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Comprehensive Solid Waste Management Plan

Learn more about our Comprehensive Solid Waste Management Plan, which sets strategies for managing solid waste over the next 6 to 20 years in King County. It guides the many public and private elements that make up the regional solid waste system.

Updating the Comp Plan

Washington State law (RCW 70.95.080) requires each county to prepare a coordinated plan for handling regional waste.

Development schedule

Updated May 2024 (subject to change)

Date Actions/Events/Public meetings
April 24, 2024 Long-Term Disposal City Subgroup Meeting
May 20, 2024 Long-Term Disposal City Subgroup Meeting
June 17, 2024 Long-Term Disposal City Subgroup Meeting
Aug 26, 2024 Long-Term Disposal City Subgroup Meeting
Sept 30, 2024 Long-Term Disposal Open House
Oct 9, 2024 Long-Term Disposal Open House
April 2025 Long Term Disposal Study Complete
2025-2026 State Environmental Policy Act and Environmental Impact Statement Process
Q1 2028 60 Day Public Review Begins
Q1 2028 120 Day Department of Ecology Review Begins
Q3-Q4 2028 Executive Office Approval, Transmit to Council for Review
Q1 2029 Council Approval
Q2 2029 120 Day City Approval Begins
Q3 2029 120 Day Ecology Approval Begins
Q4 2029 Comp Plan Adopted

Adopted Comprehensive Plan (2019) 

Washington State law (RCW 70.95.080) requires each county to prepare a coordinated plan for handling regional waste. King County’s current Comprehensive Solid Waste Management Plan was adopted in November 2019. It outlines goals and strategies for the next 6 years, with consideration for the next 20 years. We also review the plan every 3 to 5 years for necessary updates.  

2019 Comprehensive Solid Waste Management Plan

As part of the State Environmental Policy Act (SEPA), we prepared an Environmental Impact Statement (EIS) with the 2019 Comprehensive Plan. The EIS looked at potential environmental impacts of the facilities, programs, and services outlined in the plan. It also includes measures to avoid or reduce adverse impacts.

Final Environmental Impact Statement (EIS)
Notice of Issuance and Availability

Long-Term Disposal Study

The Cedar Hills Regional Landfill is projected to reach full capacity by 2040. As detailed in the 2019 Comp Plan, the Solid Waste Division must propose the County's next long-term disposal method in the next version of the Comp Plan. The Long-Term Disposal Study analyzes five disposal options to determine the best option(s) for the region.

Long-Term Disposal Advisory Committee Subgroup

Members of the Metropolitan Solid Waste Advisory Committee (MSWAC) formed a Long-Term Disposal Subgroup to fully explore long-term disposal options and provide insights. The Subgroup’s recommendations are shared with both Solid Waste advisory committees to help inform decision-making around Long-Term Disposal, Comp Plan updates, and ILA extensions.

Meeting 1
An overview of past studies on long-term disposal and a review of how the 2019 Comp Plan laid out this work to move forward.

Meeting 2
A deep dive with our consultants into 3 options: Gasification, Pyrolysis, and Refuse-derived Fuel.

Meeting 3
A deep dive with our consultants into 2 options: Waste Export by Rail and Mass Burn.

Meeting 4
A more detailed discussion on Waste Export by Rail and Mass Burn.

The above meetings provided insight into the issues around the long-term disposal options most important to the advisory committee members. With this information, the Division held two open house sessions to present the background and results of the long-term disposal work to a larger group of advisory committee members and city representatives.

Feasibility studies

Municipal Solid Waste-To-Fuels Study

2023 study exploring the feasibility of producing sustainable aviation fuel from municipal solid waste.

Study summary

Full report – Municipal Solid Waste To Liquid Fuels Study

Rate restructure study

2021 report evaluating alternative revenue options to reduce reliance on garbage fees.

Solid Waste Cost of Service and Rate Restructure Study

Waste-to-Energy and Waste Export  

2019 study evaluating the feasibility of using either Waste-to-Energy or Waste Export by Rail as the County’s next disposal method. 

Waste-to-Energy & Waste Export by Rail Transportation Study

Task 2 Waste-to-Energy Existing Conditions Memorandum

Appendix A - Waste-to-Energy Existing Conditions Memorandum

Task 3 Waste-to-Energy Options and Solid Waste Export Considerations

Nov. 6, 2017, PowerPoint presentation: Waste-to-Energy Options and Solid Waste Export Considerations - Normandeau Associates 

"Waste to Energy" and "Solid Waste Export Considerations" presentations

2007 comparison of waste export with other emerging technologies as alternative options to landfilling

Disposal Options Comparative Evaluation

Anaerobic Digestion

2017 study exploring the feasibility of an anaerobic digestion program to support resource recovery and climate action goals. 

Anaerobic Digestion Feasibility Study

Sustainable Solid Waste Management  

2014 study looking at approaches for creating a more sustainable regional system. 

Sustainable Solid Waste Management Study

Optimized Transfer Station Recycling

2013 study to identify the best national options for recycling and waste diversion. 

Optimized Transfer Station Recycling Feasibility Study

Previous plans

2007 Transfer and Waste Management Plan

In collaboration with our partner cities, we created the 2007 Transfer and Waste Management Plan. It was adopted by King County Council in 2007. We also prepared an Environmental Impact Statement (EIS) to supplement the 2001 Comp Plan final EIS. 

2007 Transfer and Waste Management Plan

Environmental Impact Statement

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