When no longer needed for monitoring or other use approved by the Bureau, unless approved for transfer as a water well, each prospect hole, other drilled hole or borehole, well, and other exposed underground opening shall be capped, sealed, backfilled, or otherwise properly managed, as required by the Bureau in accordance with the Regulatory Program. Permanent closure measures shall be designed to prevent access to the mine workings by people, livestock, fish, wildlife, and machinery, and to keep acid or other toxic drainage from entering ground or surface waters.
Md. Code Regs. 26.20.20.08