Oklahoma Earthquake Linked to Oil Extraction Wastewater

Injecting millions of liters of water and chemicals into the ground for drilling oil and gas has been linked to seismic events, including a 5.7 earthquake in Oklahoma in 2011. A study in the journal Geology suggests that related seismic activity can occur years after wastewater injections begin. “The new study adds to an increasing body of evidence that the injection of wastewater is correlated to an increase in seismic events,” reports Jason Palmer for BBC News, though the events are few in relation to the number of drilling and wastewater injections underway throughout the United States. Other seismologists argue the earthquakes could naturally occur. The Oklahoma earthquake followed conventional oil drilling, and studies will continue as researchers look into fracking, during which “water, sand and chemicals are injected into petroleum wells in a bid to extract trapped natural gas.” The EU prohibits such wastewater injections, and a ban was just lifted in Britain. Another concern from such injections, too, is contamination of groundwater. – YaleGlobal