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.
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.
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.
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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?"
Fracking wastewater contaminated Pennsylvania streambeds, study finds | The Raw Story
See also for a different perspective:
Dangerous levels of radioactivity found at fracking waste site in Pennsylvania: Co-author of study says UK must impose better environmental regulation than US if it pursues shale gas extraction
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