EPA releases final cleanup plan for WA's Lower Duwamish Waterway Superfund site

The EPA has released the final cleanup plan for the Lower Duwamish Waterway Superfund site. As part of the plan, the Washington State Department of Ecology will lead source control efforts that reduce incoming pollution to the river and support the EPA in-waterway cleanup.

SEATTLE, WA, Dec. 2, 2014 -- The Environmental Protection Agency (EPA) has officially released the final cleanup plan for the Lower Duwamish Waterway Superfund site, a major industrial waterway that includes the mouth of the Duwamish River on the south end of Elliott Bay. As part of the cleanup plan, the Washington State Department of Ecology (DOE) will continue leading source control efforts that reduce incoming pollution to the river and support the EPA in-waterway cleanup.

The cleanup plan will remove 90 percent of pollution in the river with active cleanup of 177 acres by dredging, capping and other methods. The remaining low levels of contamination will be addressed by the river's natural processes bringing in clean sediments to cover the contamination. The cleanup timeframe is estimated to be 17 years with an estimated cost of $342 million, comprising seven years of active cleanup and 10 years of natural recovery.

Industrial activity, stormwater and combined sewer overflows (CSOs) have polluted the Lower Duwamish Waterway surface water and sediments over the past 100 years. Over 40 hazardous substances were found in sediments at concentrations that pose a risk to people and marine life. Resident Duwamish fish and shellfish, which are consumed by local communities, accumulate contaminants that are harmful to human health. The primary contaminants of concern are polychlorinated biphenyls (PCBs), dioxins/furans, arsenic, and carcinogenic polycyclic aromatic hydrocarbons.

As a result of early action work already underway, pollution in Duwamish surface sediments will be reduced by 50 percent in 2015. The City of Seattle, King County, the Port of Seattle, Boeing, and Earle M. Jorgensen all recognized the need for a healthier river and helped clean up parts of it that contained the most contamination. The early action areas for cleanup are Slip 4, Terminal 117, Boeing Plant 2, Jorgensen Forge, and the Duwamish Diagonal and Norfolk CSOs. EPA used scientific studies completed by these parties to determine the extent of contamination and develop a final cleanup plan.

The cleanup plan and all the previous work to clean up the Duwamish will make the waterway less toxic to resident fish, shellfish and other food-chain organisms, resulting in fish that will be safer to eat. The Duwamish River is a source of food and recreation for local residents, including minority and low-income residents, as well as tribal and commercial fishers who rely on the river for their livelihoods.

The source control effort, coordinated by DOE in cooperation with local governments and other parties, currently involves managing 30 state and federal cleanups along or near the waterway. In addition, it is assessing pollution sources throughout the 480-square-mile Green-Duwamish watershed to support and enhance the EPA in-waterway cleanup and its source control strategy.

In developing the final cleanup plan, EPA engaged community members, local businesses, tribal governments, and other stakeholders each step of the way. It considered the comments it received and incorporated changes into the final cleanup plan based on the feedback. Specifically, the final plan calls for more dredging and a commitment to work with waterway users to ensure the cleanup is compatible with all uses where possible.

See also:

"WA firms settle CWA violations with EPA as part of Puget Sound initiative"

"Cleanup of Lower Duwamish Waterway section to cost Seattle $33 million"

###

More in Environmental
Wastewater treatment 4.0
Sponsored
Wastewater treatment 4.0