30 C.F.R. § 57.12028 Testing grounding systems.
Title 30 - Mineral Resources
Continuity and resistance of grounding systems shall be tested immediately after installation, repair, and modification; and annually thereafter. A record of the resistance measured during the most recent test shall be made available on a request by the Secretary or his duly authorized representative.
Title 30: Mineral Resources
PART 57—SAFETY AND HEALTH STANDARDS—UNDERGROUND METAL AND NONMETAL MINES
Subpart K—Electricity
Surface and Underground
§ 57.12028 Testing grounding systems.

