EFFECTS OF COAL MINING ON PERCHED AQUIFERS ABOVE ACTIVE LONGWALL AND ROOM-AND-PILLAR MINES NEAR DYSART WOODS

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 mined via longwall mining methods, with panels extending in an east/west orientation and propagating southward. The environmental impact of mining in this old forest has been a debate topic during the last few years. The purpose of the proposed work is to test the impact of mining on hydraulic properties of shallow perched aquifers within and near Dysart Woods. Hydraulic conductivities and water-table decay constants of pre- and post-mining events were analyzed using a t-test of equality of two sample means for samples with unequal variances. Results show that with 95% confidence the mean value of the population of post-mining water table decay constants for shallow and intermediate depth wells in the overburden above a longwall panel is significantly greater than the pre-mining decay constants. Hydraulic conductivities in the same wells show increases of an order of magnitude, but the results should be confirmed with additional research because of the small number of measurements of hydraulic conductivity (n=1, for each well) prior to the undermining on October 3rd, 2005. These findings suggest that underground mining can disrupt shallow groundwater systems and local perched aquifer systems on hilltops.