COLUMBUS, Ohio (AP) — A dozen earthquakes in northeastern Ohio were almost certainly induced by injection of gas-drilling wastewater into the earth, Ohio oil and gas regulators said Friday as they announced a series of tough new regulations for drillers.
Youngstown, Ohio was hit on Christmas Eve and on New Year's Eve last year by earthquakes measuring 2.7 and 4.0 on the Richter scale, respectively. No one was injured and only a few cases of minor damage were reported after the Dec. 31 event. Another nine small quakes had been reported throughout 2011, all within a five mile radius of a wastewater injection well run by Northstar Disposal Services.
Northeastern Ohio and large parts of adjacent states sit atop the Marcellus Shale geological formation, which contains vast reserves of natural gas that energy companies are rushing to drill using a process known as hydraulic fracturing.
That process involves freeing the gas by injecting millions of gallons of water, laced with chemicals and sand, into the earth. But that water needs to be disposed of when companies are done with it. Municipal water treatment plants aren't designed to remove some of the contaminants found in the wastewater, including radioactive elements. A common practice is to re-inject it into the ground, a practice banned in some states.
Scientists believe the fluids from fracking act as a lubricant for undergound rock faces, causing them slip and trigger seismic events.