Friday, July 31, 2015
Wastewater injects controversy over earthquakes in Oklahoma
A rash of earthquakes in Oklahoma has spurred calls to ban — or at least put a one-year moratorium on — the use of wastewater injection wells in the Sooner State.
But an oil and natural gas industry group says such a move would be unnecessary and counter-productive, pointing to modeling that indicates suddenly stopping the process may actually lead to new earthquakes in some areas.
“We believe that in 12 months we would see a clear decline in the earthquake activity” if a moratorium is put in place, said Johnson Bridgwater, director of Oklahoma Sierra Club. “We are not saying it would completely stop, we are not saying they would go away, but we do believe that a 12-month window would show a steady decline in earthquake activity in the area.”
Steve Everley, senior adviser for Energy In Depth, an outreach campaign funded by the Independent Petroleum Association of America, says there is “no scientific basis for suggesting a blanket ban is necessary” and a proposed moratorium “would negatively impact both the economy and the environment.”
At issue is the amount of seismic activity reported in cities and towns in Oklahoma, one of the nation’s most prolific sources for oil and natural gas.
Oklahoma is credited as one of the places where hydraulic fracturing techniques were refined in the past decade by maverick producers such as Harold Hamm, spurring what’s been called an “energy renaissance” in North America.
However, the wastewater disposal process is not the same as “fracking.”
Injection wells have been used since the 1930s, according to the U.S. Environmental Protection Agency, as a way to get rid of brine and preserved surface waters during oil and gas production by sending liquids through high pressure techniques into sites deep underground.
But in recent years, Oklahoma has seen a spike in earthquake activity.
In 2014, 585 earthquakes of 3.0-plus magnitude were felt in Oklahoma, compared with 109 in 2013, leading to concerns that disposing wastewater from sites is essentially lubricating faults that trigger seismic activity. There have been 499 earthquakes of 3.0 or greater so far this year.
On Monday, a 4.5-magnitude earthquake rumbled outside the town of Crescent.
Earlier this year, the Oklahoma Geological Survey issued a report saying, “the rates and trends in seismicity are very unlikely to represent a naturally occurring process,” adding that the “primary suspected source of triggered seismicity is not from hydraulic fracturing but from the injection/disposal of water associated with oil and gas production.”
That has energized environmental groups on one side and industry groups on the other to point to data they say back up their arguments about the future of injection wells.
“Other states have issued moratoriums when they’ve had similar situations that were not nearly as severe as ours and they definitely found that once the injection well activity was stopped within a given amount of time, the earthquakes stopped,” Bridgwater told Watchdog.org.
Energy In Depth responded by issuing a white paper citing the U.S. Geological Survey that said, “most injection wells are not associated with felt earthquakes,” and only a “small fraction” of wells have “induced earthquakes that are large enough to be of concern to the public.”
Though the USGS says it can’t rule out the possibility altogether, it reported “there is no conclusive example linking injection operations to triggering of major earthquakes.”
The Oklahoma Sierra Club points to other studies, including a USGS report issued in February that said seismic activity in places like Oklahoma “is not the result of natural processes” and “deep injection of wastewater is the primary cause of the dramatic rise in detected earthquakes and the corresponding increase in seismic hazard in the central U.S.”
Industry officials counter by saying Oklahoma City has experienced some recent earthquakes, yet no high-volume wastewater injection wells are located there.
A study released last month from Stanford University said the rising number of earthquakes coincided with dramatic increases in disposing wastewater into the state’s Arbuckle Formation. The Stanford study said the seismic activity was not due to fracking.
Oklahoma seismologist Austin Holland said it’s not known what kind of effect a moratorium would have on earthquakes in the area.
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