THE RECYCLING POTENTIAL OF PRESERVATIVE-TREATED WOOD

This paper is an assessment of the potential for recycling spent, pres ervative-treated wood products. Approximately 6 x 10(6) m(3) of wood t reated with chromated copper arsenate (CCA), pentachlorophenol, and cr eosote are disposed of annually and about 19 x 10(6) m(3)/year will be available for recycling by 2020. Currently, about 1.3 x 10(6) m(3)/ye ar of creosote-treated railroad ties and 2 x 10(6) m(3) of utility pol es treated with pentachlorophenol and creosote are available for recyc ling. The balance is primarily from CCA-treated dimension lumber and t he amount is forecasted to increase significantly due to its use in ho using and decking. The recent expansion of the wood recycling industry has not included preservative-treated wood because of technical probl ems and regulatory uncertainties. The most viable recycling option for wood treated with arsenic is probably composite manufacturing, but pr oblems such as characterization of comminution emissions and adhesive compatibility remain. Composting is also a potentially viable option, particularly for pentachlorophenol- and creosote-treated wood, althoug h comminution emissions need to be characterized and questions need to be answered about the effects of microbial growth inhibition from the potentially large preservative concentrations.