Contaminants and Waste - Treated Wood Waste

Chemical preservatives are often used to protect wood against decay. Common wood coatings such as such as paint, varnish and oil stain are not considered wood preservatives.

Caltrans frequently uses wood treated with some chemical preservatives for guardrail supports or sign posts.

Caltrans follows regulations adopted by the California Department of Toxic Substances Control (DTSC) when managing treated wood waste (TWW) to prevent releases of hazardous chemical preservatives, scavenging, and harmful exposure to people, aquatic life and animals. The regulations allow flexibility for TWW disposal. TWW may be handled as a regulated solid waste. Testing and sampling of TWW is not required. TWW may be disposed in a State Water Resources Control Board certified solid waste landfill, rather than a hazardous waste landfill.