Road salt effect on the hydrochemistry of a small drainage basin in southeastern Massachusetts

Road salt pollution of drinking water sources is an issue in Massachusetts where significant amounts of sodium chloride are used annually for winter road-deicing. A sixteen-month study of a catchment basin vulnerable to road salt contamination showed that road salt has a year-round effect on the stream hydrochemistry of the studied area. Hydrochemical parameters like a Na/(Na+Ca) molar ratio of 0.92 identified road salt as a dominant solute source for the stream water in the catchment. Road salt constituents had about 3 times higher concentrations in streams draining areas with denser road systems than in the rest of the catchment. A solutes budget assessment indicated that road salt contamination is accumulating in areas with riparian wetlands, many of which overlie shallow aquifers used for public water supply.