30 C.F.R. § 77.1000 Highwalls, pits and spoil banks; plans.
Title 30 - Mineral Resources
Each operator shall establish and follow a ground control plan for the safe control of all highwalls, pits and spoil banks to be developed after June 30, 1971, which shall be consistent with prudent engineering design and will insure safe working conditions. The mining methods employed by the operator shall be selected to insure highwall and spoil bank stability.
Title 30: Mineral Resources
PART 77—MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES
Subpart K—Ground Control
§ 77.1000 Highwalls, pits and spoil banks; plans.

