Prospect holes, other drill or boreholes, wells, and other exposed underground openings, which have been identified in the approved permit application for use in returning coal processing waste or water to underground workings, or which are to be used to monitor ground water conditions, shall be temporarily sealed before use and protected during use by barricades, fences, or other protective devices approved by the Bureau. These devices shall be periodically inspected and maintained in good operating condition by the person who conducts the surface mining activities.
Md. Code Regs. 26.20.20.07