Concrete is the most used building material in the world, but unfortunately it also leaves a major carbon dioxide footprint because of one of its main binders. Portland cement, concrete's main binding agent, accounts for between 5% to 7% of the world's carbon dioxide emissions.

Although new technologies are being developed to help with this problem, there is a viable solution for the time being—fly ash. Fly ash is a coal-combustion product that can be used constructively in many applications, including concrete. According to the American Concrete Institute, there was a 15-million-ton reduction of carbon dioxide production in 2007, thanks to the incorporation of fly ash into concrete.

Now fly ash may be labeled as a “special waste” after a dike containing a 40-acre ash storage pond at the Kingston Fossil Fuel Plant in Kingston, Tenn., failed, resulting in 5.4 cubic yards of coal ash in the Emory River, tributaries, and ponds. The spill also damaged homes and the area's ecosystem, giving a clean-up price tag of between $525 million to $825 million dollars.

This dike failure caused the Environmental Protection Agency (EPA) to publish two potential rulings under the Resource Conservation and Recovery Act (RCRA) that could classify fly ash as “special waste.” Doing this could give fly ash a public stigmatism, and could eventually lead to the removal of fly ash for beneficial use.

Under the EPA's first proposal, coal combustion residuals (CCRs), which include fly ash, would be regulated similar to hazardous wastes under RCRA Subtitle C. Under the second proposal, CCRs would be regulated as solid waste under RCRA Subtitle D.

Although the proposal addresses disposal of CCRs, it also discusses the impact that the rule would have on the beneficial uses for CCRs.

The two potential rulings put out by the EPA on June 21 are currently out for public comment for 90 days. Visit to voice your opinion, or learn more by reading details of each proposed rule and to take a survey to help the ACI provide input to the EPA. Submit your feedback to the ACI by visiting