Water Resources Research Act Program

Details for Project ID 2020MN144B

Environmental impacts of potassium acetate as an alternative deicing chemical to Lake Superior: Water chemistry and ecotoxicity

Institute: Minnesota
Year Established: 2020 Start Date: 2020-02-29 End Date: 2021-02-27
Total Federal Funds: $1,000 Total Non-Federal Funds: $43,805

Principal Investigators: Chan Lan Chun

Abstract: Chloride-based salts have been used for decades in Minnesota as an effective snow and ice management technique for winter roads, parking lots, and sidewalks. Although an effective deicer, chloride-based salts have negative environmental consequences, including corrosiveness to steel, the elevation of chloride levels in nearby water bodies, and the breakdown of soil. To improve water quality and mitigate the overall cost of road salt, an effective alternative is needed. One alternative considered to have potential is potassium acetate (KAc), which is effective at lower temperatures than chloride-based salts and is much less corrosive to steel. KAc, however, has a biochemical oxygen demand (BOD) and has documented toxicity at given concentrations to some living organisms. This project will determine levels of KAc and dissolved oxygen in meltwater and road runoff at a KAc application site and evaluate the ecotoxicity of KAc to regionally relevant flora at the observed concentrations through laboratory experiments. The field measurement will be concurrently performed with MnDOT’s KAc application in Duluth. Based on the characterization, the bioassay of KAc to the selected species (roadside plants) relevant to this region will be designed. Through the bioassay, the project will determine what concentration of KAc and its degradation product (K+) is toxic for the germination and growth of seeds. These information will be useful to predict the fate of KAc as it leaves the roadway in stormwater runoff or snow melt and is conveyed across soil and into receiving water bodies and its impacts on roadside plants.