Citizen groups request analysis of earthquake
Glenwood Springs Post Independent
Citizen activist groups have asked Colorado oil and gas regulators to analyze a recent earthquake near New Castle to determine whether nearby injection wells were a cause.
A 2.9 magnitude earthquake was reported southwest of New Castle on Christmas Day, which makes the second minor earthquake in the same area in two months.
The only other earthquake in the past year in the county came in December 2015, when another 2.9 magnitude earthquake hit west of Parachute. In the past 10 years, Garfield County’s biggest earthquakes have been 2.9 magnitude.
“It’s probable that it’s not induced by injection wells, but we want to make sure,” said Leslie Robinson, chair of the Grand Valley Citizens Alliance, which with the Battlement Concerned Citizens made the request of the Colorado Oil and Gas Conservation Commission.
A database of Garfield County injection wells shows several wells near the quake epicenters, but that doesn’t mean there’s a relationship.
“A quake of 2.9 isn’t that much; we realize that, too,” Robinson said. “But I have confidence that the Colorado Oil and Gas Conservation Commission will have a look. We need to ask the question of whether there’s a connection as injection wells are going in all around Battlement Mesa.”
The Grand Valley Citizens Alliance and Battlement Concerned Citizens are focused on injection wells at Ursa Resources’ recently approved B Pad, the company’s second well pad recently approved in Battlement Mesa.
Robinson believes Ursa Resources will soon approach Garfield County commissioners for approval of an injection well at the site.
David Ludlam, executive director of the West Slope Colorado Oil and Gas Association, called the suggestion “political opportunism rather than legitimate technical inquiry.”
He pointed to a presentation this summer given to the Garfield County Energy Advisory Board by Rick Aster, professor of geophysics and department head of Colorado State University’s department of geosciences.
“There’s been absolutely no indication that there’s any induced seismicity in this area,” Aster said during his presentation in June. But increased monitoring would help guide effective policies, he said.
Colorado’s seismic network coverage is sparse, said Aster.
Fracking by itself is not a significant seismic hazard issue, and though the process creates tiny earthquakes, only rarely does it create felt earthquakes, he said.
And a small number of injection wells in the country are associated with “induced seismicity,” according to Aster.
The professor said that Colorado Oil and Gas Conservation Commission policy is to engage injection well operators if an earthquake of 2.5 magnitude or bigger occurs within 2.5 miles of an injection well.
As Aster suggested, the citizen groups are also looking for seismographs to be placed near Battlement Mesa and through the county to monitor future quakes.
“The COGCC is reviewing the event, including assessing its proximity to nearby injection wells, number and status of such wells, and volumes and pressures of injections,” Todd Hartman, the commission’s communications director wrote to the Post Independent.
“COGCC believes it’s important to understand whether earthquakes have any connection to deep injection and has developed protocols to address this concern,” wrote Hartman.
“We are reviewing data from (U.S. Geological Survey) and from operators. At this time, we don’t believe sufficient evidence exists to link the recent seismic activity to injection, but we will continue to gather data and monitor seismicity in the area,” he wrote.
“The ability to clearly tie any seismic event to injection activities varies based on numerous facts involved and changes that may or may not occur with changes in injection practices. In areas with a consistent history of natural seismicity, it can be even more difficult to make a firm determination.”