A study from Duke University for the first time makes a link between water contamination and drilling for natural gas. The study, published Proceedings of the Natural Academy of Sciences, will probably fuel the debate over the safety of tapping Pennsylvania’s abundant natural gas reserves.
One of the most talked-about scenes in the documentary “Gasland” occurs when a resident of Dimock, Pa., sets his tap water on fire. Critics of natural gas drilling connect that impromptu torch with nearby gas wells, which they say cause methane to leak into underground water supplies.
The Duke study seems to confirm that belief.
But the industry group Energy in Depth says the study sample is too small. Spokesman Chris Tucker said that, when he was a kid growing up in Northeast Pennsylvania, he and others had always been able to set their tap water on fire. He said methane is a common component of well water in that area.
“Of course now, you try to light your faucet on fire, you’re gonna blame the oil and gas activity even though you could have done it 50 years ago,” said Tucker. “But why would you have even bothered doing something like that, it would be silly.”
Tucker does have a point–the study did not have test results for the water before gas drilling began. So, he said, there’s still no smoking gun.
Duke University professor Avner Vengosh, a study author, said water wells contaminated with high levels of methane could be traced to the deep gas reserve known as the Marcellus Shale. Previously, he said, methane leaked into water wells through shallow deposits.
“Sure we found methane in almost all wells that we collected. But we found different types of methane in wells located next to the gas well relative to the methane we found away from gas wells. They are different concentrations … so to say, “Oh yes, there is methane all over the place’ is really not accurate.”
Vengosh said the health impacts of drinking water with high levels of methane are unclear. He said he was surprised not to find any studies on the subject.
The study did not find the water wells contaminated with any of the chemical components used in the drilling process.