It’s time to take a deep look at earthquakes in Weld County

We think it would be a mistake to overreact and suggest oil and gas drilling activity and all injection wells should be shut down because of recent earthquakes in the Greeley area.

But we have to admit, we are a bit concerned.

We think there needs to be further investigation into the cause of the earthquakes and exploration of possible solutions.

Last Sunday, a 3.1 earthquake on the Richter scale was recorded just northwest of Kersey. That qualifies it as a small, minor earthquake, with only a handful of residents in the Greeley area saying they felt it. Even the Platte Valley Fire Protection District’s main fire station is less than a mile from the where the quake was and firefighters said they felt nothing.

But, this is the third earthquake in two years of similar severity.

More concerning, according to a University of Colorado seismic researcher, is the fact these were the only ones felt. There have been dozens of others of a much smaller magnitude suddenly occurring in the same region.

From July to September, 150 seismic “events” were recorded by CU in the same area, said Anne Sheehan, a professor at CU-Boulder, who has been leading studies of seismic activity in Weld County for the past two years.

“It seems fairly episodic, meaning it comes and goes,” she said. “But it has not stopped.”

We need to say this loud and clear: The quakes are not caused by fracking, which a Denver TV station reported on Sunday night. All the experts believe they are caused by injection wells, which it can be said is a result of the drilling activity in northern Colorado.

Injection wells take in waste water used in the process of drilling oil and gas wells. Water is pumped in almost two miles beneath the surface, which is slowly dispersed through porous rock, similar to a sponge as it takes on water. When rocks are under stress, pumping water in at higher rates can create earthquakes, said William Yeck, a research geophysicist at the U.S. Geologic Survey in Golden.

Researchers admit there is much left to explain about the sudden occurrence of earthquakes in an area near injection wells. There are 44 active injection wells in the county, but the majority of them do not have earthquakes.

But Sheehan caused us to raise our eyebrows a bit when she predicted the earthquakes likely will continue, and they may be more severe in their magnitude.

“I could certainly see like a magnitude 4 happen in this area,” Sheehan said.

We hope the University of Colorado, the U.S. Geologic Survey and operators of injection wells in Weld County stop to take a deep look at what is happening and consider some alternate solutions to dealing with wastewater from drilling.

We believe enough has occurred with this new phenomenon in Weld County to cause us to be concerned. 

http://www.greeleytribune.com/news/opinion/tribune-opinion-its-time-to-take-a-deep-look-at-earthquakes-in-weld-county/#