For years, the oil and gas industry has been blamed for the increase in seismic activity in various areas of the United States. Previous posts on this blog have tracked the allegations that hydraulic fracturing operations have contributed to seismic activity. A recent earthquake over the weekend has again sparked a debate regarding the alleged connection between hydraulic fracturing and seismic activity.

On Saturday, a 5.6-magnitude earthquake occurred in Oklahoma. The epicenter of the earthquake was located 9 miles northwest of Pawnee, Oklahoma, but reports suggest that several states felt the impact of the earthquake. In light of the earthquake, the Oklahoma Corporation Commission (OCC) issued an order to shut down wastewater disposal wells within a 500-square-mile radius of the epicenter of the earthquake. Officials at the OCC anticipate that the shutdown will impact 35 wastewater disposal wells.

A number of scientists and organizations have studied potential causes of the increased seismic activity. Some scientists have argued that all wastewater disposal wells in Oklahoma should be investigated to ensure the wells are not close to fault lines or areas with high levels of seismic activity. In fact, some scientists have urged states to encourage the oil and gas industry to develop alternative forms of disposal. Ohio has applied some of these suggestions by prohibiting deep injection wells close to fault lines. These scientists have suggested that the increased seismic activity is the result of the use of wastewater disposal wells in hydraulic fracturing operations. However, the wastewater in the disposal wells primarily consists of saltwater, not the fluids used in hydraulic fracturing.