Senate Environment and Conservation Committee Chairman Tommy Kilby, D-Wartburg, plans to lead a fact-finding mission to the river's edge on Friday to find out.
The group, including committee members and state wildlife officers, will wade into the river in the Hancock County town of Kyles Ford, just south of the Virginia border.
"We're afraid that the river is in danger," Kilby said.
In recent weeks, Kilby's committee has heard testimony in Nashville from the Tennessee Wildlife Resources Agency and others that the Clinch, part of the Tennessee River system, is increasingly contaminated by coal sediment and perhaps by chemicals used in the mining and processing of coal.
Don Hubbs, a TWRA biologist, said his periodic surveys of mussels in the Clinch over the past 15 years suggest the shellfish population has plunged as coal silt increased.
"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."
Hubbs said 19 of the 41 shellfish in the river are federally endangered. Because they filter bacteria in the water, he called them the proverbial canary in the coal mine for river health.
Mike Abbott, spokesman for the Virginia Department of Mines, Minerals and Energy, said his state's coal mine regulatory system is "consistently rated as one of the top programs in the country" by the U.S. Office of Surface Mining.
"We do have controls on this," he said, adding his agency has provided that information to Tennessee wildlife and environmental officials.
The Tennessee Department of Environment and Conservation, responsible for monitoring stream quality and enforcing anti-pollution rules, has failed to document any problems with the Clinch. That's frustrating Kilby and his colleagues.
"That's a bigger crime in some respects than the pollution in Virginia," said Sen. Doug Jackson, D-Dickson.