Study links injection wells, rise in quakes

Staff report

The abstract of a federal study has been released that indicates a sixfold increase in earthquakes in 2011 compared with the average that are related to deep wastewater-injection wells.

The study conducted by the U.S. Geological Survey focused on an area that spanned from west of Ohio to Utah. It included areas such as the Guy, Ark., region and Horton, Okla.

The acceleration in earthquakes that began in 2009 appears to involve regions used in oil and gas production, according to the study.

In Oklahoma, the average number of earthquakes increased from 1.2 per year in the previous 50 years to more than 25 in a year, according to the abstract.

“A naturally occurring rate change of this magnitude is unprecedented outside of volcanic settings or in the absence of a main shock, of which there were neither in this region,” according to the abstract.

This study comes about a month after the Ohio Department of Natural Resources researched and determined a link between seismic events in the Youngstown area and deep wastewater-injection wells. There were a total of 12 earthquakes with epicenters in the Youngstown area starting March 17, 2011.

ODNR’s determination led to a number of new regulations on injection wells in the state.

The full U.S. Geological Survey study will be released April 18.