November 3, 2021
Implementing BMPs can reduce salt use and reduce environmental damage
A 2001 Environment Canada report noted “[winter maintenance derived] salts are entering the environment in large amounts and are posing a risk to plants, animals, birds, fish, lake and stream ecosystems and groundwater.”
That analysis was two decades ago and the problem has only gotten worse.
Salt is processed from salt mines, and by the evaporation of seawater (sea salt) and mineral-rich spring water in shallow pools. Its major industrial products are caustic soda and chlorine. Salt is used in many industrial processes, including the manufacture of polyvinyl chloride, plastics, paper pulp and many other products, but it is often the go-to product in winter maintenance.
Since it’s almost impossible to stop salt derived chlorides once they are introduced to the environment, the best way to address environmental problems from excessive salt use is with source controls. The impact is widespread —on soils, streams and aquatic life, vegetation, wildlife and the drinking water we all rely on each day.
Research has validated time and time again the application of Best Management Practices (BMPs). In winter maintenance, BMPs can reduce the amount of salt entering the environment — and the associated damage — without compromising safety.
The application of BMPs (the right material, used at the right time, in the right amount, and in the right places) can reduce the amount of salt needed to maintain safe conditions and therefore reduce environmental damage.
There are numerous ill effects of introducing salt to our natural environment. Sodium and chloride from winter salt eventually makes its way to drinking water wells in some communities, and high chloride levels may make drinking water taste salty. As well, if vegetation is sprayed with salt, it can lose its hardiness to the cold, and be killed by freezing temperatures and high salt levels.
Salt also changes water density, which can negatively affect the seasonal mixing of lake waters. This mixing is important to increase oxygen levels required by aquatic life for survival.
Furthermore, wildlife is attracted to salt on or by the road, which increases the threat of collisions with vehicles. For our pets, salt trapped on paws can irritate and crack skin.
Salt also takes its toll on the urban environment as it can damage exterior brick, concrete and sidewalks. For vehicles, salt accelerates rusting, causing damage and increasing repair costs.