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Studies and reports

We conduct a variety of studies, in collaboration with other agencies, to help us understand the sources and pathways of pollution to the Lower Duwamish Waterway.

Green River Loading Study

Goal: Quantify sediment and toxic chemical loads associated with upstream sources in the Green River to the Lower Duwamish Waterway (LDW). Focus is on high flow/high turbidity events that may contribute more to the annual loading than average flow conditions. These improved measurements will aid in assessing the potential for future re-contamination of remediated sediment in the Lower Duwamish Waterway.

Tasks:

  • Interagency Agreement with U.S. Geological Study
  • Expand on Ecology's Environmental Assessment Program 2009 study
  • Sampling of whole water, suspended sediment, and bulk sediments at locations upstream of the LDW
  • Chemical analysis will be performed on a full suite of chemicals
  • Analyze for both PCB Aroclors and congeners

Phase 3 Quality Assurance Project Plan (QAPP)
2016 Progress Report and Data Tables
Phase 2 Report and Appendices
Phase 1 Report and Appendices

Green-Duwamish River Watershed PCB Congener Study: Phase 1

Goals:

  1. Summarize issues and considerations when evaluating historical PCB congener and Aroclor data or when collecting new data.
  2. Compile available PCB congener data in the Green-Duwamish watershed, including any available information on data quality.

Tasks:

Discuss/describe:
  • Sources of PCBs to the environment, including historical and inadvertent new sources, and the relationship between specific Aroclors and congeners to types of source material
  • Fate and transport of PCBs, including volatilization and dechlorination
  • Toxicity of PCBs, including dioxin-like PCBs
  • Relationship between Aroclor and congener data
  • Measurement of Aroclors and PCB congeners, including laboratory methods
  • Laboratory analysis and data comparability issues
  • Numerical standards/criteria under various state and federal regulations
  • PCB congener data collection and management considerations
  • Summary of available congener data, including sediment, surface water, stormwater, storm drain solids, air, tissue, soil, and groundwater
  • Data quality and comparability, available metadata, and data gaps

Green-Duwamish River Watershed PCB Congener Study: Phase 1

Cement Kiln Dust (CKD) mapping project

Goal: Compile information on CKD sites in the LDW and assess their potential as contaminant sources and human health hazards.

Tasks:

  • Map all known deposits of CKD in the Lower Duwamish uplands.
  • Assess whether CKD:
    • is a source of arsenic and other metals to the LDW
    • mobilizes other contaminants in the leachate plume
    • Poses a threat to workers who are exposed with the caustic leachate.

Cement Kiln Dust: Summary of Existing Information, Lower Duwamish Waterway

Industrial facilities monitoring project

Background: Facilities covered by Industrial Stormwater General or other permits may have LDW sediment COCs in their discharges.

Goal(s): Collect additional data from high priority facilities that may require additional monitoring of their discharges or source control.

Tasks: Sample on-site catch basins and if possible, whole water. Analyze for:

  • PCBs (Aroclors &Congeners)
  • SVOCs
  • Dioxins/Furans
  • TPH
  • VOCs
  • Metals
  • Conventionals


Lower Duwamish Waterway, 2014/2015 NPDES Inspection Sampling Support - Main Report
Lower Duwamish Waterway NPDES Inspection Sampling Support - Main Report
Lower Duwamish Waterway NPDES Inspection Sampling Support - Appendix A: Shultz Distributing
Lower Duwamish Waterway NPDES Inspection Sampling Support - Appendix B: General Recycling
Lower Duwamish Waterway NPDES Inspection Sampling Support - Appendix C: Independent Metals
Lower Duwamish Waterway NPDES Inspection Sampling Support - Appendix D: Northland Services
Lower Duwamish Waterway NPDES Inspection Sampling Support - Appendix E: ConGlobal Industries
Lower Duwamish Waterway NPDES Inspection Sampling Support - Appendix F: Emerald Services
Lower Duwamish Waterway NPDES Inspection Sampling Support - Appendix G: King County International Airport
Lower Duwamish Waterway NPDES Inspection Sampling Support - Appendix H: Cadman
Lower Duwamish Waterway NPDES Inspection Sampling Support - Appendix I: Alaska Marine Lines
Lower Duwamish Waterway NPDES Inspection Sampling Support - Appendix J: Lafarge Cement
Lower Duwamish Waterway NPDES Inspection Sampling Support - Appendix K: UPRR-Argo Yard
Lower Duwamish Waterway 2014/2015 NPDES Inspection Sampling Support - Appendix L: Recology CleanScapes
Lower Duwamish Waterway 2014/2015 NPDES Inspection Sampling Support - Appendix M: Puget Sound Coatings
Lower Duwamish Waterway 2014/2015 NPDES Inspection Sampling Support - Appendix N: Unified Grocers
Lower Duwamish Waterway 2014/2015 NPDES Inspection Sampling Support - Appendix O: South Park Marina
Lower Duwamish Waterway 2014/2015 NPDES Inspection Sampling Support - Appendix P: Chemithon Corporation
Lower Duwamish Waterway 2014/2015 NPDES Inspection Sampling Support - Appendix Q: Insurance Auto Auctions
Lower Duwamish Waterway 2014/2015 NPDES Inspection Sampling Support - Appendix R: Boeing Developmental Center
Lower Duwamish Waterway 2014/2015 NPDES Inspection Sampling Support - Appendix S: South Service Center
Lower Duwamish Waterway 2014/2015 NPDES Inspection Sampling Support - Appendix T: Duwamish Substation
Lower Duwamish Waterway 2014/2015 NPDES Inspection Sampling Support - Appendix U: Alaska Street Reload
Lower Duwamish Waterway 2014/2015 NPDES Inspection Sampling Support - Appendix V: Waste Management Eastmont Transfer Station
Lower Duwamish Waterway 2014/2015 NPDES Inspection Sampling Support - Appendix W: Waste Management 8th Avenue S
Lower Duwamish Waterway 2014/2015 NPDES Inspection Sampling Support - Appendix X: Samson Tug & Barge