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Welcome to King County's online open house for the Cedar Hills Regional Landfill 2020 Site Development Plan and Facility Relocation Draft Environmental Impact Statement (EIS)

Note: the comment period for the Draft Environmental Impact Statement closed on Nov. 6, 2020. This content is provided for informational purposes only.

Welcome to King County's online open house for the Cedar Hills Regional Landfill 2020 Site Development Plan and Facility Relocation Draft Environmental Impact Statement (EIS). The Draft EIS was prepared to comply with the State Environmental Policy Act (SEPA). This open house was designed to present a summary of the proposed alternatives so people could provide meaningful public comment on the Draft EIS. In addition to summarized information, this open house includes links to the complete Draft Environmental Impact Statement, including appendices, maps and drawings, and technical memos.

On Sept. 16, 2020, King County's Solid Waste Division published the Draft EIS for the Cedar Hills Regional Landfill 2020 Site Development Plan and Facility Relocation Project.

The public was invited to make comments on the proposed alternatives and mitigation measures, probable significant adverse impacts, and required permits or other approvals. The Solid Waste Division will review all comments received on the Draft EIS and address them in the Final EIS. The Final EIS may also include changes to the Draft EIS based on new information learned and comments received.

Comments on the Draft EIS were accepted through Nov. 6, 2020.

Background: King County's online open house for the Cedar Hills Regional Landfill 2020 Site Development Plan and Facility Relocation Draft Environmental Impact Statement (EIS)

Note: the comment period for the Draft Environmental Impact Statement closed on Nov. 6, 2020. This content is provided for informational purposes only.

The Cedar Hills Regional Landfill (landfill) is located on a 920-acre site in unincorporated King County at 16645 228th Avenue SE, Maple Valley. The site is approximately 4 miles south of Issaquah and 6 miles east of Renton and is accessed from Cedar Grove Road. Solid waste disposal at the landfill is allowed under a Special Permit, approved by the King County Board of County Commissioners in 1960. Since 1965, the landfill has provided for the safe and efficient disposal of the county's solid waste. It is the only remaining open landfill in King County.

The landfill receives over 800,000 tons of solid waste a year from about 1.4 million people in King County, except for residents in Seattle and Milton. The landfill property is surrounded by a 1,000-foot buffer where landfilling garbage is not permitted. Only a small portion of the landfill is in active operation.

In 2010, the King County Council approved a landfill development plan under which the Solid Waste Division currently operates the landfill. That plan authorized development of a refuse area (Area 8) which is currently being filled and is estimated to reach capacity in 2028.

King County contracts with renewable energy company INGENCO – doing business as Bio Energy (Washington) LLC, (BEW) – to generate renewable energy from landfill gas produced by decomposing organic material at the landfill. Since October 2010, BEW has processed the landfill gas into pipeline-quality biogas and electric power. The renewable natural gas produced by the plant each year equals the amount of energy needed to meet the natural gas needs of over 19,000 homes in King County or to substitute for the energy use of 11.2 million gallons of diesel fuel and 15 million kilowatt hours of electricity.

In 2019, the King County Council and 24 of King County's 37 partnering cities approved the 2019 Comprehensive Solid Waste Management Plan, which provides policy direction for the County's management of its solid waste. That Plan calls for the County to further develop the Cedar Hills Regional Landfill to maximize disposal capacity.

Purpose: King County's online open house for the Cedar Hills Regional Landfill 2020 Site Development Plan and Facility Relocation Draft Environmental Impact Statement (EIS)

Note: the comment period for the Draft Environmental Impact Statement closed on Nov. 6, 2020. This content is provided for informational purposes only.

King County's Solid Waste Division is working on a project to ensure there is enough capacity at the Cedar Hills Regional Landfill to continue accepting garbage beyond 2028.

The project proposes to build a new area within the landfill property to put garbage (proposed as Area 9), and to move some support facilities (maintenance shop, offices, and vehicle parking) to make room for that new area.

The purpose of this proposal and the alternatives being analyzed is to maximize the capacity and lifespan of the Cedar Hills Regional Landfill in accordance with the King County Council approved 2019 Comprehensive Solid Waste Management Plan.

The Cedar Hills Regional Landfill has provided cost-effective, environmentally responsible waste disposal for more than 50 years. However, built capacity at the landfill is estimated to be exhausted in 2028, leaving less than ten years to put the next disposal method in place. The proposed project is needed so King County's Solid Waste Division can continue to provide reliable and cost-effective solid waste disposal services to its ratepayers in 37 cities and the unincorporated areas within King County.

Note: the comment period for the Draft Environmental Impact Statement closed on Nov. 6, 2020. This content is provided for informational purposes only.

Description of alternatives

The Draft Environmental Impact Statement (Draft EIS) for the King County Cedar Hills Regional Landfill 2020 Site Development Plan and Facility Relocation Project evaluates three action alternatives plus a no-action alternative. The Draft EIS looks at the environmental impacts in several categories, including: Earth; Air (Odor); Water (stormwater, surface water, groundwater); Noise and Vibration; Greenhouse Gas Emissions: Human Health; Plants and Animals; Aesthetics, Light, and Glare; Land and Shoreline Use; Human Health; Transportation; and Public Services and Utilities.

Proposed landfill development activities:

Action Alternatives 1 through 3 expand upon the No Action Alternative with the development of additional capacity, with different sequencing in landfilling, leading to increased years of life. The three action alternatives provide a range of development scenarios that would extend the capacity of the landfill between nine and eighteen years (a range from 2037 to 2046), or between approximately 11 million and 26 million cubic yards. The proposed alternatives are as listed below:

  • No-Action Alternative: Under the No Action Alternative, the landfill is expected to reach its permitted capacity in 2028, based on 2020 solid waste tonnage forecasts. This estimate assumes that no further landfill development would occur beyond what King County planned in 2010. Main landfill support facilities would remain in their current locations, including removal, refurbishment or replacement of some facilities at the end of their useful life, and may include temporary use of interim off-site facilities. All development under the No Action Alternative is allowed under the existing Special Permit and the current Municipal Solid Waste Landfill Permit.
  • Alternative 1: Would develop approximately 34 acres for construction of a new refuse area in the southeast portion of the landfill (proposed Area 9), with landfilling in Areas 8 and 9 to no more than 800 feet above mean sea level. Landfilling would also occur in existing landfill Areas 5, 6, and 7 to no more than 788 feet above mean sea level. No additional landfilling would take place in the Main Hill, Southeast Pit, Central Pit, or Areas 2/3 and 4. Based on current tonnage predictions, this alternative would add approximately 12 million cubic yards and nine years (to approximately 2037) to the landfill capacity. Landfill support facilities would also be relocated.
  • Alternative 2: Would develop approximately 34 acres for construction of a new refuse area in the southeast portion of the landfill (proposed Area 9), with landfilling in Areas 8 and 9 to no more than 830 feet above mean sea level. Landfilling would also occur in existing landfill Areas 5, 6, and 7 to no more than 788 feet above mean sea level. Additional landfilling would take place in approximately nine acres in the southern portion of Areas 2/3, 4, and Central Pit to 788 feet. No additional landfilling would take place in the Main Hill or Southeast Pit. Based on current tonnage predictions, this alternative would add approximately 13 million cubic yards and 10 years (to approximately 2038) to the landfill capacity. Landfill support facilities would also be relocated.
  • Alternative 3: Would develop approximately 34 acres for construction of new refuse areas in the southeast portion of the landfill (proposed Area 9), approximately 66 acres in northwest portions of Areas 2/3 and 4, and the northeast portion of Main Hill and Central Pit, with landfilling in all of these areas and in Area 8 to no more than 830 feet above mean sea level. Landfilling would also occur in existing landfill Areas 5, 6, and 7 to no more than 788 feet above mean sea level. No additional landfilling would take place in the Southeast Pit. A King County-owned property adjacent to the northeast corner of the landfill would be added into the landfill site, thus revising the site boundary, and maintaining 1,000‑foot buffer inside the revised site boundary. Based on current tonnage predictions, this alternative would add approximately 26 million cubic yards and 18 years (to approximately 2046) to the landfill capacity. Landfill support facilities would also be relocated.

See Table 2-1: Estimated Landfill Area, Capacity, and Life Span by Alternative—Beyond 2028 in the Draft EIS for a side-by-side comparison of the alternatives.

Proposed landfill support facilities relocation options:

All three action alternatives would require relocation of landfill support facilities in order to construct proposed Area 9 and consider the same three options for their relocation:

  • Option 1: Would pursue a Special Use Permit to relocate and build landfill support facilities within the existing southern buffer zone. This would include but not be limited to the truck scale/scale house, truck wash, heavy equipment maintenance facility (cat shack), emergency generator, a small Moderate Risk Waste storage area, some tractor and trailer parking, the truck maintenance building, employee parking, office space, and laboratory space.
  • Option 2: Would pursue a Special Use Permit to relocate and build landfill support facilities within the existing northern buffer zone, including, but not limited to the truck maintenance building, parking, office space, and laboratory space. This option would also relocate and build some landfill support facilities in the south, but not within the buffer. These would include but not be limited to the truck scale/scale house, truck wash, heavy equipment maintenance facility (cat shack), emergency generator, a small Moderate Risk Waste storage area, and some tractor and trailer parking.
  • Option 3: Would relocate and build landfill support facilities at an off-site location at 3005 NE 4th Street in Renton, adjacent to King County's Renton Recycling and Transfer Station. (NOTE: no landfilling would occur at this location.) The Renton site was evaluated during the 2019 Cedar Hills Regional Landfill Support Facilities Evaluation (King County 2019c). The facilities to be relocated include a portion of the vehicle maintenance shop (for repairing tractors, trailers, operations vehicles, and passenger vehicles), employee offices, and parking for employees, tractors, trailers, and operations vehicles. This option would also relocate and build some landfill support facilities in the north or south areas of the landfill site. The truck scale/scale house, truck wash, equipment maintenance facility (cat shack), emergency generator, a small Moderate Risk Waste storage area, and some tractor and trailer parking would be relocated in the south. None of these facilities will be located in the buffer.
FAQs: King County's online open house for the Cedar Hills Regional Landfill 2020 Site Development Plan and Facility Relocation Draft Environmental Impact Statement (EIS)

Note: the comment period for the Draft Environmental Impact Statement closed on Nov. 6, 2020. This content is provided for informational purposes only.

  1. What is the basis for more development at the landfill?

    Since 2001, King County has made maximizing capacity of the Cedar Hills Regional Landfill one of its primary goals and a central facet in its operational planning.

    A site development plan adopted by the County Council in 2010 authorized the division to develop landfill capacity to last until approximately 2028.

    With its adoption of the 2019 Comprehensive Solid Waste Management Plan in 2019, the County Council directed the Solid Waste Division to consider several action alternatives to keep the landfill operating for an additional nine to 18 years beyond 2028.

  2. Is King County planning to expand the landfill?

    King County is planning to maximize capacity on the existing footprint of the landfill. While Alternative 3 proposes to incorporate King County owned property at the northeast corner of the site, that property would be used to maintain the 1,000-foot buffer.

  3. Are there already buildings in the landfill buffer?

    Yes. The buffer already hosts King County buildings, including a greenhouse where native plants are grown for landscaping at county-owned parks and buildings. The buffer also hosts Passage Point, a YWCA program that provides housing for women reuniting with their children after incarceration. A water storage tank that provides non-potable water for landfill operations and fire suppression is also located in the buffer.

    As the property owner, King County, not the Solid Waste Division, may authorize other uses within the buffer. A special use permit will be needed to allow non-landfilling uses, such as relocating landfill support facilities, within the buffer.

  4. What kind of support facilities would be built in the landfill buffer or next to the Renton Transfer Station?

    The types of facilities that would be relocated in the landfill buffer or next to the Renton Transfer Station would include a vehicle maintenance shop (for repairing tractors, trailers, operations vehicles, and passenger vehicles), employee offices, and parking for employees, tractors, trailers, and operations vehicles. The support facilities that would be relocated to Renton or the landfill buffer will not handle garbage or other waste. No landfilling would occur at the location next to the Renton Transfer Station.

  5. Are we going to see more traffic as a result of this project?

    From a traffic standpoint, the major differences between alternatives is the length of time the landfill would remain open, and whether the support facilities would be located at Cedar Hills or in Renton.

    All of the action alternatives would result in an increase in traffic during construction and operation. King County forecasts that the tonnage of waste going to the landfill will grow annually, which would result in additional trips to and from the landfill.

    The I 405 Southbound On-Ramp/SR 169/SE Renton Maple Valley Highway/Sunset Boulevard North intersection impact is considered a cumulative, significant, and unavoidable adverse impact that would occur with or without implementing the action alternatives.
    Examples of mitigation to reduce or offset traffic impacts could include:

    • Coordinating with the Washington State Department of Transportation on intersection improvements at State-Route 169 and SE Renton Maple Valley Highway/Cedar Grove Road SE
    • Establishing construction truck routes, timing activity, and employing flaggers to control traffic to and from construction sites.
  6. What's the deadline for submitting public comments on the Draft EIS?

    The comment period closed on Nov. 6, 2020.

  7. What will King County do with comments on the Draft EIS?

    After the comment period closes, the Solid Waste Division will review and respond to all comments received on the Draft EIS in the Final EIS. The Final EIS may also include changes to the Draft EIS based on new information learned and comments received. The King County Executive and County Council will make a final decision on which alternative will move forward after reviewing the information presented in the Final EIS.

  8. When will the Final EIS be completed?

    The Final EIS is expected to be published in spring 2021.

  9. When will King County decide on a landfill development alternative and a location for the support facilities?

    A decision is expected in spring 2021.

SEPA: King County's online open house for the Cedar Hills Regional Landfill 2020 Site Development Plan and Facility Relocation Draft Environmental Impact Statement (EIS)

Note: the comment period for the Draft Environmental Impact Statement closed on Nov. 6, 2020. This content is provided for informational purposes only.

What is SEPA and what is an Environmental Impact Statement?

Enacted in 1971, the State Environmental Policy Act (SEPA) is a law that requires state and local agencies to identify the likely environmental consequences of proposed actions and plans. The environmental consequences are identified through a SEPA review process. When potentially significant impacts are anticipated, an Environmental Impact Statement (EIS) is required. The SEPA review process is designed to help agency decision-makers, applicants, and the public understand how a proposed action or plan will affect the environment.

There are three milestones in the EIS development process:

  1. Scoping - gives the public the opportunity to review and comment on what will be studied in the Draft Environmental Impact Statement (EIS). King County hosted a scoping process on the project proposal in August 2019.
  2. Draft EIS - allows the public to review and comment on the plans or actions an agency is proposing, including the mitigation measures to reduce, minimize or avoid harmful environmental impacts. The public comment period on the Draft EIS ended on Nov. 6, 2020.
  3. Final EIS - comments on a Draft EIS are considered in the development of a Final EIS, which informs the agency's decision on which plan or action will be selected to move forward. The Final EIS is expected to be published in spring 2021.

What are "alternatives" and why are they included?

SEPA requires agencies to consider a range of alternatives that meet the goals of their proposed plans. Alternatives are important because they allow decision-makers and the public to compare the merits and impacts of different choices.

What is "mitigation"?

Mitigation is the proposed actions to avoid, reduce, repair, minimize, or monitor impacts. An example of mitigation would be designing a project to avoid sensitive habitat like a wetland, or replanting trees and shrubs to restore disturbed areas after a project is completed. Agencies may require mitigation in their development regulations, or through other local, state, or federal laws.

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