The more snow we get the more road salt we use and this is a troubling trend that has serious environmental implications.
The US uses 22 million tons of salt on its roads each year, this is more than 10 times the amount used in food processing.
We can expect more snow as the Earth warms and deicing with salt (NaCl, sodium chloride, calcium chloride) poses a number of environmental challenges.
Road salt is a potential danger to vegetation, wildlife and humans.
Salting snow and ice covered roadways has been shown to reduce traffic accidents. The benefits of using salt to remove ice on our roadways also include low cost and economic productivity afforded by keeping roads open.
Salt used on roads attracts a wide range of wildlife including deer,
moose, and birds. This causes vehicular collisions and contributes to
increased rates of human and wildlife mortality.
Road salt causes leaf damage and dieback which can allow salt-tolerant invasive species can take over road sides. Mammals and birds that drink salt water can lead to salt toxicity. Small birds confuse salt crystals with grit, and the ingestion of small amounts leads to acute toxicity and death.
Roadsalt washes into lakes and streams where it can kill amphibians and spawn dead zones. A salt water layer can form at the bottom of waterways, imprisoning nutrients away from aquatic plants and animals. In addition, elevated concentrations of salt in freshwater has detrimental effects on the growth, reproduction, and survival of a large range of invertebrates, fish, and amphibians.
When it seeps into the ground, it can infiltrate drinking water supplies where it can reside for long periods of time, in turn affecting human, animal, and vegetation health. When wells are contaminated with salt they have to be abandoned.