Road salt as a deicer continues to harm the environment


Via Flickr.

Eleanor Hildebrandt | January 3, 2022

As snow returns to Iowa, road salt is being used to deice roads and walkways while it is bad for a variety of environments.

After the state’s first major snowstorm of 2022 hit on New Years weekend, the Iowa Department of Transportation continues to primarily use rock salt to deice roads across the state. Based on Iowa DOT estimates, the department uses nearly 200,000 tons of rock salts on highways and other roadways to clear ice and snow annually. The salt, however has various negative affects on the environment.

A 2018 study found that 37 percent of the drainage in the U.S. has seen an increase in salinity in the past half-century. The dominant source of the salinity increase was found to be road salt across the country. Drainage can also see increased levels of chloride because of deicing salt. If these chemicals get into waterways and streams, it can increase levels of salt and chloride that exceed guidelines for aquatic life as well as deplete oxygen from bodies of water.

According to the Environmental Protection Agency road salt can also contaminate drinking water, increase soil erosion, and kill wildlife. There are, however, alternatives to road salt as a deicer that cause less damage to the environment. Using more porous pavement on roads removes liquid from the roads faster, limiting its ability to freeze-thaw periods and preventing too much ice from forming on roadways. Calcium chloride and magnesium chloride deicers are also less harmful. The two agents also help improve soil structure when the water drains.