“Our results show no discernible impairment of groundwater quality in areas associated with natural gas drilling and hydraulic fracturing in this region,” began professor Avner Vengosh, of Duke’s Nicholas School of the Environment. The study, jointly undertaken by Duke University and the United States Geological Survey, specifically involved testing of 127 shallow drinking water wells in the Fayettevill Shale. The scientists were looking for elements of hydrocarbons and other trace elements. They ultimately found very low concentrations of methane in the water which did not match the isotopic fingerprint of the methane they had taken from gas samples. This finding lead the scientists to conclude that the methane in the water was caused by biological activity in the shallow aquifers, not fracking.
Only a fraction of the groundwater samples we collected contained dissolved methane, mostly in low concentrations, and the isotopic fingerprint of the carbon in the methane in our samples was different from the carbon in deep shale gas in all but two cases.
The findings are very important for shale gas development, particularly in North Carolina where the state is considering the issuance of fracking permits in the next two years.