In a November 3 decision, the Texas Railroad Commission (RRC) agreed with an administrative law judge (ALJ) that two wastewater injection wells, one operated by EnerVest Operating LLC and the other by Exxon Mobil Corp. subsidiary XTO Energy Inc., did not cause a series of earthquakes near the towns of Reno and Azle from late 2013 through spring of 2014. (See our coverage of the EnerVest case here and the XTO case here.) The Commissioners’ unanimous decision found there was not enough evidence to link the wells to the seismic activity, and determined that the companies should be allowed to maintain their well permits.

The RRC decision confirms two ALJ recommendations made following an order by the RRC directing the companies to show why their permits should not be revoked, after a Southern Methodist University (SMU) study released in April concluded that the wells had contributed to earthquakes near towns atop the Barnett Shale. The companies argued that the SMU study ignored a deep fault, from which the earthquakes were originating, leading, in part, to the hearing examiners concluding that although the study indicated a “weak temporal correlation” between wastewater injection and the earthquakes, that correlation was too small to imply a causal relationship without further corroborating evidence.