Dec. 22, 2008, was filled with anticipation of Christmas in Roane County, Tenn., 85 miles northeast of Chattanooga.
What no one anticipated was the failure of a retaining dam, and 5.4 million cubic yards of coal ash spilled into the Emory River.
Also called “fly ash,” this byproduct of power generation covered the entire floodplain with black sludge, knocking houses off their foundations and uprooting trees. The subsequent seven-year cleanup, handled by the Environmental Protection Agency Superfund, cost $1.2 billion. In the years following this disaster, the federal government was criticized for not regulating coal ash disposal more tightly.
Good news came from Georgia Power last month. The company’s June 13 press release states that “all of the company’s 29 ash ponds across the state will cease operations and stop receiving coal ash within the next three years.” In existing ash ponds, the waste is going to be removed completely, or isolated from the environment with concrete barriers. Overall, Georgia Power is looking at a $2 billion investment to make it happen.
Disposing of coal ash is not an unsolvable problem. It can be recycled by using it as an additive to concrete. There again, the news is good. Science Daily introduced a new mix of concrete a few years ago, substituting coal ash for Portland cement. The resulting product, called “geopolymer,” is found to last hundreds of years, compared to ordinary concrete, whose life expectancy is only in a range of decades.
Mining and processing Portland cement contributes between 3.4 percent and 8 percent of carbon dioxide to the atmosphere worldwide, according to figures from the EPA and other sources. Substituting geopolymer for conventional cement results in a huge decrease of carbon dioxide emissions. This would be a good move for China, the world leader in coal and concrete usage.
Even better than just recycling coal ash is to cut down on coal as a power source. Five years ago, coal accounted for almost two-thirds (62 percent) of power production in Georgia. According to Public Service Commissioner Stan Wise of Cobb County, coal-powered generation of electricity dropped to 28 percent in 2015, and further reductions are anticipated.
“This is remarkable progress,” Wise said, “considering it was as high as 75 percent in 1994 when I was first elected.”
With its aggressive measures to reduce coal ash and the use of coal in generators, Georgia Power is demonstrating serious progress in protecting our state’s environment.
Rudi Kiefer, Ph.D., is a professor of physical science and director of sustainability at Brenau University. His column appears Sundays and at gainesvilletimes.com.