Facility Site ID: 62773 Cleanup Site ID: 15008

  • Site Status

  • Cleanup Started

Current Status

Block 38 West - aerial view of Alley Interim Action Area.
Block 38 West - aerial view of Alley Interim Action Area.
Updated January 2021


Ecology has reviewed and considered all comments received on the draft Interim Action Work Plan. Based on Ecology’s evaluation of the comments, no changes were necessary in the document, and it has been finalized. 

View the Interim Action Work Plan
View the Response to Comments


Work will now begin on the Remedial Investigation and Feasibility Study for determining a final cleanup action for the site. See the graphic below and visit Ecology’s cleanup process webpage to learn more about Washington’s formal cleanup process.


Fact sheets

Block 38 West Fact sheet - English
Block 38 West Fact sheet - Español
Block 38 West Fact sheet - 訊息中文版

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Site Information

Block 38 West Site - street view
Block 38 West Site - street view

Site Location

The Block 38 West Site is located in the South Lake Union neighborhood of Seattle. The property known as Block 38 West is generally located at 500-536 Westlake Avenue North, is approximately 1.06 acres in size, and consists of three parcels (Property). 

Site History

Past uses of the Property include a lumber storage yard, a blacksmith shop, warehouse storage, and retail and commercial operations and associated parking. The Property’s structures have been demolished as part of planned redevelopment of the Property.  The redevelopment includes construction of a multistory mixed-use building with a preliminary design for a 12-story office building above street level and four levels of parking below street level.

Contamination

Previous investigations at the Site found the following in soil
and/or groundwater:
•  petroleum hydrocarbons (as diesel-range and oil-range organics)
•  polycyclic aromatic hydrocarbons (PAHs), including naphthalenes and
    carcinogenic PAHs (cPAHs)
•  benzene

These contaminants were found at levels that exceed allowable standards under the state’s cleanup law, the Model Toxics Control Act (MTCA Chapter 70.015D RCW), and therefore must be addressed during the cleanup action. Cis-1,2-dichloroethene was also found in the groundwater but at concentrations below applicable cleanup levels under MTCA.

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 5
Document Title Document Date Document Type
Block 38 West Agreed Order Final April 2020 4/20/2020 Agreed Order
Block 38 West Agreed Order Public Review Draft - March 2020 2/19/2020 Agreed Order
Block 38 West - PLP Status Letter 9/5/2019 Final Potentially Liable Person Status Letter
Block 38 West - Early Notice/ Preliminary PLP Letter 8/13/2019 Early Notice Letter
Block 38 West - Early Notice Letter & Preliminary Determination of Liability 8/13/2019 Early Notice Letter
Public Information 8
Document Title Document Date Document Type
Response to Comments Block 38 West IAWP 1/22/2021 Responsiveness Summary
Block 38 West Fact Sheet Interim Action Spanish - December 2020 12/16/2020 Fact Sheet\Public Notices
Block 38 West Fact Sheet Interim Action Chinese - December 2020 12/16/2020 Fact Sheet\Public Notices
Block 38 West Fact Sheet Interim Action - December 2020 12/16/2020 Fact Sheet\Public Notices
Block 38 West Fact Sheet Legal Agreements - March 2020 CHINESE 3/12/2020 Fact Sheet\Public Notices
Block 38 West Fact Sheet Legal Agreements - March 2020 SPANISH 3/12/2020 Fact Sheet\Public Notices
Block 38 West Fact Sheet Legal Agreements - March 2020 3/12/2020 Fact Sheet\Public Notices
Block 38 West Public Participation Plan - March 2020 3/12/2020 Public Participation Plan
State Environmental Policy Act 2
Document Title Document Date Document Type
Block 38 West - Ecology SEPA Comment Letter 5/16/2019 SEPA Documents
Block 38 West - Addendum to the FEIS 4/29/2019 SEPA Documents
Technical Reports 70
Document Title Document Date Document Type
Block 38 West - AO Progress Report for February 2024 3/15/2024 Progress Report
Block 38 West - AO Progress Report for January 2024 2/13/2024 Progress Report
Block 38 West - AO Progress Report for December 2023 1/15/2024 Progress Report
Block 38 West - Alley Interim Action Report 1/5/2024 Interim Action Documents
Block 38 West - Interim Action Report (Property Cleanup) - Appx C thru Appx K 12/28/2023 Interim Action Documents
Block 38 West - Interim Action Report (Property Cleanup) - Appx B 12/28/2023 Interim Action Documents
Block 38 West - Interim Action Report (Property Cleanup) - text, figures, tables, Appx A 12/28/2023 Interim Action Documents
Block 38 West - AO Progress Report for November 2023 12/13/2023 Progress Report
Block 38 West - AO Progress Report for October 2023 11/15/2023 Progress Report
Block 38 West - AO Progress Report for September 2023 10/12/2023 Progress Report
Block 38 West - AO Progress Report for August 2023 9/14/2023 Progress Report
Block 38 West - AO Progress Report for July 2023 8/15/2023 Progress Report
Block 38 West - AO Progress Report for June 2023 7/17/2023 Progress Report
Block 38 West - AO Progress Report for May 2023 6/13/2023 Progress Report
Block 38 West - AO Progress Report for April 2023 5/15/2023 Progress Report
Block 38 West - Final Remedial Investigation Work Plan 4/26/2023 Remedial Investigation Work Plan
Block 38 West - AO Progress Report for March 2023 4/14/2023 Progress Report
Block 38 West - AO Progress Report for February 2023 3/15/2023 Progress Report
Block 38 West - AO Progress Report for January 2023 2/15/2023 Progress Report
Block 38 west - AO Progress Report for December 2022 1/16/2023 Progress Report
Block 38 West - AO Progress Report for November 2022 12/15/2022 Progress Report
Block 38 West - AO Progress Report for October 2022 11/15/2022 Progress Report
Block 38 West - AO Progress Report for September 2022 10/13/2022 Progress Report
Block 38 West - AO Progress Report for August 2022 9/15/2022 Progress Report
Block 38 West - AO Progress Report for July 2022 8/15/2022 Progress Report
Block 38 West - AO Progress Report for June 2022 7/15/2022 Progress Report
Block 38 West - AO Progress Report for May 2022 6/15/2022 Progress Report
Block 38 West - AO Progress Report for April 2022 5/13/2022 Progress Report
Block 38 West - AO Progress Report for March 2022 4/15/2022 Progress Report
Block 38 West - AO Progress Report for February 2022 3/15/2022 Progress Report
Block 38 West - AO Progress Report for January 2022 2/15/2022 Progress Report
Block 38 West - AO Progress Report for December 2021 1/17/2022 Progress Report
Block 38 West - AO Progress Report for November 2021 12/15/2021 Progress Report
Block 38 West - AO Progress Report for October 2021 11/15/2021 Progress Report
Block 38 West - AO Progress Report for September 2021 10/15/2021 Progress Report
Block 38 West - AO Progress Report for August 2021 9/15/2021 Progress Report
Block 38 West - AO Progress Report for July 2021 8/16/2021 Progress Report
Block 38 West - AO Progress Report for June 2021 7/15/2021 Progress Report
Block 38 West - AO Progress Report for May 2021 6/15/2021 Progress Report
Block 38 West - AO Progress Report for April 2021 5/17/2021 Progress Report
Block 38 West - AO Progress Report for March 2021 4/15/2021 Progress Report
Block 38 West - AO Progress Report for February 2021 3/15/2021 Progress Report
Block 38 West - AO Progress Report for January 2021 2/15/2021 Progress Report
Block 38 West - Sampling and Analysis Plan_Alley Area (Interim Action) 2/10/2021 Sampling and Analysis Plan
Block 38 West - Interim Action Work Plan_Alley Area 2/3/2021 Interim Action Documents
Block 38 West - AO Progress Report for December 2020 1/15/2021 Progress Report
Block 38 West - AO Progress Report for November 2020 12/15/2020 Progress Report
Block 38 West - AO Progress Report for October 2020 11/16/2020 Progress Report
Block 38 West - AO Progress Report for September 2020 10/15/2020 Progress Report
Block 38 West - AO Progress Report for August 2020 9/15/2020 Progress Report
Block 38 West - AO Progress Report for July 2020 8/14/2020 Progress Report
Block 38 West - AO Progress Report for June 2020 7/15/2020 Progress Report
Block 38 West - AO Progress Report for May 2020 6/15/2020 Progress Report
Block 38 West - Supplemental Subsurface Investigation Work Plan (Adjacent Alley) and Foundation Elements Memo 6/15/2020 Remedial Investigation Work Plan
Block 38 West - Farallon Interim Action Soil Data Summary Memo 5/29/2020 Interim Action Documents
Block 38 West - Monitoring Well Installation (Building Wells) Work Plan Memo 5/22/2020 Scope Of Work
Block 38 West - AO Progress Report for April 2020 5/15/2020 Progress Report
Block 38 West - SHA Rank Letter 2/18/2020 Site Specific Administrative Document - other (Administrative correspondence)
Block 38 West - Site Hazard Assessment 2/10/2020 Site Hazard Assessment Report
Block 38 West - Subsurface Investigation Results, Letter Report 1/22/2020 Remedial Investigation Report
Block 38 West - Groundwater Monitoring Program - Technical Memo 1/13/2020 Site Specific Technical Document - other
Block 38 West - Farallon Release Notification Letter 12/9/2019 Site Specific Administrative Document - other (Administrative correspondence)
Block 38 West - Independent IAWP_Part 4-Appendix F through I_Nov2019 11/8/2019 Interim Action Documents
Block 38 West - Independent IAWP_Part 3-Appendix B through E_Nov2019 11/8/2019 Interim Action Documents
Block 38 West - Independent IAWP_Part 2-Appendix A_Nov2019 11/8/2019 Interim Action Documents
Block 38 West - Independent Interim Action Work Plan (IAWP)_Part 1-Text-Figures-Tables_Nov2019 11/8/2019 Interim Action Documents
Block 38 West - SHA Notification Letter 9/11/2019 Site Specific Administrative Document - other (Administrative correspondence)
Block 38 West - Initial Investigation Field Report 7/31/2019 Initial Investigation Report
Block 38 West - Subsurface Investigation Report and Enviro Media Mgmt Plan 12/28/2018 Site Specific Technical Document - other
Block 38 West - Farallon Tech Memo: Summary of Results from Subsurface Investigations 10/16/2018 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.

Contaminants 5

Contaminant Type
Soil
Groundwater
Surface Water
Air
Sediment
Bedrock
Non-Halogenated Organics - Polycyclic Aromatic Hydrocarbons C
Non-Halogenated Organics - Benzene C
Non-Halogenated Organics - Petroleum-Diesel C
Non-Halogenated Organics - Petroleum-Gasoline C
Non-Halogenated Organics - Petroleum-Other C
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.