New USGS research shows that the salt used to winterize roads stays in nearby waterways for up to two-thirds of the year, according to Great Lakes Echo.
The study found that toxic concentrations of road salt are present in rivers, streams and lakes long after winter weather ends. In some cases, sodium chloride levels were 10 to 15 times above federal limitations. One USGS hydrologist speculated that chloride-sensitive organisms might altogether disappear from afflicted waterways.
Since the 1940s, road salt use in the United States has increased every decade, with present usage around 35 billion pounds per year. Deicing alternatives such as beet juice and sand have been explored, though they tend to cost far more than salt.
Image: A truck spreads road salt in Tennessee (Credit: Daniel Johnson, via Flickr)