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Anaerobic Digestion Feasibility Study

Anaerobic Digestion Feasibility StudyDownload PDF , 1.5 MB
This report explores the feasibility of implementing an anaerobic digestion program in the King County region to increase resource recovery and energy recovery and support county recycling and climate action goals (October 2017).

Sustainable solid waste management study

Sustainable Solid Waste Management StudyDownload PDF , 1.1 MB
An evaluation of operational and strategic planning options and a proposed implementation approach to expand these efforts into King County's solid waste management system (July 2014).

Transfer and waste management plan

Solid Waste Transfer and Waste Management PlanDownload PDF , 647 K
Solid Waste Transfer and Waste Management Plan AppendicesDownload PDF , 3 MB
Proposed recommendations that will guide King County as it prepares the solid waste system for waste export, during which time the transfer system will be upgraded, a public or private intermodal facility or facilities will be added to the system, and the county's Cedar Hills Regional Landfill will be closed. The rate proposal and forecast that accompanies the Plan is provided under Other Documents.

Final Supplemental Environmental Impact StatementDownload PDF , 2.5 MB
(Note: this is a very large file and may take several minutes to download, depending on connection speed)
Final Supplemental Environmental Impact Statement – presents an environmental analysis of the alternatives developed in Milestone Report 4 (provided below).

Milestone Report #1Download PDF , 75 K
Transfer System Level of Service Standards and Criteria – sets standards and criteria for evaluating county waste transfer system.

Milestone Report #2Download PDF , 6.7 MB
(Note: this is a very large file and may take several minutes to download, depending on connection speed)
Analysis of System Needs and Capacity – applies standards and criteria for evaluating county waste transfer system.

Milestone Report #2: AddendumDownload PDF , 121 K
Application of Criterion 17 – applies Level of Service Criterion 17 standards to the county waste transfer system, completing the second milestone report.

Milestone Report #3Download PDF , 4.5 MB
(Note: this is a very large file and may take several minutes to download, depending on connection speed)
Options for Public & Private Ownership & Operation of Transfer & Intermodal Facilities – sets forth options, policy choices and service elements and identifies characteristics.

Milestone Report #4Download PDF , 802 K
Preliminary Transfer & Waste Export Facility Recommendations And Estimated System Costs, Rate Impacts & Financial Policy Assumptions – the fourth and final milestone report in the waste export system plan development process as required by Ordinance 14971.

Milestone Report #4 Appendices

  1. Responsiveness SummaryDownload PDF , 120 K
  2. ITSG Additional IssuesDownload PDF , 31 K
  3. Forecasting Solid Waste DisposalDownload PDF , 30 K
  4. Financial PoliciesDownload PDF , 32 K
  5. Compacting Waste Feasibility AnalysisDownload PDF , 9.0 MB
    (Note: this is a very large file and may take several minutes to download, depending on connection speed)
  6. The Transfer Station Siting ProcessDownload PDF , 27 K
  7. Project Implementation SchedulesDownload PDF , 23 K
  8. Level of Service TablesDownload PDF , 86 K
  9. Financial ProjectionsDownload PDF , 39 K
  10. The Longer Term OutlookDownload PDF , 85 K
  11. Landfill CapacityDownload PDF , 25 K

Ordinance 14971Download PDF , 470 K
Planning for future solid waste system.

Independent, Third Party Review of the Solid Waste Transfer and Waste Export System PlanDownload PDF , 417 K
Third party review of the Solid Waste Division's 2006 Solid Waste Transfer and Waste Management Plan prepared by the independent firm Gershman, Brickner & Bratton for the King County Council.

Comprehensive solid waste management plan

Draft 2019 Comprehensive Solid Waste Management Plan Download PDF , 7.5 MB

Final Draft 2013 Comprehensive Solid Waste Management PlanDownload PDF , 5.7 MB

Final 2001 Comprehensive Solid Waste Management Plan
Note: This is the currently adopted plan.
Table of ContentsDownload PDF , 89 K
Chapter 1 - Plan SummaryDownload PDF , 93 K
Chapter 2 - History/PoliciesDownload PDF , 207 K
Chapter 3 - Future PlanningDownload PDF , 328 K
Chapter 4 - Waste Reduction/RecyclingDownload PDF , 783 K
Chapter 5.1 - CollectionDownload PDF , 838 K
Chapter 5.2 - Collection cont.Download PDF , 577 K
Chapter 6 - Transfer SystemDownload PDF , 381 K
Chapter 7 - DisposalDownload PDF , 323 K
Chapter 8 - CDL/Special WastesDownload PDF , 337 K
Chapter 9 - EnforcementDownload PDF , 122 K
Chapter 10 - Financing and RatesDownload PDF , 197 K
GlossaryDownload PDF , 64 K
Final 2001 Environmental Impact StatementDownload PDF , 3.7 MB

Optimized transfer station recycling feasibility study

Optimized Transfer Station Recycling Feasibility StudyDownload PDF , 5.2 MB


King County has long been a national leader in recycling and waste prevention. King County’s current recycling and waste prevention rate is significantly higher than the national average. Despite this success, the County continually seeks to achieve a goal of zero waste, through a multi-faceted approach. For example, the County is a leader in product stewardship, a process through which manufacturers of goods must take responsibility for reclaiming resources from the products they produce.

In early 2012 the Solid Waste Division obtained a grant from the Washington State Department of Ecology for a study that would identify best recycling practices throughout the nation. Ecology provided virtually all of the funding through a state Coordination Prevention Grant. Although the study includes examples from King County, Ecology funded the study led by Herrera and HDR (Herrera/HDR Study) in order produce a report that other jurisdictions could use to identify a wide array of options for recycling and waste diversion.

Key findings

Certain key findings of the report include:

  • A number of system constraints affect all King County stations, though in general they are not physical or operational limitations.
  • Much of the leverage for additional diversion at King County transfer facilities must come from the actions of its customers, with support from transfer station staff. This can be brought about with appropriate recycling policies and programs, and education and outreach.
  • Policies and programs, education and outreach, and facilities (including layout and design, operations, and processing) together “provide a comprehensive and self-reinforcing strategy to maximize diversion at County facilities.”
  • In general, the County does, and should continue to use measures in all of these areas.
  • New King County transfer stations are designed with flat floors creating versatile areas for waste collection and processing. Flat floors will allow operators to recover materials for reuse and recycling from customers. Due to the advantages provided by this design, new transfer stations designed for King County should be flat floor.
  • Additional advantages of a flat floor design include the following: Quicker and easier unloading opportunities for self-haul customers; more opportunities to safely remove material from commercial and self-haul loads; easy movement of staff and materials between areas, and ease of making future operational changes.
  • The current Factoria Transfer station cannot accommodate any recycling. The new Factoria station will initially accept thirteen materials, as follows:
    • Organics (yard debris and food)
    • Clean wood
    • Scrap metal
    • Cardboard
    • Appliances
    • Plastic film and bags
    • Carpet
    • Textiles
    • Asphalt shingles
    • Mattresses
    • Gypsum Wallboard
    • Mixed paper
    • Tires
  • At some point, it may be prudent to eliminate the acceptance of most standard curbside recyclables at transfer facilities, as it is more efficient and cost effective to collect them at the curb. The space and resources at the stations could be used instead for collection of other materials that are not easily collected curbside. (This was implemented previously, but rejected by the region.)

The division is already working to implement numerous strategies

The Division is already working to implement recommended strategies to increase diversion at its stations based on the recommendations in the Herrera/HDR report:

  • Increase material-specific actions to increase diversion:
    • Commingled mixed recycling to make it easier for customers to recycle and increase participation.
    • Using compaction to commingle recycling materials and free up space for additional recycling materials.
  • Develop and operate flexible material receiving/processing capability:
    • Conduct materials recovery pilot at Shoreline and Bow Lake
    • Factoria flat floor design
  • Enhance pictorial signage and signage in Spanish:
    • Placed easy to read material-specific signs with Yes and No’s next to the material collection location. Signs are portable enabling movement between disposal locations depending on use and demand. Signs include pictograms and Spanish to address language and cultural barriers. New signage now at Bow Lake, Renton, Houghton, and Shoreline.
  • Formalize and foster an internal staff culture that places a high value on reuse and recycling:
    • Quarterly “All Hands Meeting” to generate an enthusiastic culture around recycling and materials recovery strategies.
    • Appliance training to increase metals recycling and demonstrating the revenue benefits of recycling.
    • Hiring additional staff at Bow Lake to assist customers with recycling

Current Factoria design is consistent with Herrera/HDR recommendations

Although the study indicated that constraints on recycling and waste diversion in King County are primarily related to customer behavior and are best addressed by policies and education, the Factoria design is in fact consistent with the Herrera/HDR study. The design optimizes recycling capabilities on that site and will contribute significantly to the goal of zero waste. HDR designed the new Factoria Transfer Station, and, it incorporates the current state-of-the-art flat-floor design. The Herrera/HDR Study recommended a flat-floor design for Factoria and confirmed through extensive research that this is the preferable transfer station design. The study noted that the floor design allows for significant flexibility for recycling and materials recovery.

The study produced five recommended principles to optimize resource diversion and recovery. The current Factoria design is consistent with the recommendations, and it supports the County’s zero-waste goals:

Recommended Principles from the Study

Current Factoria Design Consistency

1.  Convert obsolete or underused facilities into recycling-only facilities and modify existing King County transfer facilities to focus on reuse, recycling, waste diversion, and/or processing of self-haul materials

An extensive recycling and reuse area is part of the new Factoria design, with a focus on ease of customer use. It will allow for flexibility to collect a full range of materials from both commercial and self-haul customers including appliances, C&D, cardboard, carpet, mattresses, organics, and tires. (Eliminating garbage collection at Factoria would require siting an additional transfer facility.)

2.  Site, design and build new King County solid waste facilities to align collection and processing in an advanced materials management system

A flat floor design allows versatility for waste collection and processing, and will provide the opportunity for Transfer Station Operators to recover materials for reuse and recycling from the waste stream.  Pilot materials recovery projects are about to begin at Shoreline, so they could be implemented seamlessly at Factoria. Design features also allow:

  • Quicker and easier unloading for self-haul customers.
  • Safer unloading of materials from commercial and residential customers as they will be on one level.
  • Easier movement of staff and materials between areas.
  • Easier space reallocation on the floor between recyclable and waste handling as volumes of each change over time, or even during the workday.

3.  Co-locate, design and build end-use and/or energy recovery facilities at existing or new King County solid waste facilities

Design flexibility from the flat floor could allow for small foot print on-site processing such as anaerobic digestion of some organic materials (food scraps and soiled paper).

4.  Proceed in a manner that is internally consistent with the structure under which the County is currently working (i.e., source-separated private collection, private MRFs for collected recyclables, private processing for commercial C&D).

The design maintains a station collection infrastructure that is consistent with the region’s private/public roles. Materials collected can be transported and processed at privately managed facilities. On site resource recovery will focus on materials delivered by the private/public customers. As indicated, most recyclables in the region are processed by the private sector.

5.  Align policies, fees, and regulations to emphasize, incentivize, and compel reuse and recycling of waste toward Zero Waste of Resources

The County has been a leader in policies and requirements that promote recycling and materials recovery. County ordinances already promote the zero waste goal in numerous ways, and the Factoria design is fully-consistent with implementing these policies and allowing for future flexibility of policies that would further recycling, diversion and recovery.

Unincorporated area single-family/multi-family research and pilots

Multifamily Recycling Pilot (King County and Waste Management) – Final ReportDownload PDF , 5 MB
2013 pilot study testing methods to increase recycling in multifamily complexes in the unincorporated area.

Yard waste signup door to door pilot (King County and Waste Management) – Final ReportDownload PDF , 3 MB
2013 pilot study testing tactics to get and retain yard waste signups for single family unincorporated area households.

Recycling and waste cart contamination reduction pilot (King County and Republic Services) – Final ReportDownload PDF , 1 MB
2013 pilot study testing cart tagging feedback to increase correct cart placement of recycling and composting materials in unincorporated single family curbside carts.

Waste-to-energy studies

Other documents

Executive Proposed: Solid Waste Disposal Fees 2013-2014Download PDF , 384 K
Proposes an increase in the basic solid waste disposal fee from $109.00 to $121.75 per ton for the two-year period of 2013-2014, which would take effect January 1, 2013. With this increase, the effect on the average customer with weekly one-can collection service would be about $0.65 per month. Implementation of the rate proposal is pending adoption by the King County Council.

Executive Proposed: Solid Waste Disposal Fees 2012Download PDF , 533 K
Proposes an increase in the basic solid waste disposal fee from $95.00 to $108.00 per ton for the one-year period of 2012, which would take effect January 1, 2012. With this increase, the effect on the average customer with weekly one-can collection service would be about $0.76 per month. Implementation of the rate proposal is pending adoption by the King County Council.

Executive Proposed: Solid Waste Disposal Fees 2008-2010Download PDF , 265 K
Proposes an increase in the basic solid waste disposal fee from $82.50 to $95.00 per ton, which would take effect on January 1, 2008. With this increase, the effect on the average customer with weekly one-can collection service would be $0.73 per month. Implementation of the rate proposal is pending adoption by the King County Council.

Comparative Evaluation of Waste Export and Conversion Technologies Disposal OptionsDownload PDF , 1.19 MB ("Conversion Technologies Report")
The purpose of this report is to review available information regarding current and emerging technologies for the processing of solid waste ("Conversion Technologies") as potential disposal alternatives to the landfilling of the County's solid waste at an out-of-county landfill ("Waste Export").

Governance Report Download PDF , 679 K
Report on the progress to date of the Interjurisdictional Technical Staff Group (ITSG) and Metropolitan Solid Waste Management Advisory Committee (MSWMAC) on what is generally referred to as "governance issues." This report is the last work product required to fulfill the directives outlined in Ordinance 14971Download PDF , 470 K.

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Fax: 206-296-0197

King County Solid Waste Division mission: Waste Prevention, Resource Recovery, Waste Disposal