A three-year, $1 million study is underway to develop new ways to deal with the wastewater as a result of
drilling. Carnegie Mellon
's Kelvin Gregory and University of Pittsburgh engineering professors Radisav Vidic and Eric Beckman received a grant from the state Department of Energy to evaluate a "holistic approach" for the treatment of flowback water. Pitt is the lead on the study.
One solution may be to use acid mine drainage water to remove toxic metals from the water and enable the reuse of hydrofracturing fluid, says Gregory, assistant professor of civil and environmental engineering, who spoke on the work as part of the MIT Pittsburgh Enterprise Forum on shale last week.
Drilling uses a tremendous amount of water, an estimated three to five million gallons per well. While some companies are committed to recycling the flowback, there is no consensus on the best way to go about it. Concerns abound regarding the risk of potentially toxic chemicals flowing into the water table as a result of gas drilling.
"We're looking for sustainable modern management solutions," says Gregory. "Not a specific treatment, but a holistic approach from fresh water withdrawl to disposal that minimizes volumes of water at both ends. We need to develop a system to minimize the disposal costs for gas producers and make water safe for all users."
How many times water can be recycled through the system and water storage methods that would reduce trucking traffic are also being reviewed.
The ability to reuse flowback water is different on a site by site basis because each area of the Marcellus has a slightly different composition, which makes the study challenging, says Gregory. Researchers are partnering with drilling companies to take samples from drilling sites.
"There is no way this water can go into publicly owned waste water treatment plants," says Gregory. "And there's no way we can keep diluting water into our rivers and streams. We don't have deep well injection sites in the state. Minimizing risks is a goal that everyone would like to see."
Writer: Debra Diamond Smit
Source: Kelvin Gregory, Carnegie Mellon UniversityImage of Kelvin Gregory courtesy of Carnegie Mellon
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