InTrans / Aug 14, 2018

Guide for minimizing the effect of preservative-treated wood on sensitive environments

Preservative-treated wood is often used for construction of
highway and foot bridges, wetland boardwalks, and other structures in or over water or sensitive environments. In these applications it is important that release of preservative from the wood into the environment is minimized. This publication addresses this concern by describing the various types of pressure-treated wood, reviewing recent research on the environmental impacts of pressure-treated wood, and discussing methods of minimizing potential environmental impacts. Recent research indicates that wood treated with these preservatives does release small amounts of chemical into the environment immediately adjacent to the treated structure, although no adverse biological impacts were observed. Environmental releases from treated wood can be minimized with appropriate treatment practices. These practices include fabricating members before treatment and specifying that the wood be treated using methods that ensure chemical fixation and prevent the formation of surface residues or bleeding. Guidance to specifying such treating practices are offered in this report and in sources such as the Best Management Practices developed by the Western Wood Preservers‰Ûª Institute. Also, responsible construction practices such as storage of treated wood under cover and containment and collection of construction residue can further reduce the possibility of negative environmental impacts. As with any other construction material, careful specification and responsible use of treated wood will optimize its performance.