Salt of the earth is a compliment, but salting the earth is bad. However, this time of year we salt roads to melt ice and that salt does not simply disappear once the roads are safe. It dissolves and runs off, contaminating the soil and water around roadways.
According to an article published last week on Scientific American, in 2018 we used nearly 23 metric tons of salt on roads and sidewalks in the U.S.
The aftermath of using salt to fight ice is evident in many communities. There are examples across the country of pine trees killed by road salt runoff.
Even though non-toxic to humans in a typical diet, used to melt ice, in addition to poisoning waterways as well as soil, causing all kinds of environmental issues, salt damages pavement and eats away at the metal on cars.
Salting roads helps melt ice because the ions in the salt disrupt the water molecules as they bind to form ice crystals. This lowers the required temperature for water to form ice.
When temperatures are so low that salt by itself doesn’t help, cars driving on the roads can create enough friction (thus heat) to warm things just enough to kick off the process. A slurry forms, and salt slows the ice reforming.
Less salt can be used if it is first dissolved following careful calculations.
We often see cinders used on roads locally as an alternative to rock salt. Cinders are the byproduct of burning coal for power. Other than clogged storm drains, I couldn’t find much about negative environmental impacts of coal ash on winter roads.
I did, however, read lots of concerns about this product. The ash contains heavy metals and other toxins at varying levels. Some of the tested levels seem minimal, but others are off the charts.
The problem I read about was that technology for testing the impact of cinders on the environment has been limited. The tools in use were designed for other situations, and so provided unreliable data.
The proponents for using coal ash say that all objectionable substances in cinders are already found in soil. I had some trouble finding information I trusted about this topic. A lot of the articles I found were quite old.
I also didn’t fully understand why testing was so difficult — soil testing around railways has shown contamination from arsenic and other preservatives in railroad ties. Why couldn’t the same technology be used in this situation?
The variability in coal ash makes more sense as a hindrance to conclusive data. Still I’m surprised that more information about the impact of this road treatment is unavailable.
Since one method is known to cause environmental damage, and the other is suspected, I really don’t know the answer to keeping our roads safe in the winter. I would love to say, everyone just stay home — but I know that doesn’t work with modern society.
All in all, I wish we lived in a more walkable world. Those who live in town could walk when the weather makes driving unsafe, and those of us who opt to live out in the country should know that there will be days when we simply cannot drive anywhere.
I suppose all I can conclude with is — stay safe out there this winter.
ALDONA BIRD is a journalist using experience gained working on organic farms in Europe to help her explore possibilities of local productivity and sustainable living in Preston County. Email columns@dominionpost.com.
