Looking south on the Lower Duwamish Waterway. South Park bridge is in the distance/
Icon of ship-loading crane at the port

Construction News

We Are Cleaning Up the Lower Duwamish Waterway

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Construction is scheduled to begin in the upper reach of the Lower Duwamish Waterway in October of 2024.

Learn more about how we’ve completed “early action” cleanups.

Project contact information:

1.888.561.LDWG (1.888.561.5394)

What’s happening now:

July 2024

  • The Lower Duwamish Waterway Group (LDWG) is excited to begin cleanup construction this fall on the Lower Duwamish Waterway Superfund Site.
  • King County, as a member of LDWG, recently hired Pacific Pile and Marine as the lead contractor to carry out cleanup construction in the upper reach.
  • Construction in the upper reach is expected to begin this October and will take place during the construction season (October – February) over the next three years, ending in February 2027. In-water construction activities are restricted to these months to limit impacts to certain fish species.
  • After the Lower Duwamish upper reach cleanup is complete, construction will continue downstream toward the south end of Harbor Island for the middle and lower reaches of the Lower Duwamish Waterway over the next decade. You can read more about the pollutants we will clean up from the river here.
  • During cleanup construction, the Cleanup Outreach team will provide many ways for you to follow along with cleanup activities and progress. This includes visiting this website, signing up for regular email updates, and reading flyers in the community.
  • You can also reach out to our team should you have questions or concerns. Reach out to us at info@ldwg.org or 1-888-561-LDWG (1-888-561-5394).
  • Learn more about the Lower Duwamish Waterway Superfund Site cleanup on the EPA website.

Stay Connected:

Read past updates

Summer 2024

Newsletters will all be posted here.

What to Expect During Construction

Map of Lower Duwamish Waterway Upper Reach

Map detail showing a highlighted construction-activity area next to an area number.Sediment Management Area (SMA) label

Construction will take place in specific areas within the waterway’s upper reach, which extends from the South 102nd Street bridge downstream to the Duwamish Waterway Park.

In general, the public can expect to see:

  • Construction equipment on the river. This includes barges for carrying contaminated sediment or clean sand, barges with dredging or excavation equipment attached, and tugboats to move the barges around.
  • Construction workers using certain shoreline areas next to the river for storing construction equipment and for transferring dredged sediment from barges to the shoreline area, then to railcars for transport to the landfill.
  • Boats on the river collecting samples of water and sediment for testing.
  • Boats surveying and monitoring the progress of dredging and clean sand placement.
  • Workers driving vehicles, parking, moving barges on the river with tugboats, and using heavy equipment.
  • Workers sometimes working at night, when necessary due to tides and other factors.
  • Workers using lights and construction equipment that will generate noise.

Construction photos

The Contractor will use a closed bucket as the primary method to dredge and remove contaminated sediment.
Example of how the contractor will offload or remove dredged sediment from the river.
The construction quality assurance team will collect sediment samples after dredging to confirm no additional dredging is needed.
The construction quality assurance team will collect water samples during dredging to confirm contractor meeting water quality criteria.

Planned Construction Activities

You can expect the following construction activities:

  • Staging of equipment and materials: Setting up, organizing, and storing materials before use in construction.
  • Offloading: Transferring materials like dredged sediment from one mode of transportation to another, such as from a barge to a truck or train.
  • Transporting materials: Transporting dredged materials and debris from one location to another, including by barge, rail, or truck.
  • Disposing of contaminated materials: Disposing of contaminated materials at a permitted commercial landfill.
  • Surveying and inspections: Documenting the condition of the work sites and surrounding areas, as well as the progress of construction before, during, and after construction (including taking photographs).
  • Removing piling and debris: Temporarily removing the piling that supports Tribal fishing, removing piles no longer in use, and removing any debris from dredged areas.
  • Installing replacement piling and reinforcing structures: Replacing any Tribal fishing piling that are temporarily removed for construction access. Reinforcing any shoreline bulkheads to allow dredging next to the bulkhead.
  • River sampling: Collecting water samples to confirm that dredging is being conducted as required, to comply with water quality standards.
  • River sediment sampling: Collecting sediment samples to confirm dredging has removed the contaminated sediment as required.
  • Site cleanup and demobilization: Removing construction equipment and materials from the work site.

Communications and construction timeline for the Upper Reach

 

2024 2025 2026 2027
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Contractor hired
Contracting and Bid
Construction Submittals
Pre-construction Outreach
2024 Construction Season 2025 Construction Season 2026 Construction Season
Ongoing Community Outreach and Communications

How EPA, LDWG, and the contractor will work to reduce the impact of cleanup construction on the community.

LDWG and the construction contractor, with the oversight of the EPA, will work to learn about and mitigate community concerns as practical through digital and in-person outreach such as responding to project emails and the project phone line, and by speaking with people at community events.

We are dedicated to limiting the impacts of construction on those who work, live, play, and gather in the area.

We welcome the community to contact the Cleanup Outreach Team with any concerns related to the cleanup. You may reach us via email at info@ldwg.org or by phone at 1-888-561-LDWG.

Resources

Handouts and materials will be posted here.