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Organic materials management

Organic materials — from food and yard waste, biosolids, and agriculture — can be valuable resources. We are working to recycle these materials through composting, using them to improve soils and crops as biosolids, and turning dairy manure into energy through anaerobic digestion. Reducing and recycling organic wastes are key goals of Washington's State Solid and Hazardous Waste Plan.

According to the 2016 Washington Statewide Waste Characterization Study, organic materials, like food scraps, green waste, animal manure, animal carcasses, and all types of paper and wood, account for 42.5 percent of residential waste. Food waste alone accounts for 10.6 percent of residential waste.

Organic materials management includes composting and many other energy recovery technologies. "Organics" refers to carbon-based materials that include forest slash, food, yard debris, manures, and other agricultural residues.

Organics management hierarchy

Ecology created an organics management hierarchy to help Washingtonians manage food scraps and yard trimmings in the most beneficial way possible. 

Organics categories

We provide technical and regulatory assistance in these areas:

Organics management regulations

Agriculture

Composting often goes hand-in-hand with agricultural practices. Much of this compost activity is exempt from the Solid Waste Handling Permit process. See the agricultural exemptions within the composting regulations, WAC 173-350-220(1)(b)(v)-(vii), (ix). The primary agencies that provide assistance and oversight to agricultural operations are Natural Resources Conservation Service and Washington State Department of Agriculture.

Anaerobic digesters

Some dairy manure anaerobic digesters do not need a solid waste handling permit. They can operate as conditionally exempt from permitting requirements. However, if anaerobic digester operations do not qualify for the exemption, a solid waste handling permit is required.

Composting facilities

Composting facility standards are listed in WAC 173-350-220. Standards include: Compost facilities must meet the performance standards in WAC 173-350-040 even if they are permit exempt. Find more information at Solid waste permits
  • Exemption categories (identifying operations that don't need solid waste handling permits)
  • Design and operating standards for permitted facilities
  • Compost quality testing requirements