Harned Bowl work not to blame for new sinkhole, say experts
March 5, 2001
Two experts agree: The hole that opened near the bookstore is probably not the result of work done last year to fix the Harned sinkhole.
Architect Lane Lyle, whose company worked at both sites, said the sinkhole, wasn't related to the work in front of Harned.
Workers for his firm placed an impervious cap over that hole and stopped surface water from flowing into it. That water now flows into the city sewer system.
He said that in the past sinkholes were plugged with concrete, but EPA rules now prohibit that practice. "If you plug natural subterranean drainage and the water doesn't find a way out, it will come to the surface. You could create a pond in someone's yard. If you stop that water source below, you don't know what could happen."
Dr. Phillip Kemmerly, professor and chair of the department of geology and geography, served as a consultant for the sinkhole remediation work done on campus. He said the latest hole is a classic example of a human-induced sinkhole and there's a high probability that the latest hole is an isolated event caused by the "backflushing" effect of the groundwater system on campus..
He suspects it's unrelated to last year's remediation work. The sinkholes between Harned and Browning are referred to as the Harned Bowl, the Miller Bowl and the University Center Bowl.
Sinkholes are so common in this area that Kemmerly has hosted two national field trips at APSU for professionals from around the world.
"This is a very famous zone," he said. 'This whole city sits on [an area with] the highest risk for sinkhole collapse in the state, and at the southern end of the second most famous sinkhole zone in the world, a zone that extends to Mammoth Cave in Kentucky and Southern Indiana."
The only place in the world at higher risk for sinkholes is in Slovenia, a former province of Yugoslavia, along the north and east sides of the Adriatic Sea.
When might the next sinkhole open? It's impossible to predict, Kemmerly says. 'We don't know when they'll occur. It's a reality of life here that sinkholes can just open up."