A Duke University study exonerates hydraulic fracturing from contaminating drinking water at sites in Pennsylvania and Texas. Instead, researchers blame faulty shale gas wells for leaking methane into the water, sometimes making it flammable.
The study was published in the Proceedings of the National Academy of Sciences this week. It's the latest article in ongoing research on the implications of fracking for natural gas. New data and isotopic evidence confirms that leaking wells are directing methane into the drinking water.
Duke University environmental sciences professor Robert Jackson is a co-author of the study. He said the study is significant because it confirms that some drinking water wells were indeed contaminated by the gas wells, but also because researchers could trace the contamination to cracks and leaks.
Jackson said the energy industry has always been careful to speak about the safety of fracking, which is, specifically, the process of breaking rock to release gas. They don't say as much about related processes, like drilling. But most people don't make that distinction.
“For people whose water has been contaminated, they don't care what step in the process has caused it,” Jackson said. “All they know is that they can't use their water.”
Jackson says companies should be more concerned with maintaining pipes and cement foundations in the top 500 feet of the surface, and worry less about what happens thousands of feet below.
But Duke water quality and geochemistry professor, and co-author, Avner Vengosh said this means companies can repair their wells and stop the leaks.
He also said North Carolina should take note, as it begins to allow companies to explore for natural gas.
“We can do some prevention, some cautious measure to prevent possible contamination,” said Vengosh. “For example, building a safety zone between the shale gas sites and the drinking water well.”
Vengosh says this doesn't mean there are no other environmental implications for fracking: Drilling and wastewater management at the sites present their own risks.