The U.S. Environmental Protection Agency (USEPA) recently sampled 20 domestic wells in Dimock, Pennsylvania, where some residents believe natural gas drilling has contaminated their domestic wells. The USEPA reported that the water quality imposed no immediate health risk for the residents. In a different study last fall, however, the USEPA did link fracking with water quality contamination in Pavilion, Wyoming. In those samples they detected benzene and methane, components of natural gas, as well as synthetic chemicals such as glycols and alcohols "consistent with gas production and hydraulic fracturing fluids."

While the USEPA did not detect any contaminants above their drinking water standards in the Pennsylvania samples, there were elevated levels of methane in many of them, which may be indicative of release of natural gas due to fracking, but not necessarily. Methane is not uncommon in groundwater. For example, many wells in the Mahomet Aquifer and overlying aquifers have significant amounts of methane, produced by the fermentation of buried organic matter.

Fracking as yet is not a major concern in Illinois, because we generally don’t have the geologic formations conducive to fracking. The New Albany Shale, found in southeastern Illinois, is the most likely candidate, but the formation in Illinois has a low thermal maturity, which limits its potential (it has larger potential in Indiana). Nonetheless, speculators have apparently bought up a number of leases in Wayne County in anticipation.

One concern not always realized by the public is the tremendous amount of water needed for fracking operations. Southeastern Illinois has limited water availability, which may prevent any large-scale fracking operations in that region. The Illinois Department of Natural Resources currently does not have any permitting authority with respect to fracking.