Factors Influencing the Effects of Underground Bituminous Coal Mining on Water Resources in Western Pennsylvania

Coal mining in Pennsylvania has been fundamental to the commonwealth’s economy for over 150 years. Since that time, over 1.2 million acres of bituminous coal have been mined using underground mining methods. Pennsylvania is also estimated to have over one million domestic water wells over its 29 million acres area. From 2003 to 2008, 2,789 water supplies were undermined with about 24.5% having reported impacts. However, not all reported impacts are related to mining. The effects of underground coal mining on the utility of these wells and other water resources have only been studied systematically within the past 20 years and are still not completely understood.\ud Pennsylvania amended its Bituminous Mine Subsidence and Land Conservation Act (Act 54) in 1994. The amended act requires that a report be submitted every five years that assesses the impacts on water resources and structures due to underground coal mining. Well and spring effects can be classified into two categories: water loss (diminution or total loss of water) and water contamination (reduced quality, increased metals, gas, etc.). Once these types of effects are identified, they are analyzed to determine the relationship between underground coal mining and water resource quality and quantity.\ud This study investigates the factors associated with water loss and water contamination due to underground coal mining. The study area includes all underground bituminous coal mining activity in Pennsylvania from August 21, 2008 to August 20, 2013. The area encompasses 10 counties in western Pennsylvania providing a diverse sample of water resource data, mining methods, and local conditions. Mining activity was conducted by 6 companies with a total of 7 longwall mines and 39 room-and-pillar mines. Factors include mining method, mining depth, proximity to mining, hydrogeological setting, topographical setting, climate, and more. A statistical analysis of these factors is used to determine the most important factors driving water resource impacts. Greater study is then conducted on the most significant factors using geographic information systems (GIS) and modeling software to better understand how effects are caused and how they can be mitigated or eliminated.\u