OceanaGold has filed an application to expand its operations at the Haile Gold Mine in Lancaster County, South Carolina. Australia-based OceanaGold restarted openpit mining operations at the historic mine about three years ago.

The company is looking to increase the operation by more than 900 acres, the State newspaper reported. 

According to the application filed with South Carolina’s Department of Health and Environmental Control, OceanaGold wants to expand operations with an underground mine that would extend up to 400 m (1,314 ft) below the surface, while combining five existing excavation pits at the site in southern Lancaster County. So far, the company has relied on strip mining to extract gold.

OceanaGold purchased the site from Romarco Minerals in 2015. The company currently employs about 400 people at the mine near Kershaw, according to The State. Employment could increase by about 250 people under the proposed expansion, which still needs approval from South Carolina and federal environmental regulators.

A tailings pond would be enlarged by about 20 percent to handle more mining waste.

At least $2 billion worth of gold was initially projected to exist far below the surface. OceanaGold now wants to mine some gold that previously had been too expensive to dig up. The rising price of gold in recent years has made it affordable to dig for those deposits, the company said. The price of gold last week was about $1,400 per ounce.

Kershaw Mayor Mark Dorman said the mine has provided an economic boost to the one-time textile community since opening. The mine is expected to close in 2031.

The U.S. Army Corps of Engineers plans to conduct an environmental study to see how the expanded mine would affect wetlands and creeks around the mining site. The study could take much of this year to complete.