The wells are for disposal of waste fluid left over from hydraulic fracturing. Also known as fracking, it involves injecting water, sand and chemicals deep into the ground at high pressure. That cracks the underground bedrock and allows oil or gas to flow. At the end of the process, there can be millions of gallons of waste-water.
The US Environmental Protection Agency explains that the wastewater can be injected into porous rock or soil underground. That’s a fluid injection well.
The Ohio Department of Natural Resources announced Friday that one injection well was closed after a series of small earthquakes in and around the well site. Then on Saturday, a magnitude 4.0 earthquake struck, releasing 40-times more energy than any of the other nearby tremors in 2011. Earthquakes are not unprecedented in the area. But the natural resources department told CNN that the state was prompted to act because there have been more of them in the past year.
Governor John Kasich is a fracking supporter. CNN reports that after Saturday’s quake, he ordered the delay of four other nearby injection wells. The wells will be out of operation until an investigation into a possible link between the earthquakes and the wells is complete.