Hydraulic fracking has been found to blame for a rash of seismic activity in Youngston, Ohio starting in 2010 and lasting until December 31, 2011. Researchers have measured seismic activity in the area since the late 1700's and the first recorded earthquake hit Youngstown just two short weeks after frackers began using the Northstar 1 injection site to dispose of wastewater from fracking operations in Pennsylvania.
The Northstar 1 well is part of the Marcellus shale which includes areas of Ohio, Pennsylvania and New York and is estimated to hold up to 489 trillion cubic feet of natural gas. That's enough natgas to supply all of New York State's gas needs for 440 years.
Tremors and earthquakes have also been observed near fracking sites in Texas, and researchers suspect Oklahoma's strongest recorded earthquake in 2011 was the result of fracking activities deep below the earth's surface.
Observers noted that seismic activity fell strongly at the Ohio site on holidays including Memorial Day, the Fourth of July, Thanksgiving and other days when crews were off work and the injection site shut down.
Geologists say the injection site is located above an ancient fault line and that pumping wastewater, made slick with residual oil and natural gas liquids, at high pressures caused the fault to become active.
After a magnitude 3.9 earthquake struck the Youngstown area on December 31, 2011, the Northstar 1 well was shut down, and the earthquakes stopped.
During 2011, 177 waste disposal sites similar to Northstar 1 were in full operation, and only Youngstown , Ohio reported tremors. Researchers speculate the injection site was largely unmanned and injection pressures may have exceeded geologic safety limits.
Opponents of fracking will be quick to issue 'I-told-you-so's', but the fact that so many wells operate without seismic disturbance indicates it is possible to inject frack water deep into the ground without blowing up the planet. Remember, this type of extraction and injection is relatively new and industry researchers will take this information and use it to better choose injection sites for fluids under pressure.
The long and the short of it here is that the scientific opinion is not that injecting wastewater 9,000 feet below the surface is harmful -- necessarily. But injection sites located on or near geologic faultlines will have to be handled with extra care. The suggestion has even been made that the 2010-2011 Ohio earthquake outbreak could have been prevented simply by closer observation of pressure gauges during injections.