Road de-icer causes UConn water to become saltier, more alkaline


On January 22, 2019, roadways, stairs, and sidewalks across campus are covered in ice-melting salt to prevent slippery surfaces after Sunday’s winter storm (Judah Shingleton/The Daily Campus)

Road de-icers have caused rivers and streams to become saltier and more alkaline over the last five decades, a trend that the University of Connecticut hopes to reverse in nearby Eagleville Brook.

Researches from UConn and the University of Maryland found that the amount of salt and alkaline in streams and rivers across the United States has increased in the last 50 years due to road de-icers and other chemicals, according to UConn Today.

The researchers also found that this salty, alkaline freshwater can release chemicals, including toxic metals and harmful nitrogen-containing compounds, from stream beds and soils in drainage basins, UConn Today said. Often times, these chemicals travel together throughout watersheds, forming what are referred to as ‘chemical cocktails.’

“Chemical cocktails can have more devastating effects on drinking water supplies and ecosystems when compared with individual contaminants alone,” UConn Today said.

Gene Likens, study co-author and Ecology and Evolutionary Biology professor, said he continues to be surprised by the scope and magnitude of the degradation of Earth’s surface waters.

“The formation of novel chemical cocktails is causing deterioration far beyond my expectations,” Likens said.

Mike Dietz, an Associate Extension Educator for UConn Extension, said the material UConn uses for de-icing is made up mostly of sodium chloride, along with a small amount of lignin, which is a plant-derived material that helps salt stick to surfaces better, and calcium chloride.

Dietz said the de-icer UConn uses to melt snow doesn’t simply go away when winter ends, but rather ends up seeping into UConn’s soil and groundwater.

“The salt that was applied last winter has now made its way to the groundwater that provides the base flow to our streams in the summer and fall months,” Dietz said.

Last fall, Dietz worked with UConn’s Technology Transfer Office to train UConn’s facilities staff to reduce the amount of salt applications, he said.

As part of those efforts, facilities crews now calibrate the spreaders on their plow trucks and document and track the salt needs across campus, according to UConn Today.

Additionally, Michael Jednak, associate vice president of facilities, said UConn Facilities Operations and Building Services will continue to monitor its use of road salt on campus.

“We’re interested in doing all we can to keep roads and walkways usable and safe while also being mindful of minimizing environmental impacts,” Jednak said.

Over the last seven years, Dietz has been documenting changes in the amount of salt in Mansfield’s Eagleville Brook. He said after last season there was a major decrease in the amount of salt applied, and he credited that decrease to the efforts implemented by UConn facilities staff, as well as to the effects of a wet summer.

“However, we still have a long way to go, and this problem is not unique to UConn,” Dietz said.

Gabriella DeBenedictis is a senior staff writer for The Daily Campus. She can be reached via email at

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