Five disposal wells have been shut down for testing after a 4.0 magnitude earthquake rocked the Venus area south of Mansfield Thursday evening.

The Texas Railroad Commission wants to look at the pressures within rock formations for all wells in a 100-mile radius of the quake’s epicenter. The goal is to determine whether there’s a link between the disposal wells, used to inject waste water from oil and gas wells, and increased seismic activity in the area.

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