Kansas Geological Survey says earthquake problem continues

? A reduction in the number of earthquakes rattling southern Kansas should not make anyone complacent about studying the problem, according to the head of the Kansas Geological Survey.

Oil-waste regulations that seem to have contributed to lowering the number of earthquakes are set to expire Sept. 13. But Rex Buchanan said this week at a seminar that it doesn’t mean people should view it was a problem “that has gone away or is going away.”

“I think we would be pretty short-sighted if we did look at this that way,” he said. “We’ve got to look at other places and we’ve got to be better prepared than we were last time.”

The Kansas Corporation Commission approved regulations in March to limit the underground disposal of saltwater that comes up with the oil during drilling. Injecting that water back into the ground is considered a likely cause of increased earthquakes in Oklahoma and Kansas, The Wichita Eagle reported. The KCC staff is staff is currently drafting recommendations on how to proceed after the regulations expire.

Kansas recorded 115 earthquakes so far this year, compared with 127 last year. Most of those quakes were felt before the reduction in wastewater injection, Buchanan said. Since then, the quakes have been less frequent and smaller. The reduction also could be attributed to a drop in oil production due to falling prices, he said, but that oilfield activity — and its resulting waste — eventually rebounds.

The problem is compounded in Harper and Sumner counties, where wells produce about 16 barrels of wastewater for every barrel of oil, said Lynn Watney, senior scientific fellow with the geological survey. That wastewater is too salty to be responsibly disposed of above ground, Buchanan said.

“When I was a kid, we put it in evaporation pits out in central Kansas,” he said. “The water just went into the subsurface and contaminated the shallow groundwater and we’re still dealing with that today, particularly up in the Halstead-Burrton area.”

David Garrett, an environmental scientist for the Environmental Protection Agency, said the federal agency is not aware of any underground source of drinking water being contaminated as a result of seismic activity caused by wastewater injections.

Buchanan said scientists studying human-induced earthquakes are more informed than they were a year ago, partially because of more monitoring. Three years ago, Kansas had only two monitoring stations but it now has 21 state and federal monitoring sites in southern Kansas and work is underway on a statewide monitoring network, he said.