Operators of five North Texas injection wells will be required to conduct testing following a 4.0 magnitude earthquake Thursday evening in rural Johnson County, the Railroad Commission of Texas says.
The earthquake was reported just before 6 p.m. between the communities of Venus and Lillian, about 30 miles southwest of Dallas.
The state agency said five wells within 100 square miles of the estimated epicenter will undergo testing, and the data will help researchers evaluate whether there is a connection to seismic activity.
The well operators include Bosque Disposal Systems, LLC; EOG Resources, Inc.; MetroSaltwater Disposal, Inc.; and Pinnergy, Ltd.
No damage was found to the wells following Thursday's earthquake, officials said.
Thursday's quake was the sharpest detected in North Texas since seismic activity in the area increased in recent months.
USGS maps show the tremor was felt from southern Fort Worth and Arlington south to Hillsboro.
There were no injuries reported, but Johnson County Emergency Management Coordinator Jamie Moore said two mobile homes had their cinder-block foundations shift slightly.