Frequently Asked Questions
The East Waterway is one of the most active commercial waterways in the Pacific Northwest, supporting shipping and water-based industries. Most vessel traffic consists of shipping container vessels and tugboats.
In addition, the East Waterway serves ecological functions as a deep-water estuary at the mouth of the Duwamish River. It is part of the Muckleshoot Tribe’s and Suquamish Tribe’s usual and accustomed area, with treaty-protected uses including a commercial fishery for salmon as well as ceremonial and subsistence uses. The general public also fishes the waterway from the Spokane Street Bridge.
The East Waterway is part of the larger Harbor Island Superfund Site. The cleanup area stretches one mile and covers 157 acres. It is located immediately downstream and north of the Lower Duwamish Waterway Superfund Site, along the east side of Harbor Island.
The East Waterway Group, or EWG, is composed of three public entities: the City of Seattle, Port of Seattle and King County. The EWG has worked collaboratively under the direction of the U.S. Environmental Protection Agency since 2006 to collect hundreds of sediment, tissue and water samples; perform human health and ecological risk assessments; perform sediment transport modeling; and develop and compare potential cleanup actions for addressing contaminated sediment.
The East Waterway is being cleaned up due to unacceptable risks to human health and to the environment. Sediments at the bottom of the waterway contain contaminants that include polychlorinated biphenyls (PCBs), arsenic, dioxins/furans and carcinogenic polycyclic aromatic hydrocarbons (cPAHs) that pose risk to human health. There are 29 contaminants, including PCBs and mercury, which pose risks for benthic invertebrates that are the base of the food chain. PCBs also pose risk to fish within the waterway.
Most of the sediment contamination in the East Waterway is from historical releases during more than 100 years of industrial and commercial activity along and upstream of the waterway.
The Port, City and the County have spent decades reducing sources of contamination and continue to take actions in the storm water drainage system and to control combined sewer overflows to further reduce contamination.
Based on the Feasibility Study cleanup alternatives, we expect that the majority of the East Waterway will be dredged. This will provide substantial removal of contaminated sediment while maintaining proper water depth of the waterway for commercial navigation. In addition, we expect that in some areas, such as under piers, contaminated sediments will be capped, treated, or monitored to ensure natural recovery over time. Contaminated dredged materials will be transported to a landfill for disposal.
Based on Feasibility Study Cost Estimates, the estimated cleanup cost could range from $300 million to $400 million.
The EPA released the Proposed Plan for the East Waterway cleanup on April 20, 2022. Following public comment, EPA will release its Record of Decision (ROD).. As outlined in the Feasibility study, clean up alternatives would take 3-5 years to design and 8-10 years to construct. . The cleanup will occur over multiple construction seasons to ensure the work is being done within salmon protection windows. We will coordinate with the tribes to ensure that cleanup activities do not hinder tribal treaty protected fishing activities.
After the cleanup, we will conduct extensive monitoring to confirm that the remediation is performing as designed. This monitoring data will be used to re-evaluate seafood advisories established by the Washington State Department of Health.
The cleanup may affect shipping and trade activities. As is customary with cleanups in other areas, and to the extent possible, activities will be scheduled to allow shipping and trade activity to continue.
The cleanup options outlined in the June 2019 Feasibility Study will meet cleanup goals for fish and other animals that live in and use the waterway and will substantially reduce risk to human health. However, the State Department of Health currently advises people not to eat resident fish and shellfish caught in the East Waterway now and during the cleanup period.
The EPA released its Proposed Plan for the East Waterway cleanup on April 20, 2023. The EPA has scheduled public comment period from April 28 – June 27, 2023. The EPA will also hold a virtual public meeting on May 25, 2023 and an in-person public meeting on June 3, 2023. The public can read the EPA’s Proposed Plan for the East Waterway cleanup, submit comments, and learn more about upcoming public meetings through EPA’s Harbor Island website HERE.
More information and documents related to the cleanup are available at Resources page.
The EPA will accept public comment on its Proposed Plan to cleanup the East Waterway between April 28 – June 27, 2023. EPA will finalize its decision on the East Waterway cleanup after considering public comments. The EPA will respond to comments received during the public comment period in a Responsiveness Summary in the anticipated Record of Decision (ROD).