No surface mining activities shall be conducted closer than 500 feet to any point of either an active or abandoned underground mine, except to the extent that—

(a) The activities result in improved resource recovery, abatement of water pollution, or elimination of hazards to the health and safety of the public; and

(b) The nature, timing, and sequence of the activities that propose to mine closer than 500 feet to an active underground mine are jointly approved by the regulatory authority, the Mine Safety and Health Administration, and the State agency, if any, responsible for the safety of underground mine workers.

[48 FR 24651, June 1, 1983, as amended at 81 FR 93392, Dec. 20, 2016; 82 FR 54979, Nov. 17, 2017]