The Ecological Effect of Road Salt and Sand in Minneapolis

Road salt makes our roads safer to drive on, but also has negative consequences for our local lakes and waterways. University of Minnesota researchers at the St. Anthony Falls Laboratory have found that as much as 70% of salt spread on the roads stays within our watershed. Unlike the salt that makes it into the Mississippi River and ultimately back into the ocean, salt accumulates in lakes and ponds, and affects the balance of the eco system, affecting fish, aquatic animals and plants.

The researchers say that area lakes and creeks are becoming significantly more salty and while it's not yet an environmental disaster, it could become one if road salt usage isn't reduced, or means to reduce the amount of salt reaching the lakes aren't implemented.

Reducing the amount of salt used on the roads has clear economic benefits too, with salt use in the Twin Cities metro area coming in at just under 350,000 tons every winter at a cost of about $46 per ton. In recent years, Minneapolis and other cities in the Metro area have been upgrading trucks with more efficient salt spreading equipment, and focused on pre-treating roads before snowfall rather than after, which is a much more effective use of salt. And even something as simple as pre-wetting the salt with water increases the salt's effectiveness by making it stick to the roadway better.  So it's possible to use less salt, save money, and still de-ice roads as effectively.

The University of Minnesota isn't just talking the talk. Based on the principles above and other recommendations for reducing salt use without reducing road safety, the University reduced salt usage by 41% last year, and saved $50,000.