Pennsylvania lies over the heart of the Marcellus Shale formation, a rock unit underlying approximately 65-million acres of land from West Virginia to New York. This formation has been estimated to have a resource value of up to 500-trillion cubic-feet equivalents of natural gas, and has spawned a boom of gas-well drilling in the southwest, northcentral and northeastern portions of the commonwealth. Between January and September, the Pennsylvania Department of Environmental Protection issued 2,514 Marcellus Shale drilling permits, and 1,388 wells were reported as having been drilled.
Litigation related to Marcellus Shale development is similarly on the rise. Claims brought by private litigants focus on claimed impacts from well drilling and related activities, including hydraulic fracturing, referred to colloquially as “fracing” or “fracking.” Hydraulic fracturing, in combination with horizontal drilling techniques, enables the extraction of natural gas trapped in shale rock through the use of large amounts of pressurized fluids, consisting primarily of water and sand with limited amounts of chemical additives, to induce small fractures to form in the rock surrounding the well casing within the Marcellus Shale formation. Those fractures, in turn, allow the natural gas in the shale to pass into the well casing and be captured. For wells tapping the Marcellus Shale formation in Pennsylvania, the hydraulic fracturing process is focused on shale that is typically at a depth of between 5,000 and 8,000 feet below the ground surface.
