CHARLOTTE, N.C. -- Duke Energy has already started drying out its coal ash ponds on the banks of Mountain Island Lake.
Duke would like to move this ash to the Charlotte Douglas Airport and use it for fill dirt under new runways – wrapped in a liner like a giant burrito – a construction material known as “structural fill”.
Airport and city leaders are backing away from that idea.
But an engineer affiliated with the University of North Carolina at Charlotte’s Energy Production and Infrastructure Center, known as EPIC, encourage Charlotte to remain open to the idea.
“It's been done in many places. And there are studies on this that say it's actually one of the preferential fills if you have a large quantity of excess ash,” said Chris Hardin, a professional engineer and industry partner at EPIC.
As an engineer, Hardin has literally put his stamp of approval on the use of coal ash as structural fill in other construction projects.
Hardin says the risks of using coal ash at the airport would be minimal since there are no water wells nearby and the coal ash can be locked up in liners or even cement.
“You can't say you've done all your due diligence in a couple of days or couple of weeks; you have to look into it and there really is a responsibility to work with the local utility,” Hardin said.
Interim Aviation Director Brent Cagle and Assistant Charlotte City Manager Hyong Yi have both expressed serious doubts about the use of coal ash as structural fill at the airport while saying the due diligence investigation is ongoing.
“I think it’s time to sharpen the pencils and look at all the options,” said John Daniels, the interim chair of UNCC’s department of civil and environmental engineering.
And Ed Driggs, the vice-chair of the city council’s environmental committee, has said the city should know the other alternatives for the almost 5 million tons of coal ash now sitting at the old Riverbend Steam Station on Mountain Island Lake before dismissing the airport option out of hand.