Post-EPA rule fly ash consumption eclipses pre-recession level

The volume of coal fly ash used in concrete production increased to 13.1 million tons in 2014, exceeding the 12.6 million ton utilization mark set in 2008, according to the American Coal Ash Association’s (ACAA) “Production and Use Survey,” released in late 2015. Increases in the use of synthetic gypsum from power plant emissions control equipment also helped to push the recycling rate for all types of coal combustion products (CCP) to a record 48 percent.

“After a half decade of stalled growth in the utilization of coal combustion products, 2014 finally began to show signs of recovery,” says ACAA Executive Director Thomas Adams, encouraged that the industry is positioned “to once again focus on growing a practice that conserves energy and natural resources, reduces greenhouse gas emissions, and safely keeps ash out of landfills and disposal ponds.”

The volume of coal ash utilization lagged between 2009 and 2013 as the U.S. Environmental Protection Agency pursued a protracted rulemaking process that posed the threat of a “hazardous waste” designation for landfill-bound coal ash. Producers, specifiers and users restricted material use in light of the regulatory uncertainty and publicity surrounding EPA measures. In early 2014, the agency began signaling that the “hazardous waste” designation proposal was off the table and, per a late-year federal court deadline, finalized coal ash disposal regulations under the non-hazardous section of the Resource Conservation and Recovery Act.

The ACAA survey finds 62.4 million tons of CCP were beneficially used in 2014—up from 51.4 million tons in 2013 and above the 2008 peak of 60.6 million tons. A total of 129.7 million tons of CCP were produced in 2014 versus 114.7 million tons the prior year. The volume of coal fly ash and bottom ash produced in 2014 actually declined from the prior year, reflecting a reduced amount of coal consumed by electric utilities in response to environmental regulations and energy market conditions. Net fly ash production declined nearly 3 million tons, to 50.4 million tons, while bottom ash production declined nearly 2 million tons, to 12.5 million tons.

Overall fly ash utilization in 2014 was about even with the prior year at 23.2 million tons, but the use shifted toward concrete applications, ACAA affirms. Use in concrete and cement production increased 1.9 million tons, while use in mining, oil field services, and other applications declined. While ash production declined, output and use of another “non-ash” CCP increased substantially. Consumption of synthetic gypsum—a byproduct of flue gas desulphurization units or “scrubbers” serving coal-fueled power plants—is on the rise. As more power plants install and operate this type of emissions control equipment, the volume of synthetic gypsum grows rapidly.

Synthetic gypsum production in 2014 increased 9.7 million tons to 34.1 million tons, for example, and utilization increased 4.8 million tons to 16.8 million tons—driven by wallboard production and agricultural applications in which gypsum improves soil conditions.

“Although 2014’s results show a significant improvement, it’s important to remember that the United States is still disposing of more than half of the coal combustion products that could be put to good use,” Adams notes. “Additionally, the coal ash beneficial use industry is taking significant strides in developing strategies and technologies for reclaiming coal ash materials that were previously disposed.”

Adams cites an ACAA-commissioned, 2015 American Road and Transportation Builders Association study (note companion item) projecting ample supplies of CCP for beneficial use over the coming decades. “The future of CCP utilization is bright,” the study concludes. “Growing demand in construction markets is expected to increase CCP utilization by over 48 percent. Forecast models project that CCP utilization rises to 63 percent of production by 2033. Even under alternative scenarios of accelerated coal-fueled electric generating unit retirements, CCP production is still expected to exceed overall demand.”

Volume and use, 1991–2014

American Coal Ash Association confirmed positive trends in its “2014 Production and Use Survey” of coal combustion products. ACAA has quantified annual U.S. CCP generation and use for 50 years. Data is compiled by directly surveying electric utilities and combining it with U.S. Energy Information Administration figures. Results are widely utilized by the U.S. Environmental Protection Agency, U.S. Geological Survey and other federal agencies.