Virginia Tech CCA Wood Research Hits the Deck

Lynn Schenkman

RESEARCHERS AT THE WOOD SCIENCE and Forest Products Department of Virginia Tech, Blacksburg, Va., are working toward a solution that would keep wood treated with chromated copper arsenate (CCA) out of landfills, particularly out of older, unlined landfills where chemicals could leach into groundwater.

In March, the Washington, D.C-based U.S. Environmental Protection Agency granted termination requests halting all residential uses of CCA-treated wood. The most pronounced residential use of CCA-treated wood is in outdoor decks, which means that as homeowners begin dismantling old decks, they will be sending the final wave of CCA-treated wood to landfills. Researchers have indicated the amount of discarded CCA-treated wood reaching landfills is increasing, and the tonnage is expected to rise substantially during the next few years. Because CCA contains arsenic, the EPA has found that the wood poses a health risk to children. In large doses, exposure to arsenic is fatal, the EPA says.

However, Virginia Tech's research has indicated that more than 80 percent of a discarded CCA-treated deck can be recovered as usable lumber. Led by Bob Smith and Dave Bailey, the research team has found that several household products may be constructed from discarded CCA wood, such as residential decks and deck components, railings, steps, posts, and trellises. Smith and Bailey also have made trash can containers, pallets and outdoor furniture, including chairs, benches, porch swings and utility tables from the discarded wood. The strength characteristics of the spent wood were similar, but not as high as newly treated CCA wood, the research states.

“If you look at it from a holistic view, there's a whole bunch of community folks who could use this wood,” Smith says. Examples he cites are decks for nonprofit home-building organizations, such as Habitat for Humanity, or garden clubs and civic groups that focus on community beautification.

“In a perfect world, I envision that landfill owners would separate usable wood from unusable wood. That wood then could go to groups to construct the products themselves, or it could go to recycling companies.”

However, Smith notes that many landfill operators are unable to distinguish CCA-treated wood from other wood. “[The search for a solution] is kind of a progression,” he says. “Now we know that products can be made and that somewhere along the line, we have to find the best possible way to collect the wood from landfills. That will probably be our next plane of research. Collection and distribution of the wood is a problem, so that's why I think the next study has to happen at the landfill level.”

Smith and his team say that to study effective retrieval methods, they will need funding. “We're looking to local government decision-makers and landfill facility owners. We know the U.S. Forest Service has financially supported similar projects, so we may look to them, too.”