North Texas Earthquakes
North Texas isn’t known for earthquakes, but all that has changed. Since 2008, there have been more than 120 here, according to researchers at Southern Methodist University, who are working with the U.S. Geological Survey to determine what’s causing them. One theory is that they are manmade, a result of underground fault lines lubricated by “frack waste,” or chemical-laden salt water produced as a by-product of hydraulic fracturing. Millions of gallons are injected miles underground in North Texas daily, according to government oil and gas permits. Scientists have linked the injection of fluid underground to seismic activity since the 1960s, resulting in bans of injection wells in some parts of the country. But the Texas Railroad Commission, which oversees oil and gas operations, has said there is no evidence at the present time to prove a relationship. There are about 7,500 disposal wells in Texas, compared to approximately 180,000 oil wells and 103,000 natural gas wells statewide.
Using RRC data, we have plotted active injection disposal wells in seven counties: Denton, Ellis, Hood, Johnson, Parker, Tarrant and Wise (there are none of these type wells in Dallas County). We have also added an inactive well on DFW Airport property that began operation in January 2008 and ended its permit in September 2013. (That well was plugged May 23, 2014.) In addition to location, we have also included information on the amount of fluid the wells are permitted to inject daily, at what pressures and at what depths. Through the U.S. Geological Survey, we have also mapped earthquakes of magnitude 1 and greater occurring in North Texas from 2008 through January 2015, which includes quake clusters near DFW Airport, Cleburne, Azle and most recently near the old Texas Stadium site in Irving.