This is what it looks like when science turns into planning, which turns into design: real-world solutions to tackle real-world problems.
For nearly a decade, our team has worked alongside King County and Kitsap County, through funding from the Washington State Department of Ecology, to help understand and address the impacts of 6PPD Quinone (6PPDQ)—a chemical derived from tires that has been directly linked to Coho salmon mortality in urban streams.
In support of King County, we developed a stormwater treatment media approved in 2021, which has since demonstrated strong performance in removing 6PPDQ in lab studies. We also were the County’s consultant in developing the roadway classification model featured in King County’s recent video, helping to identify high-risk areas where stormwater carries the greatest potential harm to salmon-bearing streams. These tools are guiding where and how stormwater solutions are being prioritized and applied.
As featured in the video, this work is moving forward in Longfellow Creek, a small but iconic urban stream where we’re currently planning the Longfellow Starts Here project. Elsewhere in King County, we’ve supported Seattle Public Utilities on roadside bioretention retrofits in the Longfellow, Pipers, and Thornton Creek watersheds.
Now, we’re building on that progress again with further testing through the Geneva Project in Whatcom County. This critical next step will validate that these solutions can scale and succeed on the landscape.
This is science+planning+design in action, shaping watersheds across the West Coast. It reflects the strength of our cross-disciplinary team – including Dylan Ahearn, Tim Clark, Meghan Feller, Alice Lancaster, Neil Schaner, and a host of others —translating science into real-world impact: protecting salmon, restoring streams, and supporting healthier communities.
