(a) Except as provided in paragraph (f) of this section, you must case, line, otherwise manage each exploration hole, drilled hole, borehole, shaft, well, or other exposed underground opening in a manner approved by the regulatory authority to -

1. (1) Prevent acid or other toxic drainage from entering groundwater and surface water.
2. (2) Minimize disturbance to the prevailing hydrologic balance.
3. (3) Ensure the safety of people, livestock, fish and wildlife, and machinery in the permit area and the adjacent area.

(d) Except as provided in paragraph (c) of this section, you must permanently close each exploration hole, drilled hole, borehole, well, or underground opening that mining activities uncover or expose within the permit area, unless the regulatory authority -

1. (1) Approves use of the hole, well, or opening for water monitoring purposes; or
2. (2) Authorizes other management of the hole or well.

(e)

1. (1) Except as provided in paragraph (c) of this section, you must cap, seal, backfill, or otherwise properly manage each shaft, drift, adit, tunnel, exploratory hole, entryway or other opening to the surface from underground when no longer needed for monitoring or any other use that the regulatory authority approves after finding that the use will not adversely affect the environment or public health and safety.

2. (2) Permanent closure measures taken under paragraph (e)(1) of this section must be -

   1. (i) Consistent with § 75.1771 of this title;
   2. (ii) Designed to prevent access to the mine workings by people, livestock, fish and wildlife, and machinery; and
   3. (iii) Designed to keep acid or toxic mine drainage from entering groundwater or surface water.