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Water securityTreated fracking wastewater may pollute Pennsylvania water sources for years

Published 20 July 2017

Given Pennsylvania’s abundant natural resources, it’s no surprise that the Commonwealth has become a mecca for hydraulic fracturing. Researchers, however, have recently discovered that releasing millions of gallons of treated hydraulic fracturing wastewater each year into area surface waters may have longer-lasting effects than originally thought.

Given Pennsylvania’s abundant natural resources, it’s no surprise that the Commonwealth has become a mecca for hydraulic fracturing. Researchers, however, have recently discovered that releasing millions of gallons of treated hydraulic fracturing wastewater each year into area surface waters may have longer-lasting effects than originally thought.

According to the U.S. Energy Information Administration, hydraulic fracturing accounted for more than one-half of U.S. oil production and two-thirds of U.S. gas production in 2015. That percentage is expected to rise as more states begin to adopt the practice. Although studies show that hydraulic fracturing does produce less greenhouse emissions than older technologies like coal, it does come with other environmental concerns. At the top of that list is the wastewater it produces, which contains a multitude of potentially hazardous contaminants. In 2015 alone, Pennsylvania’s unconventional gas wells produced nearly 1.7 billion gallons of wastewater. While there are facilities dedicated to treating the wastewater before its release, they provide only limited treatment, leaving many of the pollutants intact.

PSU says that to gain a better understanding of the impact of these contaminants on the environment, Penn State environmental engineering professor Bill Burgos and his colleagues studied sediment samples collected from a reservoir in western Pennsylvania. The study was published in the most recent issue of Environmental Science & Technology

“There wasn’t a water keeper who was sitting in these rivers collecting these samples at a great continuous clip, so in a way, a lot of information just flowed by,” Burgos said. “But in certain reservoirs, where sediments collect over time, there are layers of sediment that are like rings of a tree; you can look into the sediments and capture time and spatially composite samples.”

The objective of the study was to use the sediments that had built up to reconstruct the industrial oil and gas activity that was happening during the boom of the Marcellus Shale development in Pennsylvania, from roughly 2008 to 2015, in order to gain a better understanding of the historical impact of oil and gas wastewater disposal.

“You need a lake or a reservoir that allows sediments to lay down undisturbed in those layers,” said Burgos. “The words we use are a ‘coherent temporal record.’ You only get a coherent temporal record if it’s a lake that continuously accumulates sediments and isn’t subject to a flood or scour.”