LOWER DUWAMISH WATERWAY
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On this page:
- What Is the Current Site Status?
- Activity and Use Limitations
- Sampling and Monitoring
- Enforcement Information
On related pages:
The Lower Duwamish Waterway (LDW) Superfund site is a five mile segment of Seattle’s only river, the Duwamish. The river flows between the neighborhoods Georgetown and South Park and through the industrial core of Seattle into Elliott Bay. The LDW has served as Seattle’s major industrial corridor since the early 1900s. This has caused the Waterway’s sediments (river bottom) to be contaminated with toxic chemicals from many sources, ranging from stormwater runoff, wastewater, and industrial practices. While environmental regulation and cleanup of older infrastructure, soils, sediments, and groundwater have helped reduce pollution sources, legacy contamination and ongoing sources continue to impact people and the environment. There are many chemical contaminants in LDW sediment, fish and shellfish. Most of the human health risk comes from polychlorinated biphenyls (PCBs), arsenic, carcinogenic polycyclic aromatic hydrocarbons (cPAHs), as well as dioxins and furans. As a result, consumption of resident fish and shellfish, as well as contact with contaminated sediments, pose a risk to human health. The Washington Department of Health issued a fish advisory recommending no one eat crab, shellfish and fish (except salmon) from the Lower Duwamish Waterway. Salmon (except blackmouth salmon) are the healthiest choice because they spend a short time in the Duwamish Riv
The EPA declared the Lower Duwamish Waterway a “Superfund” site in 2001, meaning it was eligible for a special federal cleanup program due to the severity of its contamination. The EPA is responsible for administering the cleanup of sediments in the Waterway, and the Department of Ecology is responsible for controlling sources of pollution to the Waterway. The City of Seattle, King County, the Port of Seattle, and the Boeing Company joined together as the Lower Duwamish Waterway Group (LDWG). As a group, LDWG stepped forward to complete a comprehensive study, called a Remedial Investigation (RI). LDWG maintains a website with EPA-approved project documents. The remedial investigation identified some of the most contaminated areas where they could start early cleanups, called Early Action Areas (EAAs). Several EAAs were selected for action by the EPA and Ecology. By the end of 2015, 50 percent of PCB contamination in the river bottom was removed through these early action cleanups, including:
- Norfolk Combined Sewer Overflow (CSO)/Storm Drain (SD)
- Duwamish/Diagonal CSO/SD
- Slip 4
- Terminal 117 (T-117)
- Boeing Plant 2
- Jorgensen Forge
What Is the Current Site Status?
The EPA is the lead agency for the in-waterway cleanup. The LDW was designated a Superfund site by the EPA in 2001. The LDW Superfund site encompasses upland sources of contamination as well as contamination within the waterway. The Washington Department of Ecology (Ecology) is the lead agency for control of upland sources ("source control").
The site is being addressed through potentially responsible party (PRP) actions with EPA and state oversight. Like other complex Superfund sites, the Lower Duwamish Waterway (LDW)
Superfund site is a multi-phased process. Since LDW became a Superfund site in 2001, five Early Action Area (EAA) cleanups have focused on sediment hotspots (areas of highly contaminated mud on the river bottom). The EAAs are expected to reduce average PCB levels across the waterway by 50%. In 2014, EPA completed the study of the overall site and published a final cleanup plan (Record of Decision) for remaining contaminated sediments
This year, waterway users are being surveyed to make sure that changes in land use are factored into the cleanup design. In 2017 and 2018, testing of sediment, water, and seafood will be done to establish new baseline conditions. Over the coming years, EPA expects PRPs (parties potentially responsible for cleanup costs) to design and construct the remaining sediment cleanup and to monitor and maintain the site over time. As cleanup and source control continue, testing will be repeated to assess progress towards long-term cleanup goals.
Fishing in the Duwamish
Many people enjoy fishing on the Duwamish River. However, the resident seafood that live in the river year-round are not safe to eat. To get a better idea of who fishes on the river and their fishing practices, EPA completed the Fishers Study in 2016. Some of the key findings from the Study were:
- Fishing is an important activity for the wellbeing of fishers and creates a sense of community
- Fishers on the Duwamish are very diverse, represented more than 20 ethnic/language groups
- Fishers continue to consume and share their catch, including resident fish, crab and shellfish
- The advisory information is hard to understand, and signs are not entirely effective in promoting safe fish consumption
Promoting healthy fish consumption must connect with the local fishing culture. Rather than asking “why don’t fishers follow the advisory?” the question should be reframed as “how do we meet the needs of the fishers to promote healthy fish consumption?”
In January 2017, EPA entered into a Cooperative Agreement (CA) with Public Health Seattle-King County to establish a community-based Healthy Seafood Consumption Institutional Control (IC) Program for the LDW Superfund Site. The CA establishes a community-based participatory process to develop culturally-appropriate IC tools that can be implemented throughout the cleanup of the LDW Superfund Site. The program will promote healthy seafood consumption before, during, and after the cleanup.
More information on fishing in the Duwamish can be found in the documents linked below:
Fishers Study Final Report (PDF) - in English (181 pp, 6.87 MB)
Fact Sheet about Fishers Study Final Report and Next Steps: Spanish/en español (PDF) (2 pp, 1.61 MB)
Fact Sheet about Fishers Study Final Report and Next Steps: Lao (PDF) (2 pp, 614.06 KB)
About half of the PCB contamination in the waterway has already been removed through early cleanups of the most contaminated spots. These cleanups, called Early Action Areas or EAA, are parts of a Superfund site that may become a threat to people or the environment before the long-term cleanup is completed. The following areas have already begun or completed cleanup activities:
- Slip 4 - This site is located on the east side of the waterway, just north of the Boeing Plant 2 site. The City of Seattle dredged and removed contaminated sediments, including the eroding banks, and placed engineered caps of clean sand and gravel over the remaining sediments. Cleanup was completed in 2012. Overall, the cleanup resulted in a net gain of over an acre of shallow and riparian habitat for threatened Puget Sound Chinook and Coastal/Puget Sound bull trout.
- Terminal 117 - This site is in Seattle’s South Park neighborhood, between 14th Avenue South, Dallas Avenue South, and South Donovan Street. The uplands and off-shore sediments of Terminal 117 (T-117) and some streets and yards near the terminal were primarily contaminated with PCBs. EPA issued a cleanup plan for the T-117 site in 2010. The Port of Seattle and City of Seattle did the cleanup work, which replaced soil and sediment and updated the storm drainage system, from 2012 to 2015. Final site modifications, including permanent stormwater controls and regrading the Dallas and Donovan streets, will be completed in 2017. The Port is developing habitat restoration plans.More information on this EAA is available at www.T117.com
- Boeing Plant 2: This site is located on the east bank of the Duwamish Waterway at 7755 East Marginal Way South in Seattle and Tukwila.
- In-water work - In 2015, Boeing completed its work to dredge and remove contaminated sediments in the waterway next to the Plant 2 site. In addition to removing contamination, Boeing transformed nearly one mile of mile of former industrial waterfront into an award-winning new habitat areas. Boeing continues to monitor the quality of the mud, or sediment, at the site.
- Upland work - Boeing has completed the majority of interim soil cleanups and installed stormwater treatment systems to control contaminants from entering the waterway. EPA will provide public notice and an opportunity to comment on a proposed Final Cleanup Plan, known as a Statement of Basis, for the upland area of the site in 2018.
- More information about this cleanup can be found on the Boeing Plant 2 webpage.
- Jorgensen Forge 24-inch Pipe - This site is located at 8531 East Marginal Way South in Seattle, and is adjacent to the Boeing Plant 2 facility. This underground pipe to an old outfall released PCBs. The pipe and contaminated dirt below the pipe were excavated in phases, in 2015 and 2017. Land use restrictions will address remaining contamination left in place.
- Earle M. Jorgensen Forge -This site is located at 8531 East Marginal Way South in Seattle, and is adjacent to the Boeing Plant 2 facility. While Ecology is overseeing upland cleanup studies, EPA has been overseeing the EAA sediment cleanup. Some of the PCB-contaminated sediments and river bank dirt were removed in 2014. However, samples collected after the excavation found that some sediments were still contaminated. EPA is requiring EMJ to evaluate additional cleanup work to address this sediment contamination. This evaluation will be described in a Supplemental Engineering Evaluation and Cost Analysis, which will evaluate ways to clean up the remaining PCB contamination.
In addition to its Superfund cleanup work, EPA is cleaning up other contaminated sites in the Duwamish area:
- Rhone-Poulenc (also currently known as Container Properties) - The eastern half of the site has been cleaned up and is now owned by the Museum of Flight. Toluene, metals, and high pH affect groundwater, soil, and sediments throughout the western half of the site, known as the West Parcel. A groundwater pump-and-treat system with a barrier wall currently contains much of the soil and groundwater contamination at the West Parcel. EPA is also working with the responsible parties to begin an onsite study to inject carbon dioxide into the groundwater to see if it will lower pH at the site, and to conduct additional groundwater sampling to better understand the groundwater contamination. Information from this study and sampling along with prior investigations will be used to help determine alternatives (known as Corrective Measures) for cleaning up the West Parcel. More information about this cleanup can be found on the Rhone-Poulenc webpage.
- Boeing Electronics Manufacturing Facility (EMF) - The groundwater beneath the site was contaminated with trichloroethene (TCE), which breaks down to vinyl chloride
and other chlorinated volatile organic compounds (VOCs). Groundwater treatment pilot testing has been ongoing since 1997. EPA proposed continuing treatment of groundwater to destroy the VOCs and will issue a cleanup plan in an Action Memorandum.
Other cleanup work in the Lower Duwamish Waterway has been completed by the Washington Department of Ecology and local agencies:
- Duwamish Diagonal - Sediment cleanup project just upstream from Harbor Island was completed in 2005 by King County's Sediment Management Program.
- Norfolk CSO - Sediment cleanup project around the Norfolk Combined Sewer Overflow (CSO) near the south end of Boeing Field was completed in 1999 by King County's Sediment Management Program.
- Source Control Program - Source control is crucial to the success of EPA’s in-waterway cleanup. When the sources of pollution are sufficiently under control, cleanup of the river sediments can start. Ecology leads the effort to control sources of contamination from the land area surrounding the Lower Duwamish Waterway (LDW) Superfund
Site. Ecology is managing 21 cleanup sites through its formal cleanup process. Many other sites are being cleaned up under Ecology’s Voluntary Cleanup Program. These cleanups are part of source control – stopping or reducing contaminant sources before they reach the river. Source control also includes many other actions, such as business inspections, controlling stormwater runoff, coordination between agencies, and education. For more information on Ecology’s work in the LDW, please visit:
- Green-Duwamish Watershed Pollutant Loading Assessment will identify sources of pollution in the Green-Duwamish watershed and strategies to reduce those sources. Ecology partnering with the U.S. Environmental Protection Agency (EPA) to conduct this multi-year project.
The Record of Decision - or "ROD" - is the EPA’s cleanup plan to reduce risks to people’s health and the environment from toxic chemicals in the river.
The plan includes details of the cleanup of about 177 acres in the waterway. Cleanup will involve dredging, capping, and natural sedimentation. The cleanup will cost an estimated $342 million.
These cleanup actions complement the work of state, county and city agencies to improve the health of the Green/Duwamish watershed. All of these actions together will remove over 90 percent of contamination in the waterway.
- Record of Decision Errata Correction Memo (PDF) (12 pp, 355K) - August 2015
- Final Record of Decision (PDF) (181 pp, 7.3MB) - November 2014
- Response to Public Comments on EPA's Proposed Plan (PDF) (164 pp, 2.5MB) - November 2014
- Memorandum of Agreement Between EPA and Ecology (PDF) (5 pp, 382K) - November 20, 2014
- Short Fact Sheet on the Final Cleanup Plan (PDF) (2 pp, 611K)
- Long Fact Sheet on the Final Cleanup Plan (PDF) (8 pp, 1.3MB)
- (Spanish) Hoja informativa sobre el Plan Definitivo de Limpieza (PDF) (2 pp, 699K)
- (Vietnamese) Tờ Thông tin về Kế hoạch Dọn Vệ sinh (PDF) (2 pp, 900K)
Activity and Use Limitations
At this site, activity and use limitations that EPA calls institutional controls are in place. Institutional controls play an important role in site remedies because they reduce exposure to contamination by limiting land or resource use. They also guide human behavior. For instance, zoning restrictions prevent land uses – such as residential uses – that are not consistent with the level of cleanup.
For more background, see Institutional Controls.
Most of the human health risk comes from polychlorinated biphenyls (PCBs), arsenic, carcinogenic polycyclic aromatic hydrocarbons (cPAHs), as well as dioxins and furans. As a result, consumption of resident fish and shellfish, as well as contact with contaminated sediments, pose a risk to human health.
Fish are nutritious and good for your health. Many people enjoy fishing on the Duwamish River. Unfortunately, the river has harmful chemicals, such as PCBs, that can cause health problems in humans. You cannot see these chemicals in the fish. They get into fish, shellfish and crab that spend their entire lives in the river (“resident fish”). The Washington State Department of Health recommends salmon as the healthiest choice to eat because they spend a short time in the river.
For more information regarding fishing in the Duwamish, please visit Public Health Seattle/King County's website, "Angling for Health" https://www.kingcounty.gov/depts/health/environmental-health/healthy-communities/healthy-fishing.aspx http://www.epa.gov/epahome/exitepa.htm
Sampling and Monitoring
In 2017 and 2018, testing of sediment, water, and seafood will be done to establish new baseline conditions. Over the coming years, EPA expects PRPs (parties potentially responsible for cleanup costs) to design and construct the remaining sediment cleanup and to monitor and maintain the site over time. As cleanup and source control continue, testing will be repeated to assess progress towards long-term cleanup goals.
Who Pays for the Cleanup?
The EPA's policy is to have the polluters pay for cleaning up pollution they created. Since pollution has been entering the Duwamish River for over 100 years from many different sources, it can be difficult to determine who should pay for the cleanup.
Lower Duwamish Waterway Group - In the interim, four organizations have stepped forward to pay for the Remedial Investigation and Feasibility Study: City of Seattle, King County, Port of Seattle, and the Boeing Company, collectively known as the Lower Duwamish Waterway Group
General Notice Letters - General notice letters inform recipients that they are identified as "potentially responsible parties" at Superfund sites, that they may be liable for cleanup costs at the site, and explain the process for negotiating the cleanup with the EPA.
- List of General Notice Letter recipients (PDF) (3 pp, 81K) - December 2013
- More about Notice of Liability Letters
Information Collection Requests - To help us learn more about known or suspected releases of contamination, we're continuing to send Superfund Information Collection Requests (also called "CERCLA 104e letters") to current and former property owners near the site.
- List of Information Collection Request recipients (PDF) (9 pp, 67K) - November 2012
- Fact Sheet: Information on 104(e) and General Notice Letters (1 pg, 1 MB)
- More about Information Collection Request letters