You expect to hear about earthquakes in San Francisco and parts of Alaska, but until recently I thought that was one of the natural disasters we least had to fear in Northern Colorado. May 31st Greeley was struck by a magnitude 3.4 tremor, and got shook by a 2.6 magnitude quake yesterday (June 23). 

Two quakes in an area that rarely sees any seismic activity has the Colorado Oil and Gas Conservation Commission so worried that they have halted work at a Greeley waste water injection site.

The United States Geological Survey reports the second earthquake in a month struck approximately 5 miles northeast of Greeley, or 15 miles due east of Windsor, at a depth of approximately 5,000 meters. Although, this quake wasn't as wide felt as the Greeley quake on May 31st, it has raised eyebrows.

There is no word on whether officials believe that waste water injection is triggering the quakes, but they have ordered High Sierra Water Services stop injecting waste water into the site for 20 days while researchers try to determine if the site is the epicenter of seismic activity in the area.