OKLAHOMA CITY (AP) — Three Oklahoma energy companies want a federal judge to dismiss a lawsuit demanding they reduce injection volumes at wastewater disposal wells that could be triggering earthquakes.
The lawsuit was filed in February by members of the Oklahoma Sierra Club. It asks that Devon Energy Corp., Chesapeake Energy Corp. and New Dominion LLC reduce production waste at wells.
But the companies say in legal filings that the Oklahoma Corporation Commission is already taking action to reduce volumes of wastewater in disposal wells, The Oklahoman reported Friday.
The commission has issued a series of voluntary directives covering more than 600 disposal wells. In addition, the Coordinating Council on Seismic Activity brings together regulators, researchers and energy industry representatives to respond to seismicity.
"Through the efforts of the governor, the state Legislature, the OCC and other state agencies, Oklahoma is in the midst of implementing a coherent, well-coordinated and comprehensive public policy to address seismicity," Chesapeake Energy said in a court filing.
While the three companies were responsible for about two-thirds of the wastewater injected in 2014, they said any injunction against them wouldn't cover other operators who might also be contributing to induced seismicity.
The companies also said anybody with concerns should go through the OCC to modify injection well permits.
In response, the Sierra Club said it had no issues with the state's response, but believes more could be done. It said commission action hasn't stopped the earthquakes, with more than 300 recorded since the beginning of the year with magnitude greater than 3.0.
The group said it hasn't had any opportunity to oppose permits because all the volume reductions so far have been voluntary.
"The OCC has not yet issued a mandatory order to reduce injection," the Sierra Club said. "In addition, the voluntary directives issued to date have not stopped the earthquakes, or even reduced their frequency or intensity."
In its answer to the lawsuit, Devon disclosed it is selling some disposal wells as part of a previously announced $200 million deal to sell noncore assets in Oklahoma's Mississippian formation. White Star Petroleum LLC, formerly American Energy-Woodford LLC, is the buyer.