Road salt. Can we all just agree that this valuable yet vexing substance is a necessary evil?
Yes, it is messy and corrosive, but we must realize that if we are to get around safely in our winters, we must abandon hope of radically reducing our salt consumption.
Road salt soils pant legs and rusts out cars, but when you are venturing out on a slick road, do you not heave a sigh of relief when you come across a salt spreader, laying down a carpet of ice-killing abrasive?
Salt stains floors, however, we need grit and de-icing cocktails to safely get around sidewalks and parking lots.
Salt eats away at our roads and bridges, damages roadside vegetation and contaminates water. Yet, there are few other viable options.
People complain about the over-use of road salt but then also are quick to complain when streets are greasy.
For decades, roads departments have been tinkering with various ways to cut back on the application of sodium chloride (rock salt) and magnesium chloride. But so far, nothing compares to the conventional traction aid.
All of the alternatives to traditional rock salt have disadvantages, such as higher prices and lack of effectiveness.
Beets don’t cut it
At one time, there was hope that beet juice may be a feasible replacement for salt. Several jurisdictions across North America have taken the juice for a spin. Alas, beets don’t cut it.
From January to April 2020, the City of Cornwall conducted a trial using beet juice with one of its units to assess its effectiveness. However, the city found that equipping its fleet for proper beet juice application proved to be costly, and the material itself was significantly more expensive than the current magnesium chloride solution. Overall, city officials did not see a substantial improvement over existing methods.
Of course, weather determines the volume of materials that must be applied to keep streets and highways safe.
The United Counties of Stormont-Dundas-Glengarry transportation department has put down an average of 24,970 tonnes of salt and 400,342 litres of magnesium chloride per year over a 15-year period. The highest application rates occurred in 2018, when road crews poured out 38,022 tonnes of salt and 547,183 litres of magnesium chloride.
Sand and stone dust are sometimes used on some rural roads. But salt remains the go-to material.
About five million tonnes of road salt are used in Canada each year, says Environment and Climate Change Canada.
The effects of contamination are widespread but not always evident. For example, salt has been associated with damage to organisms in soil, to birds and to other wildlife. Almost all chloride ions from road salts eventually find their way into waterways, whether by direct runoff into surface water or by moving through the soil and groundwater. In surface water, road salts can harm freshwater plants, fish and other organisms that are not adapted to living in saline waters, the federal department observes.
No. The Government of Canada will not ban road salts. “Road safety is a top priority. Accordingly, the environmental risk management strategy for road salts that has been developed in cooperation with all interested stakeholders focuses on the development of best practices respecting storage, spreading and snow disposal while ensuring that road safety is not compromised,” says the department.
In some areas, new technologies for roadway applications have shown significant reductions of as much as 20 percent or more while improving road safety.
The storage of salt has been identified as a potential threat to drinking water in the draft Drinking Water Source Protection Plan presented for public input recently by the South Nation and Raisin Region Conservation Authorities.
The plan covers drinking water risks for 26 municipal drinking water systems across a district that encompasses about 7,000 square kilometres. The latest updates have been directed by the Ministry of the Environment, Conservation, and Parks and focus on threats related to the storage and application of salt, snow, fuel, agriculture, waste, and wastewater storage.
“The road salt application rate has been steadily increasing in Ontario as roads and parking lots continue to develop across the landscape,” notes the plan.
Previously, there were no significant drinking water threats related to salt application identified in the region. Under the new Technical Rules, the storage and application of salt must now be considered as a potential threat to municipal drinking water sources. As a result, salt storage policies have shifted from municipal-storage facilities to almost all forms of salt storage based on the level of exposure to precipitation.
The proposed strategy suggests, in cases where there would be a significant threat to water, the prohibition of future large partially exposed salt storage (over 500 kilograms) and the prohibition of future and existing exposed storage and handling of greater than 20 kg. of road salt. The authorities and municipalities would develop “an ongoing education and outreach program” for the application of road salt on commercial/industrial properties and the handling and storage of road salt at volumes between 100 and 500 kg., where these activities would be a significant drinking water threat.
The demand for salt, or some form of surface de-icer, is not going to decrease. While this has been an “old-fashioned” winter with ample snowfall, our weather continues to shift dramatically. Freezing rain has become the norm. Fewer trees mean that we have lost many natural snow barriers, leading to more drifting, more black ice.
While roads departments are obliged to employ current methods, citizens can help reduce their environmental footprints by adopting “green” alternatives to make their steps and driveways safe. Wood ash, stone dust, sand, cat litter are all effective.
But remember when spring arrives, all of this stuff eventually ends up in our water.
Let us know what you think at rmahoney@seawaynews.media
