The Sierra Club is threatening to sue four oil companies, alleging their wastewater disposal operations have caused hundreds of earthquakes in Oklahoma.

The group's call for the drillers to curtail operations is the first major move by a national environmental group in response to Oklahoma's earthquake swarms. Until now, it primarily has been local activists and a handful of people who have filed lawsuits.

"Oklahoma is literally being shaken to its core by the operations of these oil and gas companies," said Paul Bland, executive director of Public Justice, which has teamed with the Sierra Club for the legal action. "There is a clear and present danger posed by these irresponsible operations. If the energy companies do not voluntarily take action to stop it, we will take them to court."

Public Justice and the Sierra Club yesterday released a notice of intent to sue under federal environmental laws.

The letter names four companies: Chesapeake Energy Corp., Devon Energy Corp., New Dominion LLC and SandRidge Energy Inc. Chesapeake, Devon and New Dominion declined to comment. Officials with SandRidge did not respond to requests for comment.


The letter calls on the companies, which all have high-volume disposal operations in Oklahoma, to reduce the amount of waste fluid they're injecting into deep disposal wells. It also says they should reinforce vulnerable structures and establish an "independent forecasting body" to study the seismic effects of deep injection.

If the companies don't meet those demands in the next 90 days, the letter says, the Sierra Club will file a lawsuit in federal court.

The hope is that a federal judge would step in and declare moratoriums in some areas and restrict the volumes that companies can inject and the pressures they use to force the fluid down. State officials have said they lack the authority to impose a moratorium, though they've shown no desire to do so.

Putting it under a federal judge "takes the politics out of the process," said Scott Poynter, a Little Rock, Ark., lawyer who is part of the legal team pursuing the case. He is currently suing New Dominion on behalf of a woman injured in a November 2011 quake. He has also filed a class-action suit.

Oklahoma had 585 earthquakes last year of magnitude 3 or greater and has already had more than 740 such quakes this year. The Sierra Club's letter says there aren't just more of them than last year -- they're also getting bigger.

Scientists say the unprecedented swarms of man-made earthquakes are likely the result of favorably aligned faults and production methods in Oklahoma that create uniquely large volumes of wastewater. The fluid seeps into the faults, changing the pressure, and they slip.

The Sierra Club's letter says that the quakes have occurred near wells belonging to the four named companies or along faults close to the companies' wells.

Arkansas, Colorado, Texas, Ohio, New Mexico and West Virginia have also had quakes with suspected links to wastewater from oil and gas operations. Additionally, the swarm in north-central Oklahoma has pushed north into Kansas.

Scientists at the U.S. Geological Survey began warning in 2012 that a "remarkable" surge in earthquakes in Oklahoma and the middle of the country was likely linked to disposal operations.

State officials came around to that position in April after years of waffling. Elected officials are reluctant to criticize an industry that is linked to one in five jobs in the state. And some industry leaders exerted pressure on scientists when they voiced concerns that the shaking might be linked to oil operations (EnergyWire, June 23).

The Oklahoma Corporation Commission, which regulates oil and gas in the state, has restricted volumes and pressure in two areas in the state, including near the pipeline hub of Cushing. Before that, it focused on ensuring that wells were not drilled too deep.

A Tulsa company recently challenged OCC's authority to restrict disposal wells because of earthquakes (EnergyWire, Oct. 13).

Two members of the commission have questioned whether they have the legal authority to enact those restrictions. But the third commissioner, Dana Murphy, asserted last week that the commission has statutory authority for emergency response.

Poynter, though, said the question of legal authority remains.

"That is a legal question with merit to it," Poynter said.

Other environmental groups have weighed in on oil and gas wastewater issues. A coalition pressed U.S. EPA for changes in August (EnergyWire, Aug. 27). But their effort didn't focus on earthquakes.