A new study questions whether hydraulic fracturing chemicals could migrate into drinking water supplies faster than some experts believe, but several scientists have said the study is based on faulty assumptions, according to a ProPublica story.
The study, which was published in the journal Ground Water last month, uses computer modeling to conclude that natural faults and fractures caused by the fracking process could allow chemicals to reach the surface in a few years, according to the news story.
The study did not sample ground water to assess the contamination risks or confirm its conclusions. Rather, the study is based on computer models that forecast how fracking fluids migrate over time.
The energy industry has staunchly defended fracking, claiming the process has been done safely for years without contaminating ground water. The industry has based its defense around an idea that chemicals are safely locked under nearly a mile of impermeable rock.
This latest study, which was paid for by two upstate New York organizations that oppose gas drilling, questions whether the layer of rock is as impermeable as the industry believes, according to ProPublica.
“Simply put, [the rock layers] are not impermeable,” author Tom Myers, a hydrogeologist who has worked with the federal government and environmental groups, told ProPublica. “The Marcellus shale is being fracked into a very high permeability. Fluids could move from most any injection process.”
Myers added that the permeability might be higher in other shale plays, including those in Arkansas and northeast Texas.
Scientists, however, have already begun to question Myers’ conclusions.
Terry Engelder, a professor of geoscience at Penn State University, told ProPublica that the study’s conclusions are unsophisticated and based on fault assumptions about the Marcellus Shale.
If the conclusions were true, he said fracking wouldn’t be necessary to unlock trapped natural gas.
“This would be a huge fracture porosity,” Engelder said. “So I read this and I say, ‘Golly, does this guy really understand anything about what these shales look like?’ The concern then arises from using a model rather than observations.”