HARRISBURG, Pennsylvania Pennsylvania's chief environmental regulator said on Friday he saw no evidence that the chemicals used in the shale gas drilling process known as hydraulic fracturing contaminates underground water supplies.
But John Hanger, the Department of Environmental Protection secretary, told Reuters in an interview that officials have found cases of water contamination caused by spills and leaks of drilling materials on the surface of so-called "fracking" operations during Pennsylvania's current drilling boom.
"It's our experience in Pennsylvania that we have not had one case in which the fluids used to break off the gas from 5,000 to 8,000 feet underground have returned to contaminate ground water," Hanger said.
Hanger's comments echo frequent statements by energy companies that there have been no proven cases of water contamination from hydraulic fracturing, a process used to remove natural gas from shale beds deep underground.
Hanger said the public and the media appear to overestimate the risks of hydraulic fracturing.
"There's a lot of focus in the media and the public on the problems that we have not had," he said during an hour-long interview in his office.
Gas drilling in Pennsylvania, and in particular in the Marcellus Shale Field, which stretches across parts of Pennsylvania, New York, Ohio and West Virginia, has drawn the attention of energy companies due to estimates that the region holds enough gas to meet total U.S. needs for a decade or more.
But attention is also being drawn to the region by groups concerned about possible health risks from the controversial drilling technique used to extract the gas from the shale.