6PPD Stormwater Best Management Practices Research
This page is run by the Washington State Department of Ecology and is a space for sharing publications from 6PPD stormwater research.
Ecology is supporting several research projectsandidentifyingbest management practices (BMPs) that are effective at managing 6PPD and 6PPD-quinone (6PPDQ) in stormwater.These studies will help informappropriate policy, regulatory, and rulemaking processes around 6PPD and 6PPDQ to protect aquatic life, ecosystems, and human communities.
Summary Publications
The following publications provide a big picture overview of our 6PPD BMP effectiveness research:
King County- King County Multi-Criterion Decision Tool to Address 6PPDQ and Tire Wear Particles
King County - Testing Removal of 6PPDQ and Coho Salmon Lethality by High Performance Bioretention Media Blends
King County - Treatment effectiveness of a Full-scale Stormwater Facility using High Performance Bioretention Soil Media for 6PPD-quinone and other Toxic Chemicals
King County Environmental Lab - Characterizing Stormwater Pollutant Concentrations in Mixed Residential and Highway Runoff in Seattle
Effectiveness of Street Sweeping pilot study report (2025)
City of Spokane - Bioretention Soil Media Study: Development of Non-Vegetated BMPs
Description: Evaluates the effectiveness of bioretention soil mix (BSM) and high performance bioretention soil mix (HPBSM) at removing stormwater pollutants, including 6PPDQ, at a full-scale facility when they are installed without vegetation
Standard operating procedure (SOP) to quantify 6PPDQ from 6PPDQ-free sediments (2024)
Standard operating procedure (SOP) to quantify 6PPDQ from environmental sediments (2025)
Project summary (2025)
EA Engineering, Science, and Technology Inc., PBC - The Use of Unamended Soils for Treatment of 6PPDQ in Stormwater: Persistence, Soil Types, and Influence of Vegetation
Description: Comparing the persistence and reduction of 6PPDQ in unamended and amended soils and evaluating potential uptake in vegetation
King County - King County Multi-Criterion Decision Tool to Address 6PPDQ and Tire Wear Particles
Description: Testing the effectiveness of grassy roadside embankments and developing a web-based Screening Model to estimate 6PPDQ generation from roadway types
King County - Treatment effectiveness of a Full-scale Stormwater Facility using High Performance Bioretention Soil Media for 6PPD-quinone and other Toxic Chemicals
Description: Testing high performance bioretention soil media at a full-scale facility
The Nature Conservancy -Puget Sound Stormwater Heatmap Version 2.0
Description: Developing a user accessible Stormwater Heatmap tool to support local jurisdictions in stormwater retrofit long-term planning, which includes pollution hot spots, hydrology, and climate modeling
NV5 - Verification of BMP Effectiveness, Crumb Rubber Investigation, and Street Sweeping and Traffic Density Characterization
Description: Verifying the effectiveness of BMPs in the BMP Effectiveness Report, testing for 6PPDQ from land uses with crumb rubber, and street sweeping frequency needs
University of Washington - Tacoma - Development of Chemical Indicators to Detect, Track, and Assess Pollutants
Description: Assessed the effectiveness of seven stormwater treatment systems for managing select salmonid toxicants, including a mix of Zeolite, Perlite, and granular activated carbon, bioretention systems with compost media, and bioswales
University of Washington - Tacoma - Enhanced Watershed Monitoring & Toxicological Analysis of CECs
Description: Filling data gaps in the spatial and temporal variation of contaminants of emerging concern (CECs), including 6PPDQ, using passive sampling in the Puyallup and Stillaguamish watersheds
University of Washington - Tacoma - Sampling, Occurrence, and Toxicity of 6PPD-quinone and Related Chemicals
Description: Characterizes 6PPD, 6PPDQ and other PPD-quinone concentrations and dynamics in key small watersheds of the Puyallup, Nisqually, Deschutes, and the South Sound
Ecology is addressing 6PPD and 6PPDQ through several efforts. For more information about our agency’s 6PPD work beyond BMP effectiveness research, please visit these websites: