Ohio has suspended the underground disposal of wastewater from natural-gas drilling operations "indefinitely" in the Youngstown after a series of 11 recent earthquakes, including one on Saturday with a magnitude of 4.0.
(GlobalPost reports: Eastern Ohio hit with 4.0-magnitude earthquake)
The Ohio Department of Natural Resources said it was halting operations at five Mahoning County wells owned by Northstar Disposal Services LLC as a precaution, citing concerns of a possible link between well activity and the quakes.
"We are being overly cautious in order to ensure public safety in asking the company to halt disposal injections at one site on Friday and then asking for a halt to any injections in a five-mile radius Saturday," department deputy director Andy Ware told the news agency.
Like the other earthquakes, Saturday's quake was "centered near a well that has been used for the disposal of millions of gallons of brine and other waste liquids produced at natural-gas wells, mostly in Pennsylvania," according to The New York Times.
The quake released at least 40 times more energy than any of the previous 10 or more tremors that had rattled the region in 2011, CNN reported.
Ware told CNN that Ohio Department of Natural Resources Director James Zehringer and Gov. John Kasich subsequently ordered that four nearby injection well projects will not open in the coming weeks, as had previously been planned.