Interstate Technical Group on Abandoned Underground Mines
Fourth Biennial Abandoned Underground Mine Workshop
Abstract: Assessing the Impact of Underground Mining on Pennsylvania's Corridor O
Laurance A. Beck
Matthew Lock Skelly & Loy, Inc.
Corridor O will serve as a connector road between Interstates 80 and 99 passing through Centre and Clearfield Counties in Central Pennsylvania. The corridor traverses the edge of the Ridge and Valley Physiographic Province from I 99 and passes up the Allegheny Front onto the Allegheny Plateaus where it connects with I 80. The entire route is geologically challenging, and the sections within the Allegheny Plateaus are mainly Pennsylvanian Age rocks in which extensive underground mining has been conducted in multiple cyclic deposited coal seams found in this area of Pennsylvania.
The corridor is presently in the preliminary evaluation phases with exploratory drilling now being started. The environmental aspects being studied in this preliminary phase include the impacts due to extensive underground mining; these mining impacts include:
The potential subsidence of underground workings caused by surface activities.
Acid rock drainage (also known as acid mine drainage) caused by the interception of zones influenced by underground mine pools.
Potential damage to habitat caused or influenced by mine features.
The structural geology and lithology of this area of the Allegheny Plateaus has been amenable to coal and clay mining that began in the 1800's. The intensity of this mining can be easily appreciated by examining the mine permit areas compiled since Pennsylvania started regulating mining in the 1950's. The legacy of problems created by unregulated mining and reclamation can be further understood by examining the inventories of mine related problems established by the Pennsylvania Department of Environmental Protection (formerly Department of Environmental Resources) Bureau of Abandoned Mine Reclamation. The methods required in this preliminary evaluation have involved extensive research of underground mine maps from governmental and private sources. These maps have been entered into a CAD and GIS electronic database for modeling the subsidence potential along the various possible routes through the corridor. These maps are also being used to study the mine hydrology across the many watersheds within the corridor. The location of reported old mine openings are being field viewed for potential habitat openings and wetland habitat formed from mine discharges.
The goal in this preliminary phase has been to determine the extent of mine related impacts along the several possible routes. This information will then be tied into the other environmental and design factors to help to select an optimum route.