GRAND JUNCTION,Colo. (KKCO) - The earthquake Wednesday night has many people guessing what exactly caused the 3.9 magnitude earthquake.
The most likely cause is a deep well injection of brine water project by the Bureau of Reclamation.
"They generate earthquake activity in the Paradox Valley on a regular basis, it's just they typically don't exceed a magnitude 2.5," said Dave Wolny, seismologist.
The purpose of the project is to lower the salt load in the Dolores and Colorado River.
"That is an area that's a salt dome. The river is picking up a lot of salt through that area and the salt in the river has to be removed before it can be used for domestic uses, for farmers, for animals," said Justyn Hock, with the Bureau of Reclamation.
The project caused a 3.9 earthquake near the same area in 2004.
"We're taking water out of the river, we're evaporating it down to a brine, and then we're injecting that into a well, deep into the earth," said Hock.
"It's really related to the stress and strain that's applied to the rocks due to the injection process and at some point you exceed the ability of the rocks to stay in one place," said Wolny.
The Paradox Valley Salinity Control Unit was operating during the time of the earthquake Wednesday night, and shut down everything within three minutes.
The Bureau of Reclamation doesn't plan on operating again until the investigation of whether they caused the earthquake or not is over.