Sanford, N.C. — State geologists say North Carolina's Sandhills region is sitting on a bonanza of natural gas, but some residents say the energy isn't worth the risk of drilling for it.

The shale rock throughout the region, which is as much as 800 feet thick in places, contains enough natural gas to satisfy North Carolina's needs for 40 years, according to experts. Three test wells were dug 20 years ago in Lee County to test for gas, but no one has been able to go further.

Simple drilling for the gas isn't possible because of the high cost of extracting limited amounts from deep deposits. But a technique known as hydraulic fracturing, or "fracking," has been shown to increase output and lower costs.

In fracking, after drilling down a few thousand feet, crews drill horizontally and then fill the cavity with chemicals and water.

"You put that water under a great deal of pressure, which fractures the rock," releasing natural gas, said Russ Knight, a Lee County landowner who helped form a group called North Carolina Oil and Gas.

Knight said he favors gas exploration in the area if it can be done safely and if landowners can be properly compensated.

“Further regulations have to be put in place for us to feel overly confident in doing this in a safe way,” he said.

The question of safety is what brings controversy to the surface in the fracking debate.

"The U.S. Mint can't print enough money to induce me to let fracking take place on my land," said Moore County landowner Joe McDonald, who heads up a group called Save Our Sandhills.

McDonald says the group has not taken an official position on fracking.

“I’m concerned not just about the fracking operation, but the clearing of land and installation of equipment and truck traffic," he said.

Opponents say fracking poses environmental risks like contaminated groundwater. State geologists and environmental officials held a meeting in Sanford Monday night to address people's concerns.

Fracking proponents said such risks are overstated, and North Carolina cannot afford to ignore its own energy reserves.

“There is no real history of problems from fracking anywhere,” said Russ Patterson, a geologist with Patterson Exploration Services of Sanford.

"It's under us, and it's accessible," landowner Benny Lee said. "I think it would be foolish for people think that we shouldn’t explore it."