EPA probe of fracking contamination includes retrospective

EPA probe of fracking contamination includes retrospective by Don Hopey, Pittsburgh Post-Gazette, August 5, 2011.
The EPA, in a statement released Wednesday evening, also said it has identified several other cases where contamination of drinking water wells allegedly occurred due to nearby gas well “fracking,”…The EPA also noted that, “While it may be difficult to definitively prove a specific link between hydraulic fracturing and drinking water contamination, we know that there are circumstances under which steps in the natural gas extraction process can lead to contamination.” [Emphasis added]