Colorado officials recently suspended injections of fracking wastewater underground, following the discovery that disposing of wastewater in a local well might be linked to seismic activity in the area, Reuters reported.

The Colorado Oil and Gas Conservation Commission issued an order to well operator High Sierra Water Services, requesting that it stop disposing of water for 20 days as a precautionary measure. The decision to stop injection activity was taken after two earthquakes with an epicenter near the well occurred in the area within less than a month. The first one was on May 31 and was measured at a magnitude of 3.4, while the second happened on June 21 and was weaker, measuring 2.6.

A spokesperson for the Commission told Reuters that the well in Weld County was the first instance of fracking wastewater injection activities in Colorado being linked with seismic activity. However, it is not the first time fracking as a process has been associated with triggering earthquakes.

Data from the Colorado Geological Survey shows that induced earthquakes are not a rare occurrence in the state. But prior to the recent fracking boom, most of that triggered seismic activity was put down to coal mining. Between 2007 and 2009 almost 200 earthquakes with a magnitude ranging between 2.8 and 3.4 were detected in the Paonia area, the state Geological Survey said.