https://blog.wwf.ca/blog/2019/11/16/fieldnotes-otter-less-salty-winter/

How can we be less salty during the winter? 

We need to find a balance between public safety and environmental safety. Road salt is only effective between 0 and –10 degrees, so if it’s too cold, it does nothing but contaminate the environment. Salt is only for ice, not snow removal, and can be used sparingly — about 2.5 tablespoons can clear a square metre! 

Shoveling your property and keeping drains clear can help prevent icy conditions, and clearing areas you use daily, like a walkway or driveway, is better than clearing your entire property. This automatically reduces the amount of road salt you’re using during the winter.