The 5.7-magnitude earthquake that damaged 14 homes and injured two Oklahomans in November 2011 was the nation’s largest quake linked to injecting wastewater from oil and gas production deep underground. But neither that quake near Prague, nor Oklahoma’s recent spike in seismic activity, has provoked lawmakers or regulators here to write rules to protect public safety.
By contrast, a number of states that experienced smaller quakes linked to oil and gas activity are taking or considering more forceful steps intended to prevent them from happening again. That includes neighboring states like Arkansas, which has placed a moratorium on disposal well operations in a seismically active part of the state, and Colorado, which requires a seismic review before disposal well permits are issued.
StateImpact reviewed the rules and laws in a half-dozen states where seismologists have linked wastewater disposal wells to earthquakes: Arkansas, Colorado, Ohio, Texas and West Virginia. That review, along with interviews with oil and gas authorities and geoscientists, shows a more ambivalent approach to the issue in Oklahoma than elsewhere, and considerable reluctance to conclude that man-made earthquakes are a problem at all.
Oklahoma regulators have begun a process of crafting voluntary guidelines for disposal well operators to follow if they wish. These “best practices,” if adopted, would lack the regulatory teeth of some of the policies in place or under consideration in the other states.
In Ohio, a series of earthquakes shook the ground near Youngstown in December 2011 and January 2012. The swarm peaked with a 4.0-magnitude tremor, and regulators responded with what they bragged in a press release were among the “nation’s toughest” rules on brine disposal.
Ohio regulators have banned disposal wells in areas with certain geologic formations that have a higher earthquake risk. And before new disposal wells are permitted, regulators review geologic data “for known faulted areas,” and require operators to install electronic sensors and follow other procedures to better track and monitor injection pressures and volumes.Arkansas did something similar after a swarm of quakes shook the state in 2010 and 2011. The state’s Oil and Gas Commission shut down four disposal well operations and issued a moratorium on disposal well operations in a region where an unusual swarm of earthquakes had occurred. “We know this has occurred once,” Larry Bengal, director of the Arkansas Oil and Gas Commission, told the Arkansas Democrat-Gazette.
“The basic geologic premise is if it happens once things can happen again….and the injection wells being the trigger, was not something we were willing to take a risk and allow to occur if in fact there was another fault present.”
In Colorado, permits for disposal wells must be reviewed by state seismologists, Thomas Kerr, the permit and technical services manager at the Colorado Oil and Gas Conservation Commission tells StateImpact.
And lawmakers in Illinois are considering legislation that includes a “traffic light” system that will allow authorities to scale down injection operations if earthquakes occur. The proposed bill’s language:
The additional mitigation requirements … shall provide for either the scaling back of injection operations with monitoring for establishment of a potentially safe operation level or the immediate cessation of injection operations.
The proposed law addresses earthquakes that might be caused by a type of disposal well used with high-volume hydraulic fracturing — or fracking — operations, says Bob Bauer, a geologist with the Illinois Geological Survey.
“The bill has not yet passed, and some issues are still being worked out,” Bauer says. “This may not be the exact final language, but these intents should remain.”
In Texas, scores of earthquakes have been linked to disposal wells, but regulators there are taking a “wait-and-see” approach, StateImpact Texas reports:
In an email to StateImpact Texas, Commission spokesperson Ramona Nye wrote that staff welcomes more data about “theories that hypothesize” a causation between seismic events and injection wells. But the Commission would not make any staff members available for interview.
The Railroad Commission is starting the process of writing new rules about disposal wells. But in an email to StateImpact Texas, the Commission said those proposed amendments “do not address seismic activity.”
No new rules or laws addressing manmade earthquakes have been proposed in Oklahoma. But the Corporation Commission — Oklahoma’s oil and gas regulator — is considering voluntary guidelines for well operators to follow if they want to.
That process actually has been underway for at least a couple of years. Currently, it’s in the hands of the Oklahoma Geological Survey, the state’s official earthquake authority, which concluded the Prague earthquake was a natural occurrence unrelated to wastewater disposal.
That view is disputed by University of Oklahoma seismologist Katie Keranen, who recently published a study that concluded Oklahoma’s November 2011 quake was likely triggered by wastewater disposal wells used by the oil and gas industry. The study appeared in the journal Geology and was co-authored by researchers at Columbia University and the U.S. Geological Survey.
Seismologist Austin Holland with the Oklahoma Geological Survey is leading the process of drafting the guidelines on induced seismicity. The agency has invited earthquake researchers and energy industry experts to weigh in on the list of possible guidelines, Holland says.
The proposed guidelines will be made public and discussed at a conference this summer. Oil and gas companies, academics, environmental groups and regulators — “experts from around the country and interested stakeholders from here in Oklahoma,” Holland says — will all be invited to discuss the guidelines.
Later, a final draft will be sent to the Corporation Commission to approve or reject.
Asked why Oklahoma has taken a less forceful approach to man-made earthquakes than other states, Commission spokesman Matt Skinner cited the state Geological Survey’s doubts.
“There is no consensus,” on the cause of the November 2011 quake, Skinner says. “The commission cannot arbitrarily take action, they have to be able to defend their action on a scientific basis.”
While the number of earthquakes suspected of being triggered by oil and gas activity is relatively small, the risks merit some kind of regulatory response, says William Ellsworth, a geophysicist with the U.S. Geological Survey who studies induced seismicity. He says the oil and gas industry and regulators should collaborate on a proactive approach to policies regarding man-made earthquakes.
“I certainly think this is a problem that can be solved,” Ellsworth says. “If one looks broadly, there are tens of thousands of deep wastewater disposal wells of which only a few are problematic.”