The Department of Toxic Substances Control (DTSC) has issued a variance to Transportation & Public Works - County of Sonoma (CAD981451396) to generate and accumulate treated wood waste on-site. The treated wood waste is generated as a result of sign and guardrail posts and treated plywood. The variance allows treated wood waste to be managed under procedures different from, but equally protective to human health and the environment to, the provisions of California Health and Safety Code (HSC) Articles 6, 6.5 and 9 of Chapter 6.5 and California Code of Regulations (CCR), Title 22, Division 4.5, Chapters 12, 13, 14, 15, 16, 18, and/or 20. Under the terms and conditions of Variance TWW-2021-LG-00527, Transportation & Public Works - County of Sonoma will ensure the treated wood waste will be appropriately managed. Treated wood waste is a fully regulated California-only hazardous waste because it exhibits the hazardous waste characteristic of toxicity. From 2007 to December 31, 2020, treated wood waste was managed under alternative management standards, established in 22 CCR 67386. The legislation that authorized the alternative management standards for treated wood waste expired on December 31, 2020. Transportation & Public Works - County of Sonoma conducts road maintenance, including bridge work, traffic control and culvert installation. Under the variance, the authorized large quantity generator may generate and accumulate treated wood waste on-site. Accumulation of treated wood waste includes taking appropriate precautions to prevent unauthorized access to and prevent leaching to the environment of the treated wood waste. No transportation activities are authorized as a part of this variance. The variance will expire on November 23, 2021 with possibility of extension for an additional six months.