The content, and even the title, of your sidebar article about fly ash in your February 2011 issue (“Proposed Fly Ash Reclassification Could Curtail Its Use”) was very misleading. It has led to some of my colleagues’ confusion about the use of fly ash.
In June 2010, the U.S. Environmental Protection Agency (EPA) proposed two options for the regulation of coal combustion residuals, both of which would continue to exempt fly ash used in concrete from classification as hazardous waste. Anyone who has come to think otherwise has done so by pure conjecture, or else they have been swayed by articles such as yours. Rather than factual information, your article contains statements such as, “There is concern that reclassification ... would carry a stigma,” and “It is rumored that specifications are being revised to exclude fly ash ... and plans are being made to stop shipping fly ash.”
The EPA has announced that they have no plans to restrict the use of fly ash used in concrete. Period!
As structural engineers, we have been specifying the use of fly ash in concrete mix designs for years, frequently having to debunk inaccurate information about the material in order to gain acceptance for its use. We applaud the American Concrete Institute, Farmington Hills, Mich., and the Portland Cement Association, Skokie, Ill., for acknowledging that the appropriate use of supplementary cementitious materials (SCMs) such as fly ash is an appropriate way to reduce concrete’s carbon emissions.
I am an advocate of the use of concrete—its durability and large thermal mass are extremely sustainable and beneficial properties. Continued use of fly ash and other SCMs can ensure that concrete maintains its place as a sustainable building product, now and in the future. I urge you to fulfill your role as an industry-leading publication and clarify the facts about this important issue.
James A. D’Aloisio
PE, SECB, LEED AP BD+C
Klepper, Hahn & Hyatt
East Syracuse, N.Y.
Concrete Construction Response:
We agree with you that the use of SCMs in concrete is an important way to reduce the carbon footprint. Our concern is not with the EPA’s proposal but with how the special designation is or might be perceived. You’re right, though, that we might have been more emphatic about EPA’s endorsement of fly ash use in concrete: the agency has done nothing to directly restrict fly ash use. Nonetheless, there is concern that any sort of hazardous waste definition (even if not directed at ash used for beneficial purposes) could taint this valuable SCM. The American Concrete Institute, the industry’s technical leader, cautioned the EPA that a hazardous designation would likely result in fly ash being removed from all specifications and standards, including the ACI 318-08, “Building Code Requirements for Reinforced Concrete.” ACI concluded that, “EPA should not risk harm to the environmental and material benefits of fly ash use in concrete when addressing the impoundment requirements for fly ash, nor abrogate the ability to make effective and safe use of this industrial byproduct.”
During public hearings last fall, EPA heard from many passionate people on this issue and when I last spoke with Tom Adams at the American Coal Ash Association, Aurora, Colo., he indicated that everything is currently in limbo. On April 7, Congressman David McKinley, R-W.Va., introduced the Recycling Coal Combustion Residuals Accessibility Act of 2011, which would prohibit the U.S. Environmental Protection Agency from regulating coal combustion residuals. But, interestingly enough, there are some in the disposal industry who think that a hazardous waste designation actually would increase coal ash reuse since that would be cheaper than disposal as a hazardous waste. All of this uncertainty serves to make some even more cautious.
This is obviously a very complex and politically charged issue that we have not heard the last of. I’m with you completely in your effort to clear the air on this and educate everyone that under no currently contemplated scenario will fly ash use be restricted. That, I think, should be our primary message.
Thanks again for your insightful message.