CFR > Title 30 - Mineral Resources > CHAPTER I—MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR > SUBCHAPTER K—METAL AND NONMETAL MINE SAFETY AND HEALTH (parts 56 to 58) > PART 57—SAFETY AND HEALTH STANDARDS—UNDERGROUND METAL AND NONMETAL MINES > SUBPART T—Safety Standards for Methane in Metal and Nonmetal Mines (§57.22001 to §57.22608) > 57.22241—Advance face boreholes (I-C mines).

57.22241—Advance face boreholes (I-C mines).

(a) Boreholes shall be drilled at least 25 feet in advance of a face whenever the work place is within—
(1) 50 feet of a surveyed abandoned mine or abandoned workings which cannot be inspected; or
(2) 200 feet of an unsurveyed abandoned mine or abandoned workings which cannot be inspected.
(b) Boreholes shall be drilled in such a manner to insure that the advancing face will not accidently break into an abandoned mine or abandoned working.