Grant County Has Become 'Earthquake Central' in OklahomaFri, 26 Sep 2014 15:24:50 CDT
The U.S. Geological Survey logged 3,625 earthquakes in Oklahoma during the first 266 days of this year – and fully 15% of them occurred in Grant County.
Earthquakes rattle buildings and nerves in Medford almost daily – often more than once a day – and occur “almost like clockwork,” Barbara Bush said recently. “They usually start between 6 and 7 a.m. – so you don’t want to be in the shower when it does,” said Mrs. Bush, the city clerk/treasurer for almost 35 years.
“It goes on day and night,” she said, “and I can’t get back to sleep. It’s unnerving.”
Robert Moss, who lives about seven miles east of Medford, told a newspaper reporter that his house was shaken by a temblor earlier this month. During an earthquake on Sept. 15, items on shelves in Mrs. Bush’s house toppled to the floor and pictures on her walls were knocked askew. City Manager Dea Mandevill said her house shook twice on the morning of Sept. 19 and once the night before. And ceiling tiles in Medford’s civic center had to be repositioned after one recent earthquake.
Many of the tremors are preceded by a loud noise, area residents say. A magnitude-4 ‘quake the night of Sept. 18 southeast of Medford, at Hunter in Garfield County, “sounded almost like a sonic boom,” Mrs. Bush said.
The USGS recorded 29 earthquakes of magnitude-2.5 or greater in or near Medford, as well as two others west southwest of nearby Caldwell, Kan., between Aug. 26 and Sept. 20.
They’re occurring so often that several Medford residents have earthquake apps on their smartphones that provide them with immediate data about the time, location and magnitude of earthquakes in their vicinity.
Earthquake insurance is growing in popularity, too. Mrs. Bush said she and her husband, Harvey, have a policy on their brick home that features a low premium but a high deductible. “It’s basically catastrophic insurance,” she said. Lisa Skrdla, the deputy city clerk, said she too has earthquake coverage.
The Oklahoma Geological Survey listed 546 earthquakes that occurred in Grant County between New Year’s Day and 3 p.m. Sept. 23. They ranged in magnitude from barely perceptible by sensitive metering equipment, to a magnitude-4 on June 20 and another on Sept. 19, a 4.1 on July 14, a 4.2 on Sept. 8, and a 4.4 on July 29. Fifteen ’quakes occurred in one day, Aug. 17; nine have been recorded on each of three days, and eight have occurred on three others.
The Denver office of the U.S. Geological Survey has logged 51 earthquakes of magnitude-3 or greater within 20 kilometers (12.4 miles) of Medford, and 15 temblors of magnitude-3+ within 10 kilometers (6.2 miles) of Medford, over the last three years, since June 2011.
To put that in perspective, the USGS recorded only one earthquake greater than magnitude-3 within a dozen miles of Medford from 1974 through June 2011 – a period of 37 years.
“The frequency and the intensity of these earthquakes are growing in Grant County and elsewhere in central and north-central Oklahoma,” said state Sen. Jerry Ellis, D-Valliant.
What has changed is resurgent oilfield activity, along with the number and volume of saltwater disposal wells. (Energy production generates as much as 10 barrels of saltwater with every barrel of oil. A barrel is equivalent to 42 gallons.)
“This has been going on since they started drilling all of these wells,” Mrs. Bush said, and Grant County Commissioner Max Hess confirmed that production in the oil patch picked up in the spring of 2011.
The oilfield activity “has been wonderful for our community,” Mrs. Bush said. The drilling is producing not just gas and oil and saltwater, but a lot of money, too, she said.
An athletic facility featuring a swimming pool plus a basketball/tennis court is under construction in Medford, financed largely with oil royalty revenue. ONEOK, a major natural-gas supplier in Oklahoma, has a facility at Medford, and Conoco has some above-ground tanks nearby. At least three oilfield service/supply companies have operations in Medford.
Few, if any, residential housing units are still available for rent to oilfield workers, no motel rooms for oilfield workers or travelers are available “within miles of here,” and several mobile home parks have been established in Medford recently, Mrs. Bush said.
Several farmers have sold their mineral rights to energy companies, and Harvey Bush, an attorney, keeps busy with paperwork on oil and gas leases and royalty issues.
Although the city sales tax rate in this community of about 1,000 population has remained at 4 cents on the dollar for several years, receipts have nearly quadrupled: from $321,479 in 2009 to $1,264,658 in 2013. The 4% levy produced more than $561,000 during the first nine months of this year, ledgers reflect.
Nevertheless, concerns are growing about the potential effect of repeated earthquakes on structural integrity, property values and underground utility lines.
“We’ve had oilfield activity around here for many years, but not to this extent,” said Mrs. Bush, who moved to Medford in 1979.
According to records maintained by the Oklahoma Corporation Commission, which has regulatory authority over the oil and gas industry, the number of saltwater disposal wells in Grant County almost doubled in four years, from 45 in 2008 to 83 in 2012, and the volume of saltwater injected into those wells has nearly tripled: from 14.5 million barrels in 2008 to 39.4 million barrels in 2013.
Ten of those disposal wells are located within a six-mile radius of Medford, and accepted more than one million barrels of wastewater in 2011 and 2013 and nearly two million barrels in 2012.
At least 3,356 of the approximately 12,000 injection wells in Oklahoma are disposal wells, according to Matt Skinner, the Corporation Commission’s public information manager. Saltwater disposed of in Oklahoma has been rising steadily, Corporation Commission records show: from 844 million barrels in 2007 to nearly 1.09 billion barrels of wastewater – 45.8 billion gallons, equivalent to the carrying capacity of 504 oceangoing supertankers – generated from oil and gas production operations in 2012.
Many geologists and other scientists believe that high volumes of wastewater injected underground lubricate faults, which in turn triggers earthquakes.
“We do not want to hurt the oil business,” Mrs. Bush stressed. “But isn’t there some way to get rid of some of that saltwater, such as trucking it somewhere else?” The subterranean faults in Grant County have existed for centuries “but now they’re being aggravated,” said Mrs. Bush, a 1974 graduate of Oklahoma State University.
Bob Jackman, an independent petroleum geologist from Tulsa, has similarly recommended that some oilfield wastewater be spread around among various disposal wells sited away from seismically active faults, and that disposal wells be prohibited on defined faults.
During a meeting at the Corporation Commission headquarters in Oklahoma City last month, Tim Baker, director of the commission’s Oil and Gas Conservation Division, said the commission required five disposal wells in Oklahoma to be closed because of seismic activity in their immediate vicinity.
Lt. Gov. Todd Lamb met recently with Medford and Grant County officials to discuss a variety of matters, but offered no potential solutions to the earthquake issue, people who attended the event said.
Also, no one from the Oklahoma Corporation Commission, the Oklahoma Geological Society, nor the Oklahoma Independent Petroleum Association, has held a public meeting in Medford to discuss local concerns, townspeople said.
The Corporation Commission, the OGS and the OIPA have a “cooperative collaboration” on this issue, Commissioner Dana Murphy told Senator Ellis during a meeting last month.
And during that same meeting, OGS research seismologist Austin Holland said the Geological Survey has increased the number of its monitoring stations to 34 permanent and temporary stations, and 50 of the units will be installed by the end of the year, to “more accurately determine the locations and magnitudes” of the earthquakes in this state.
Holland maintains that further studies need to be performed, but Jackman disagrees. “Claiming that we need more studies is just a form of denial,” he said Wednesday.
“We don’t need more studies. The Geological Survey, the Corporation Commission and the oil industry already know what needs to be done, and I’m waiting for them to do it,” Ellis said Thursday.
“I don’t know of anybody who wants to shut down the oil industry,” he continued. “But we do want this state to be a safe place to live and raise a family. The Corporation Commission and the energy industry need to impose some limits on these disposal wells before somebody in this state gets injured or killed in an earthquake.”
In a report issued June 24, the USGS said that after a “rigorous statistical analysis” it concluded that the increase in earthquakes in Oklahoma since October 2013 “is not due to typical, natural fluctuations in natural earthquake rates.” Instead, the analysis “suggests that a likely contributing factor to the increase in earthquakes is triggering by wastewater injected into deep geological formations.”
And in a study published July 3 in the journal Science, a research team led by Dr. Kathleen Keranen of Cornell University concluded that the dramatic increase in earthquakes in central Oklahoma since 2009 can likely be attributed to subsurface wastewater disposal wells. Keranen, a geophysicist who is an assistant professor of Earth and Atmospheric Sciences at Cornell, formerly taught at the University of Oklahoma and previously was an employee of the U.S. Geological Survey in earthquake hazards.
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