In June 1999, DEP prepared the first report on the surface impacts of underground coal mining, as required by the 1994 amendments to the state Bituminous Mine Subsidence and Land Conservation Act (Act 54).

The act requires DEP to assess the surface impacts of underground mining on structures, water supplies and streams every five years.  The report covers underground mining conducted between August 1993 and August 1998 in a 10-county area of western Pennsylvania.  During that time period, 39,000 acres (61 square miles) of surface lands with approximately 91 miles of streams were undermined by coal operations.

In preparing the 1999 report, DEP identified the need to develop a supplemental report to present information on damage claims that were pending.  Using information gathered from additional investigations and surveys, DEP has published a supplemental report to provide a more complete picture of the impacts of underground mining and the resolution rates for damages.