed for testing rather than a structure.