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Toxic chemicals in Puget Sound

Much of the pollution that enters the environment comes from the small but steady release of toxic chemicals contained in everyday products, such as brakes on cars, flame retardants in furniture, softeners in plastics, and building and roofing materials. As products are used and disposed, the toxics they contain can enter rivers, streams, lakes, and Puget Sound.

Exposure to these toxic chemicals can cause harm to human health and the animals exposed to them in the environment. Infants and children are especially at risk. Some toxic chemicals impair development, some affect reproduction and disrupt body chemistry, and some cause cancer. Known as persistent bioaccumlative and toxic chemicals (PBTs), they can linger in the environment  for decades and be found in the fatty tissue of  people and animals long after their use has been stopped or products banned.

Our toxics efforts focus on identifying priority toxic chemicals and developing plans to reduce or eliminate their use, or to mitigate their impacts on people and the environment. Our approach is:

  • Prevention: Reduce the use of toxic materials and prevent them from entering into use in homes and industry.
  • Management: Clean up contaminated water bodies with source control planning efforts.
  • Research: Use monitoring data to inform decisions and prioritize actions.

Studying how toxics get into Puget Sound

Research boat in the sunset on Puget Sound

Our scientists are analyzing how chemicals get into Puget Sound and identify the sources of the chemicals. This allows us to prioritize actions for prevention and cleanup. We conducted a series of multi-year studies to quantify the amounts of 17 toxic chemicals or chemical groups delivered to the Sound from known pathways. The pathways studied were:

  • Surface runoff
  • Groundwater
  • Ocean exchange
  • Wastewater treatment plants
  • Atmospheric deposition
The Assessment of Selected Toxic Chemicals in the Puget Sound Basin, 2007 – 2011 is the final report from the Puget Sound Toxics Loading Analysis. It summarizes the loading pathways, estimates the volumes coming from various sources, and provides technical information to help develop toxic chemical control strategies for the Puget Sound basin.

Focus on Puget Sound: Puget Sound Toxics Assessment is a short fact sheet on the study.

Puget Sound Toxics Control: Toxics Projects in Puget Sound, 2011-2018, funded by the NEP Toxics and Nutrients Prevention, Reduction, and Control Cooperative Agreement is an updated synthesis of toxics work conducted in Puget Sound since the 2011 assessment.

Surface runoff most common pollutant pathway

The most common delivery pathway toxic chemicals take to reach Puget Sound is through polluted surface runoff — also known as stormwater. Rain hits roofs, roads, developed areas, and other hard surfaces and runs into storm drains. It then goes mostly untreated into lakes, streams, and rivers that drain to Puget Sound..

The highest concentrations of toxic pollutants come from developed areas that contain residential, commercial/industrial, and agricultural land uses. These types of land uses also have a large amount of impervious surfaces, like pavement and roofs that prevent rainwater from soaking directly into the ground. This creates the conditions for these chemicals to be carried away in runoff.

Targeted chemicals of concern

Scientists assessed the relative hazards posed by target chemicals in the assessment report. Results of the hazard evaluation suggest that the following chemicals are most likely to be found at concentrations of concern:

  • Copper, used in brake pads and boat paints.
  • Mercury from fluorescent light bulbs, dental fillings, and other sources.
  • Polychlorinated biphenyls (PCBs), from legacy products and some current paints and dyes.
  • Polychlorinated dioxins and furans (PCDD/Fs), compounds formed during combustion.
  • The pesticide DDT (and its metabolites DDD and DDE).
  • Polycyclic aromatic hydrocarbons (PAHs) from petroleum, creosote, and wood combustion.
  • Bis(2-ethylhexyl) phthalate (DEHP), a plastic additive.

Petroleum-related compounds from motor oil drips and vehicle leaks account for slightly less than two-thirds of the total estimated initial release of petroleum-related compounds.

Other chemicals studied in the assessment, such as PBDEs and many that have yet to be studied, are also present at levels of concern, but hazard thresholds for most compounds are lacking.

Ongoing monitoring of toxic chemical sources

Roofing materials assessment

We began studying toxic chemicals in roofing runoff in 2012. The final report of that study is Roofing Materials Assessment: Investigation of Toxic Chemicals in Roof Runoff from Constructed Panels in 2013 and 2014. The Washington Stormwater Center at the Washington State University Puyallup Research and Extension Center continues the investigation, conducting water samples and bioassays of roof runoff water. Quality Assurance Project Plan - Roofing Materials Assessment: Investigation of Toxic Chemicals in Roof Runoff is the plan for the study.

Copper and zinc

An investigation of the primary sources of copper and zinc in a commercial-industrial watershed, the land use with the highest contribution of these metals, is underway. Copper and Zinc in Urban Runoff: Phase 1 – Potential Pollutant Sources and Release Rates is the report from the first phase of that study. During Phase 1 of the study, we calculated the potential loading from various sources of copper and zinc using literature release rates. POSTER: Copper and Zinc in Urban Runoff: Potential Pollutant Sources and Release Rates summarizes the Phase 1 report.

Phase 2 is measuring copper and zinc in urban runoff in the winter of 2017-2018, studying runoff from building roofing and siding, chain-link fencing, streetlights, and roof gutters. These sources were determined in Phase 1 to have the highest potential to contribute copper or zinc to the environment. They also had the greatest variability around estimated loading values. Quality Assurance Project Plan: Copper and Zinc in Urban Runoff: Phase 2 – Rainwater Runoff Monitoring describes the Phase 2 study.

Quality Assurance Project Plan: Copper, Zinc, and Lead in Five Marinas within Puget Sound is the plan for a study to assess current levels of metals in marinas throughout the Sound to provide a baseline against which to gauge effectiveness of RCW 70.300.020, recent legislation phasing out copper-containing boat paint.

PAHs & metals near railroad tracks

Quality Assurance Project Plan: Screening for PAHs and Metals in the Puget Sound Basin at Aquatic Habitats Adjacent to Mainline Railroad Tracks is the plan for a study underway to assess PAH levels in aquatic environments near railroad track.

Other studies describe toxics in the Sound