Oil companies are sued over Okla. quakes

Oklahoma residents are suing several petroleum companies they say have been causing damaging earthquakes across the state.

The lawsuit filed this week comes a month after a 5.0- magnitude quake damaged homes and buildings near Cushing, a small town between Oklahoma City and Tulsa that is home to a major oil storage facility. State officials said about 30 homes were damaged, and the class- action lawsuit names multiple oil companies as defendants.

The lawsuit was filed by the same firm that helped the Sierra Club bring a similar action against other companies for similar damages elsewhere in Oklahoma. All of the lawsuits remain pending. They ask judges to order the oil companies to pay for the damages and to install better monitoring systems.

Experts say the quakes likely are caused by oil companies pumping contaminated water deep underground after pumping it out of newly fracked oil and gas wells. Unlike other areas, underground oil in Oklahoma usually is found mixed with water, and the only way to get out the oil is to withdraw the water.

Scientists have known that deep- injection wells can cause earthquakes, likely by lubricating fault lines andmaking them slip. While the connection between the amount of water pumped down, and at what pressure, remains unclear, there’s a growing consensus the disposal wells are causing quakes in a state that never used to have so many.

“These are human- induced earthquakes, not an act of God,” said Curt Marshall, an attorney with the firm Weitz & Luxenberg, which filed the class- action suit.

Oil and gas companies say injection wells are an inexpensive way to dispose of the contaminated water, and argue themajority of wells cause no problems.