A geophysicist from the University of Colorado is hoping to settle the question of whether a small earthquake last weekend near Greeley was caused by wastewater injection wells.
The Greeley Tribune reports Friday that Anne Sheehan and a team of graduate students have been deploying seismographs to study the 3.4 magnitude quake.
The May 31 earthquake caused no damage.
Weld County has 28 injection wells for oil and gas waste, or "Class II" disposal wells.
State drilling regulators said earlier this week they were skeptical that the wells caused the earthquake.