Presented on April 28, 2022, by Sara Nedrich - State of Michigan, EGLE, Water Resources Division - at the 2022 Emerging Contaminants in the Environment Conference (ECEC22)

Recent studies have identified a new emerging contaminant, 6PPD-quinone (N-(1,3-dimethylbutyl)-N-phenyl-p-phenylenediamine), which has been attributed to significant salmon mortality in rivers in the Pacific Northwest (Tian et al., 2021). Sampling for 6PPD-quinone was conducted in surface water and standing road water in 11 watersheds throughout Michigan. Sample sites were selected to address various research questions, including whether 6PPD-quinone release would increase with recycled crumb rubber road paving technologies. Surface water samples (n=17) were collected from rivers or creeks adjacent to or intersecting roadways following storm events in August-September of 2021. Five standing road water (puddle) samples were also collected. Only two of 17 surface water samples exceeded detection limits (MDL = 3 ng/L) at 12 and 37 ng/L., which fell below the reported LC50 for coho salmon of 95 ng/L (Tian et al. 2022). All five puddle samples had elevated concentrations of 6PPD-quinone, ranging from 54-660 ng/L. All surface water sites sampled along crumb rubber mixed asphalt and asphalt rubber chip seal roadways were non-detect for 6PPD-quinone. Additional sampling is proposed for the summer of 2022 to target a river adjacent to a highly trafficked roadway that is reported to support spawning sport fish.

Download slides: http://hdl.handle.net/2142/114134