Understanding Impacts of Salt Usage on Minnesota Lakes, Rivers, and Groundwater

Minnesota uses an increasing amount of salt (sodium chloride) to de-ice our roads, parking lots, and sidewalks and soften our water. Deicing salt infiltrates into roadside soils during snowmelt events or directly runs off into surface waters. Water-softening salt is often discharged from wastewater treatment plants to surface waters and also from private septic systems directly into adjacent soils. The sodium is trapped by the soil and other particles, but chloride will move through the soil to receiving water bodies or groundwater. This project will quantify the current water softening salt loads in Minnesota, assess alternative softening materials and methods and quantify the transport of chloride from de-icing and softening through the soil. It will enable us to minimize the long-term impacts of de-icing and softening salt on surface waters and groundwater across Minnesota. The outcome of this project is to enhance strategies that improve water quality by providing methods to reduce the chloride load from water softening and developing tools that predict salt movement through the soil. The methods and tools developed during this project will inform state, municipal and private entities using de-icing salt, municipal wastewater treatment system operators, and thousands of rural communities and property owners with subsurface sewage treatment systems in Minnesota.

Project Staff: 

John Gulliver, Sara Heger, Alycia Overbo, Heinz Stefan, Connie Fortin, Andrew Erickson, and William Herb