Abandoning years of official skepticism, Oklahoma’s government on Tuesday embraced a scientific consensus that earthquakes rocking the state are largely caused by the underground disposal of billions of barrels of wastewater from oil and gas wells.
The state’s energy and environment cabinet introduced a website detailing the evidence behind that conclusion Tuesday, including links to expert studies of Oklahoma’s quakes. The site includes an interactive map that plots not only earthquake locations, but also the sites of more than 3,000 active wastewater-injection wells.
The website coincided with a statement by the state-run Oklahoma Geological Survey that it “considers it very likely” that wastewater wells are causing the majority of the state’s earthquakes.
The statement noted that the most intense seismic activity “is occurring over a large area, about 15 percent of the area of Oklahoma, that has experienced significant increase in wastewater disposal volumes over the last several years.”
The statement and the website’s acknowledgment amount to a turnabout for a state government that has long played down the connection between earthquakes and an oil and gas industry that is Oklahoma’s economic linchpin.
As recently as last fall, Gov. Mary Fallin, a Republican, indicated that suggestions of a relationship between oil and gas activity and seismicity were speculation, and that more study was needed.
In a news release issued Tuesday, Ms. Fallin called the Geological Survey’s endorsement of that relationship significant, and said the state was dealing with the problem.
“Oklahoma state agencies already are taking action to address this issue and protect homeowners,” she said in a statement.
Tuesday’s actions met a mixed response from the oil and gas industry and the governor’s critics. The Oklahoma Oil and Gas Association disputed the Geological Survey’s conclusions, saying in a statement that further study of the state’s quakes remained necessary.
“There may be a link between earthquakes and disposal wells,” the group’s president, Chad Warmington, said in the statement, “but we — industry, regulators, researchers, lawmakers or state residents — still don’t know enough about how wastewater injection impacts Oklahoma’s underground faults.”
Nor is there any evidence that halting wastewater injection would slow or stop the earthquakes, he said.
One of the most prominent advocates of stronger action on the earthquake issue, State Representative Cory Williams, a Democrat, said he had been pleasantly surprised by the change in what he called the state’s “head in the sand” approach to the quake problem.
But Mr. Williams, from earthquake-rattled Stillwater, criticized officials for failing to announce further steps to actually curtail the tremors.
Separately, he called on Tuesday for the state to halt wastewater disposal in a 16-county section of central and north-central Oklahoma that the Geological Survey has identified as posing the highest seismic risk.
“I want a moratorium and then an action plan,” he said. “The only way to protect the public is to say, ‘We’re done for now.’ ”
Oklahoma oil and gas regulators have taken steps to ensure that newly drilled disposal wells do not create seismic risks. But they say they have no authority to impose a moratorium, and only limited powers to address the existing wells that are behind the increase in tremors. Neither the governor nor the Legislature has pushed to increase their powers.
Ms. Fallin has also approved a directive from state regulators that Oklahoma insurance agents take courses in earthquake coverage. But few residents had coverage before the quakes began escalating in 2010, and policies have become increasingly restrictive as the pace of tremors has quickened. Some homeowners with significant damage have filed lawsuits seeking to recover repair costs from oil and gas operators.
In past decades, Oklahomans experienced only about one and a half earthquakes exceeding magnitude 3.0 in an average year. But since a boom in oil and gas exploration began in the mid-2000s, that number has mushroomed. The state recorded 585 quakes of 3.0 or greater last year, more than any state except Alaska, and is on course to register more than 900 such tremors this year.
Most of the quakes result in little more than cracked plaster and driveways, but residents in quake zones say the cumulative damage — to their property and to their nerves — is far greater.
Larger quakes have also occurred. A series of shocks in 2011 exceeding magnitude 5.0 caused millions of dollars in damage. Some seismologists have warned that the state is risking larger and more damaging quakes unless it acts to reduce the number of tremors.
Learn more here http://earthquakes.ok.gov/what-we-know/earthquake-map/