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The Final Environmental Impact Statement (Final EIS) for the Cedar Hills Regional Landfill, 2010 Site Development Plan was issued on July 27, 2010.


The King County Solid Waste Division (division) is exploring ways to extend the useful life of the Cedar Hills Regional Landfill by developing more disposal capacity at the site. The division evaluated five action alternatives that would provide additional landfill capacity, as well as a No Action Alternative. The division has recommended a preferred alternative in the Final EIS that maximizes the available space at the landfill with no significant adverse impacts on the environment.

Environmental review process

The division, as lead agency on the project, has completed environmental review under the State Environmental Policy Act (SEPA) (external), which requires that state and local agencies consider the likely environmental consequences of a project before taking action.

2010 Final EIS cover
View or download the 2010 Final EIS in PDF format.

Steps completed in the environmental review process include:

  1. SEPA determination: The division determined that one or more of the alternatives under consideration could potentially have significant adverse impacts on the environment and issued a Determination of SignificanceDownload PDF 192 K. This determination meant that an Environmental Impact Statement, or EIS, would need to be prepared. The purpose of an EIS is to provide an impartial evaluation of potential significant environmental impacts, identify reasonable alternatives, and propose mitigation measures that would avoid or minimize adverse impacts.
  2. Scoping process: A scoping process, which provided an opportunity for the public and other agencies to comment to the division on the issues to be evaluated in the EIS, took place between March 30 and May 1, 2009. Both the natural environment (earth, air, water, plants and animals, energy and natural resources, etc.) and the built environment (environmental health, land use, transportation, public services and utilities, etc.) were evaluated. During the scoping process, the division held a public scoping meeting on April 20, 2009 to receive written and oral comments.
  3. Draft EIS: In accordance with the State Environmental Policy Act (SEPA), under RCW 43.21C.030(2)(c), a Draft EIS was prepared that analyzes the potential significant adverse impacts of each alternative and mitigating measures to avoid or minimize impacts. The public comment period on the Draft EIS ran from Sept. 30–Nov. 6, 2009.
  4. Public Hearing: On Oct. 22, 2009, the division held a public hearing at the Greater Maple Valley Community Center, to receive comments on the Draft EIS.  At the hearing, there was also a presentation about the project and an opportunity for participants to ask questions.  At least twenty-two people from the community attended the hearing.
  5. Final EIS: The division prepared a Final EIS that includes responses to comments received on the Draft EIS and identifies a recommended preferred alternative. The Final EIS was made available for review at the following locations:
    • King County Solid Waste Division office: 201 S. Jackson St., Suite 5701, Seattle, and the division’s website
    • Five public libraries:
      • King County Library – Issaquah
        10 W. Sunset Way, Issaquah
      • King County Library – Fairwood
        17009 140th Avenue SE, Renton
      • King County Library – Maple Valley
        21844 SE 248th Street, Maple Valley
      • Renton Public Library – Main Branch
        100 Mill Avenue South, Renton
      • Renton Public Library – Highland Branch
        2902 NE 12th Street, Renton

Public involvement & project schedule

Public involvement

There were several opportunities for public comment and involvement on this project (see below).

Project schedule



March 30, 2009

King County Solid Waste Division Director issued a SEPA Determination of SignificanceDownload PDF 192 K, the first step in the environmental review process.

March 30 – May 1, 2009

Scoping process public comment period - an opportunity for the public and other agencies to comment to the division on the issues to be evaluated in the EIS.

April 20, 2009

A public scoping meeting was held at the Greater Maple Valley Community Center. In response to comments received during the scoping process, the Solid Waste Division conducted additional studies.

Sept. 30, 2009

The Draft EIS became available for review and public comment.

Oct. 22, 2009

A public hearing was held at the Greater Maple Valley Community Center to receive public comments on the Draft EIS.

Sept. 30 – Nov. 6, 2009

Draft EIS public comment period.

July 27, 2010

Final EIS issued that includes responses to comments received on the Draft EIS and identification of a recommended preferred alternative.

Dec. 6, 2010

King County Council unanimously approved the Project Program Plan – Cedar Hills Regional Landfill 2010 Site Development Plan, which recommended Alternative 2 as the preferred alternative for development of the landfill. Review the Project Program PlanDownload PDF 1.4 MB.


Laura Belt
Project Manager
King County Solid Waste Division
Telephone: 206-477-5215, TTY Relay: 711
Fax: 206-296-8431

Cedar hills regional landfill

For questions or comments about the operation of the landfill, call 206-477-4466, TTY Relay: 711. This phone line is answered 24 hours a day, 7 days a week.


Cedar Hills Project Program PlanDownload PDF 1.4 MB

Final EIS

(Note: some of the following PDF files are very large file and may take several minutes to download, depending on connection speed)

Final EIS Notice of Issuance Download PDF 344 K

Final EIS cover letter, fact sheet, table of contents, abbreviations, glossary and summaryDownload PDF 2.5 MB

Final EIS, Chapter 1: Introduction and BackgroundDownload PDF 6.9 MB

Final EIS, Chapter 2: AlternativesDownload PDF 2.3 MB

Final EIS, Chapter 3: EarthDownload PDF 697 K

Final EIS, Chapter 4: Air and OdorDownload PDF 4.1 MB

Final EIS, Chapter 5: Surface WaterDownload PDF 3.8 MB

Final EIS, Chapter 6: GroundwaterDownload PDF 5 MB

Final EIS, Chapter 7: Upland Vegetation, Wetlands, and WildlifeDownload PDF 5.6 MB

Final EIS, Chapter 8: Noise and VibrationDownload PDF 1.9 MB

Final EIS, Chapter 9: Human HealthDownload PDF 689 K

Final EIS, Chapter 10: Land UseDownload PDF 5.5 MB

Final EIS, Chapter 11: Scenic Resources – Aesthetics, Light, and GlareDownload PDF 2.8 MB

Final EIS, Chapter 12: Cultural ResourcesDownload PDF 1.2 MB

Final EIS, Chapter 13: TransportationDownload PDF 1 MB

Final EIS, Chapter 14: Public Services and UtilitiesDownload PDF 674 K

Final EIS, Chapter 15: Greenhouse GasesDownload PDF 700 K

Final EIS, Chapter 16: ReferencesDownload PDF 683 K

Final EIS, Responsiveness SummaryDownload PDF 2.4 MB

Final EIS, Appendix A: Special Permit and Related DocumentsDownload PDF 1.8 MB

Final EIS, Appendix B: Municipal Solid Waste Handling PermitDownload PDF 1.5 MB

Final EIS, Appendix C: Distribution List for Final EISDownload PDF 159 K

Final EIS, Appendix D: Threatened and Endangered Species DocumentationDownload PDF 90 K

Final EIS, Appendix E: Supplemental Technical MemorandaDownload PDF 1.6 MB

Final EIS, Appendix F: Complaint Response PlanDownload PDF 268 K

Contact Us

 Call: 206-477-4466

TTY Relay: 711

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