http://www.thetimes-tribune.com/opinion/mussel-study-validates-regulation-1.2402957 > Although well-established and highly active, the deep-drilling natural gas industry in Pennsylvania is just over a decade old. That means that the long-term environmental and public health consequences are not yet fully understood. But a new study by Penn State and Union College researchers, published in the journal Environmental Science and Technology, offers insight into the environmental impact. In 2011 other researchers discovered that water and sediment downstream from treatment plants that had handled fracking wastewater, contained significant amount of chemicals and radioactive minerals even when the wastewater had been treated. The state government asked conventional treatment plants not to accept fracking wastewater and the industry responded responsibly by moving aggressively to recycling the water. Now, the Penn State and Union College researchers say the previous releases of the wastewater have long-lasting effects. They studied freshwater mussel shells taken from the Allegheny River up to 1.2 miles downstream from a treatment plant in Warren County that had handled fracking wastewater between 2008 and 2011. They compared them to shells taken upstream from the plant and to others from the Juniata and Delaware rivers, which had received no discharges from plants treating fracking wastewater. Shells downstream from the Warren County plant showed significantly elevated levels of the radioactive mineral strontium, which did not appear in the shells of the upstream, Juniata and Delaware rivers mussels. Most significantly, the researchers said, is that the amount of strontium in the shells did not decrease significantly after the industry switched to wastewater recycling in 2011, indicating that the river sediment continues to hold substantial amounts of fracking-related pollution, including other heavy metals. “We know that Marcellus development has impacted sediments downstream for tens of kilometers,” said Nathaniel Warner, an assistant professor of environmental engineering at Penn State. “And it appears it still could be impacted for a long period of time. The short timeframe that we permitted the discharge of these wastes might leave a long legacy ... Making the proper choices about how to manage that water is going to be pretty vital.” The researchers plan next to examine whether the impact has spread beyond the mussels, which are part of the food chain that supports fish and mammals such as muskrats. As gas continues to supplant coal as a primary fuel and its markets grow domestically and abroad, government regulators must be aware that the long-term impact does not end with the economic benefits. The study, and other known impacts to date, validate strong regulation.