Treated wood waste (TWW) comes from wood that has been treated with chemical preservatives. These chemicals help protect the wood from insect attack and fungal decay while it’s being used. Fence posts, sill plates, landscape timbers, pilings, guardrails, and decking, to name a few, are all examples of chemically treated wood.
Note: The statutes (HSC 25150.7) and regulations (22 CCR 67386.1 et seq.) that allow treated wood waste to be handled with alternative management standards are due to expire after December 31, 2020. After that date, all hazardous treated wood waste managed in California will have to be stored and manifested as hazardous waste and transported to class I hazardous waste landfills for disposal.
Because TWW contains hazardous chemicals, at elevated levels, it is subject to California’s Hazardous Waste Control Law. Generators of TWW can presume their TWW is hazardous waste. Until December 31, 2020, Generators can manage their TWW in accordance with the alternative management standards, including disposal at approved non-hazardous waste landfills as they become non-hazardous waste pursuant to Health and Safety Code section 25150.8