YOUNGSTOWN - A fluid injection well here has been shut down through an agreement between the Ohio Department of Natural Resources and the well's owner following a series of earthquakes.
The well is located on the property of D&L Energy Group property, 2761 Salt Springs Road. It is owned and permitted by Northstar Disposal Services LLC of Youngstown.
ODNR Director James Zehringer said there is no conclusive evidence linking the seismic activity to the well, but the agency is taking a cautious approach.
"We are going to make sure this process is done right and won't hesitate to stop operation of disposal sites if we have concerns," Zehringer said in a statement. "And while our research doesn't point to a clear and direct correlation to drilling at this site and seismic activity, we will never gamble when safety is a factor."
The injection well is used to dispose of wastewater that's a byproduct of oil and gas drilling. Thousands of gallons of brine are injected into the well daily, and much of it is shipped in from out of state.
Earthquakes that register above 4 magnitude are typically known to cause surface damage, ODNR noted.
Following a series of low-level quakes this year in the area surrounding the injection well, ODNR invited Columbia University's Lamont-Doherty Earth Observatory to position four seismometers in the area to capture more detailed information about seismic activity.
"Information freshly obtained from the Columbia University scientists, and further analyzed by ODNR geological experts, indicates that an earthquake occurred on Dec. 24 approximately two miles below and within a mile of the injection site," Zehringer said. "As a precautionary measure we've reached agreement with the well's owner to halt injections until we are able to further assess and determine any potential links with recent seismic events."
So far this year, ODNR's seismic monitoring network has documented 10 seismic events occurring within two miles of this injection well. Each of these events registered at 2.7 magnitude or lower.
"It is because there were so many in a relatively small area that we decided to look at these earthquakes," Mike Hanson, coordinator of the ODNR's Ohio Seismic Network division, said earlier. "If it had been only one or two small quakes we probably would not have taken that much of a notice beyond recording that they occurred.
A 4-magnitude quake generally releases approximately 40 times the energy of a 2.7-magnitude event.
Hanson said he is reviewing all of the statistics surrounding the earthquakes.
"These are very small earthquakes," Hanson said. "However, because they were located in a densely population area, they were felt by more people."
Although a series of small earthquakes striking in a single area of Ohio is not common, what has been happening in the Mahoning Valley is not unique.
"We had a similar situation in 2006, where there were multiple earthquakes in an area outside of Ashtabula," Hanson said. "In that case, it clearly was not a man-made occurrence because the earthquakes began in Lake Erie."
The Northstar well is a Class 2 injection well, which means non-hazardous materials are injected into it to release the oil and gas embedded in the rock below. Class I wells may use hazardous materials in the injection.
"There has never been an established connection found in Ohio between Class II wells and earthquakes," Hanson said.
There are 177 Class 2 deep well injection sites operating in Ohio.