An Act amending the act of April 27, 1966 (1st Sp.Sess., P.L.31, No.1), known as The Bituminous Mine Subsidence and Land Conservation Act, further providing for procedures for securing restoration or replacement of affected water supplies, for restoration or replacement of water, for restoration or compensation for structures damaged by underground mining and for procedure for securing repair and or compensation for damage to structures caused by underground mining; establishing the Longwall Mining Commission; and providing for a backfilling study.