Second, road salt harms and eventually kills roadside native vegetation, leaving an opening for invasive plant species that thrive under the conditions and soon spread far beyond the roadside. This becomes an issue for local wildlife, which are not accustomed to the new species and may find it unsuitable.
Third, salt accumulates, meaning the salinity of soils, wetlands, ponds, and streambeds increases every year lots of salt is spread by road crews.
Fourth, road salt also ends up in groundwater, where in rural areas it can have ill effects ranging from reduced milk production from cows to problems for people on low-sodium diets.
What’s to be done? Always use salt sparingly, only when it’s absolutely necessary, such as a route to the hospital or a hill, and then dispense the minimum amount to get the job done. Try mixing a little salt with lots of sand or fine gravel. Wood chips work. Massachusetts pretreats road before a storm with brine, which reduces salt use up to 30 percent. Consider more expensive, less harmful alternatives, such as potassium chloride or what Minnesota is trying, potassium acetate.
As our climate continues to warm, the number of snow-free winter days will likely increase, but so will the incidence of heavier snowfalls and blizzards. The best solution may well be to confine driving only to emergency and essential services until the roads clear largely of their own accord—a restriction the Covid-19 pandemic quarantines have shown can be observed by many with little short-term inconvenience.
Here find well-rounded thoughts from researchers at the Cary Institute.