Fracking waste water contaminated Pennsylvania streambeds, study finds (+video)
Outflow from a treatment facility that handles fracking waste in Pennsylvania left radioactive hot spots and elevated levels of contaminants in sediment near and downstream from a discharge pipe, the study found.
Despite being treated, waste water from fracking and other forms of gas and oil extraction can leave elevated levels of contaminants in streambeds at the point they are discharged and well downstream, according to a study published Wednesday.Skip to next paragraph
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Among the potentially harmful effects of the waste-water discharges, the study found, is the creation of radioactive hot spots from naturally occurring radium that settles out of the treated water and into streambed sediments.
The study, which tracked contaminants once they become part of a stream's flow, examined the outflow from a waste water-treatment facility on Blacklick Creek in western Pennsylvania and its effects on the creek's water and bottom sediments.
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The facility is one of three in the region involved in a settlement with the US Environmental Protection Agency (EPA) in May that resulted in a $83,000 penalty for the owner, Fluid Recovery Services, LLC, for violating provisions of its water-treatment discharge permit.
Researchers from the University of Pittsburgh's Graduate School of Public Health found high levels of barium, benzene, chlorides, strontium, and other contaminants at the end of the outflow pipe in excess of state and federal water-quality standards.
They presented their results at an EPA workshop on the fate and transport of waste water from fracking in March 2011 and formally published their results last March in the journal Environmental Science and Technology.
Four months after the EPA workshop, Pennsylvania's Department of Environmental Protection collected sediment samples from inside the discharge pipe at the site and found radium-226 levels some 44 times higher than drinking-water standards allow. Several tens of yards downstream, levels were 66 times higher than standards allow. Radium-226 has a half-life of 1,600 years.
Fracking, or hydraulic fracturing, involves pumping liquids at high pressure into underground rock formations to break up the rock and get at oil or gas deposits that otherwise would be uneconomical to exploit.
The northeastern quadrant of the United States has become a hotbed of production using this technique, with the activity centered largely on the Marcellus Shale deposits buried beneath New York, Pennsylvania, Ohio, and West Virginia.
The extraction industry in Pennsylvania reused some 70 percent of its waste water in 2011, notes the new study, conducted by Nathaniel Warner, a postdoctoral fellow at Dartmouth University, Duke University geochemist Avner Vengosh, and two other colleagues.
They note, however, that depending on the contents of the waste water – brines that flow back up from depth, or drilling fluids, for example – between 8 and 20 percent of the waste is delivered to treatment plants, with the outflow entering local streams. The remainder of the waste is disposed of using other approaches, such as deep-well injection.
The question the team was trying to help address: "What's the larger, overall impact of all this new shale-gas development," Dr. Warner says. "We looked at interactions with shallow ground water and didn't find major impacts. But what happens with surface-water disposal?"