Approved Compost and Bioretention Soil
The City of Seattle has mandatory specifications for soil, including compost and bioretention soil, for all City-funded projects within city limits. See section 9-14 of the City Standard Plans and Specifications.
Consistent with "closed-loop" theory and Resolutions 30990 and 31459 and the City's Sustainable Purchasing Policy, approved materials suppliers are those that have contracts to remove organic waste (feedstock or yard waste) from within the city of Seattle limits, compost the material and then resupply into City projects or sites.
Please contact City Purchasing and Contracting Services, for the current list approved suppliers.