"No single source of criticism of hydraulic fracturing is more pronounced than the claim that it pollutes groundwater. “Fracking,” according to the Sierra Club, is “known to contaminate drinking water.” Food & Water Watch says hydraulic fracturing “threatens the air we breathe, the water we drink, the communities we love and the climate on which we all depend.” The Center for Biological Diversity begins its litany of criticisms of hydraulic fracturing with: “Contaminated water.” In his FAQ page, Gasland director Josh Fox says water contamination from fracking is “very serious.”
But when these same critics are asked to prove the claim, the evidence is far more elusive than their statements would suggest. At a major Senate hearing earlier this year, representatives from both the Sierra Club and the Natural Resources Defense Council, when pressed by Sen. Mary Landrieu (D-La.), could not name a single confirmed case of hydraulic fracturing contaminating groundwater.
Experts and regulators, meanwhile, have stated time and again that there is little to no evidence of “fracking” ever contaminating groundwater:"...
