UT Geologist Studies Red Clay Pollution

KNOXVILLE, Tenn. — Red clay dirt and shale are part of East Tennessee’s unique landscape, but they also present a unique environmental problem, a University of Tennessee-Knoxville geologist said Tuesday.

Dr. Larry D. McKay said it is difficult to track, clean and predict the flow of pollutants in red clay and shale. Much of the research on the movement of pollutants has been done in other types of soils.

McKay is studying the problem as part of a new U.S. Department of Energy plan to invest nearly $50 million in environmental research.

McKay said solvents such as those used by dry cleaners, electronics manufacturers and machine shops are very dense. When spilled on the ground, they sink through soil, cracks in rock, and the water table, he said.

Groundwater slowly spreads residue through tiny pores and cracks, causing widespread contamination. A single spill can act as a long term source of pollution that is difficult to remove, he said.

“Solvents’ movement through red clay and shale

can be quite erratic and hard to predict,” McKay said. “When there is a spill, we often have a great deal of difficulty even figuring out where the contaminant has gone.

“There’s been a lot of work done on these solvents in sand and gravel, which are simple systems. Of course, the problem is that a good portion of the world is not nice, simple sand and gravel.

“Very little work has been done on fractured rock and clay, which is the predominant ground structure in East Tennessee. Improving our understanding of it can have a very immediate effect on how we deal with it.”

Contact: Dr. Larry D. McKay (423-974-2366)