Disposal of Pressure Treated Wood in Construction and Demolition Debris Landfill
T G Townsend, B Dubey, J Jambeck, H M Solo-Gabriele
Pressure treated wood is often disposed in landfills in the US, very frequently in construction and demolition (C&D) debris landfills. C&D debris disposal facilities in many states are not equipped with liner systems to protect underlying groundwater. In this paper, issues associated with the disposal of metal-containing treated wood in C&D debris landfills are discussed. C&D debris landfills can be biological active systems, dominated by the activity of sulfate reducing bacteria. The leachate is characterized by relatively low biodegradable organic compound concentrations, high salt concentrations, a neutral pH, and a moderately to strongly reducing environment. Simulated landfills containing CCA-treated wood often show relatively high concentrations of As and Cr, but only minimal concentrations of Cu. Cu-based preservatives such as alkaline copper quaternary (ACQ) also show minimal copper leaching, suggesting that disposal of Cu-based wood preservatives posees minimal impact to groundwater from Cu leaching.