UPDATE: Ecology's new website will be live on Monday morning! Our official web address will be https://ecology.wa.gov

toxic loading photo identifier

Control of Toxic Chemicals in Puget Sound


The Washington Department of Ecology is working in collaboration with the Puget Sound Partnership and other state and federal agencies to deliver three phases of scientific data about toxic chemicals in Puget Sound. The goal of the science is to inform decisions about actions to restore Puget Sound.

Phase 1 and Phase 2 of the Puget Sound toxic loading studies have informed policy options for the state’s Action Agenda to reduce and control releases of toxic chemicals.

Phase 3 will support implementation of the actions that the Puget Sound Partnership identifies in the Action Agenda, such as improved wastewater permitting.

The Puget Sound toxic loading studies will help guide decisions about how to most effectively direct resources to resolve toxic contamination issues in Puget Sound. For example, the studies will help identify which sources or pathways of toxic chemicals should receive priority attention and which areas of contamination should be cleaned up first. The nine main pathways to Puget Sound targeted by these studies are:

  • Surface runoff
  • Atmospheric deposition
  • Wastewater discharges
  • Combined sewer overflows
  • Spills directly to surface water
  • Groundwater discharge
  • Exchange with the ocean
  • Contaminated marine sediments
  • Migration of contaminated biota

Copper and Zinc in Urban Runoff: Phase 1 – Potential Pollutant Sources and Release Rates is designed to discover how copper and zinc are entering stormwater in the Puget Sound basin. During Phase 1 of the study, we calculated the potential loading from various sources of copper and zinc using literature release rates, the exposed surface area of construction materials, and the annual vehicle miles traveled. (October 2017)

Poster: Copper and Zinc in Urban Runoff: Potential Pollutant Sources and Release Rates offers more information on the study. (October 2017)

Surface Runoff Study This study was designed to determine relative chemical contributions from different land-cover types and refine chemical load estimates. (May 2011)

Focus on Toxics in Surface Runoff to Puget Sound (May 2011)


Preventing toxic pollution key for protecting Puget Sound, new scientific assessment shows (11/3/11)

Assessment Report

Report: Ecology Toxic Chemical Assessment report

Website: Puget Sound Toxics Assessment website


Forests not the problem for toxics in Puget Sound (8/1/2011)