CHARLOTTE -- The Catawba River is number five on the newly released list of America's Most Endangered Rivers. American Rivers ranked the Catawba that high mainly because of concerns about the effects of coal ash pollution on water quality and recreation.  The rivers runs through both Carolinas.

The environmental group argues the soon-to-be-closed Duke Energy Riverbend coal ash pond near Charlotte is believed to be contributing to the pollution. Sam Perkins with the Catawba Riverkeeper said the company must do a better job containing the byproduct of its energy production.

"Holding back the coal ash with an impoundment like this is like piling up your mashed potatoes and trying to hold back the gravy on your plate," he said.

According to American Rivers, coal ash has been dumped into 551 acres of ponds at the Riverbend site that lack liners to protect the ground water. The Catawba River provides drinking water to 1.7 million people. The river flows 300 miles from it's origin in the North Carolina mountains to the coastal wetland.

Peter Raabe with American Rivers said he hopes something can be done before it's too late.

"We have this opportunity now to deal with coal ash and its potential threats in a really responsible way. We're asking Duke Energy to do that, and they've been resistant to that to date," Raabe said.

Recently the Catawba Riverkeeper filed a notice of intent to file a lawsuit against Duke Energy, alleging violations of the Clean Water Act.

The Catawba River topped the list for America's Most Endangered Rivers in 2008, but at that time, it was because of sprawl and urban development. This year, the Colorado River topped the list.

(With Contributions from Stephnaie Carson, North Caroilna News Service)