An underground wastewater disposal from oil and natural gas production is to blame for the third-largest earthquake in Oklahoma, according to a report issued Monday by the U.S. Geological Survey.
The USGS said the 5.1 magnitude earthquake that struck northwest of Fairview in February was likely induced by distant disposal wells. The agency’s report revealed the area’s volume of injected fluid had increased more than seven times over three years.
The Fairview tremor had been the largest in the central U.S. since the 2011 Prague earthquake which registered a 5.7 magnitude on the Richter scale. In September, a 5.8 magnitude earthquake occurred near Pawnee, becoming the largest earthquake recorded in the state. A study is being conducted to examine the relationship between wastewater injection activities and the Pawnee earthquake.
In 2016, a USGS study suggested that the sharp rise in Oklahoma earthquakes during the past century was presumably the result of industrial activities associated with the oil and gas industry.
The Oklahoma Corporation Commission is the state regulatory agency responsible for oil and natural gas oversight. State regulatory officials have taken action regarding disposal wells in specific zones around the state based on seismic events, including modification of the reporting requirements for Arbuckle formation disposal wells.
In response to research suggesting a link between the earthquakes and wastewater disposal practices, state regulators have ordered the shutdown of some disposal wells and asked producers to reduce disposal volumes in earthquake-prone regions of the state, according to the USGS.