At least 7,770 lakes in the North American Lakes Region are experiencing rising salinity due to road salting.
More roads and more road salt – that’s the situation we are in. Since the use of road salt began around the 1940s, we have added more road miles and increased our expectations of travel in winter weather.
15-32 million metric tons of road salt is applied to roadways each year – and much of it washes into nearby water bodies, where it is recognized as a major source of pollution to groundwater, streams, rivers, and lakes.
We are working to understand the scope of the problem, to help guide targeted management.
The team looked at chloride levels in lakes and linked these numbers with the amount of impervious ground cover – surfaces like roads and parking lots – around the lakes. They found that even 1% impervious cover around a lake could trigger increasing salinization.
The group found that salty, alkaline freshwater can release a variety of chemicals, including toxic metals and harmful nitrogen-containing compounds, from stream beds and soils in drainage basins. The results further suggest that many of these chemicals travel together throughout watersheds, forming “chemical cocktails” that can have more devastating effects on drinking water supplies and ecosystems when compared with individual contaminants alone.
Salty drinking water is cause for concern, particularly for people on sodium-restricted diets.
Roads and other impervious surfaces adjacent to a lake’s shoreline are a recipe for salinization. We need to manage and monitor lakes to ensure they are kept ‘fresh'.Kathleen Weathers
Roads and other impervious surfaces adjacent to a lake’s shoreline are a recipe for salinization. We need to manage and monitor lakes to ensure they are kept ‘fresh'.