The Texas Railroad Commission says wastewater injection wells located northwest of Fort Worth are not the cause of a cluster of area earthquakes that happened over a year ago and they agreed to allow two energy companies to keep their drilling permits. Like the state examiner determined in June, commissioners found insufficient evidence to tie the wells, associated with the fracking process, to seismic activity.

The Railroad Commission, the state agency responsible for regulating oil and gas activity, unanimously agreed with hearing examiners there was not enough evidence to support findings that those wells contributed to seismic activity from November 2013 to January 2014 and these companies should be able to keep their permits for operating the wells, the Fort-Worth Star Telegram reported.

Southern Methodist University (SMU) conducted studies to determine the cause of increased earthquake activity in North Texas earlier this year. Their findings in the City of Irving were inconclusive. Irving sits on top of the Balcones Fault line. Another SMU report hypothesized that the high volume salt wastewater mixture used in the fracking extraction process was the most likely or possible cause for Azle quakes in Tarrant County. EnerVest Operating and XTO Energy control the wells named in the report and are located northwest of Fort Worth in the cities of Reno and Azle.

In April, SMU summarized: “While the SMU Azle study adds to the growing body of evidence connecting some injection wells and, to a lesser extent, some oil and gas production to induced earthquakes, SMU’s team notes that there are many thousands of injection and/or production wells that are not associated with earthquakes.”

Hearing examiners discounted the SMU study calling it “a commendable first-order investigation” but it “presents data indicating a weak temporal correlation between injection and seismic activities — too small, however, to imply a causal relationship without further corroborating evidence,” the Fort Worth newspaper also reported.

Energy companies use disposal wells to store large volumes of water used as part of the oil and gas drilling process. Previously, fracking critics blamed earthquakes on the injection well drilling method, which includes blasting water, sand, and other chemicals beneath the ground’s surface. However, state seismologist Craig Pearson said he did not see any “substantial proof” to connect the Fort Worth area shakers to oil and gas activity. Additionally, the Railroad Commission’s final orders say that the wells by XTO and EnerVest were properly built and operated and that the evidence does not support a finding that fluids are escaping and contributing to seismic activity.

In September, Railroad Commissioner Ryan Sitton told the Star-Telegram he went into the review thinking that there might be a connection between oil and gas activity and the earthquakes but the state hearing examiner simply found that the SMU study was too limited and in scope and capability.

Texas lawmakers approved a $4.5 million comprehensive earthquake study underway at the University of Texas at Austin’s Bureau of Economic Geology. Called TexNet, the system plans to add 22 permanent and 36 portable seismograph stations around the state to detect tremors and determine their causes.

In May, Gov. Abbott signed a bill that essentially bans fracking bans, restricting cities and towns from imposing local ordinances that regulate oil and gas drilling or attempt to ban fracking operations. The law followed the controversial North Texas fracking ban battle in the City of Denton, which cost thousands their jobs in the oil and gas industry, resulted in a costly legal struggle, and found local anti-fracking movement activists in bed with “green” lobbyists and lawyers who vowed to spread fracking bans across Texas.

EnerVest and XTO officials were pleased with the commission’s decision.

Follow Merrill Hope on Twitter @OutOfTheBoxMom.