Source: Chronic releases of hazardous substances following the industrialization of the waterway in the early 1900s to the present.

Release: Polychlorinated biphenyls (PCBs), phthalates, polycyclic aromatic hydrocarbons (PAHs), metals, pesticides, and dioxins/furans.

Primary Injury:

Resources at risk in the Lower Duwamish River include the benthic community, flatfish, and salmon, particularly Chinook salmon and steelhead, which are listed as threatened under the Endangered Species Act. Contaminants of concern include polychlorinated biphenyls (PCBs), phthalates, polycyclic aromatic hydrocarbons (PAHs), metals, pesticides, and dioxins/furans. Clean-up of the highly industrial Lower Duwamish River is being addressed through EPA led (Superfund and the Resource Conservation and Recovery Act) and state led programs.

Remedial Assessment

Lower Duwamish Waterway site: The Lower Duwamish Waterway Superfund site includes the 5 mile stretch from the southern end of Harbor Island to slightly past the Turning Basin, upstream. Contaminants vary throughout the waterway, including PCBs, PAHs, metals, phthalates, and dioxins/furans.

The site was listed on EPA’s National Priorities List in 2001. Early Action sites have been identified to address highly contaminated areas ahead of the overall process. Some of the Early Actions are RCRA sites which were in progress prior to the Superfund listing and others are high priority sites based on existing sediment data. Overall, the site is in the final phase of the remedial investigation to determine which contaminants pose a risk to human health and representative ecological receptors. This information will feed into the feasibility study, which will develop cleanup goals and provide alternatives to meet those goals.

LDW Early Action sites:

• Boeing Plant 2 (RCRA)
• Duwamish Diagonal
• Norfolk
• Philip Georgetown
• Rhone Poulenc (RCRA)
• Slip 4
• Terminal 117

Harbor Island site: The Harbor Island site was listed on EPA’s National Priority List in 1983 due to releases of lead from a secondary lead smelter on the island as well as the release of other hazardous substances (primarily fuels and oily wastes) from other industrial sources. There are upland units as well as four marine sediments units. Contaminants in sediment vary by location, including PCBs, PAHs, metals, and pesticides.

Harbor Island Marine sediment units:

• Todd Shipyards: remedial action complete
• Lockheed Shipyards: remedial action complete
• East Waterway: removal action was conducted in a portion of the site in 2003; EPA initiated the Phase 2 Remedial Investigation across the entire site in 2006.
• West Waterway: EPA determined that a remedial action was not required in portions outside Todd and Lockheed Shipyards.

Lockheed West Seattle site: The Lockheed West Seattle site was transferred from the Department of Ecology to EPA in 2006 and subsequently listed on the National Priorities List in March 2007. This former shipyard is located on the southwestern shoreline of Elliott Bay and adjacent to Harbor Island. During almost 50 years of operation, the shipyard was used as a vessel repair, maintenance and outfitting facility, ending in 1987. The primary contaminants of concern include heavy metals, tri-butyl tin, PCBs, and PAHs. EPA is currently in the remedial investigation phase of the cleanup process.

Department of Ecology sites: Ecology is working closely with EPA on Superfund sites and taking the lead on source control. The agency has made agreements with several parties on the waterway for upland clean-up and is continuing to identify new upland sites through the Lower Duwamish Source Control Action Plan.

Injury Assessment

Information from the remedial investigation and other sources is being used in the assessment of injury to natural resources in the Lower Duwamish River.