Soil and Sediments - Restoring Contaminated Sites to Productive Use

The Challenge

In expanding Seaport facilities, the Port of Seattle has purchased former industrial sites, many of which were contaminated by more than 90 years of unregulated industrial use. Investment in Seaport infrastructure fuels the local economy and at the same time "recycles" these former unproductive industrial sites. Cleaning up existing soil and sediment contamination and then controlling usage to prevent any recontamination makes these sites once again usable for activities and businesses that require waterfront access.

The Projects

Recent development and expansion projects have provided numerous opportunities to clean up contaminated soils while fostering opportunities for economic growth.

Terminal 18 on Harbor Island

Terminal 18 is a prime example of the Port combining redevelopment with environmental stewardship. Harbor Island is a federal Superfund site. The property's soil was contaminated with mercury, lead, arsenic, petroleum hydrocarbons and polychlorinated biphenyls. While adding 90 acres of cargo facilities and creating some 2000 new jobs, the Port was also able to:

Substantially increase intermodal rail capacity (reducing dependence on highway use).
Excavated, treated and disposed of nearly 8,000 tons of highly contaminated soils.
Capped less contaminated soils to prevent infiltration of rainwater and to limit direct soil exposure.
Provided a new public park that includes access to the shoreline, wonderful views, picnic areas and paths for walkers and bicyclers.

This project was EPA Region Ten's 2004 Phoenix Award winner. This award recognizes innovative yet practical remediation projects, which bring blighted, old commercial and industrial sites back to productive use.

Operating Area Connecting Piers 90 and 91

In building the connection between the two piers, the Port used contaminated sediments from south Elliott Bay and safely confined them from the marine environment, while yielding critically needed additional marine use area. As a result of the project:

More than 180,000 tons of contaminated sediments were removed as an aquatic threat.
A new five-acre cargo handling area was created and functionality of the piers greatly increased by connecting the piers south of Magnolia Bridge.
The modeling and monitoring program associated with the project was the first of its kind and provided important new data on tidally-fluctuating groundwater processes applicable to other contaminated shoreline sites.
A new public bicycle and pedestrian pathway was built across the terminal
Historic fill was removed from the shoreline and an historic dredged area filled, enlarging the shallow salmon habitat in adjoining slip by 0.86 acres.

Restoring the Duwamish

Running through the heart of industrialized south Seattle, the lower Duwamish Waterway was added to the Superfund list, a roster of the most toxic contaminated sites in the U.S., in 2001. This waterway is vital to the area's economic health and its restoration is key to our region's environment. Salmon still return to the river and waterway is home to the only remaining saltwater marsh in King County, an important habitat for birds and other wildlife.

The Lower Duwamish Waterway Group, a public-private partnership, made up of The City of Seattle, King County, Boeing, and the Port of Seattle (as the Lower Duwamish Waterway Group), is working with the Environmental Protection Agency and Washington Department of Ecology to address the environmental issues related to this Superfund site.

The completed Phase One Remedial Investigation accessed the existing condition of the river. This data was then used to identify seven Early Action area for clean-up. The Port in conjunction with the City of Seattle is working on Terminal 117.

EPA Brownfield Assessment Grant – Terminals 91 and 106W

Redevelopment planning for the Port's Terminal 91 and 106W will likely require the management and cleanup of regulated hazardous wastes, originating from historic site industrial activities (prior to Port ownership). To promote comprehensive assessment and cleanup and advance redevelopment of contaminated industrial land, the Port was awarded grant funding by the U.S. EPA under the U.S. Brownfields Act for both terminal properties. The environmental data obtained from the assessment work will support the planning of future site redevelopment and help determine whether cleanup is warranted. The following documents are available for review and provide additional information regarding the grant program and the findings of the grant-funded assessment work.

Terminal 91 Historical Research Overview (50 MB, PDF)
Terminal 91 Phase 2 Field Sampling and Analysis Plan and Quality Assurance Plan (16 MB, PDF)
Terminal 91 Phase 2 Site Assessment Report (25 MB, PDF)

Terminal 106W Phase 1 Environmental Site Assessment (9 MB, PDF)
Terminal 106W Phase 2 Field Sampling and Analysis Plan and Quality Assurance Plan (10 MB, PDF)
Terminal 106W Phase 2 Site Assessment Report (16 MB PDF)

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