The purpose of this study is to investigate the susceptibilitycharacteristics of domestic and agricultural water supplies that maybe vulnerable to diminution or total loss of supply when activelongwall mining is in the vicinity of the potable aquifer systems ofsouthwestern Pennsylvania. The study focuses on water supplies inGreene and Washington Counties with reported losses or reductionsin supply that were attributed to the seven active longwall minesin operation between 2003 and 2008. The undermined watersupplies represent a variety of hydrogeological settings and miningconditions prevalent in the southwestern Pennsylvania longwallcoalfield. The susceptibility characteristics investigated includehydrogeological setting, proximal location to mining, and climaticconditions at the time of impact. The investigation considersthe relationship between geological and mining characteristics.Geological characteristics include overburden composition andgeomorphology of the surface; mining characteristics includemining method, depth, and extraction thickness.It was determined from the study that the average overburdenthickness at each mine site is indicative of hydrological changes topotable aquifer systems, with the overall impact frequency at eachsite decreasing as depth to mining increases. However, depth tomining was not the governing factor when hydrological responseswere determined on a case-by-case basis. To fully analyze andhopefully predict potential impacts by longwall mine subsidence,it is necessary to consider additional factors including topography,distance to mining, mining method, and climatic conditions at timeof undermining. The investigation serves the purpose of enhancingour understanding of hydrogeological responses to longwallmining and will aid in predicting potential impacts to southwesternPennsylvania’s wells and springs in proximity to future mining.
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