Here’s a good start on an official look into the recent surge in minor North Texas earthquakes: Railroad Commissioner David Porter says he’ll hold a town hall meeting on the subject Jan. 2 in Azle.
The prime suspect for a cause in the 30 (and counting) earthquakes near Azle since early November has been the area’s waste water disposal wells, which inject millions of gallons of Barnett Shale natural gas drilling waste deep underground.
There’s no specific proof the disposal wells are behind the quakes, but the Railroad Commission is in charge of regulating the wells. It has not been a hard-nosed regulator.
Nor is Porter known as a sharp-toothed industry watchdog. His online biography says his CPA practice in Midland is built on “providing accounting and tax services to oil and gas producers, royalty owners, oil field service companies” and other clients.
Still, give him credit for stepping into the arena and making himself available to North Texas residents who want to get to the bottom of all of this.
Another 3.3-magnitude earthquake struck just outside of Azle at 7:11 a.m. Monday.
That’s the same size as the one northwest of the city just after 11:30 a.m. Sunday, according to the U.S. Geological Survey.
A 3.3 quake is not quite earth-shaking enough to cause damage to structures, in most cases, and no injuries have been reported.
The Railroad Commission says on its website that its staff is “closely following various studies that are being conducted to determine possible man-made causes of recent seismic events.”
But it also says, “Texas has a long history of safe injection [of drilling wastes], and staff has not identified a significant correlation between [earthquakes] and injection practices.”
Commission regulations require an evaluation of underground faults and geologic traits before it grants permits for disposal wells. Injection is confined to specific flow rates and intervals.
The website says the commission staff could suspend or terminate a permit “if science and data indicated a problem.”
Chesapeake Energy voluntarily closed one of its two injection wells at Dallas/Fort Worth Airport after a spate of earthquakes there in 2009, although the company said a scientific link between the wells and the quakes was not shown.
An SMU researcher said the injection wells were a “plausible” cause of the quakes.
The USGS website cites “evidence that some central and eastern North America earthquakes have been triggered or caused by human activities that have altered the stress conditions in [the] earth’s crust sufficiently to induce faulting.”
The agency lists “injection of fluid into the earth’s crust” among the suspect activities.
But it’s hard to say for sure.
“Even within areas with many human-induced earthquakes … the activity that seems to induce seismicity at one location may be taking place at many other locations without inducing felt earthquakes,” the USGS says. “In addition, regions with frequent induced earthquakes may also be subject to damaging earthquakes that would have occurred independently of human activity.”
Any suspected triggering activities would have to be investigated for how they might have altered natural stresses in bedrock and how the quakes differ from natural earthquakes in the region.
A statement from the Railroad Commission says Porter “will listen to residents’ concerns and outline what he plans to do …”
Other state and local officials also will attend the 7 p.m. Jan. 2 meeting at the Azle High School Auditorium, the statement says.
The more, the better. Local residents deserve this opportunity to air their concerns.
Porter should be commended for bringing the meeting to them rather than making them trek to Austin to have their voices heard.