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Anaerobic Digestion Feasibility Study

Sustainable solid waste management study

Transfer and waste management plan

Comprehensive solid waste management plan

Optimized transfer station recycling feasibility study


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

Waste-to-energy studies

Other documents

  • Solid Waste Cost of Service and Rate Restructure StudyDownload PDF 1 MB
    Report that evaluates an alternative solid waste revenue structure to reduce reliance on the existing garbage tipping fee structure as the Solid Waste Division works toward a goal of waste reduction and increased recycling.
  • 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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King County Solid Waste Division mission: Waste Prevention, Resource Recovery, Waste Disposal