Chemicals used to melt ice can be harmful to environment
The mention of it brings two pictures to mind. First, the little crystals that tumble out of a shaker and onto our food to bring out flavors.
The second picture depicts larger chucks being spread onto our driveways and sidewalks to melt ice and hard-packed snow, and to provide traction on slippery surfaces in the winter.
It's this second picture that causes concern.
Scientifically, sodium and chloride atoms combine to make salt. It is the chloride that can be toxic to aquatic species like fish and plants.
It's also dangerous to vegetation, like trees and shrubs. An online report from Lake Superiors Streams -- www.duluthstreams.org -- states that "the most visible impacts of road salt are usually on roadside vegetation where a fringe of dead or dying trees and shrubs may be apparent on major highways and streets."
Have you ever see a row of pine trees on the highway and wondered why the closest row to the road look brown and stunted while the trees farther back look healthy? This might be one reason.
But even our sidewalks and driveways can contribute to the problem, according to a press release from the Crow River Organization of Water, based in Buffalo. The release says that, along with the road salt used to keep our roads and street dry, "salt enters our lakes and rivers through runoff, storm drain discharge and plows pushing a combination of snow/salt ..."
What can be done to combat this? Much of the "salt" purchased by consumers is not really salt at all. A report from the University of Minnesota Extension Service notes four of the common substances, know as "de-icers," and their various properties.
Common salt, according to this report, is the most damaging of all. It has high potential to damage plants and soil, pollute the water and damage concrete and metals. Calcium chloride is less dangerous to plants and soil, but still is hazardous. It also will corrode metal and damage concrete.
Calcium magnesium acetate has a low risk of plant and soil damage and does not pollute water or corrode metals or damage concrete. Urea (lawn fertilizer) will burn plants and lawns if over applied and can add to the pollution of water during spring runoffs.
The best way to use de-icers is to use these chemicals as a "pre-treatment," according the Crow River Organization. Use any de-icing product before snow or freezing rain as a barrier of protection. It will require less use of the chemicals than after the snow.