COLUMBUS, Ohio — The 4.0 magnitude earthquake near Youngstown last New Year’s Eve brought the practice known as fracking to a halt. But the controversial drilling technology, which involves high-volume, deep-shale hydraulic fracturing to reach gas below the ground’s surface, has been given the green light in Ohio.

This month the Ohio Department of Natural Resources (DNR) officials gave the go-ahead to proceed with 31 scheduled wells, including eight in Portage County alone. That county already has 16 active wells. Portage County is expected to have as many as 25 injection well sites, which would make it the leading disposal area for fracking waste in the state.

The new wells are the first to be approved since that earthquake nearly a year ago. Officials at Columbia University say the quake was likely caused by fluid from an underground injection well leaking into a fault line.

Fracking was once front-page news, but during the past 11 months remained a quiet topic. State regulators shut down five wells at the epicenter of the earthquake and froze the application process. New well construction rules are in place and seismic testing will be ordered by the DNR before any new injection wells can be approved.

With drilling set to resume, critics persist with concerns about seismic activity linked to injection well sites across the state, as fears that these wells could seep into drinking water, something that has reportedly never happened in Ohio.

Right now, Ohio’s 179 active injection wells are the disposal sites for oilfield waste fluids that are the product of fracking, in which millions of gallons of chemical-laced water are used to crack open rock formations holding gas deposits deep under the Earth’s surface.

State records show Ohio on pace to store a record amount of the waste in 2012, nearly 14 million barrels. The barrels of waste typically contain a brine-water mix including chemicals used in the oil and gas production process, some of them toxic.

Tom Stewart, vice president of the Ohio Oil and Gas Assoc., said the new injection wells in Ohio are needed to lower prices for disposal, which have risen as demand has increased in recent months.

“Like anything else, it’s market-driven,” he said. “As the capacity has become constrained, the costs to dispose have increased for producers.”

According to Stewart, injection wells are the safest place to store waste until technological advancements someday allow for full recycling of fracking waste fluids.