When a well is no longer producing commercial quantities of oil or natural gas, a company abandons
the well. Abandoning a well properly involves removing some of the casing and other surface equipment, plugging the well with cement so that it is no longer a conduit for fluids migrating from beneath the surface,
and then reclaiming the surface. If wells are improperly abandoned, they can act as a connection between the
surface and the depth of the well. In most cases, improperly abandoned wells are older and relatively shallow,
but when the Marcellus Shale is being exploited at shallower depths, like in central NY, improperly abandoned
wells could potentially connect a fracture network to a groundwater source. Improperly abandoned wells
were considered when the DEC suggested that stimulation of Marcellus Shale should be at least 3,000 feet
beneath the surface to sufficiently decrease risk of contamination of potential groundwater sources.