Puget Soundkeeper has a long history of working to stop stormwater pollution to Puget Sound. This legislative session we continued this legacy by helping secure funding for studies of 6PPD-quinone – an oxidation product of a chemical additive in tires that is intended to prevent damage to tire rubber from ozone. Researchers recently demonstrated that 6PPD-quinone causes Urban Runoff Mortality Syndrome (URMS) in coho salmon.

What is URMS? For decades, scientists noticed that coho salmon returning to urban streams throughout the Sound were dying in large amounts before being able to spawn – sometimes up to 90% or more of the return. The phenomenon is called coho prespawn mortality. From 2002 to 2009, various federal and state agencies conducted surveys on coho, Chinook, and chum salmon that use Longfellow Creek in Seattle as well as other urban creeks in Puget Sound as spawning habitat. Research confirmed the link between coho prespawn mortality and polluted stormwater runoff in our urban streams, and the term “Urban Runoff Mortality Syndrome” was coined. Coho exhibiting URMS gasp for breath, swim at the surface of the water, swim in confused circles, and can die within just a few hours.

Why study 6PPD? It will be important to discover if there are safe alternatives to this toxic chemical in order to replace it. That is why Soundkeeper supported efforts to secure funding for the Department of Ecology to study 6PPD and report back to the legislature by December 1st, 2021. In the meantime, however: advocates and scientists alike know that using Low Impact Development (LID) techniques, and in particular, Green Stormwater Infrastructure, is the best way to control polluted stormwater runoff and stop coho prespawn mortality!

Green Stormwater Infrastructure consists of water management practices that mimic nature, using vegetation, soils, and other elements to filter and slow stormwater. One Green Stormwater Infrastructure technique that is particularly effective at controlling stormwater pollution and preventing URMS in coho is filtering stormwater through a column of soil, sand and bark. This can be done using bioretention. “Bioretention” is, essentially, a vegetated depression or shallow basin used to slow and treat stormwater by collecting it and allowing it to filter down through soils before it is conveyed downstream by an underdrain system or allowed to infiltrate into the underlying soil. Bioretention has been shown to be a highly effective means of reducing many pollutants in stormwater runoff, especially contaminants associated with particulate matter. We must increase the use of Green Stormwater Infrastructure throughout the Sound to protect water quality and salmon.

While Soundkeeper worked in the legislature this year to support funding for this important toxic chemical research, we are also implementing numerous other strategies to address URMS and stop polluted stormwater runoff. For example, at Soundkeeper, we:

  • Coordinate annual community science salmon prespawn mortality surveys on Longfellow Creek,
  • Advocate for Green Stormwater Infrastructure code update compliance throughout Puget Sound. This work is to ensure that municipalities follow the law and require that LID be used for new development, redevelopment, and new construction,
  • Push the Department of Ecology to implement stronger Clean Water Act protections against stormwater, through Clean Water Act Permit advocacy,
  • Appeal Clean Water Act Permits when necessary. Soundkeeper is currently appealing the 2019 Municipal General Stormwater Permits for Western Washington to secure better stormwater pollution protections. These include requiring more Green Stormwater Infrastructure and Low Impact Development projects for existing development (called “retrofits” or “structural stormwater controls”), and actions to stop URMS. And,
  • Research the implementation of stormwater retrofits in large municipalities as part of a new Retrofits Report Card project,

We know that tires, stormwater, and salmon don’t mix. Soundkeeper will continue to push for solutions that will protect water quality, restore salmon, and help meet the goals of the Clean Water Act, and we hope you’ll help us!