Webinar to address wastewater challenges in Marcellus shale drilling

October 21, 2009
University Park, Pa. -- One million gallons is a lot of water. When Marcellus shale gas drillers probe for natural gas using the hydrofracture technique, they inject about three million gallons of water underground. Typically, about 30 to 40 percent of the injected water -- or about 1 million gallons -- returns quickly to the surface at the wellhead. This wastewater, known as "flowback," carries large amounts of dissolved solids and high concentrations of salt and must be treated before it is returned to surface-water sources.
What to do with this wastewater is the subject of an upcoming online seminar from Penn State Cooperative Extension. "Treatment/Disposal Options for Wastewaters from Shale Gas Drilling" will be webcast at 1 p.m. on Oct. 28. The "webinar" is free and open to the public. Instructions for pre-registration are available at http://naturalgas.extension.psu.edu/Events.htm.
"It's a pretty huge topic right now," said Joann Kowalski, economic and community development extension educator in Susquehanna County. "There is going to be a lot of wastewater produced, and there are not many places to take it right now."
The three main challenges with this wastewater, according to Bryan Swistock, Penn State water resources extension specialist, are the large volume of water involved, the high concentrations of impurities in the water and the difficulty in treating them. In addition, these waste fluids may vary greatly from site to site, so there is no single waste-treatment protocol that fits all sites.
State water-quality regulations are changing, said Swistock, and they require the discharge to be cleaner than previously mandated. However, few places in the state have the capacity to handle that much wastewater. Much of the drilling activity, particularly in the northeast part of the state, is far removed from water treatment infrastructures. Smaller nearby sewage treatment plants simply can't handle the volume or the pollutants, he said.
Without suitable local options, some wastewater must be transported long distances by truck or train, which can greatly increase the cost of treatment, Swistock explained.
"It's slowing the process down," said Swistock. "They have nowhere to send the fluid, so they have to reuse and recycle it." Many drilling operations are reusing the flowback and diluting it with fresh water to use on the next drilling site. Swistock said it remains to be seen if reuse and recycling can be an effective long-term strategy to deal with these waste fluids.
The water forced into subterranean pockets as part of the drilling process dissolves many chemicals out of the rock, causing the water to become impure, Swistock said. These impurities may include large amounts of iron, calcium, magnesium, strontium and barium, and small amounts of arsenic and lead. There also are enormous amounts of sodium and chloride as water comes in contact chemicals left behind by ancient sea water.
Kowalski encouraged webcast viewing for any interested party -- residents, community officials, firms that build new treatment plants or officials involved with granting land-use permits. She noted that there will be an interactive portion during the live program when participants may type in questions for the presenters to answer. "It’s valuable for people to get up-to-date, research-based information right at their computers," she said. "It's easy, and there's no cost."
For more information on the webinar, contact Kowalski at 570-278-1158 or by e-mail at jmk20@psu.edu.

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Last Updated October 26, 2009