Institute for Transportation

About the research

The goal of this research project was to determine the environmental impact of potassium acetate (KAc) as a deicer, including its effects on water quality and the resulting toxicity to biota. The motivation for the research was the Minnesota Department of Transportation’s (MnDOT’s) exploratory use of KAc to significantly reduce the use of chloride-based deicers in controlling snow and ice on roads and the potential benefits, including reduced environmental effects.

This study evaluated the environmental impact of KAc as a deicer through field measurements, laboratory experiments, and modeling. Field sites, including bridges and tunnels, were selected to investigate a range of conditions, and sampling characterized KAc concentrations in soil and water as well as measured dissolved oxygen, biochemical oxygen demand, pH, and other water-quality parameters. Laboratory experiments investigated the persistence of KAc and its microbial toxicity at higher resolution than possible in field sampling.

To predict the spatial and temporal extent of KAc’s environmental effects, models of the fate and transport of KAc in runoff to streams and lakes were constructed and evaluated. A detailed user’s manual for the models is provided as an appendix in this report.

The researchers recommend that the two models, KAcStream and KAcLake, be used by MnDOT to guide its choice of sites and concentrations of KAc deicer applications. These models also allow for initial estimates of the environmental impact of KAc applications.