Road salts commonly used in the winter to melt ice and keep roads clear are not being effectively absorbed by mitigation measures, allowing the salt to reach groundwater and wells, according to Joel Snodgrass, professor and head of the Department of Fish and Wildlife Conservation at Virginia Tech (Blacksburg, Va.).

“Current stormwater management practices don’t completely stop chemicals from reaching streams and we have seen chemical contamination year-round,” Snodgrass said.

Research findings

Snodgrass and his research team recently published a study in March 2017 in Environmental Science and Technology. The article describes how they discovered that routing runoff contaminated with road salts to stormwater ponds resulted in plumes of highly contaminated groundwater moving from ponds to streams. The abstract of the article, “Influence of Modern Stormwater Management Practices on Transport of Road Salt to Surface Waters” states “we know little about how modern stormwater management practices affect the movement of road salt through urban watersheds.”

The study examined two stormwater ponds in Baltimore County, Md., for contamination and transportation of road salts.

The abstract concludes, “that modern stormwater management practices are not protecting surface waters from road salt contamination and suggest they create contaminated plumes of groundwater that deliver Cl– and Na+ to streams throughout the year.”