Study of De-icing Salt Accumulation and Transport Through A WatershedStatus: CompleteReport Date: 12/18/2017 Summary: Road salt (sodium chloride), a road deicer used extensively in most states that experience snow and ice, has caused environmental chloride accumulation that has become a widespread concern. In the Twin Cities metro area, some lakes and streams show chloride levels exceeding state and federal water quality standards, and recently the median concentration of chloride in urban wells was five times higher than in rural wells. In this study, conducted over three winter seasons, researchers monitored chloride from deicer runoff from two roads as the runoff moved through a suburban watershed at six sites, including ponds, basins and wetlands. Study results show that chloride is not transported entirely in surface runoff and snowmelt; instead, much of it infiltrates into the soil and is likely transported by subsurface waters. The results provide new knowledge for investigators who will examine how to mitigate chloride buildup in the environment. Final Deliverables: Report #2017-50 Research Summary Related Materials: Related Research: Environmental Effects of Deicing Salt on Water Quality in the Twin Cities Metropolitan Area Study of Environmental Effects of De-icing Salt on Water Quality in Minnesota. Adaptive Management to Improve Deicing Operations