KNOXVILLE — A barren mountain of mine tailings in Polk County, Tenn., is proving fertile ground for University of Tennessee researchers testing new techniques for reclaiming spoiled terrain.
A research team led by Dr. Tom Ammons from the UT Institute for Agriculture is testing methods that may bring vegetation to 350 acres of desertlike limestone sand left from copper mining in the 1960s and ’70s.
The sand is all that remains of a large pond used to hold the spoils from the mill that processed copper ore. In places the tailings are 60 to 70 feet deep.
“We found that the soil was lacking in phosphorus and other nutrients,” said Ammons, whose background includes research in reclaiming abandoned strip mines. “Surprisingly, we didn’t find any contamination by heavy metals.”
Ammons’ team is testing a variety of plants and different phosphorus applications to see which will produce the best ground cover. They are also testing the effectiveness of sewage sludge in making the tailings fertile, using sterilized sludge from a Chattanooga waste treatment plant.
“We’re giving Mother Nature a hand,” said UT graduate student Thomas Cook, a Nashvillian who is monitoring the two one-acre test plots.
An evaluation of the project after a year found both phosphorus and sewage sludge treatments were successful in giving grasses a foothold on the barren soil, Ammons said. The sludge gave the vegetation a faster start but, because the two treatments offer different nutrients, the non-sludge plot may be more effective in the long term, Cook said.
The research is funded with a $215,000 grant from Glenn Springs Corp., a subsidiary of Occidental Petroleum, which owns the property and plans to remediate it.
Research assistant Vanessa Stevens of Camden, Tenn., is studying two major wetlands created when the tailing pond was drained. Stephens estimates that 57 acres are classified as wetlands, and she is studying the surrounding soil to determine how far the moisture extends into the tailings.
Given the scarcity of wetlands in East Tennessee, Glenn Springs is concerned that these be preserved.
“We don’t want anything we do to contaminate our wetlands,” said Franklin Miller, the company’s vice president for operations.