70% of the US population lives in areas that experience ice and snow, and rely heavily on road salts and other deicing techniques to maintain road safety. Road salts are crucial for decreasing automobile accidents, but they can have unintended consequences on the environment.
Increasing Salt Levels in Freshwater
A recent study found that freshwater contamination from road deicing salts caused significant increases in the salinity of the freshwater. These include lakes, streams, rivers, and wetlands, resulting in issues with native wildlife as well as widespread contamination of drinking water supplies. The contamination is primarily from excess chloride and sodium, which affects both surface water and groundwater, for municipal water suppliers as well as private wells. Sodium is not the only concern, however, as scientists have recognized that magnesium chloride and calcium chloride can be more toxic to freshwater organisms than sodium chloride.
Heavy Metals Can Leach From Pipes
In addition, deicing salts can leach heavy metals (such as mercury, lead, cadmium, copper, and zinc) from sediment and plumbing pipes into the drinking water. This can occur in municipal water systems as well as private wells. While there are scientific methods to remove salt from water
, such as reverse osmosis, they are resource intensive and far too expensive for most water authorities to realistically consider using them in treatment plants.
In groundwater, scientists have observed a strong correlation
between increases in salinity and increases in the concentration of radium in the water.
No Easy Solution
As with many other water contaminants, it is often expensive and impractical to remove these from the water at the municipal level. The best solution is to reduce the amount of salt used that can enter the environment. Individual households can do this by reducing the use of deicing salts as well as reducing the use of salts for water softeners. Individuals can also encourage local city managers/road commissioners to seek and use alternatives to road salt application that use less salt in order to slow down the rise in salinity in our freshwater and drinking water.