GettyA primary claim of the hydraulic fracking industry is that deeply buried rock layers will always seal and contain the dangerous chemicals that are injected thousands of feet underground.
But a new study released in the Proceedings of the National Academy of Sciences concluded that fracking for natural gas under Marcellus Shale in Pennsylvania may lead to harmful gas or liquids flowing upward and contaminating drinking-water supplies.
The study found that salty, mineral-rich fluids deep beneath Pennsylvania's natural gas fields are seeping upward thousands of feet into drinking water supplies. Although it found no evidence of fracking chemicals doing the same, the findings suggest that there are paths that would let hazardous gas or fluids flow up after drilling:
"The biggest implication is the apparent presence of connections from deep underground to the surface," Robert Jackson, a biology professor at Duke University and one of the study's authors, told ProPublica. "It's a suggestion based on good evidence that there are places that may be more at risk."
The study supplements another recent study that used computer modeling to predict how fracking fluids would move over time and found that they could migrate toward drinking water supplies far more quickly than experts have previously predicted.
Critics of the study said that it doesn’t prove that fracking fluids have traveled up to aquifers and argue that gas and water from fracking will flow into the well and not up through fissures that may exist.
Hydraulic fracking is a process in which water, sand and chemicals are injected into deep shale formations to crack the rock and free trapped gas.
The natural gas in Marcellus Shale, which stretches from New York to Tennessee and may hold enough gas to supply the U.S. for three years, has led to permits for more than 11,000 wells. The practice had been an economic boon for Pennsylvania and has helped set decade-low natural gas prices nationwide.
But there is growing evidence of the hazards of fracking. Last year some of the same Duke researchers published findings that methane contamination of drinking water accompanied fracking.
Researchers at the Colorado School of Public Health recently found that air pollution caused by hydraulic fracturing raises the risk of acute and chronic health problems for those living near natural gas drilling sites.
The oil and gas industry doesn't have to publicly disclose most of the chemicals it pumps into the ground, but we know the list contains several carcinogens. Even landfills have begun to reject fracking fluid waste.
The powers that be may know the risk of those chemicals being known as there is a new "doctor gag rule" law in Pennsylvania that provides doctors access to trade-secret chemicals used in natural gas drilling so that they can treat people who have been made sick but prohibits doctors from sharing that information with anyone, even other doctors.
No matter what science concludes, there is no doubt that the fracking industry has a powerful lobby to protect its interests.