More earthquakes, this time from oil & gas waste disposal
Posted January 3, 2012
Injection of oil and gas waste water into a disposal well is suspected as the cause for a swarm of earthquakes around Youngstown, Ohio. A magnitude 4.0 earthquake on New Year’s Eve was the biggest of 11 earthquakes that occurred in the region since mid-March. The Ohio Department of Natural Resources (ODNR) halted injection at the suspected well and also suspended activity at four additional disposal wells that are not yet operational. A map showing these wells can be found here.
Induced seismicity tied to the injection or withdrawal of fluids is well established and documented, as I wrote in my previous blog. And just like the induced earthquakes in the UK and Oklahoma, these earthquakes in Ohio likely could have been prevented by proper planning and site characterization.
Underground injection is regulated by the U.S. Environmental Protection Agency (EPA) through the Underground Injection Control (UIC) program under the authority of the Safe Drinking Water Act (SDWA). There are six classes of wells in the UIC program, each designed to regulate the injection of a specific fluid or process. Oil and gas waste is regulated under Class II.
However, owners and operators of Class II injection wells are not required to consider seismic risks when siting their wells.
This is despite the fact that induced seismicity is a well known risk associated with underground fluid injection. The permit application and well files for the Ohio injection well show that seismic history and the presence of faults were not considered.
The case in Ohio is not the first time oil and gas waste disposal wells have been suspected of causing earthquakes. A similar swarm of earthquakes in the Dallas-Fort Worth area, where the Barnett Shale is being developed, was linked to produced water disposal wells. The Arkansas Oil and Gas Commission shut down a disposal well and enacted a permanent moratorium on future disposal wells in an approximately 1,200 square-mile area in the Fayetteville Shale after injection caused hundreds of earthquakes. In fact, this is not even the first time an injection well has caused earthquakes in Ohio: a series of earthquakes in Ashtabula, Ohio in 1987, 2001, and 2003 were caused by a disposal well.
These incidents are yet another example of how the oil and gas industry gets special treatment when it comes to our bedrock environmental laws.
The science on the risk of induced seismicity from fluid injection is well established. Empirical evidence has shown that fluid injection volume and earthquake magnitude are strongly correlated. Researchers have determined the probability of inducing an earthquake of a given magnitude based on injection pressure, time, and geologic and geophysical properties of the injection site.
Through proper planning, site characterization, and the application of this scientific knowledge, the risk of inducing earthquakes can be significantly reduced.
The regulations for underground disposal of oil and gas waste water must be updated to accurately reflect these risks and to protect the environment and the public.
 Seeber L, Armbruster JG, Kim, W-Y. A Fluid-Injection-Triggered Earthquake Sequence in Ashtabula, Ohio: Implications for Seismogenesis in Stable Continental Regions. Bull. Seis. Soc. Am. 2004; 94: 76-87.