Recognizing that road salt can threaten freshwater ecosystems, soil, vegetation and wildlife, Environment Canada has released a set of performance indicators and national targets to better protect the environment. On average, more than 5 million metric tons of road salts are used in Canada each year. A 2001 environmental assessment concluded that road salts were entering the environment in significant quantities through losses at salt storage and snow disposal sites, as well as through runoff and splash from roadways. The new "code of practice" is voluntary but mandatory measures are not ruled out in the future.
Road salts were declared toxic close to the same time as ammonia, and in some ways have similar challenges as ammonia – like being the product of a municipal activities that are vital to public health and safety. It’s interesting to see the different management strategies employed for the two substances.
Canadian Water and Wastewater Association