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Latest information on the Lower Duwamish

Ecology, EPA, King County, and the City of Seattle work continuously to    control sources of contamination to the Lower Duwamish Waterway (LDW). We post the latest source control information on this page, including reports and updates on work underway. 

January 2018

Ecology Issued an Immediate Action Order to Seattle Iron & Metals

We issued an Immediate Action Order to Seattle Iron & Metals, Corp. related to discharges from their 601 S Myrtle Street location. The Order requires Seattle Iron and Metals to:
  • Monitor and maintain their stormwater treatment system to improve its effectiveness.
  • Stop industrial activities on the North and South Docks until adequate stormwater controls are approved by us.
  • Prevent sheet flow of stormwater into the river.
  • Update their stormwater pollution prevention plan (SWPPP) to reflect these changes. 

We began initial discussions with Seattle Iron and Metals to review their plans for complying with the Order. Visit our website to view the immediate action order.

Agreed Order finalized to address stormwater discharges at Boeing Developmental Center

We signed an Agreed Order with Boeing that requires them to take the following actions at the Boeing Developmental Center:
  • Begin sampling and monitoring seven additional drainage basins at the facility. These new sampling locations are in addition to the four other locations that are already being sampled under the permit.
  • Add monitoring parameters, including total petroleum hydrocarbons (TPH) and polychlorinated biphenyls (PCBs).
  • Sample monthly, and average results for quarterly permit reporting.
  • Install catch basin inserts to help remove pollutants from stormwater.
  • After a set period of time, if levels are still above permit requirements, advanced treatment is required.  
Visit our website to view the agreed order.

Work plans completed for the West of 4th Cleanup Site

We reviewed and approved the following revised work plans for two pilot studies and a partial cleanup action planned for the West of 4th Cleanup Site in Georgetown:

Draft versions of these documents went through a public comment period in the fall.  After the comment period, the potentially liable parties (PLPs) submitted revised documents that we approved.

The pilot studies will help determine which cleanup options are most effective. Both studies will add chemicals to groundwater to decrease concentrations of contaminants. The Interim Action will clean up soils and shallow groundwater beneath Capitol Industries' Plant 4. It will add chemicals to groundwater, as well as soils, to decrease concentrations of chlorinated organic contaminants.

Next steps for this cleanup include:

  • The pilot studies and interim action (will take 12-15 months).
  • Once completed, the PLPs will submit reports describing the studies' findings and the effectiveness of the interim action.
  • The PLPs will then prepare an updated Feasibility Study to include additional information about the studies and interim action.

After reviewing the updated Feasibility study, we will choose our preferred cleanup action and draft a Cleanup Action Plan (CAP) for public review.

For more information, visit the project website.

Green River Loading Study Phase 3 Report is now available

The purpose of the Green River Loading Study is to find out how much suspended sediment and chemical pollution is coming downriver into the LDW Superfund site. Between September 2016 and April 2017, the U.S. Geological Survey collected water and suspended sediment samples at river mile 10.8. They analyzed the samples to estimate the concentration of PCBs dissolved in the water. Results are outlined in the Phase 3 Report and its Appendix