sentences:  As of 2013, XTO Energy had requested a hearing on the matter.In April 2015, a study published by researchers at Southern Methodist University (SMU) in Dallas allegedly connected two XTO-operated wastewater disposal wells with a series of earthquakes in Azle, Texas, occurring in 2013.In August 2015, preliminary findings by investigators with the Texas Railroad Commission found a disposal well operated near Azle by XTO Energy was unlikely to have caused the seismic activity, which contradicted the SMU study.