While some view “garbage science” as questionable research, Dr. Mort Barlaz takes the term more literally and has turned the study of landfills into a career. Now, the U.S. Environmental Protection Agency is tapping his expertise to address a concern that never existed in the pre-9/11 world: How do you dispose of materials that have been contaminated with chemical or biological agents during a terrorist attack?
The problem first arose three years ago, when the discovery of anthrax in U.S. Senate offices, some postal facilities, and the offices of two media companies forced each to be closed and decontaminated. “You could potentially have a large quantity of contaminated building debris10,000 cubic yards of carpet, ceiling tiles, office furniturethat needs to be disposed of,” Barlaz says. “You don’t want to clean up one problem and create another one.”
The EPA’s National Homeland Security Research Center has awarded $800,000 over three years to a team of Barlaz and Drs. Francis de los Reyes and Detlef Knappe in NC State’s Department of Civil, Construction, and Environmental Engineering. They plan to study the issue and develop recommendations to help first responders, emergency management personnel, and the waste industry handle contaminated debris.
Barlaz and a colleague at the Technical University of Denmark are working on a computer model to predict how certain chemicals, such as those in nerve gas, react in landfills. Do the contaminants sit there forever, biodegrade, or escape into the air with methane and other gases produced by rotting trash? Or do they drain out with the liquid leachate into the bottom of the landfill or nearby groundwater? The effort mimics work Barlaz has done for years to study the decomposition of materials like household chemicals and new polymers in dumps. “I’ve shoveled through more garbage than you’ll ever know,” he says.
The computer model currently views everything as constant within the landfill. After it is refined, Barlaz hopes to factor in variables like the effects of the addition of fresh refuse to partially decomposed trash, rainwater filtering through the layers of garbage, and changes in the surrounding climate. A simulated landfill in the basement of NC State’s Riddick Laboratory lets him test his theories. By shredding household trash, filling a metal container heated to 100 degrees Fahrenheit and circulating leachate through it, he can produce 20 years of normal decay within six months.
“Preparedness is the major point here,” he says. “We all hope we won’t ever be in a position where we have contaminated building debris, but we need to know how to respond if the situation does arise.”