A new USGS study reports that shale-gas production in northern Pennsylvania has not currently caused widespread hydrocarbon contamination in the upland aquifer zone used for domestic supply.
The study focused on groundwater in upland settings—high or hilly land—where natural processes are less likely to contribute methane and other hydrocarbons to shallow groundwater. Untreated water samples were collected and analyzed from 35 domestic wells in northeastern Pennsylvania where shale gas is under production, and from 15 domestic wells in southern New York where shale gas is not in production. Methane concentrations in the Pennsylvania wells were not significantly different from those in the New York wells.