“It is believed that the power outage may have created a situation where a number of producing wells were shut in, then simultaneously came back on line,” the letter states.

“When the wells began producing again, this apparently resulted in a tremendous volume of produced water being disposed into the Arbuckle formation at the same time.”

The Corporation Commission recommended that if a similar power outage occurs in the future, production volumes should be phased in over a period of time. However, the letter gives no direction on what is acceptable in that regard.

Spokesman Matt Skinner said Oil & Gas Conservation Division staff found data that indicates a potential correlation among power outages at the disposal well sites, sudden resumption of disposal well operations and the earthquakes.

“It’s essential that we make that data known to the research community for its analysis and recommendations,” Skinner said. “Because we have been told by experts that sudden changes in the pressure in seismically active areas pose a potential risk of inducing earthquakes, it is important that operators know of this data, as well, and why OGCD is recommending gradual start-ups after power failures.”