The Roanoke River - which flows from Virginia’s Blue Ridge Mountains to North Carolina’s Outer Banks - slots in at number three. American Rivers says the watershed provides water to more than one million people for drinking, farming, fishing, and boating.
American Rivers said the problem is not what's in the river now, but what could happen if Virginia lifts a ban on uranium mining.
"There's so much we don't know and there's so much we can't control," explained Andrew Lester with the Roanoke River Basin Association.
Lester has made it his life-mission to stop Virginia from lifting its 30-year moratorium on uranium mining.
"The mining folks think they can bring in 300 people. People need jobs, but think about how many people they're going to run away," Lester offered.
About 60 miles west of Kerr Lake, a company called Virginia Uranium is lobbying for that moratorium to be lifted. They're ready to dig on land just north of Danville that's basically a goldmine for uranium. They'd dig huge holes in the ground, grind up the dirt, extract the big pieces of uranium, and then put what's left - what are called "tailings" - into huge containment cells. That's the part where Lester and other critics say they start getting worried.
"These tailings, once they're exposed to rain and oxygen, they decay and they form what's called their 'children,' which are really bad things," said Lester.
Most agree that if the containment cells do what they're supposed to, those tailings aren't a problem. But it's that if that put the Roanoke River on the ten most endangered list and has so many, so concerned.
"You've got the next generation and the next generation coming along and I'm concerned about them and their health," Sythe Hill, Virginia resident Tip Waller told ABC11.
The proposed mining site is located just off the Route 29 corridor - an area that Lester says is prone to hurricanes, tornadoes, and even small earthquakes.
"It's very vulnerable terrain," he said.
If uranium did get into the Roanoke River, it likely go downstream to Kerr Lake, Lake Gaston, and then through Roanoke Rapids - all the way on to the ocean, to the Outer Banks.
But Virginia Uranium disputes the claims and concerns of environmentalists.
"It really is a safe industry," said project manager Patrick Wales.
Wales said the containment cells would be located underground, making them less prone to environmental catastrophe. He points out other uranium mining sites in Florida and Louisiana have proven safe despite more powerful and more frequent hurricanes than North Carolina usually sees.
And, he says the building requirements for the containment cells are more rigorous than almost anything else in the country.
"These are not things you throw up willy nilly," he said. They have to be designed for 1000 years. I'm not sure of anything we build in this country, infrastructure-wise, that has a design criteria lifetime of 1000 years."
But for Lester, all those assurances don't add up to a guarantee that nothing will go wrong. He told ABC11 he fears just question mark alone will have consequences all its own.
"It's the stigma. Even if it was a pristine operation mining wise, the stigma itself will be a problem for any economic development," he said. "Everything east of the location - to the ocean front, to the Outer Banks - has everything to lose and nothing to gain."
Nothing to gain perhaps except hundreds of new jobs and a new industry in an area that's seen its share of shuttered doors. It's a debate playing out in the Virginia legislature right now, but one that could have life-altering effects for North Carolinians down river.
Since we have a big stake in Virginia's decision, there's a two-state panel set to meet on the moratorium later this month in Roanoke Rapids:
Roanoke River Basin Bi-State Commission
Monday, May 23, 2011 from 10:00a.m. until 12:00p.m.
Halifax Community College, Building 1, Room 108, 100 College Drive, Weldon, NC 27890.
An agenda can be found here.