Jeff Scott: The Countryside View – The effects of road salt
Winter has finally left us – left us with piles of sand, salt and dirt on our roads, parking lots and sidewalks. There is always a mess after a long winter, especially if there hasn’t been a really good spring rain. Looking at the remains of what we put on our roads every year, I am wondering about the effects of how we deal with winter’s snow and ice – and the effect that salt, in particular, is having on our environment.
There are 34 million people living around the edges of Lakes Michigan, Huron, Erie and Ontario, mainly in huge cities like Chicago, Detroit and Toronto. There are many, many roads in and around these cities that get covered in snow and ice every winter, causing dangerous driving conditions. Coarse rock salt is spread onto road ice to deal with this problem. Salt water freezes at a lower temperature, which allows the ice to melt and run off the road when the air and highway are well below the freezing point. Then spring rains come along and wash much of this road salt down the creeks and rivers into the Great Lakes.
My first concern is what impact all of this road salt is having on the lakes. Even though the lakes are the least salty of any in the world, they do still have salt in them. Fifty million tons of salt naturally occur in the lakes, but this amount is small because they have so much water. Since there is 10,000 cubic kilometres of water in the lakes, the salt from the roads is not having a marked effect on them yet. Ironically, the largest salt mine in the world is well underneath Lake Huron, in Goderich, Ontario. This mine produces 8,000 kilotons of road salt every year.
Where the real damage is occurring is in the rivers and estuaries along the edge of the lakes, where all of the urban storm sewers are dumping the run-off. Frenchman’s Bay outside Pickering is so polluted with road salt that it has been effectively cleared of fish. Blue Crabs from the ocean have shown up in Toronto’s Mimico Creek, which has almost become as salty as the ocean. The soils along the edge of the rivers have been much affected, and salt-tolerant cattails have taken over to replace native plants.
Road salt doesn’t only spread around into the water, it also dries out and gets carried by the wind onto the plants at the side of the road. Trees along our major highways are scarred by the desiccating salt, and those closest to the roadway die away completely.
Salt is a necessary evil for keeping our roads safe and clear in the winter. Roads departments are now taking the problems with salt more seriously, and it is being used in a much better and more sensible way. Less salt is being used and it is now being applied at the time when it will be of best use. It is also being applied to roads just before freezing rain as a pre-treatment to keep the ice from adhering to the asphalt. There is another treatment being experimented with these days: The mixing of beet juice with the salt. The sugar in the beet juice acts the same way that salt does in keeping water from freezing. This method has been tested out this past winter, and the results are looking really good. Let’s hope that this is new method of controlling our icy roads works, so that the Great Lakes remain the largest fresh body of water in the world, and not an inland sea.
Jeff Scott is a former councillor for the City of Kingston (Countryside District), and has contributed editorial content local publications for a number of years. He continues to live, work and write in the Countryside district of Kingston, and runs his own blog, The Countryside View. Visit his Facebook page at www.facebook.com/jeffscottthecountrysideview to read more of Jeff’s content.