"A Tainted Water Well, and Concern There May Be More"

Oil and gas executives have long claimed that there is no case in which hydraulic fracturing has contaminated a drinking water aquifer. But such a case exists. And one of the biggest bars to enumerating suspected additional cases is the oil and gas industry's refusal to allow disclosure of them -- a condition of court settlements with landowners.

Ian Urbina reports for the New York Times August 3, 2011.