Chip Groat, a prominent geologist at the University of Texas, released yesterday preliminary results of a study underway that is examining impacts of drilling and hydraulic fracturing on drinking water and ground water. See http://www.statesman.com/news/local/preliminary-study-says-minimal-imapct-from-fracking-1960103.html. The UT team states that its review of data so far indicates that spills and leaks at the surface are the major source of impacts on water and that the rate of these problems appears greater at shale gas operations than conventional gas drilling sites.
Professor Groat is quoted as saying: "Hydraulic fracturing doesn't seem to be of concern to groundwater."
The UT study will cost $300,000 and is being paid for completely by the University of Texas. Final results from the UT study are expected in the coming months.