SECTION 460:20-45-5. Casing and sealing of underground openings:

(a)   Each mine entry which is temporarily inactive, but has a further projected useful service under the approved permit application, shall be protected by barricades or other covering devices, fenced, and posted with signs, to prevent access into the entry and to identify the hazardous nature of the opening. These devices shall be periodically inspected and maintained in good operating condition by the person who conducts the underground mining activities.

(b)   Each exploration hole, other drill hole or borehole, shaft, well, and other exposed underground opening which has been identified in the approved permit application for use to return underground development waste, coal processing waste or water to underground workings, or to be used to monitor ground water conditions, shall be temporarily sealed until actual use.

(c)   When no longer needed for monitoring or other use approved by the Department upon a finding of no adverse environmental or health and safety effects, or unless approved for transfer as a water well under Section 460:20-45-8(g), each shaft, drift, adit, tunnel, exploratory hole, entry way or other opening to the surface from underground shall be capped, sealed, backfilled, or otherwise properly managed, as required by the Department in accordance with Section 460:20-45-4 of this Subchapter and consistent with Section 30 CFR 75.1711. Temporary closure measures shall be designed to prevent access to the mine workings by people, livestock, fish and wildlife, and machinery and to keep acid or other toxic drainage from entering ground or surface waters.

[Source: Amended at 31 Ok Reg 2101, eff 9-12-14; Amended at 36 Ok Reg 1935, eff 9-14-19]