KEYSTONE BITUMINOUS COAL ASSN. v. DUNCAN

KEYSTONE BITUMINOUS COAL ASSN., a Pennsylvania unincorporated association of bituminous coal producers, individually and as represented by certain of its member companies; Helvetia Coal Company, a Pennsylvania corporation; Rochester & Pittsburgh Coal Company, a Pennsylvania corporation; U.S. Steel Mining Co., Inc., a Delaware corporation, individually and as a trustee ad litem for Keystone Bituminous Coal Assn.; United States Steel Corporation, a Delaware corporation; and Consolidation Coal Company, a Delaware corporation, Appellants, v. Peter S. DUNCAN, indiv. and in his capacity as Secretary of the Commonwealth of Penna. Dept. of Environmental Resources, Philip Zullo, indiv. and in his capacity as Chief, Div. of Mine Subsidence of the Bureau of Mining and Reclamation of the Comm. of Penna., Dept. of Environmental Resources, and Thomas B. Alexander, indiv. and in his capacity as Chief, Section of Mine Subsidence Regulation of the Div. of Mine Subsidence of the Bureau of Mining and Reclamation of the Comm. of Penna., Dept. of Environmental Resources.