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6PPD in Road Runoff: Assessment and Mitigation Strategies

Publication number Date Published
22-03-020October 2022
VIEW NOW 6PPD in Road Runoff: Assessment and Mitigation Strategies (Number of pages: 234) (Publication Size: 6557KB)

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Author(s) Environmental Assessment Program and Water Quality Program
Description Vulnerable ecological areas exist across our lowlands where Pacific salmonids and untreated road runoff meet. In December 2020, a Puget Sound-based stormwater science team identified the contaminant responsible for pre-spawn coho mortality observed in urban areas for many decades. The contaminant is
• 6PPD: N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine, a tire additive that enhances tire longevity, with
• 6PPD-q: 6PPD-quinone, the transformation product.

With this harmful contaminant identified, steps were needed to address the threat to aquatic life from roadway runoff. The Washington State Department of Ecology (Ecology) was directed by the state Legislature to seek interim strategies to address the issue until longer-term solutions could be identified. The interim strategies describe best management practices (BMPs). Priority areas were defined by their vulnerability to the co-occurrence of the contaminant and salmon. Analytical 6PPD-q in water methods were developed to support future research efforts.

In collaboration with Washington State Department of Transportation, University of Washington Tacoma, and Washington State University Puyallup Extension, two expert workgroups convened to form technical advisory committees to help review scientific and technical information in order to inform next steps for assessment strategies and mitigation actions.

A contact author is listed below under “Contact.” A second contact author is Brandi Lubliner, or 360.407.7140.
The mission of the Department of Ecology is to protect, preserve, and enhance Washington’s environment. To help us meet that goal, please consider the environment before you print or request a copy.

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Keywords CECs, 6PPD, toxicant, lab analysis, tires, BMPs, toxics monitoring, toxic chemicals, best management practices, streams, stormwater, salmon, contaminants of emerging concern

Focus On: Finding Solutions to 6PPD

Quality Assurance Project Plan: Monitoring of Tire Contaminants in Coho Salmon Watersheds

Focus on: Monitoring 6PPD-q in the environment