"I had a previous recollection of what the river was supposed to look like, and then you come back in five-year intervals, and suddenly there was coal everywhere," he said. "It was shocking to me."

Deputy TDEC Commissioner Paul Sloan said the department has classified the Clinch as a "high quality" stream, though it is open to revisions of that standard and is in the process of seeking updated information."

"Why don't we know?" said Sen. Doug Jackson, D-Dickson, in one hearing after hearing a TDEC report. "To sit here and say, 'We don't know,' is no excuse. That's a bigger crime in some respects than the pollution in Virginia."