Green-Duwamish Watershed 6PPD-q small stream monitoring
Pacific salmon and trout, especially coho, are threatened by a toxic contaminant resulting from tire additives that end up in untreated road runoff. This contaminant, 6PPD-q, has been associated with high rates of coho pre-spawn mortality in streams, including in the Green-Duwamish watershed. Many coho spawning streams in the watershed are predicted to be at high risk for “urban runoff mortality syndrome.” The significant impact of industrial land use in the watershed has disproportionately affected residents and tribal fisheries dependent on clean river habitats. Much remains unknown about the behavior of 6PPD-q in freshwater streams, including sampling strategies, persistence, ongoing sources, and timing of occurrence. It is essential to conduct further research to understand the persistence, bioaccumulation, and ecological impacts of this contaminant.
This project will develop analytical methods at two USGS laboratories to address 6PPD-q and its parent tire particles. Additionally, we will build upon USGS field sampling methods with improvements for sampling small tire particles and use of automated storm samplers.
Problem:
Coho pre-spawn mortality events are documented throughout underserved areas of the Green-Duwamish watershed, and many non-surveyed coho spawning streams in the watershed are predicted to be at high risk for “urban runoff mortality syndrome” (Feist and others, 2011). Much remains unknown about the 6PPD-q behavior in freshwater streams, such as its persistence, ongoing sources, bioaccumulation, and uptake. Importantly, little is known about the correlation and timing of tire wear particle entry into the waterway and continued leaching of 6PPD-q.
Objectives:
This project will develop analytical methods with emerging capabilities at two USGS laboratories: the Wisconsin Mercury Research Lab (microplastics) and the Kansas Organic Geochemistry Research Laboratory (tire-derived chemicals). We will build upon field sampling methods developed by the Urban Water Partnership in the northeast for microplastic sampling with improvements for sampling smaller microplastic-sized tire particles (<220 microns). The dataset will form the first co-occurrence study of tire particles and 6PPD-q concentrations in water and sediment. It will address the challenges of stormwater sampling by utilizing innovative methods.
Relevance and Benefits:
The EPA Trash Free Waters program recently identified the need for additional tire particle research in our nation's waters. Researching and developing methods to quantify the persistent source of 6PPD-q and the occurrence of tire particles throughout the watershed streams supports USGS goals of quantifying the ecosystem threat of water quality degradation, provides local stakeholders with needed data to assess stormwater management, and fosters federal, state, and local partnerships identified in the Green-Duwamish UWFP work plan.
Approach:
We are conducting a descriptive study of tire particles and chemical occurrence in urban streams with known coho spawning in the Urban Waters Federal Partnership recognized Green-Duwamish Watershed. This investigation uses three methods:
- A recently released ASTM method for microplastic collection using ISCO-pumped water samples over a sieve stack; flow-through water will also be collected for 6PPD-q measurement.
- Passive samplers in sediment and surface water to investigate dissolved fractions of 6PPD-q.
- Sediment samples throughout the watershed to quantify tire particle deposition and occurrence.
6PPD-Quinone
Pacific salmon and trout, especially coho, are threatened by a toxic contaminant resulting from tire additives that end up in untreated road runoff. This contaminant, 6PPD-q, has been associated with high rates of coho pre-spawn mortality in streams, including in the Green-Duwamish watershed. Many coho spawning streams in the watershed are predicted to be at high risk for “urban runoff mortality syndrome.” The significant impact of industrial land use in the watershed has disproportionately affected residents and tribal fisheries dependent on clean river habitats. Much remains unknown about the behavior of 6PPD-q in freshwater streams, including sampling strategies, persistence, ongoing sources, and timing of occurrence. It is essential to conduct further research to understand the persistence, bioaccumulation, and ecological impacts of this contaminant.
This project will develop analytical methods at two USGS laboratories to address 6PPD-q and its parent tire particles. Additionally, we will build upon USGS field sampling methods with improvements for sampling small tire particles and use of automated storm samplers.
Problem:
Coho pre-spawn mortality events are documented throughout underserved areas of the Green-Duwamish watershed, and many non-surveyed coho spawning streams in the watershed are predicted to be at high risk for “urban runoff mortality syndrome” (Feist and others, 2011). Much remains unknown about the 6PPD-q behavior in freshwater streams, such as its persistence, ongoing sources, bioaccumulation, and uptake. Importantly, little is known about the correlation and timing of tire wear particle entry into the waterway and continued leaching of 6PPD-q.
Objectives:
This project will develop analytical methods with emerging capabilities at two USGS laboratories: the Wisconsin Mercury Research Lab (microplastics) and the Kansas Organic Geochemistry Research Laboratory (tire-derived chemicals). We will build upon field sampling methods developed by the Urban Water Partnership in the northeast for microplastic sampling with improvements for sampling smaller microplastic-sized tire particles (<220 microns). The dataset will form the first co-occurrence study of tire particles and 6PPD-q concentrations in water and sediment. It will address the challenges of stormwater sampling by utilizing innovative methods.
Relevance and Benefits:
The EPA Trash Free Waters program recently identified the need for additional tire particle research in our nation's waters. Researching and developing methods to quantify the persistent source of 6PPD-q and the occurrence of tire particles throughout the watershed streams supports USGS goals of quantifying the ecosystem threat of water quality degradation, provides local stakeholders with needed data to assess stormwater management, and fosters federal, state, and local partnerships identified in the Green-Duwamish UWFP work plan.
Approach:
We are conducting a descriptive study of tire particles and chemical occurrence in urban streams with known coho spawning in the Urban Waters Federal Partnership recognized Green-Duwamish Watershed. This investigation uses three methods:
- A recently released ASTM method for microplastic collection using ISCO-pumped water samples over a sieve stack; flow-through water will also be collected for 6PPD-q measurement.
- Passive samplers in sediment and surface water to investigate dissolved fractions of 6PPD-q.
- Sediment samples throughout the watershed to quantify tire particle deposition and occurrence.