The Pennsylvania Department of Environmental Protection admits that it erred in trying to compile a list of the chemicals used by companies drilling in the Marcellus Shale formation. A DEP spokesman says a list of the chemicals that was given to the Associated Press included not only the chemicals in the water used to frack the shale and release the natural gas....but also other chemicals used at well sites. Spokesman Tom Rathbun says the non-fracking chemicals have other uses including cleaning equipment.
Environmental groups are concerned that the chemically-treated water that flows back and that which remains underground can taint water sources. But DEP officials say they are not aware that this has happened in Pennsylvania. Some of the chemicals are considered to be harmful to humans in large enough amounts.