Toxic Chemicals in Puget Sound photo identifier

Toxic Chemicals in Puget Sound

Final Study Reports

Phase 1: Initial estimates

This study provided us with initial toxic chemical loading estimates for the following five of the nine main pathways:

  • Surface runoff
  • Atmospheric deposition
  • Wastewater discharges
  • Combined sewer overflows
  • Spills directly to surface water

Key finding: Surface runoff When we added up the contributions from all chemicals and across all the pathways to Puget Sound, surface runoff (both river inputs and stormwater) was the dominant pathway contributing millions of pounds of toxic chemicals per year.

The eight other pathways were likely still important for particular chemicals and geographic areas.

Final report: Phase 1 - Toxics Loading Estimates (November 2007)

For more information, see the Study Archive.


Phase 2: Improved Loading Estimates

Phase 2 built on the initial Phase 1 investigation by focusing on specific pathways and sources of toxic chemicals. These first two phases contributed to an improved understanding of toxic loadings into and movement within the Puget Sound ecosystem, and helped inform the development of the toxics reduction elements in the Puget Sound Partnership's Action Agenda.

Key finding: Phase 2 findings improved our loading estimates for the following pathways:

  • Surface runoff
  • Wastewater discharges
  • Exchange with the ocean
  • Contaminated marine sediments

Some of these projects also furthered development of tools to predict the fate of contaminants in the Sound and their effects on humans.

Various parties conducted the studies in the seven sub-tasks described below, and the staff of the Puget Sound Partnership has been coordinating the synthesis of these studies.

Final reports:

For more information, see the Study Archive.


Phase 3: Targeting Priority Toxic Sources

Phase 3 continues to develop a strategy to measure and control the sources of toxic chemicals in Puget Sound. Several of these projects have included collection and analyses of environmental samples of fresh and marine waters, sediments, atmospheric deposition, and various plants and animals. Improvements have also been made to the fate and transport models of toxics chemicals in Puget Sound.

Final reports:

For the complete list of study subtasks, see the Study Archive.