The Ohio Department of Natural Resources on Monday ordered a drilling company to halt operations in Mahoning County in the wake of two small earthquakes there.
The order affects Hilcorp Energy, which has been drilling horizontal wells in Poland Township. The company has drilled a dozen wells overall in the area.
The state took its action “out of an abundance of caution,” according to a statement from ODNR.
The order affects only Hilcorp, the only driller in the area at this time.
The two quakes were centered near Lowellville, just west of the Ohio-Pennsylvania line and were about 1.2 miles underground, according to the U.S. Geological Survey.
The first quake occurred about 2:26 a.m. and initially measured magnitude 2.8. It later was upgraded to magnitude 3.0.
It was reportedly under the Carbon Limestone Landfill, where Hilcorp Energy is drilling some of its wells.
The second quake occurred after 11 a.m., southeast of the first quake. It measured magnitude 2.6.
No injection wells are in the area where the quakes occurred, ODNR said.
Injection wells have been blamed for small earthquakes in Ohio and other states, but horizontal drilling has not been linked to earthquakes.
Injection wells came under scrutiny in Ohio after a series of earthquakes around Youngstown last year were linked to an injection well in Mahoning County.
In November, a coalition of Ohio eco-groups and individuals submitted testimony to the U.S. Environmental Protection Agency with citizens’ concerns about injection wells in the state.
The federal government is auditing the Ohio Department of Natural Resources and what critics called the state’s poor oversight of injection wells that handle liquid drilling wastes.
ODNR said Monday it is beginning to analyze all data from the two earthquakes.