Water Treatment and Hydraulic Fracturing (RigZone)

Water Treatment Key to Hydraulic Fracturing's Future

Rigzone Staff

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Tuesday, August 10, 2010

The Marcellus shale gas exploration rush that has washed over Pennsylvania has created concerns over how hydraulic fracturing impacts local water supplies. A single well hydrofracture in the Marcellus may require two million to five million gallons of fracturing fluid, of which 25 percent to 100 percent may be returned to the surface as "flowback" or "produced water." Historically, flowback and produced water has traditionally gone to metals-precipitation plants, where metals and items are removed. The fluid that leaves the plant is clean salt brine, which has gone to sewage treatment plants where the salt is not removed, but diluted with treated sewage and discharged to the rivers. In the past, this was never an environmental concern as the salt levels were very low and did not harm the environment. However, the sharp rise in Marcellus shale drilling in recent years means that the amount of water from shale gas operations being released into state waters would grow from a trickle to a tidal wave. To address the issue of TDS levels in recycled water, the Pennsylvania Independent Regulatory Review Commission on June 17 passed new stringent treatment regulations for the recycling of flowback and produced water in the Marcellus shale. The ruling, which takes effect in January 2011, mandate a maximum of 500 parts per million (ppm) TDS and 250 ppm chlorides in water discharged into the state's water supply. The amount of produced water generated by drilling will likely increase as oil and gas companies continue drilling the Marcellus shale play, which contains an estimated 489 Tcf of gas. READ MORE HERE