58 Pa. Stat. § 1103
The following words and phrases when used in this act shall have the meanings given to them in this section unless the context clearly indicates otherwise:
"Department." The Department of Environmental Protection of the Commonwealth.
"Mine drainage" or "mine pool water." Water contained in a mine pool or a surface discharge of water caused by mining activity.
"Mine operator." The permittee of an active or closed coal mine that treats mine drainage or mine pool water under a permit issued by the department.
"Oil or gas well development." The drilling, completion, hydraulic fracturing or other development of a conventional or unconventional oil or gas well.
"Treated mine water." Water from an active or closed coal mine that is treated by a mine operator under a permit issued by the department.
58 P.S. § 1103