Launch Slideshow

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The Fly Ash Threat

The Fly Ash Threat

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    The Kingston, Tenn., area before Dec. 22, 2008.

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    The Emory River is inundated with coal slurry ash after a containment pond ruptured.

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    Simple loading and storage procedures would require new permitting and safety procedures if the EPA classifies fly ash as a hazardous material.

The construction industry as we now know it may be changing in response to an event that happened on Dec. 22, 2008.

At a Tennessee Valley Authority (TVA) electric generating plant in Kingston, Tenn., a containment pond dike ruptured and spilled more than 5.4 million cubic yards of coal ash slurry. The Emory River was inundated with more than 300 acres of wet fly ash. Cleanup may cost more than $1 billion.

As a result, the EPA wants more authority to regulate flay ash than the current law allows. The agency doesn't trust the states to properly regulate coal combustion products (CCP, which includes fly ash, bottom ash, and flue-gas desulfurization material). There is no legal way to regulate it federally other than to designate the material as hazardous under Subtitle C. This attitude of distrust prompted EPA Administrator Lisa Jackson to pledge during her confirmation hearing last January to come up with new disposal regulations for CCPs by the end of 2009.

Few doubt that there should be tighter regulations governing containment ponds' design, construction, and maintenance. But to many proponents of fly ash use in concrete, regulating a final disposal method is a completely separate matter than designating fly ash as a hazardous waste under Subtitle C.

This puts the use of fly ash in masonry and concrete at real risk. The American Coal Ash Association predicts that the EPA will need to take regulatory action to satisfy environmental activists who are not looking at the science.

The EPA considers fly ash a nonhazardous waste material, so individual states have jurisdiction over the material's storage and disposal. Environmental groups want this ruling changed so that fly ash is classified under Subtitle C of the Resource Conservation and Recovery Act (RCRA), which is hazardous waste regulated by the federal government.

The current ruling has been true since 1980 under the so-called Bevill exclusion, which excluded "solid waste from the extraction, beneficiation, and processing of ores and minerals" from regulation as hazardous waste under Subtitle C of RCRA. In 2000, the EPA again determined that CCPs were exempt from classification as a hazardous waste.

To many, the EPA's need to respond to the coal ash dam failure is based not on scientific evidence but on pressure from current politics fueled by a long-term desire on the part of some environmental groups to eliminate burning coal for electricity generation.

Unintended consequences

Unfortunately, Jackson's pledge may have created a greater environmental problem than she intended. And while EPA has for many years promoted using fly ash, even sponsoring the Coal Combustion Products Partnership to increase the beneficial use of fly ash, it now appears that some sort of hazardous designation is likely.

In December, InsideEPA.com reported that the EPA's current proposal is an unusual “hybrid” approach: designating fly ash as hazardous if it's disposed of in a containment pond or landfill but not hazardous (under Subtitle D of RCRA) when recycled for “beneficial uses.” This could mean that concrete producers and power plants would have to transport, store, and treat fly ash as a hazardous waste in its powder form, but not once it's incorporated into concrete.

However well-intended, this classification would cause our nation significant problems. Any hazardous designation is likely to greatly reduce using fly ash in concrete. ACI warned the EPA that a hazardous designation would likely result in removing fly ash from all specifications and standards, including the ACI 318 Building Code Requirements for Reinforced Concrete.

The American Coal Ash Association (ACAA) says that one potential outcome of a hazardous waste classification is that the electric utilities, which generate fly ash as part of their pollution control efforts in treating flue gases, will simply stop selling fly ash since they would also be liable.

Limiting fly ash use and availability affects concrete's role in helping shape a better environment. Using fly ash in a concrete mix reduces the amount of cement needed, thereby reducing the carbon footprint.

Another implication, according to the Environmental Council of the States (ECOS), would be to overwhelm hazardous waste landfills with 135 million tons of CCPs. Today, they handle only about 2 million tons of hazardous materials. Under current rules, concrete batched with fly ash consumes an industrial waste product rather than sending it to a landfill. The Electric Power Research Institute (EPRI) estimates that beneficial use of CCPs annually saves 159 trillion Btu, 32 billion gallons of water, 11 million tons of CO2 released to the atmosphere, and 51 million cubic yards of landfill space.

William D. Palmer is with Complete Construction Consultants and is the former editor-in-chief of Hanley Wood's CONCRETE CONSTRUCTION magazine. E-mailwpalmer@cee3.com.