Road Salt 101: How it Works and Its Alternatives
Salt is synonymous with American and Canadian winters.
Salt for snow removal and ice prevention has been a part of North American history since the 1930s. New Hampshire was the first state in the US to use salt for snow removal. Granular sodium chloride was an experimental choice for winter ice prevention in the area. By the 1940s, 5,000 tons of salt were being spread across the United States. Today, this number has grown up to 20 million tons of salt. As the impact of road salt use becomes more well know, road salt alternatives have become a popular topic in the winter.
Salt For Snow Removal
Road salt is also called rock salt. It is a compound of sodium and chloride, the same chemical makeup of table salt. The difference between road or rock salt and table salt is that table salt is ground much finer, is often purified and has additives like Iodine and anti-clumping aids. Other than that, it’s the same stuff.
Salt is used to reduce the chances of a person slipping or of a car skidding off the road. It is used to improve traction and keep walkways, roads, parking lots, and public and commercial areas safe during the winter. But there is a lot of misinformation out in the world about the value and purpose of this little rock and it’s time that the contractor’s relationship with salt becomes more well known.
Common Misconceptions Of Road Salt Use
Road salt is not used to stop ice from forming. The purpose of salt is to lower the freezing point to facilitate melting and prevent water from freezing. However, salt is also not a one-size-fits-all solution; salt only works in certain conditions and temperatures.
Once temperatures fall below 14°F (-10°C), the effectiveness of salt is reduced. It is also not a great resource to be used on its own; salt works within the aforementioned temperature range and is more effective when used in conjunction with anti-icing methods or additional traction aids like sand.
Unfortunately, road salt has taken the role in the public eye as the best and go-to solution for keeping roads and sidewalks ice-free and safe. In fact a single regular-sized mug of salt is enough to cover 10 sidewalk squares, or an entire driveway.
The Salt Shortage
The winter of 2018 – 2019 brought with it a set of “unprecedented” challenges for snow removal contractors. A strike at a salt mine in Ontario – the largest underground salt mine in the world – as well as flooding in another mine in Cleveland left many in Ontario and the northern USA without access to road salt. Even that single mug was out of reach
The Ontario mine had to stop production when workers went on a three-month strike. The strike forced the company to pull from reserves to provide salt to municipalities and priority customers, leaving people who relied on bulk-purchases of salt – like contractors – to find alternative solutions. By the end of the season, municipalities were running low on salt as well.
The salt crisis lead to private contractors coming together to order a large salt order to be shipped across the ocean from Morocco and Egypt. The high demand for the product resulted in a price hike of almost 50%. Some believe that this spike in price will continue and the new expectations for salt prices have been set by this shortage.
Although salt is seen as a primarily unlimited resource, increasing costs and expected continual shortages in the future put the economic appeal of it into question: is it really cheaper?
While all this was going on, the winter season brought more ice and snow than previous years. As this year’s winter season approaches, the prediction is that salt will be another tender topic for those in snow removal. An advisory from Landscape Ontario calls to its members to stockpile salt this coming year as the fallout from last years shortage remains unknown; Only time will tell if there will be enough salt for everyone in the coming months.
The Argument for Road Salt Alternatives
The environmental impact and infrastructure destruction caused by salt use takes over the news every fall as the call to action starts up again: Reduce how much salt we are using on our roads and sidewalks! Road salt alternatives are a hot topic every winter as studies highlight the impact salt has on our water, plant and animal welfare, and even our own health. The salt shortage of 2018 – 2019 is seen as a foreshadowing of future continued salt shortages, making road salt alternatives more appealing than ever. The reliance on road salt must end. The time has come to diversify how we tackle the slippery season of ice and snow.
Environmental Concerns
From our drinking water to the health and safety of our wildlife, the impact of salt on roads, highways and infrastructure in our towns and cities is unimaginable. The reach of salt use goes far beyond what you may think.
Water
Runoff of salted public areas are sometimes more highly concentrated in saline than ocean water. This water runs off into groundwater systems, water reservoirs and well systems. This is the main source for how salt goes on to impact our vegetation, food, and even our own health.
If the saline content in our drinking water is being impacted by water runoff, those working to lower their salt intake or to eat a low sodium diet could be drinking more than their daily allowance of salt. The Cary Institute of Ecosystem Studies conducted a study in 2008 of the well water in Dutchess County, New York. The Environmental Protection Agency recommends 30 – 60 mg/liter of water. The study conducted by the Cary Institute found that some well water had as high as 347mg/liter. Although there are many factors which could cause a spike in the saline levels of well water, excessive road salt use is recognized as the biggest one.
Animals
Salt runoff into lakes and streams as well as the presence of salt on roads and on curbs all impact the health and wellness of wildlife. Amphibians cannot regulate the salt content of their bodies and are at risk of death from the increased saline content in their habitats.
Larger animals like moose are attracted to the salt on roadways. This increases both the danger to them and to drivers who can be caught off guard by a large animal in the middle of a road either during the day or at night. It also results in an increase in roadside deaths of larger animals during the winter months.
Plants and Trees
Plants, trees and habitats by roads are impacted by salty meltwater. Salt which is transferred from roads to plants by tire spray can actually burn the leaves, stems, and roots of plants and trees. In the spring, the impact of salt runoff is more apparent by dying buds, browning leaves, and branch dieback. It happens every year, without fail.
Infrastructure
Salt is highly corrosive. The presence of salt in water increases the conductivity it has, increasing the concentration of ions and the rate of oxidation of metal that water is touching. You see this happen in the underside of your car as salt mixed with slush and melted snow water eats away at the metal of your truck’s undercarriage.
But this corrosive activity goes far beyond damage to your car. The metal rebar in roads, bridges, and even the steel supports of buildings are impacted by the increasing levels of salt that we use every year to help keep our roads and sidewalks salt-free. It is a slow process that happens over time and leads to the destruction of our roads, bridges and buildings. Montreal Quebec’s Champlain Bridge is an example of this; Estimated to take about 10 years and $5 billion to repair, the 49-year-old bridge has been deemed deficient in functionality. The cause? “Significant deterioration of the concrete and steel” due to salting.
Road Salt Alternatives
As the impact of excessive salt use becomes more predominant in our water, the health of plants, and the harm to animals, alternative anti-ice and de-icing materials have been explored. When used properly, or in conjunction with highly reduced amounts of ice, the effectiveness of these alternatives is equal to – and sometimes greater than – road salt.
Sand as a Road Salt Alternative
Sand has been used to improve traction on roads for safe winter driving. Mixing salt and sand in a 5% salt, 95% sand ratio could help to reduce the amount of salt used on roads.
Sand is not a very popular alternative, however, because it is extremely expensive to clean for reuse and is often disposed of after the season is over. It can run off roads to clog sewer systems or any other kind of run-off infrastructure.
The use of sand did indicate a desire to find alternatives to salt. Although it isn’t the best alternative, it got people thinking about a change.
Beet Molasses as a Road Salt Alternative
More and more cities are beginning to use beet juice or molasses to battle icy roads and walkways. The brine from cheese making and pickling has the same benefits as beet juice and has been gaining popularity in use as well.
The beet molasses is a bi-produce of beet sugar refining. The sugar content in it acts in a similar way as salt does and lowers the freezing temperature of the water. The mixture is mixed with low quantities of salt – much like the sand/salt mixture – and sprayed on roads. The stickiness of the mixture reduces salt runoff and helps to maximize the effect of salt.
Beet molasses is already being used in some cities such as Calgary, Toronto, and Barrie Ontario.
Cheese and Pickle Brine as a Road Salt Alternative
The salty brine used to make cheese and pickles work much the same way as road salt except the salt is held in the liquid as opposed to large salt rocks. The brine actually soaks into the concrete or asphalt, providing a deeper source of natural antifreeze. The brine has a lower freezing temp than regular salt making it more effective than road salt. A brine layer between the pavement and the falling snow helps in preventing snow from sticking and the wet pavement can make it easier to shovel snow because of this.
Cheese brine is especially popular as a salt alternative in Wisconsin where they actually make cheese and have an excess abundance of cheese brine.
Homeowners can minimize their own road salt use by filling a spray bottle with pickle brine, or a combo of beet juice/molasses and salt to treat their own driveways and sidewalks.
A Real Change is Needed
There are an abundance of alternatives to help reduce the amount of salt going on our roads and – ultimately – into our water and ecosystems. However, the real source of over-salting and excessive salt use is the liability practices that threaten snow contractors (link to part 2) all over Canada and the United States.
The same articles which critique the use of excessive salt use do not put it in the context of those put in charge of clearing snow and ice. Until contractors see the protection they deserve for accidents involving snow and ice, reduction of salt use, either through the use of these alternatives or through another method, will not be widely practiced by private contractors and snow removal companies.
