Several U.S. states are banding together to combat the mounting risks of earthquakes tied to the disposal of wastewater from hydraulic fracturing for natural gas.
Regulators from Kansas, Texas, Oklahoma and Ohio met for the first time this month in Oklahoma City to exchange information on the man-made earthquakes and help states toughen their standards.
“It was a very productive meeting, number one, because it gave the states the opportunity to get together and talk collectively about the public interest and the science,” Gerry Baker, who attended as associate executive director of the Interstate Oil and Gas Compact Commission, a group that represents energy-producing states, said in an interview. “It was a good start in coordinating efforts.”
U.S. oil and gas production surged to a two-decade high last year as technological advances such as fracturing, or fracking, let drillers coax liquids from rock formations. The process, in which a mix of water and chemicals is shot into shale to free trapped gas and oil, also generates large volumes of wastewater. As fracking expanded to more fields, reports tied quakes to underground disposal wells from Texas to Ohio.
Pumping fracking wastewater underground has been linked to a sixfold jump in quakes in the central U.S. from 2000 to 2011, according to the U.S. Geological Survey.
The goal of the regulators is to develop a set of common procedures to monitor for earthquakes, investigate their cause and draft rules and regulations to prevent them, said Scott Anderson, senior policy adviser for the Environmental Defense Fund in Austin, Texas, who has been in communication with state regulators on the issue.
Researchers this month installed five monitors in a production field near the Kansas-Oklahoma border after an increase in seismic activity, said Art McGarr, a geophysicist with the U.S. Geological Survey in Menlo Park, California. Quakes began as drillers switched to fracking from conventional drilling, he said.
Within the past year, earthquakes thought to be tied to wastewater disposal wells were recorded in Azle, Texas; Jones, Oklahoma; and northeastern Ohio, McGarr said. Researchers also have linked wells to earthquakes in Youngstown, Ohio; Guy, Arkansas and Fort Worth, Texas.
“There’s close to 150,000 injections wells and the number where there’s even been a connection suggested is just a handful,” Dan Whitten, a spokesman for America’s Natural Gas Alliance, an industry group in Washington, said in an interview. “It’s appropriate that this be addressed at the state level.”
Arkansas, Illinois, Ohio and Oklahoma are among states that proposed or adopted rules targeting the man made earthquakes. Others may follow.
More than 800 people attended a Jan. 2 town hall meeting in Azle, 60 miles (97 kilometers) west of Dallas, to complain the state isn’t doing enough in response to dozens of recent earthquakes.
Since 2009, earthquake reports in Oklahoma are almost 40 times higher than in the previous three decades, according to the Oklahoma Geological Survey. Most occur in the Arbuckle formation where wastewater is buried 6,000 feet (1,828 meters) to 10,000 feet underground, said Austin Holland, a research seismologist with the Oklahoma Geological Survey.
“Disposal wells have been operating in the state for decades and so the question becomes why now,” Holland said in an interview. “If we start shutting down disposal wells indiscriminately it’s going to have a major impact on the state’s economy.”
Scientists linked Oklahoma’s biggest recorded earthquake to wastewater wells. The 5.7-magnitude temblor near Prague, Oklahoma, on Nov. 6, 2011, may be the biggest tied to drilling wastewater, according to researchers from the University of Oklahoma, Columbia University and the U.S. Geological Survey.
The state’s geological office disagreed, saying the link was inconclusive. Prague is about 50 miles east of Oklahoma City and 65 miles southwest of Tulsa.
The Oklahoma Corporation Commission this month said well operators will have to record injection well pressure daily instead of monthly. The rule needs state Legislature approval and the signature of Governor Mary Fallin.
Oklahoma would be the first state to require daily test, said Kristy Hartman, energy and policy specialist at the National Conference of State Legislatures.
In 2011, Arkansas regulators permanently shut four disposal wells in the Fayetteville shale formation after an outbreak of earthquakes near the town of Guy, including a 4.7-magnitude temblor.
Rules that took effect in Ohio last year ban injection wells in certain formations and let the state require seismic monitoring, said Mark Bruce, a spokesman for the Ohio Department of Natural Resources.
“Wastewater disposal is a big industry in Ohio,” McGarr said. “They certainly want to maintain that industry but at the same time they’re realistic about the seismic hazard.”
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