Facility Site ID: 2180 Cleanup Site ID: 1324

  • Site Status

  • Cleanup Started

Current Status

Asphalt cap on SPPD property, looking north.
Asphalt cap on SPPD property, looking north.
Updated February 2020

City of Seattle begins work on Interim Action

The City of Seattle is in the preliminary engineering phase for an interim action on their property, approved in January 2016. This partial cleanup is designed to reduce the chance of human contact with contaminants, control landfill gas, and further reduce stormwater and groundwater contamination at the site. For complete details, see the Interim Action Workplan in the 2016 Agreed Order Amendment.
 
This interim action is very similar to the one completed by South Park Property Development (SPPD) in 2015 (see Previous Cleanup section below). 

To view site reports and fact sheets, click on the "View Electronic Documents" link to the right.
 
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.

Site Information

Site location

The former South Park Landfill is a 40-acre area located in the South Park neighborhood along the 8100 & 8200 blocks of Second Avenue South 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 property, originally owned by King County, was 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, when the City of Seattle built the South Recycling and Disposal Station (SRDS) on the site to ship trash out of the area.
 
In 2013 the City opened its South Transfer Station on the other side of South Kenyon Street, as a replacement for the SRDS. In 2014, a portion of the SRDS was reopened as the South Transfer Station Phase II to accept yard waste.

In 2017 the City plans to redevelop the former SRDS for improved recycling facilities and a place to process material cleaned out from stormwater and sewer lines. More information about their redevelopment plan is available at: http://www.seattle.gov/util/southrecyclingrebuild.
 
Part of the landfill was also used as an auto wrecking yard from the 1950s - 1970s. From 1984 to 1996, King County leased portions of the site for storage, mostly consisting of truck storage.

Several different parties now own the former landfill property:SPPD owns 19.4 acres which is currently used for school bus parking.The City of Seattle owns 11 acres which is used by Seattle Public Utilities to collect yard and household hazardous waste, and for parking and vehicle washing (South Transfer Station Phase II).The northwest portion known as Kenyon Industrial Park is privately owned by Harsch Investment Properties, LLC., with a smaller parcel within this area owned by 7901 2nd Ave S. LLC (7901 Property).


Contamination

The contaminants of potential concern for soil, groundwater and air at the site include:

Soil:

•Arsenic and lead
•Diesel and oil range petroleum hydrocarbons

Groundwater:

•Arsenic, iron, and manganese
•Vinyl chloride
•Benzene and cis-1,2-dichloroethene

Air:

•Landfill gas (methane and carbon dioxide)


Previous cleanup work

Site investigations began in the mid-1980s. In 1999, King County entered into Ecology’s Voluntary Cleanup Program (VCP) to address contamination on the site, some of which had migrated off the landfill properties. King County made progress towards defining the nature and extent of contamination.
 
Recent site investigation and cleanup work is being completed through a formal cleanup process following the Model Toxics Control Act (MTCA) regulations. In 2009, Ecology entered into a legal agreement (Agreed Order) with the City of Seattle and SPPD  for cleanup investigation and evaluation of cleanup options.

Two interim cleanup actions have been approved for the site, one in 2013 by SPPD and another in 2016 by the City of Seattle. Each were implemented as amendments to the 2009 Agreed Order after undergoing public comment.

The two interim actions include the following elements:
Constructing a landfill cap to prevent human contact with the landfill, and keep rain and stormwater from coming into contact with 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.

SPPD completed the interim action on their property in early 2015. The City is now starting the second interim action on their property. These actions will not interfere with any reasonable alternatives for final cleanup of the whole South Park Landfill site.
Landfill gas mitigation equipment and control box on SPPD property.
Landfill gas mitigation equipment and control box on SPPD property.

General Cleanup Process

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 17
Document Title Document Date Document Type
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 11
State Environmental Policy Act 6
Technical Reports 58
Document Title Document Date Document Type
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
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 11

Contaminant Type
Soil
Groundwater
Surface Water
Air
Sediment
Bedrock
Other Contaminant - Base/Neutral/Acid Organics C C C
Halogenated Organics - Halogenated Organics C C S
Metals - Metals Priority Pollutants S C S
Halogenated Organics - Polychlorinated biPhenyls (PCB) C S S
Non-Halogenated Organics - Petroleum Products-Unspecified C C S
Non-Halogenated Organics - Phenolic Compounds S
Non-Halogenated Organics - Non-Halogenated Solvents S S
Non-Halogenated Organics - Polycyclic Aromatic Hydrocarbons C S S
Other Contaminant - Conventional Contaminants, Organic C C S
Other Contaminant - Conventional Contaminants, Inorganic C C S
Pesticides - Pesticides-Unspecified S 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.