The economy has shrunk, but Santee Cooper's need for landfill space has not.

The problem: 40,000 tons of ash and 30,000 tons of gypsum are piling up each month at the state-owned utility's Cross Generating Station in Berkeley County. The glut is an unintended consequence of a slowdown in the construction business, according to Santee Cooper.

About 90 percent of the ash and gypsum, byproducts of the coal-burning power plant in Cross, is normally sold off to be recycled into building materials, such as concrete and drywall board.

But the sharp downturn in housing and other building activity over the past two years has cut demand for the waste by about half.

Santee Cooper applied to the state Department of Health and Environmental Control in late 2008 to more than triple the height of its existing 90-acre landfill at the Cross site to 130 feet from 40 feet to house the mounting leftovers.

That's not all it's doing.

The Moncks Corner-based power and water utility also has asked the county to rezone 835 additional acres surrounding the existing 1,400-acre plant site from agricultural to heavy industrial use so it can expand its landfill in the future.

No new landfill is imminent, though.

"We would not seek a permit to expand the landfill until we needed it," Santee Cooper spokeswoman Mollie Gore said. "We just want to preserve the right to future landfilling."

About 165 of the 835 acres are earmarked for future landfill space, she said. Most of that acreage is adjacent to the current waste-storage area just off Viper Road, near the generating station.

"We do think there will be some wetlands impact," Gore said. "If a future landfill impacts any wetlands, we will work with the Army Corps of Engineers to look at alternative sites or mitigate the impact.

"Our first goal, however, is going to be to try to recycle as much as we can. Until the economy turned south, we were successful in doing that. We all hope the economy turns around and our landfill expansion will be very, very slow," she said.

Berkeley County Council will consider the rezoning request Monday. A public hearing and possible final approval are set for March 22.

As for increasing the height of the existing landfill, Santee Cooper has demonstrated a need for the change, and the proposed dimensions are consistent with buffering requirements and other regulations, said Juli Blalock, a DHEC project manager and environmental engineer.

"Now they have to submit a formal application," she said, a process that could take a year or longer.

Reach Warren Wise at 937-5524.