CompostWise

About the CompostWise program

Applying compost improves environmental outcomes for the King County region. It aids agriculture, horticulture and landscaping, stormwater management, ecosystem conservation and restoration, and contaminated site remediation. It helps us close the loop on the organics circular economy by supporting waste reduction and cultivates local green jobs.

King County’s CompostWise Program works to bolster the regional compost market. We do this by providing education, training, technical assistance, and resources to help you improve your soils through the use of compost. We also lead by example by procuring and using food and yard waste compost in King County projects.

CompostWise technical assistance program

The CompostWise program is here to help you and your teams. If you need assistance or have questions about compost, reach out to compost@kingcounty.gov.

Procuring and using compost

• Comprehensive Guides (Quick and Detailed), how to specify and use compost in landscapes, erosion control, and stormwater management
• Video: The Do's and Don'ts of Applying Compost
• King County Surface Water Design Manual, descriptions of approved applications of compost for stormwater management and filtration
• One-Pager: Using Compost on Small Farms for Healthy Plants

Request technical assistance

• Reviews of general and project specifications
• Presentations and demonstrations for design and engineering professionals
• Assistance with planning and evaluating innovative uses of compost in landscapes, stormwater applications, and agriculture

Specifying and procuring quality compost

• APWA format specification for compost and soil mixes
  PDF | Word
• CIS format specifications for compost and soil mixes, plus procedure for effective installation of soils
  PDF | Word
• Video: Common Senses: How to Tell if Compost is Good

Meeting soil improvement requirements

• Brochure: King County's Post Construction Soil Standard required for all new landscape construction
• King County Permits
• Compost and Topsoil Calculator, calculate volumes of compost and topsoil needed to meet the Post Construction Soil Standard
• Creating a Soil Management Plan and Calculations Required for Permit Applications
  Video | PowerPoint

Additional resources

• King County's Re+ Plan
• King County's Strategic Climate Action Plan
• King County's Solid Waste Management Plan
• King County Loop Biosolids
• King County's Value of Organic Amendments: Ecosystem Services
• US EPA's Environmental Value of Applying Compost
• WA Department of Ecology's Compost 101
• Washington Organics Recycling Council (WORC)
• US Composting Council (USCC)