Environment Canada: Should road salt be banned?

OTTAWA (March 19, 2001) — Amid mounting concern about the impact of salt-laden runoff on wetlands, Environment Canada is considering whether road salt and calcium chloride should be declared toxic substances under the Canadian Environmental Protection Act.

While road salt has already been proven to be harmful to fish, Environment Canada says the effects are just as dire for the benthic, or bottom, layer of aquatic ecosystems. A study of a pond near Hwy. 401 in Burlington, Ont., found that when salt-water runoff sinks to the bottom of a pond or lake, it prevents the normal water-mixing process and deprives benthic organisms of a fresh supply of oxygen.

The water within the sediments can also attain high concentrations of salt, which, in turn, increases the concentration of heavy metals, such as cadmium.
Should road salt be identified as toxic, Environment Canada could call for reduced usage or a complete ban.