FOLLOWUP: New hope for removing salmon-killing tire chemicals from West Seattle waterways

| Environment | West Seattle news | Wildlife

By Hayden Yu Andersen
Reporting for West Seattle Blog

Last weekend, we reported on the annual Longfellow Creek cleanup event, hosted by Puget Soundkeeper Alliance and Delridge Neighborhoods Development Association. Each year, teams gather to clean up the park and chat with Puget Soundkeeper’s salmon-survey team.

In the wake of the event, Puget Soundkeeper shared their mid-survey data with us. Of note is the fact that this is their first year performing necropsies on both female and male salmon. So far this year, the team has counted 402 live salmon and 125 dead salmon in Longfellow Creek, for a total recorded population of 529. See the data for this year and last year here.

For the past several years, in addition to tracking the coho population, they’ve been monitoring for Urban Runoff Mortality Syndrome (URMS), a condition caused primarily by chemical runoff from car tires. So far this season, the team has recorded 13 live coho with URMS.

When it works its way into a coho population, URMS can be devastating to population numbers. A key element of Puget Soundkeeper’s work has been both tracking and combating the use of 6PPD-Q, the chemical responsible for URMS.

“Unfortunately, the chemical 6PPD-Q has been standard in tire construction for years and is an essential safety mechanism,” said Ewan Henderson, a Clean Water Program Specialist with Puget Soundkeeper. “This means it’s in every tire on the road and can’t really be banned until a viable alternative is on the market.”

But, according to Henderson, last week saw a significant reason for hope. In the past seven days, Wales-based company Perpetuus Advanced Materials and Ohio-based company Flexsys have both announced alternatives to 6PPD-Q, both of which may lead to a reduced environmental impact. However, Henderson pointed out, there are still no policy changes stemming from these developments.

For now, Henderson says the “main focus is on filtering polluted storm water before entering streams,” including using green infrastructure, which has proved effective at reducing the levels of 6PPD-Q in waterways. Here’s a video Henderson recommended from King County Natural Resources and Parks, which explains how green infrastructure works.

In the meantime, if you’re interested in volunteering or donating, or learning more about Puget Soundkeeper Alliance, you can go here.

Salmon volunteer November 24, 2025 (6:50 pm)

Great news on finding alternatives!! As a minor clarification: Soundkeeper Teams are counting salmon sightings every day and recording each fish, so it may be more accurate to say 402 salmon sightings vs live salmon (as the same fish may be counted each day.) Each fish is only necropsied once, then tails are removed so they’re not recounted.

Christopher B. November 24, 2025 (7:15 pm)

Excellent video. I’ve been reading about this smoking gun for years. So I’m happy to hear that some progress is being made.

anonyme November 25, 2025 (6:57 am)

Do they also test for pesticides, and for the myriad of drugs that people flush down their toilets in various forms? Drugs that are not and cannot be filtered, and end up in Puget Sound and beyond?

WSB November 25, 2025 (12:16 pm)

Reply

Don’t know but it’s not the same thing. The sewer lines don’t feed into creeks; sewage goes to West Point through pipelines. The tire chemicals are in runoff from streets that does go into waterways like this unless intercepted (via green-stormwater infrastructure for one). But that aside, your concern is explored here – wish I had time to do more than skim! https://apps.ecology.wa.gov/publications/documents/0803112.pdf

J November 25, 2025 (7:44 am)

That’s great to hear that there may be alternatives coming at some point, hopefully which are less toxic to the environment since we know car tires aren’t going away tomorrow as much as I support decreased reliance on cars. NOAA’s Southern Resident Recovery Plan guidelines recommend that highest population areas on Puget Sound and the Georgia basin should be reducing polluted runoff, yet Seattle is planning to increase it by removing significantly more mature trees for the next 20 years, even though they are aware of the SRKWs, the salmon, the recovery plan, and mature trees are used by the USDA for toxic waste cleanup, and they are recommended by KCDNRP and the EPA for reducing both volume and temperature of stormwater runoff. Every time it rains, what is on the streets gets washed down storm drains, many of which still go straight into the sound or streams, and even those that go through places like West Point, they don’t remove all toxic chemicals. But it gets better… Seattle is now trying to quietly during the holiday remove most SEPA environmental review for the next 20 years, using the grossly inadequate environmental impact statement that is being appealed for excluding endangered species like the SRKWs, in the comprehensive plan.