The ash left over from burning coal in power plants to generate electricity is used in the construction industry, especially in making concrete for transportation infrastructure.
A new study sponsored by the foundation of the American Road and Transportation Builders Association, concludes that "infrastructure costs would rise by $5.2 billion annually if coal ash were unavailable for construction purposes," according to an item in the newsletter from the Interstate Mining Compact Commission. "More than 75% of concrete used to build and maintain U.S. transportation infrastructure relies on coal ash as a component in its cement blend, according to the foundation." Some ash is also used in roofing and wallboard, but a lot stays in ponds or dry landfills.
The study was prompted by anticipated EPA rules for regulating coal ash under the Resource Conservation and Recovery Act (RCRA). The study "claims road and bridge construction costs would soar if the EPA regulates coal ash as hazardous waste." The collapse of a coal ash pond in Tennessee in 2008, triggered a re-examination of similar ponds nationwide.
Two Arizona power plants, Cholla and Apache Station, have a total of nine coal ash ponds, that would be affected by the rules. [Right, Google Earth view of coal ash ponds at Cholla power plant]