The Hydrogeology of an Old Growth Forest with Implications for Defining Impact Zones Associated with Underground Mining

Dysart Woods is a predominantly oak and hickory old-growth forest that was given to Ohio University by The Nature Conservancy for research and public use.  Dysart Woods is being undermined via longwall and room-and-pillar mining methods.  Buffer zones based upon the angle of influence have been placed around Dysart Woods to protect it from the influence of underground mining.  While this concept is sufficient for architectural structures it was not designed to prevent changes in hydrogeologic properties (i.e., recharge, residence time, etc.) that typically accompany underground mining.  The minimum lateral distance of the buffer along the boundary of Dysart Woods is 300 ft.  Longwall mining has occurred east of Dysart Woods with panels that extend in an east/west orientation and propagate southward.   A room-and-pillar section is currently being mined from southeast to northwest, crossing underneath Dysart Woods to the western boundary of the buffer zone where longwall mining will resume.  The purpose of the proposed work is to assess hydrogeologic impacts in a watershed context beyond the recharge area delineated by a buffer zone that has been determined by the angle of influence.   This will be achieved by hydrogeological field data to construct an appropriate physical and hydrogeological model of pre- and post-mining conditions, modeling of the system using the program MODFLOW, and evaluating pre- and post-mining groundwater residence times.  The final objective is to determine the evolution of the water table with time.  It is assumed the data will show that hydrogeologic properties were altered within the current proposed no-impact zone based on the current buffer zone.  This may result in new considerations for underground mining regulations when preserving ecosystems, in particular, extending the zone of impact to be defined on the basis of watershed-scale hydrology for recharge as opposed to buffer zones based on the angle of influence.