Contaminated portions of this site at 800 Mercer St. will undergo cleanup as part of redevelopment. The buildings will be occupied by biotech and life science companies, with commercial space and public amenities on the ground level.
The South Lake Union area has a long history of industrial and commercial activities that contaminated soil and groundwater. These two sites are part of the extensive redevelopment of the area, as contamination gets cleaned up and new commercial and residential buildings are built.
Both sites are moving forward and you now have an opportunity attend an online public meeting and comment on proposed cleanup plans and related documents for each site.
- Comment period for Mercer Parcels and Dexter Parcel: Monday, Dec. 6, 2021, through Wednesday, Jan. 19, 2022
- Public meeting for both sites: Jan. 6, 2022, 6 – 7 p.m., with Q&A following the meeting
Seattle DOT Dexter Parcel site
Currently, there's a parking lot and warehouse on this site, which is located at 615 Dexter Ave N. Proposed redevelopment plans include demolishing the existing building and constructing a residential tower for affordable housing.
The completed development at the Seattle DOT Dexter Parcels site will include an 18-story tower and an underground parking garage that will encompass the entire footprint of the property. The building will be a multi-family residential tower and include a mix of units, including market rate and income-restricted units ranging from 60 to 85 percent area median income. Redevelopment is expected to begin in 2022 and completed by 2024.
Investigations at the site found the following contaminants in soil and/or groundwater:
- Gasoline-range petroleum hydrocarbons
- Diesel-range petroleum hydrocarbons
- Benzene
Learn more by visiting the Seattle DOT Dexter Parcel site webpage.
Seattle DOT Mercer Parcels site
The completed development at the Seattle DOT Mercer Parcels site, located at 800 Mercer St, will include two 13-story towers with a shared parking garage. The buildings will be occupied by biotech and life science companies, with commercial space and public amenities on the ground level.
Most recently, the property was a construction staging area. It is now vacant. Redevelopment is expected to begin in 2022 and completed by late 2024.
Investigations at the site found the following contaminants in soil and/or groundwater:
- Gasoline-range petroleum hydrocarbons
- Diesel-range petroleum hydrocarbons
- Benzene
- Lead
Learn more by visiting the Seattle DOT Mercer Parcels site website.
Proposed cleanup actions
The selected cleanup action for each site meets standards for permanence, protectiveness, implementability, public concerns, compliance with cleanup standards and state and federal laws, and ability to provide compliance monitoring. After considering comments and approving the cleanup plan, we’re proposing to sign legal agreements with 800 Mercer, LLC and SLP 615 Dexter LLC to carry out the plan for each site.