WASHINGTON, D.C. — New research is providing some of the first scientific evidence that a controversial gas drilling technique can contaminate drinking water.
Higher concentrations of methane gas were found in water from wells near drilling sites in Pennsylvania. But there was no trace of the chemicals used in the process.
An industry group says the research doesn’t prove the technique called hydraulic fracturing or fracking is to blame for the methane levels. Methane is not known to be toxic, but in high concentrations it can be explosive and dangerous.
Gas drilling has expanded in Pennsylvania and other states where shale formations hold lots of natural gas. To get it, companies inject water and chemicals underground.
The study was published Monday in the Proceedings of the National Academy of Sciences.