Vulnerability Assessment Methodology for Road Salts

Abstract

De-icing agents such as road salts is one of the most commonly used winter road management strategies employed in Canada and the United States. However, the use of chloride has caused negative impacts on aquatic habitats and drinking water supplies. The purpose of this study is to develop a methodology using readily available GIS data to identify salt vulnerable areas, through evaluating the impact the application of road salts have on areas of interest and quantifying the vulnerability to the area in order to prioritize implementation of best management practices. The proposed methodology for assigning a vulnerability score to a given watershed has been divided into two receiving receptors; surface water and groundwater recharge. The methodology employs a chloride mass balance approach. The vulnerability assessment was performed on seven sites in four watersheds in the Greater Toronto Area and validated using Hanlon Creek watershed in Guelph, ON.