Facility Site ID: 2180 Cleanup Site ID: 1324

December 04, 2023-January 17, 2024 Public Comment Period - Now Closed

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We recently held a public comment period on a Amended Agreed Order and Interim Action Workplan and are in the process of reviewing the public comments received during that time. Responses to the those comments will be sent directly back to the commenters and posted on this website for reference. You can view the one comment we received and our response here.

Documents available for review and comment during the most recent comment period:

  • Amended Agreed Order: This site’s legal agreement is being amended to update the current interim action work plan. The previous Agreed Order described an interim action requiring redevelopment on the City of Seattle’s property, but the plan for the interim action has changed since the Agreed Order was last amended in 2016. The Agreed Order will be amended to reflect the current plan for an interim action.
  • Amended Interim Action Work Plan and Completion Report: This work plan is part of the above document. It has been revised to reflect the City’s current plans for the site which involves less extensive redevelopment than originally planned. The work plan also provides information about interim actions performed since 2016. The cleanup for this parcel will be conducted under another legal agreement (a consent decree) which was finalized in 2019.

Download the fact sheet here. 

Learn more about this cleanup and others along the LDW! Join us at Community Office Hours - new in 2024! 

View the office hours schedule.

We are offering monthly community office hours in 2024 at different locations in Georgetown and South Park. Drop-in to talk with cleanup site managers, outreach, and technical staff about the Lower Duwamish Waterway cleanup. Phone interpretation available in Spanish, Chinese, Vietnamese, and Khmer. All ages welcome!

Site Information

Aerial View of South Park Landfill cleanup site (Click to Enlarge)
Aerial View of South Park Landfill cleanup site (Click to Enlarge)

Location and source control information

The South Park Landfill is a closed solid waste landfill located on an approximately 40-acre area between Highway 99 and Highway 509 in Seattle's South Park neighborhood. It is located about 1,600 feet southwest of the Lower Duwamish Waterway. 

The site is bordered to the north by Seattle Public Utilities’ South Transfer Station (across South Kenyon Street), to the west by Occidental Avenue South, to the south by South Sullivan Street, and to the east by Highway 99 and Fifth Avenue South. It is surrounded to the south and east by the residential neighborhood of South Park.

The Lower Duwamish Waterway drainage basin is divided into source control areas. This site is located within the 1st Ave S Storm Drain (river mile 2.1) source control area along the west bank of the river. Current data indicate the landfill is not affecting the LDW, but monitoring will continue in order to confirm this.

Site history

The South Park Landfill property was originally owned by King County and used as a landfill as early as the 1930s. Open refuse burning was a common practice at the site until 1961.  The landfill was closed according to existing laws in 1966. Part of the landfill was also formerly used as an auto wrecking yard from the 1950s - 1970s. By 1970, several facilities had been built on top of the former landfill, including several industrial-use warehouse facilities and the City of Seattle-built South Recycling and Disposal Station (SRDS). From 1984 to 1996, King County leased portions of the site for storage, mostly consisting of truck storage.

Several different parties now own portions of the former landfill property:

• CenterPoint South Park LLC owns a 21-acre parcel which is currently used for vehicle parking. This parcel was formerly owned by South Park Property Development, LLC (SPPD) and is still referred to as the SPPD parcel.

• The City of Seattle owns 10.55 acres which is used by Seattle Public Utilities to support
operations and as a household hazardous waste collection facility.

• Schnitzer Properties, LLC owns the 6.49-acre parcel in the northwest portion of the former landfill. This area is referred to as the Kenyon Industrial Park (KIP) Area.

• 7901 2nd Ave S LLC owns a smaller 0.72-acre parcel on the north side of the landfill. 

Site cleanup progress

Site investigations began in the mid-1980s.  In 2009, Ecology entered into a legal agreement (Agreed Order) with the City of Seattle and SPPD for additional cleanup
investigation and evaluation of cleanup options. The Agreed Order was previously amended in 2013 and 2016. Two interim cleanup actions were conducted at the site under the Agreed Order, one between 2014 and 2015 by SPPD and another between 2018 and 2021 by the City of Seattle.

In 2019, Ecology entered into a legal agreement (Consent Decree) with the City of Seattle and SPPD. The Consent Decree covered the City of Seattle and SPPD portions of the South Park Landfill. The Consent Decree included a Cleanup Action Plan (CAP) which
required the following actions:

• Constructing or maintaining a landfill cap to prevent human contact with the landfill, and to keep rain and stormwater from encountering landfill waste.

• Installing landfill gas and surface water control systems to control the release of landfill gas emissions from the site and move rainwater away from the site.

• Restricting future land use activities to minimize potential exposure to contamination and maintain the effectiveness of cleanup actions.

• Establishing groundwater and landfill gas monitoring to evaluate the performance and effectiveness of the interim cleanup actions.

Current Status - January 2024

South Park Landfill historical photo from the 1950s.
South Park Landfill historical photo from the 1950s.
Next steps:  
Ecology will consider all comments received during this public comment period and may make changes to the documents.  If the documents require significant changes, we will hold another public comment period. If no significant changes are made, Ecology will finalize the documents and the PLPs will proceed with finalizing the legal agreements. Ecology anticipates a separate public outreach event for an Amended Consent Decree and associated Cleanup Action Plans for other properties at the Site.

Why this cleanup matters
The landfill and its associated contamination (including methane) could pose risks to human health and the environment in surrounding areas. This site is also part of Ecology’s Lower Duwamish Waterway source control efforts, because it is located near the Lower Duwamish Waterway (LDW) Superfund Site

The US Environmental Protection Agency (EPA) put the lower 5 miles of the Duwamish River on its Superfund National Priorities List in 2001. EPA leads cleanup of the river sediments. The sediments contain a wide range of contaminants due to decades of industrial activity and urban runoff. 

Ecology is leading efforts to control sources of contamination from the land area surrounding the LDW. Contaminants in the soil and groundwater around the river can find their way into the river through storm runoff and other pathways. The long‐term goal is to reduce recontamination of the sediments and restore water quality in the river. For more information, visit our Source Control page.

General Cleanup Process

Click to Enlarge Image
Click to Enlarge Image
The Model Toxics Control Act (MTCA; Chapter 70.105D RCW is Washington’s environmental cleanup law). It provides requirements for contaminated site cleanup and sets standards that protect human health and the environment. Ecology enacts the MTCA and oversees cleanups. The MTCA site cleanup process is completed in steps (see graphic below) over a variable timeline.
Legal 21
Document Title Document Date Document Type
South Park - 3rd Amended Agreed Order - Signed 8/2/2024 Agreed Order Amendment
South Park - 3rd Amended Agreed Order 11/7/2023 Agreed Order Amendment
Final Determination of Liability for Release of Hazardous Substances - CenterPoint 3/1/2023 Final Potentially Liable Person Status Letter
Status of Agreed Order 6706 3/2/2022 Order Notice of Satisfaction/Status
Environmental Covenant (SPPD Parcel) 7/30/2020 Environmental Covenant; Alternative Mechanism
Environmental Covenant SRDS Parcel 5/8/2019 Environmental Covenant; Alternative Mechanism
South Park Landfill Consent Decree Exhibit C 3/26/2019 Consent Decree
South Park Landfill Consent Decree Exhibit B 3/26/2019 Consent Decree
South Park Landfill Consent Decree Exhibit A. Cleanup Action Plan 3/26/2019 Consent Decree
South Park Landfill Consent Decree 3/26/2019 Consent Decree
Final Determination of Liability for Release of Hazardous Substances 10/30/2017 Final Potentially Liable Person Status Letter
Final Determination of Liability for Release of Hazardous Substances 10/30/2017 Final Potentially Liable Person Status Letter
South Park Landfill Draft Consent Decree 10/30/2017 Consent Decree
South Park Landfill - Agreed Order Amendment 2016 2/1/2016 Agreed Order Amendment
South Park Landfill - Final Agreed Order Amendment Cover Letter 2013 6/6/2013 Agreed Order Amendment
South Park Landfill - Final Agreed Order Amendment 2013 6/6/2013 Agreed Order Amendment
South Park Landfill - Final Agreed Order 5/4/2009 Agreed Order
South Park Landfill - Draft Agreed Order 11/14/2008 Agreed Order
Determination of Potentially Liable Person Status - SPU 10/16/2006 Final Potentially Liable Person Status Letter
Determination of Potentially Liable Person Status - KCSWD 10/16/2006 Final Potentially Liable Person Status Letter
Determination of Potentially Liable Person Status - SPPD 8/31/2006 Final Potentially Liable Person Status Letter
Public Information 17
Document Title Document Date Document Type
South Park Landfill - Comment and Response for Amended AO 6/5/2024 Responsiveness Summary
South Park Landfill Amended AO fact sheet - Khmer 11/29/2023 Fact Sheet\Public Notices
South Park Landfill Amended AO fact sheet - Vietnamese 11/29/2023 Fact Sheet\Public Notices
South Park Landfill Amended AO fact sheet - Chinese 11/29/2023 Fact Sheet\Public Notices
South Park Landfill Amended AO fact sheet - Spanish 11/29/2023 Fact Sheet\Public Notices
South Park Landfill Amended AO fact sheet - English 11/17/2023 Fact Sheet\Public Notices
PUBLIC PARTICIPATION PLAN SOUTH PARK LANDFILL SEATTLE, WASHINGTON 5/22/2018 Public Participation Plan
South Park Landfill Public Participation Plan 10/27/2017 Public Participation Plan
Vertedero de South Park: Documentos de Limpieza y Decreto de Consentimiento 10/26/2017 Fact Sheet\Public Notices
South Park Landfill Cleanup Documents and Consent Decree 10/26/2017 Fact Sheet\Public Notices
South Park Landfill - Agreed Order amendment/Interim Action Fact Sheet 2015 11/19/2015 Fact Sheet\Public Notices
South Park Landfill - Agreed Order amendment/Interim Action Fact Sheet 2013 4/15/2013 Fact Sheet\Public Notices
South Park Landfill - Agreed Order Fact Sheet (Spanish) 3/9/2009 Fact Sheet\Public Notices
South Park Landfill - Agreed Order Public Comment Period - Responsiveness Summary 3/9/2009 Responsiveness Summary
South Park Landfill - 2009 Public Participation Plan 3/9/2009 Public Participation Plan
South Park Landfill - Agreed Order Public Meeting Notice 3/9/2009 Fact Sheet\Public Notices
South Park Landfill - Agreed Order Fact Sheet 3/9/2009 Fact Sheet\Public Notices
State Environmental Policy Act 6
Technical Reports 70
Document Title Document Date Document Type
2024 Cap Inspection Report 9/28/2024 Site Specific Technical Document - other
South Park Landfill Second Quarter 2024 Progress Report 7/15/2024 Progress Report
South Park Landfill First Quarter 2024 Progress Report 4/12/2024 Progress Report
2024 Operations, Maintenance, and Monitoring Annual Report V2 3/1/2024 Site Specific Technical Document - other
2024 Operations, Maintenance, and Monitoring Annual Report V1 3/1/2024 Site Specific Technical Document - other
South Park Landfill Fourth Quarter 2023 Progress Report 1/12/2024 Progress Report
South Park Landfill Third Quarter 2023 Progress Report 10/24/2023 Progress Report
2023 Cap Inspection Report 8/1/2023 Site Specific Technical Document - other
South Park Landfill Second Quarter 2023 Progress Report 7/20/2023 Progress Report
South Park Landfill First Quarter 2023 Progress Report 4/10/2023 Progress Report
2023 Interim Action Work Plan and Completion Report 2/21/2023 Interim Action Documents
South Park Landfill Fourth Quarter 2022 Progress Report 12/22/2022 Progress Report
South Park Landfill Third Quarter 2022 Progress Report 12/5/2022 Progress Report
2022 Landfill Cap Inspection 7/22/2022 Site Specific Technical Document - other
2021 Operations, Maintenance, and Monitoring Annual Report V1 3/31/2022 Site Specific Technical Document - other
South Park Landfill Second Quarter 2022 Progress Report 3/31/2022 Progress Report
South Park Landfill December 2021 Progress Report 1/10/2022 Progress Report
South Park Landfill May 2021 Progress Report 6/22/2021 Progress Report
South Park Landfill April 2021 Progress Report 5/21/2021 Progress Report
Reprogramming Technical Memorandum South Transfer Station Phase II 5/7/2021 Site Specific Administrative Document - other (Administrative correspondence)
South Park Landfill February 2021 Progress Report 4/12/2021 Progress Report
2020 Operations, Maintenance, and Monitoring Annual Report South Park Landfill 3/31/2021 Site Specific Technical Document - other
South Park Landfill February 2021 Progress Report 3/10/2021 Progress Report
South Park Landfill Remedial Investigation/Feasibility Study February 2021 Revised Final Appendices F-M 2/12/2021 Remedial Investigation / Feasibility Study
South Park Landfill Remedial Investigation/Feasibility Study February 2021 Revised Final Appendices A-B 2/12/2021 Remedial Investigation / Feasibility Study
South Park Landfill Remedial Investigation/Feasibility Study February 2021 Revised Final 2/12/2021 Remedial Investigation / Feasibility Study
South Park Landfill January 2021 Progress Report 2/10/2021 Progress Report
South Park Landfill October 2020 Progress Report 11/13/2020 Progress Report
South Park Landfill August and September 2020 Progress Report 8/12/2020 Progress Report
South Park Landfill July 2020 Progress Report 8/10/2020 Progress Report
South Recycling Center and South Park Landfill Regulatory Considerations under the Consent Decree 7/15/2020 Site Specific Administrative Document - other (Administrative correspondence)
South Park Landfill May 2020 Progress Report 6/11/2020 Progress Report
South Park Landfill April 2020 Progress Report 5/30/2020 Progress Report
South Park Landfill March 2020 Progress Report 4/10/2020 Progress Report
Supplemental Groundwater Investigation Report (Ecology Review Draft) 3/27/2020 Remedial Investigation Report
Progress Report No. 2, Supplemental Groundwater Investigation 2/25/2020 Progress Report
South Park Landfill December Progress Report 1/16/2020 Progress Report
SPU portion of the South Park Landfill November Progress Report 12/31/2019 Progress Report
Progress Report No. 1, Supplemental Groundwater Investigation 12/4/2019 Progress Report
SPU portion of the South Park Landfill October Progress Report 11/5/2019 Progress Report
SPU Portion of the South Park Landfill September Progress Report 10/7/2019 Progress Report
LANDFILL CAP ANNUAL INSPECTION PROGRESS REPOR 018 SPPD PROPERTY SOUTH PARK LANDFILL SITE, SEATTLE, WASHINGTON FARALLON PN: 408-002 7/5/2019 Interim Action Documents
LANDFILL GAS COLLECTION AND CONTROL EM INTERIM ACTION PROGRESS REPORT—2018 SPPD PROPERTY SOUTH PARK LANDFILL SITE ASHINGTON FARALLON PN: 408-002 7/5/2019 Interim Action Documents
South Park Landfill Final Cleanup Action Plan 3/26/2019 Cleanup Action Plan
LANDFILL CAP ANNUAL INSPECTION PROGRESS REPORT—2017 SPPD PROPERTY SOUTH PARK LANDFILL SITE SEATTLE, WASHINGTON FARALLON PN: 408-002 4/17/2018 Interim Action Documents
LANDFILL GAS COLLECTION AND CONTROL SYSTEM INTERIM ACTION PROGRESS REPORT—2017 SPPD PROPERTY SOUTH PARK LANDFILL SITE SEATTLE, WASHINGTON FARALLON PN: 408-002 4/17/2018 Interim Action Documents
South Park Landfill RI-FS Appendices F-M 10/27/2017 Remedial Investigation / Feasibility Study
South Park Landfill RI-FS Appendices A-D 10/27/2017 Remedial Investigation / Feasibility Study
South Park Landfill Cleanup Action Plan Appendices 10/27/2017 Cleanup Action Plan
South Park Landfill Cleanup Action Plan Text, Tables, Figures 10/27/2017 Cleanup Action Plan
South Park Landfill RI-FS Text, Tables, Figures 10/27/2017 Remedial Investigation / Feasibility Study
LANDFILL CAP ANNUAL INSPECTION SUMMARY REPORT—2015 SPPD PROPERTY SOUTH PARK LANDFILL SITE SEATTLE, WASHINGTON FARALLON PN: 408-002 4/4/2017 Interim Action Documents
LANDFILL CAP ANNUAL INSPECTION SUMMARY REPORT—2016 SPPD PROPERTY SOUTH PARK LANDFILL SITE SEATTLE, WASHINGTON FARALLON PN: 408-002 4/4/2017 Interim Action Documents
LANDFILL GAS COLLECTION AND CONTROL SYSTEM INTERIM ACTION SUMMARY REPORT—2016 SPPD PROPERTY SOUTH PARK LANDFILL SITE SEATTLE, WASHINGTON FARALLON PN: 408-002 4/4/2017 Interim Action Documents
SPPD PROPERTY LANDFILL GAS COLLECTION AND CONTROL SYSTEM OPERATION, MAINTENANCE, AND MONITORING PLAN (Part 2) - SPPD Parcel 6/7/2016 Interim Action Documents
SPPD PROPERTY LANDFILL GAS COLLECTION AND CONTROL SYSTEM OPERATION, MAINTENANCE, AND MONITORING PLAN (Part 1) - SPPD Parcel 6/7/2016 Interim Action Documents
LANDFILL GAS COLLECTION AND CONTROL SYSTEM INTERIM ACTION PROGRESS REPORT—2015 SPPD PROPERTY SOUTH PARK LANDFILL SITE SEATTLE, WASHINGTON FARALLON PN: 408-002 5/10/2016 Interim Action Documents
Archaeological Monitoring Plan for Seattle Public Utilities’ South Transfer Station Phase II Project, City of Seattle, Washington 12/1/2015 Site Specific Technical Document - other
INTERIM ACTION CONSTRUCTION COMPLETION REPORT (SPPD Parcel) 8/14/2015 Interim Action Documents
Operation and Maintenance Plan Landfill Cap (for South Park Property Development property) 8/14/2015 Operation and Maintenance Plan
South Park Landfill - Draft Interim Action Work Plan 2015 7/24/2015 Interim Action Documents
Engineering Design Report Landfill Gas Collection and Control System (Interim Action) 6/19/2015 Engineering Design Report
March 2014 Interim Site-Wide Groundwater Monitoring Results 6/27/2014 Groundwater Monitoring Report
South Park Landfill - DRAFT Remedial Investigation / Feasiblility Study Figures 6/27/2014 Remedial Investigation / Feasibility Study
South Park Landfill - DRAFT Remedial Investigation/Feasibility Study - Text Tables 6/27/2014 Remedial Investigation / Feasibility Study
July 2013 Interim Site-wide Groundwater Monitoring Results 10/16/2013 Groundwater Monitoring Report
April 2013 Interim Site-Wide Groundwater Monitoring Results 9/18/2013 Groundwater Monitoring Report
Interim Site-wide Groundwater Monitoring Plan 12/7/2012 Interim Action Documents
RE: DEtermination of Potentially Liable Status 11/2/2006 Site Specific Administrative Document - other (Administrative correspondence)
Seattle-King County Abandoned Landfill Toxicity/Hazard Assessment Project 12/31/1986 Site Specific Technical Document - other
Voluntary Cleanup Program 1
Document Title Document Date Document Type
South Park Landfill - VCP Termination Letter 9/11/2008 VCP Administrative Document
There may be more documents related to this site. To obtain documents not available electronically, you will need to make a public records request.

Places to see print documents

  • Northwest Regional Office
    15700 Dayton Ave N
    Shoreline, 98133
    Please schedule an appointment to view print documents at this location.
  • South Park Branch / Seattle Public Library
    8604 Eighth Avenue South
    Seattle, 98108
    This location may only have print documents available during open comment periods.

Contaminants 10

Contaminant Type
Soil
Groundwater
Surface Water
Air
Sediment
Bedrock
Other Contaminant - Base/Neutral/Acid Organics C C
Halogenated Organics - Halogenated Organics C C
Metals - Metals Priority Pollutants C C
Halogenated Organics - Polychlorinated biPhenyls (PCB) C S
Non-Halogenated Organics - Petroleum Products-Unspecified C C
Non-Halogenated Organics - Non-Halogenated Solvents C C
Non-Halogenated Organics - Polycyclic Aromatic Hydrocarbons S S
Other Contaminant - Conventional Contaminants, Organic C C
Other Contaminant - Conventional Contaminants, Inorganic C C
Pesticides - Pesticides-Unspecified S S
S
Suspected
C
Confirmed Above Cleanup Levels
B
Below Cleanup Levels
RA
Remediated-Above
RB
Remediated-Below
R
Remediated
This contaminant list was based on our best information at the time it was entered. It may not reflect current conditions at the site.