A well used to dispose of fracking-related fluids in the northeastern corner of Ohio is believed to have been responsible for about a dozen minor earthquakes in the town of Youngstown over the past year, with the latest one coming on New Year's Eve, according to state regulators.
Following the most recent quake, the operations at the wastewater well and four production wells were suspended. Northstar Disposal Services LLC of Youngstown, the owner of the four wells, said it voluntarily shut down the wastewater well. The four other wells were already inactive, according to the company.
The Ohio Department of Natural Resources (DNR) ordered Northstar Disposal to halt operations at the wells, saying it was concerned that storing wastewater from hydraulic fracturing (fracking) operations in the injection well might have triggered the quake activity. Thousands of gallons of brine were injected each day into the Youngstown well, which opened in 2010.
After the largest quake last Saturday (4.0 magnitude), DNR officials said they suspected that injecting wastewater near a fault line may have caused the earthquake. John Armbruster, a seismologist associated with Columbia University's Lamont-Doherty Earth Observatory in Palisades, NY, believes it may take as much as a year for the quake activity to subside.
The quake activity in the Youngstown area began on March 17 and lasted through Christmas Eve (2.7 magnitude) and New Year's Eve.
"We believe the situation in Youngstown is a rare and isolated event that should not cast doubt about the effectiveness or usage of Class II injection wells, which have been used safely and reliably as a disposal method for wastewater from oil and gas operations in the U.S. since the 1930s and is the preferred method for oilfield waste management under the Safe Drinking Water Act," said Thomas E. Stewart, executive vice president of the Ohio Oil and Gas Association (OOGA), which represents 1,700 oil and natural gas producers within the state.
He said the OOGA "fully supports" the Ohio DNR's decision to suspend the well operations while it investigates whether there is a correlation between the disposing of oil and gas wastes and the earthquake activity in and around Youngstown. "We want firm, scientific proof [from Ohio DNR] to establish that" this is the case, he said.
Stewart said there are 180 Class II underground injection wells up and down eastern Ohio into which 7 million bbl of waste are injected each year. This has been taking place since 1985, and this is the first time that concerns about earthquakes have been raised, he said.
Earthquakes in Arkansas last year were thought to be related to wastewater injection wells in that state. Regulators established a moratorium on such wells in the region of the quakes (see Shale Daily, July 29, 2011).