Coal Ash Repurpose Proposal FAQ
What is coal ash?
The term ‘coal ash’ refers to the non-combustible residues that remain when coal is burned to generate
electricity. They range in size from small pebbles to a powdery ash. Coal ash typically contains nonhazardous levels of metallic elements, similar to those found in the earth’s crust. The U.S. EPA promotes
the beneficial reuse of coal ash in construction backfill, roadbeds, and in products such as cement,
gypsum and metal alloys.
What is the proposed project?
The City is evaluating the possibility of working with Duke Energy and Charah, a company with more
than 25 years of experience in coal ash management, to use coal ash from unlined impoundments near
Duke Energy’s retired Riverbend Steam Station to a fully lined engineered structural fill for future
appropriate projects at the Charlotte Douglas International Airport. This project is only a proposal. Full
due diligence will be performed on any solutions proposed.
What environmental safeguards are taken for these types of projects?
Similar projects of this kind have included the protection of a synthetic liner system. The coal ash is fully
encapsulated with a liner, in accordance with EPA Subtitle D requirements, and then covered by multiple
feet of dirt. All shipments of the material have been placed in tarped trucks to minimize any impacts to
the public. These trucks are washed at the points of departure and arrival. Water that comes in contact
with the ash is managed through the traditional wastewater treatment process.
What are the benefits to the City?
If this proposal moves forward, this approach could provide an environmentally beneficial repurpose of
coal ash. It also could offset the cost of purchasing dirt for fill to use in future projects at the airport.
Based on similar projects, it also provides the additional potential of creating more than 100 jobs over a
four-year period.
What would be the size of the project, and would it be safe?
While its exact size is yet to be determined, the preliminary estimates indicate the project could include
approximately 4 million tons of coal ash. Coal ash is not regulated as a hazardous material and has been
used for decades in roadbeds, structural fills, cement and concrete products, as well as for landfill cover
and soil stabilization.
Where have similar projects been undertaken?
A coal ash engineered structural fill project has been undertaken at the Asheville Regional Airport.
What are next steps?
There has been some preliminary review by City staff. Duke Energy and Charah have officially invited
the City to engage with them in a due diligence review concerning the project. The Charlotte Mayor and
City Council will hear a presentation on it, as well as additional background on the use of coal ash in the
coming weeks. Management of coal ash at the Riverbend Steam Station has been referred to the City
Council’s Environment Committee for further study and discussion. The City has already begun to
engage key stakeholders including residents, environmental groups, regulators and business
organizations.