USEPA's study of the potential impacts of hydraulic fracturing for oil and gas on drinking water resources

“There was no reported sampling of soil or ground water to determine whether or not chemicals migrated into the soil.” (p. 5-69) “The lack of information regarding the composition of chemical additives and fracturing fluids, containment and mitigation measures in use, and the fate and transport of spilled fluids greatly limits our ability to assess potential impacts to drinking water resources.” (p. 5-73)