Researchers at Duke University have published another study on possible impacts of gas drilling on groundwater. This study sampled 127 drinking water wells in Arkansas and found no drilling impact.
In Arkansas, the Duke researchers found little methane in the sampled groundwater, and the methane that they did find was not shale gas in nearly all instances, according to isotopic testing. This is good news.
In Dimock, Pennsylvania, isotopic testing was also used by the Department of Environmental Protection in 2010. There DEP isotopic testing documented that methane had migrated from gas wells, where mistakes were made, to contaminate 18 water wells.
In the press release announcing its Arkansas findings, the Duke team interestingly restates its different findings in Pennsylvania and argues its studies in the two states are not contradictory. Duke suggests different geology in the two states and better industry performance in Arkansas than Pennsylvania explain the differing outcomes.
Methane migration is a real problem. Stopping methane from migrating from gas wells as a result of cementing or other problems to water wells must be a top priority for regulators and gas producers.