30 CFR 816.13 - What special requirements apply to drilled holes, wells, and exposed underground openings?
(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) Prevent acid or other toxic drainage from entering groundwater and surface water.
(2) Minimize disturbance to the prevailing hydrologic balance.
(b) If the approved permit identifies an exploration hole, drilled hole, borehole, well, or other exposed underground opening for use to monitor groundwater or to return coal processing waste or water to underground workings, you must temporarily seal the hole or opening before use and protect it during use by installing barricades, fences, or other protective devices approved by the regulatory authority. You must periodically inspect these devices and maintain them in good operating condition.
(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) Approves use of the hole, well, or opening for water monitoring purposes; or
(2) Authorizes other management of the hole or well.
(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) Permanent closure measures taken under paragraph (e)(1) of this section must be -
(i) Consistent with § 75.1771 of this title;
(ii) Designed to prevent access to the mine workings by people, livestock, fish and wildlife, and machinery; and
(f) The requirements of this section do not apply to holes drilled and used for blasting for surface mining purposes.