High levels of radioactivity and salinity have been found in river water and sediments near a wastewater discharge site connected to a fracking operation in Pennsylvania. 
 
 A Duke University-led team of researchers collected sediment and water samples from a creek in western Pennsylvania where treated fracking wastewater is discharged. Fracking, or hydraulic fracturing, is a controversial method of natural gas extraction from shale deposits achieved by mixing water with sand and chemicals and injecting it into bedrock at high pressures. The process enables a level of natural gas extraction previously unattainable, but opponents decry the practice as a pollutant to groundwater. 
 
 Samples collected near where the Josephine Brine Treatment Facility discharges into Blacklick Creek were found with raduim levels 200 times greater than in samples collected just upstream from the treatment plant. 
 
 The researchers determined that some of the discharged water is flowback from the expansive Marcellus shale deposit, which is naturally high in salinity and radioactivity. The fracking wastewater is treated before it's released into the waterways, but the researchers say the treatment does not remove all unwanted matter. 
 
 "The treatment removes a substantial portion of the radioactivity, but it does not remove many of the other salts, including bromide," said Avner Vengosh, a geochemist at Duke. "When the high-bromide effluents are discharged to the stream, it increases the concentrations of bromide above the original background levels. This is significant because bromide increases the risks for formation of highly toxic disinfection byproducts in drinking water treatment facilities that are located downstream." 
 
 Robert Jackson, professor of environmental science at Duke, highlighted some causes of concern connected with the wastewater discharge. 
 
 "The radioactivity levels we found in sediments near the outflow are above management regulations in the U.S. and would only be accepted at a licensed radioactive disposal facility," he said. "The facility is quite effective in removing metals such as barium from the water, but it concentrates sulfates, chlorides and bromides. In fact this single facility contributes four-fifths of the total downstream chloride flow at this point." 
 
 Vengosh said that even though the treatment facility does a good job reducing barium levels is the wastewater, "the amount of radioactivity that has accumulated in the river sediments still exceeds thresholds for safe disposal of radioactive materials." 
 
 "Years of disposal of oil and gas wastewater with high radioactivity has created potential environmental risks for thousands of years to come," he said, adding that his team's study makes a clear case for the more adequate treatment of fracking wastewater. 
 
 "This could be a long-term legacy of radioactivity," said researcher Nathaniel Warner. 
 
 The researchers' work is published in the journal Environmental Science & Technology. 

 Hydraulic fracturing, or fracking, extracts oil and gas from deep underground by injecting water into the ground and breaking the rocks in which the valuable hydrocarbons are trapped. But it also produces wastewater high in certain contaminants — and which may be radioactive. 
 
 In a study published today (Oct. 2) in the journal Environmental Science and Technology, researchers found high levels of radioactivity, salts and metals in the water and sediments downstream from a fracking wastewater plant on Blacklick Creek in western Pennsylvania. 
 
 Among the most alarming findings was that downstream river sediments contain 200 times more radium than mud that's naturally present upstream of the plant, said Avner Vengosh, a co-author of the study and a professor of geochemistry and water quality at Duke University. Radium is a radioactive metal naturally found in many rocks; long-term exposure to large amounts of radium can cause adverse health effects and even diseases like leukemia. [5 Everyday Things that Are Radioactive] 
 
 Contaminated waters 
 
 The concentrations of radium Vengosh and his team detected are higher than those found in some radioactive waste dumps, and exceed the minimum threshold the federal government uses to qualify a disposal site as a radioactive dump site, Vengosh told LiveScience. While the Josephine Brine Treatment Facility removes some of the radium from the wastewater, the metal accumulates in the sediment, at dangerously high levels, he added. Radium can make its way into the food chain by first accumulating in insects and small animals, and then moving on to larger animals, like fish, when they consume the insects and smaller animals, Vengosh added. But it's not known to what extent this is happening, since this study didn't address that question, he said. 
 
 For two years, the team monitored sediments and river water above and below the treatment plant, as well as the discharge coming directly from the plant, for various contaminants and levels of radioactivity. In the discharge and downstream water, researchers found high levels of chloride, sulfate and bromide. 
 
 Levels of salinity in the plant's discharge were up to 200 times higher than what is allowed under the Clean Water Act — and 10 times saltier than ocean water, Vengosh said. But fracking wastewater is exempt from that law, Vengosh said. 
 
 Plants that treat oil and gas wastewater are shown in red. The Josephine water treatment plant is shown in black. Credit: Warner et al / Environmental Science and Technology 
 
 The high bromide concentrations that were found were particularly concerning, since bromide can react with chlorine and ozone — which is used to disinfect river water and produce drinking water — to yield highly toxic byproducts. But there's no direct evidence that this has happened yet, Vengosh said. 
 
 Several of these contaminants, particularly radium and bromide, may be present in high enough concentrations to cause harm to human health and the environment, but that wasn't addressed in this study, Vengosh said. 
 
 'Alarming' 
 
 "The occurrence of radium is alarming — this is a radioactive constituent that is likely to increase rates of genetic mutation" and poses "a significant radioactive health hazard for humans," said William Schlesinger, a researcher and president of the Cary Institute of Ecosystem Studies, in Millbrook, N.Y., who wasn't involved in the study. 
 
 Researchers say they are sure the contaminants are coming from fracking because the Josephine facility treats this oil and gas wastewater, and the water contains the same chemical signature as rocks in the Marcellus Shale Formation, Vengosh said. This wastewater is often called "flowback," as it's the water that flows back to the surface from underground after being injected into rocks in the fracking process. 
 
 In Pennsylvania, some of this water is transported by oil and gas companies to treatment locations like the Josephine facility, where it is processed and released into streams and rivers. However, much of the water used in fracking is treated by oil and gas companies and reused, or injected into deep wells, said Lisa Kasianowitz, an information specialist at the Pennsylvania Department of Environmental Protection (DEP). 
 
 The treatment facility did remove some contaminants, including some of the radium, though enough made it through to accumulate in high levels in sediments, Vengosh said. It also "did nothing" to remove certain salts, like bromide, he said. Traditional wastewater plants are not built to remove these contaminants, he added. 
 
 The study "really seals the verdict that it's flowback waters that are contaminating the streams," Schlesinger told LiveScience. 
 
 The Pennsylvania DEP confirmed that the Josephine facility is accepting and discharging "conventional oil and gas wastewater in accordance with all applicable laws and regulations," Kasianowitz said. 
 
 Vengosh said that the research suggests that similar contamination may be happening in other locations with discharge of fracking wastewater throughout the Marcellus Shale formation, which underlies parts of Pennsylvania, New York and Ohio. 
 
 Email Douglas Main or follow him on Twitter or Google+. Follow us @livescience, Facebookor Google+. Article originally on LiveScience.
– Add this to ongoing debate about the merits and potential dangers of fracking: A Duke study uncovered high levels of radioactivity in water and sediment downstream from a fracking treatment plant in Pennsylvania, reports LiveScience. The researchers discovered the unexpected levels of radium in a creek near the Josephine Brine Treatment Facility. While radium is a naturally occurring radioactive metal, levels were 200 times higher than those found upstream of the plant, reports USA Today. "We were surprised by the magnitude of radioactivity," says a co-author of the study published in Environmental Science & Technology. He called for more such sites to be investigated. Wastewater treatment plants can remove most of the radioactivity but not all, say the researchers, who traced the water in their study back to the state's large Marcellus Shale Formation. (Click to read about a Department of Energy study from earlier this year that found no dangers to drinking water near fracking sites. The fracking boom, meanwhile, is helping the US overtake Russia as the world's largest energy producer.)