A new study released this week by Duke University researchers seems to excuse fracking from at least one groundwater hazard in Pennsylvania.
The report, issued by researchers in Duke's Nicholas School of the Environment, indicated "natural pathways" in drill-heavy northeastern Pennsylvania could be to blame for elevated levels of underground salts and gases in the region's drinking water.
According to the Duke study, researchers found higher levels of salt content with similar geochemistry to Marcellus brine in drinking water samples, although there seemed to be "no direct links between the salinity and shale gas exploration in the region."
The higher salinity can pose drinking water hazards in cases where the water was found to have elevated barium levels.
Avner Vengosh, a professor of geochemistry and water quality at the Nicholas School who co-authored this week's report, said Marcellus brine contains high levels of metals and naturally-occurring radioactivity.
The report seems a very modest victory for backers of fracking, the controversial drilling technique in which gas companies inject pressurized chemical stews underground to break loose shale-trapped natural gas.
Questions remain about the long-term environmental and health impacts of the drilling, which has been dogged by widespread reports of water pollution and increased seismic activity in drilling states. Two weeks ago, fracking was cleared to begin as soon as 2014 in North Carolina thanks to a veto override in the N.C. General Assembly that never should have happened.
Duke's newest study comes more than a year after university scientists reported methane levels 17 times higher in wells near fracking sites in northeastern Pennsylvania and New York. The long-term health impacts of drinking methane are unknown at this point, although the gas is explosive in high concentrations.
Last year's study was met with expected criticism from fracking backers who argued the Duke report did not support its findings. Vengosh told the Indy Thursday that the gripes didn't affect the continuing research.
"We are not supported by the industry, so we are totally free in terms of our data and interpretation," he said. "It was amusing, but it has nothing to do with the research direction or interpretation. It seems like everyone is taking what they want to see from these studies."
Vengosh said the school's researchers plan to delve into additional components related to fracking, venturing outside of northeast drilling zones and into southeast states like Arkansas. University scientists are also gathering baseline water quality data in likely drilling sites in North Carolina.