, Professor Emeritus, Civil, Environmental and Geo-Engineering
Chan Lan Chun, Senior Research Prgrm Mngr, Env Eng, UMD-Civil Engineering
Road salt (NaCl) is used predominantly across Minnesota for winter road anti-icing (as brine) and deicing (as a solid) operations. Road salt is used because it is inexpensive and effective, but the thousands of tons used annually have resulted in increasing chloride concentrations of surface water bodies throughout Minnesota. In many cases, chloride concentrations are above regulatory limits, which results in the loss of aquatic biota and the water body being labeled as impaired. Thus, there is a need for one or more road salt alternatives (RSAs) that are effective, relatively inexpensive, and environmentally friendly. This project investigated the environmental impacts of potassium acetate (KAc), which is effective at lower temperatures than most other potential RSAs and is also less corrosive to steel than conventional road salt. Field measurements indicated that current applications of KAc do not have a substantial influence on biochemical oxygen demand (BOD) and microbiological water quality in Lake Superior. However, KAc concentrations due to application to 25 percent of the roads in the Miller Creek watershed are predicted to be above the toxic limit for water fleas. Researchers believe that KAc could be used in the most precarious winter driving safety locations, but not over all watershed roads or for all storms. Acetate could be used as a general organic anti-icer, but in combination with another cation, such as sodium or magnesium.