A newspaper analysis finds that the average number of 2.0 magnitude and higher earthquakes occurring in Ohio each year has risen.
The rise reported by The Columbus Dispatch coincides with an average increase in tremors nationally and to an increase in oil-and-gas drilling and deep injection activity in eastern Ohio.
Ohio Department of Natural Resources data reviewed by the newspaper showed Ohio averaged two earthquakes annually of 2.0 magnitude or greater between 1950 and 2009. Between 2010 and 2014, that average rose to nine.
Ohio officials are advising oil and gas companies to share information on the toxic chemicals they use with local authorities, including first responders.
The Columbus Dispatch reports that Ohio notified companies this month that federal disclosure law trumps a 2001 state law requiring only that the information be filed with the Ohio Department of Natural Resources.
The amount of waste from the shale gas and oil drilling process injected into disposal wells in Ohio is continuing to rise.
The Ohio Department of Natural Resources says that 14.2 million barrels of fluids and other waste from the process of hydraulic fracturing - or fracking - were injected into disposal wells in the state in 2012. That was up 12 percent from the previous year.
Officials say drilling in Ohio's Utica shale region nearly doubled the output of oil and natural gas there since 2011.
The Ohio Department of Natural Resources announced Thursday that the drilling process known as hydraulic fracturing, or fracking, in the shale region of eastern Ohio increased the oil output by 93 percent and the natural gas output by 80 percent in that time.
Some environmentalists are asking the federal Environmental Protection Agency to do a full audit and investigation of the Ohio Department of Natural Resources, the state agency that grants permits for injection and extraction wells. Brian Rothenberg of Progress Ohio says the state agency is not doing due diligence in regulating those wells in Ohio.