A new rule proposed by the Washington Department of Ecology aims to prevent contamination in compost by setting a universal limit on allowable levels of contamination in the material that comes into composting facilities and in the finished material that goes out. Washington is expected to collect four times as much organic material by 2035 due to a 2022 law requiring most local governments in Washington to provide residents and businesses food and yard waste collection services by 2030.
When food waste enters a landfill, it becomes one of the largest contributors to climate pollution in Washington. The draft rule proposes setting a 5% by volume physical contamination limit on incoming loads of organic material used as feedstock. It also adds a section to establish new pre-processing standards to address loads contaminated above 5%. The proposed rule aligns with Washington Department of Transportation compost procurement standards by setting contamination limits in finished products to 0.5% by dry weight. Film plastic contamination cannot exceed 0.1%.
The proposed rule is out for public comment. See more information about the rulemaking.
