COLUMBUS, Ohio -- A dozen earthquakes in northeastern Ohio were almost certainly induced by injection of gas-drilling wastewater into the earth, state regulators said Friday as they announced a series of tough new rules for drillers.
Among the new regulations: Well operators must submit more comprehensive geological data when requesting a drill site, and the chemical makeup of all drilling wastewater must be tracked electronically.
The state Department of Natural Resources announced the tough new brine injection regulations because of the report's findings on the well in Youngstown, which it said were based on "a number of coincidental circumstances."
For one, investigators said, the well began operations just three months ahead of the first quake.
They also noted that the seismic activity was clustered around the well bore, and reported that a fault has since been identified in the Precambrian basement rock where water was being injected.
"Geologists believe it is very difficult for all conditions to be met to induce seismic events," the report states. "In fact, all the evidence indicates that properly located ... injection wells will not cause earthquakes."
Northeastern Ohio and large parts of adjacent states sit atop the Marcellus Shale geological formation, which contains vast reserves of natural gas that energy companies are rushing to drill using a process known as hydraulic fracturing.
That process involves freeing the gas by injecting water into the earth, but that water needs to be disposed of when companies are done with it. Municipal water treatment plants aren't designed to remove some of the contaminants found in the wastewater, including radioactive elements. A common practice is to re-inject it into the ground, a practice banned in some states.
Past earthquakes have been linked to energy exploration and production, including from injections of enormous amounts of drilling wastewater or injections of water for geothermal power, experts said.
They point to recent earthquakes in the magnitude 3 and 4 range -- not big enough to cause much damage, but big enough to be felt -- in Arkansas, Texas, California, England, Germany and Switzerland. And in the 1960s, two Denver quakes in the 5.0 range were traced to deep injection of wastewater.
The improper placement of the Youngstown well stemmed in part from inadequate geological data being available to regulators, the Ohio report states. New rules would require a complete roll of geophysical logs to be submitted to the state.
"These logs were not available to inform regulators of the possible issues in geologic formations prior to well operation," the document says.
Requiring well operators to submit more comprehensive geologic data is just one of the added regulations the department will either impose immediately or pursue through legislative or rule changes.
Among other changes:
-- Future injection into Precambrian rock will be banned, and existing wells penetrating the formation will be plugged.
-- State-of-the-art pressure and volume monitoring will be required, including automatic shut-off systems.
-- Electronic tracking systems will be required that identify the makeup of all drilling wastewater fluids entering the state.
"Ohio has developed a new set of regulatory standards that positions the state as a national leader in safe and environmentally responsible brine disposal," Natural Resources Director James Zehringer said in a prepared statement.
"Ohioans demand smart environmental safeguards that protect our environment and promote public health. These new standards accomplish that goal," he said.
The U.S. Environmental Protection Agency gave Ohio regulatory authority over its deep well injection program in 1983, deeming that its state regulations met or exceeded federal standards. The new regulations would be added to those existing rules.