The shale gas boom has been a rare bright spot in the U.S. economy, so much of the country let out a shudder two weeks ago when the Environmental Protection Agency issued a "draft" report that the drilling process of hydraulic fracturing may have contaminated ground water in Pavillion, Wyoming. The good news is that the study is neither definitive nor applicable to the rest of the country.

"When considered together with other lines of evidence, the data indicates likely impact to ground water that...