Webinar to address recycling wastewater from gas drilling

February 09, 2010

The calls to "reduce, reuse and recycle" have long been the watchwords of resource conservation, and when it comes to disposing of wastewater from shale-gas operations, those refrains still run deep, sometimes thousands of feet beneath groundwater sources.

"Our primary goal is to protect drinking water," said Karen Johnson, chief of the ground water and enforcement branch in the water protection division of the U.S. Environmental Protection Agency. "The Underground Injection Control Program, under the Safe Drinking Water Act, requires protecting underground sources of drinking water, used for both private and public wells."

Johnson, who has worked in the ground water and water quality protection programs for the entire 30-year history of the EPA's injection well program, will be the featured expert in a free, Web-based seminar titled "Underground Injection Wells as an Option for Disposal of Shale Gas Wastewaters: Policies and Practicality," which will take place at 1 p.m. on Feb. 18.

Sponsored by Penn State Cooperative Extension, the "webinar" will provide an overview of Safe Drinking Water Act legislation, oil and gas injection well history, and strategies to deal with large volumes of wastewater generated by resource extraction processes.

Fuel extraction, either from oil wells or natural-gas wells, produces huge amounts of wastewater, the disposal of which is overseen by federal and state law, according to Johnson. Disposing of wastewater to surface waters is regulated under the Clean Water Act, which mandates which impurities are removed in publicly-owned treatment plants and industrial discharges prior to returning wastewater to surface water sources.

Disposal of wastewaters to subsurface geologic formations is regulated under the Safe Drinking Water Act, overseen by Johnson's EPA Region III office which covers Pennsylvania, West Virginia, Virginia, Maryland, Delaware and the District of Columbia.

Pennsylvania had the first oil production wells in the country, drilled more than 150 years ago. However, there were no regulations, Johnson explained. The underground injection control program has very stringent well-construction standards, requiring multiple layers of protection that specify standards for surface casing, long string casing, tubing and cementing. Regulations require the testing of wells to make sure there are no leaks. Operators also are required to carry insurance to ensure that they will take financial responsibility for repairing or plugging any wells that fail.

"We actually have no jurisdiction over production wells," Johnson said. "We only regulate subsurface disposal of brine and enhanced recovery of oil and gas." Brine disposal involves injecting produced fluids into deep wells by gravity or under pressure from above-ground storage tanks. Enhanced recovery systems involve pumping water or natural gas through underground formations to push oil and gas to production wells.

Pennsylvania presently has seven active brine-disposal wells, Johnson noted, compared to West Virginia, which has about 70, and Ohio, which has about 150. Pennsylvania has one commercial brine well. All the other wells are privately owned so they can inject only their own water from their gas-production wells. Johnson said these wells have been operating successfully since the mid-1980s and that they still have the capacity to handle additional volumes of produced fluid. She said she expects more brine operations will seek permits as Marcellus operations increase, but EPA has not yet received any applications.

Most subsurface injection systems in the commonwealth involve enhanced recovery processes, according to Johnson. Enhanced recovery, also known as secondary recovery, involves injecting produced fluids, fresh water or carbon dioxide into existing gas or oil formations to force out additional stores of hydrocarbons that were not initially pumped to the surface.

Old gas-bearing formations that have produced natural gas for 20 to 50 years are ideal sites for injection wells, according to Johnson. "In some of the old Oriskany and old Devonian formations, the reservoir pressure is low," she said. "Basically the gas has been produced and the pore space is open, so the formations are capable of taking fluids.

"You're taking salt water out of a formation like the Marcellus shale and putting it back in, maybe above or below the formation you've extracted it from. It's safer to put it in at depths from 4,000 to 9,000 feet, well below the groundwater," she said.

The wastewater from oil and gas operations is not being merely injected down a hole unchecked, Johnson explained. The Safe Drinking Water Act contains very specific standards for well construction, casings and cementing. It also requires constant pressure monitoring, routine tests of the injection casings and specifications for a well's operation over its projected lifespan, she said.

Johnson's Feb. 18 presentation is part of an ongoing series of workshops addressing issues related to the state's Marcellus shale gas boom. The next one-hour webinar will be held at 1 p.m. on March 18. "The Impact of Marcellus Shale: What Do the Economic Impact Studies Imply?" will be presented by Timothy Kelsey, Penn State Cooperative Extension state program leader for economic and community development.

Previous webinars -- which covered topics such as water use and quality, legal questions surrounding natural gas exploration, and gas-leasing considerations for landowners and implications for local communities -- can be viewed at http://naturalgas.extension.psu.edu/webinars.htm online.

For more information, contact Joann Kowalski, extension educator in Susquehanna County, at 570-278-1158 or by e-mail at jmk20@psu.edu.

Last Updated February 16, 2010