Road Salts & Alternatives

Road salt is toxic to the environment, particularly in large concentrations. With more than five million tonnes of road salts used in Canada each year, we all know the damage they can do: they eat the metal in our cars, corrode body work and brake lines, contaminate roadside streams where we fish, and damage concrete bridges and parking garages.

Green Venture prefers touse construction-grade sand for deicing. We do not recommend using road salt or road salt alternatives, with the limited exception of "Eco-Traction" (see below). 

What are the environmental concerns associated with road salts?

In August 2000 Environment Canada completed a five-year study of the effects of road salt on the environment. They concluded that road salts (sodium chloride, calcium chloride, potassium chloride, magnesium chloride, and ferrocyanide salts) are toxic to the environment, particularly in large concentrations. In the United States, deicing salt is considered a possible pollutant under the National Pollutant Discharge Elimination System (NPDES).

The heavy use of road salts can lead to damage to vegetation, 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 run-off 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.

But it doesn't stop there — road salts also threaten drinking water security. For example, the region of Waterloo has found chloride levels in its municipal water wells as high as 233mg/L, close to the unsafe level of 250mg/L set by the Ministry of the Environment.

Because most ice melters contain salt, they can also injure pets and children. Doctors and veterinarians routinely treat cases of poisoning and painful skin and jaw lesions that are caused by these salt deicers. Animals can be poisoned when they lick ice-melting products off their feet, so be sure to use a damp towel to wipe your pet's paws and underside after being outside.

Environmentally Friendly Alternatives

Keeping ice and snow off your driveway and sidewalks is important for safety. Most homeowners, churches, schools, and small business use salt, sand, or another product for deicing purposes. These substances almost always end up polluting water resources and compromising environmental health. Consider using a product that is less damaging to the environment on your driveway, walkway, and sidewalks.

Sand.  This is a great alternative to salt.  Sand provides traction, is inexpensive, does not harm the environment, and sweeps up easily.  Brick sand is best because it is coarser and more granular than regular sand.  Brick sand can be purchased from building supply stores.  Sand also has a relatively low albedo, which means it will absorb sunlight, helping to warm ice/snow and contribute to faster melting. It does tend to track easily into homes, however.

Ashes.  If you have a wood burning fireplace at home, ashes are a convenient and economical alternative to salt.  Ashes provide traction and will melt ice quickly when it is sunny (ashes have a low albedo, which means they will absorb sunlight).  Please be careful to keep ashes away from food gardens, as there may be heavy metals present in ashes.

Kitty Litter.  This option may be more expensive than other alternatives, but it provides a great deal of traction.  If you already have kitty litter at home, this can be an easy alternative to salt. Unfortunately, the residual material has a tendancy to turn into mush as the snow and ice melts. 

EcoTraction.  One commercial alternative that shows promise is "EcoTraction". Limited application of this product, used in conjunction with sand, has worked well at EcoHouse in recent winters. Check out the EcoTraction website for more information on this salt alternative.  http://www.ecotraction.com/

Other comments from our website visitors: *Consider increasing permeable surfaces around your home.  Very little ice build-up will occur on permeable surfaces because water can instantly be soaked up by the ground below (which is generally warmer than concrete/asphalt).  On hard surfaces, snow/ice will melt, pool, and refreeze because it has nowhere to go.


Tips to Reduce Salt Use

The following tips from Envirocast can help you choose the best deicing product for your home and the environment:

Buy Early ~ Make sure to buy your deicing product well before the big storm hits; otherwise, you could be looking at empty shelves and have few, if any, environmental choices to make at the store.

Check the Label ~ The table below provides a summary of the pros and cons of the various main ingredients of common deicing products. Check the package label closely to see what you are buying. Experts recommend using calcium chloride over sodium chloride (rock salt).

Check the label for ...

Shovel Early and Often ~ When it comes to snow removal, there is no substitute for muscle and elbow grease.Deicers work best when there is only a thin layer of snow or ice that must be melted. Get out the snow shovel and move as much snow as you can during the storm. Another good thing is to sweep after removing the snow.  It gets rid of any bits of snow that can turn to ice or cause slipping and it helps reveal where there is ice.A flat hoe can then help to scrape ice off the surface before any deicers are applied.

Be careful when chopping the ice build-up that you don't damage your sidewalk. Also, be careful when shoveling snow. Snow is heavy and overexertion can lead to heart attacks.

 

another good thing to do for snow and ice is to sweep after removing> the snow.  It gets rid of any bits of snow that can turn to ice or cause> slipping and it helps reveal where there is ice.

Know Your Salt Risk Zone ~ You wouldn't want to kill your favorite tree, shrub or grass, so check out the plants that grow within five or ten feet of your driveway and sidewalk (and the road, for that matter). The table below summarizes some of the salt sensitive plants that might be at risk. If you have salt-sensitive trees, shrubs or grasses in this zone, you should avoid any deicing product that contains chlorides (rock salt and calcium-, potassium-, or magnesium- chloride), or use very small doses. You may want to use CMA as a safer alternative, or stick with sand for traction.

 

Plants at Risk from Salt Damage 

Avoid Products that Contain Urea ~ Some folks recommend the use of urea as a safer alternative to more common deicing products, arguing that it does not contain chlorides and, as a form of nitrogen, will help fertilize your yard when it washes off. In reality, urea-based deicing products are a poor choice. To begin with, urea is fairly expensive and performs poorly when temperatures drop below -6°C. More importantly, the application rate for urea during a single deicing is ten times greater than that needed to fertilize the same area of your yard. Of course, very little of the urea will actually get to your lawn, but will end up washing into the street and storm drain. Given that nitrogen is a major problem in our waterways, it doesn't make sense to use nitrogen-based products, such as those containing urea, for deicing.

If You Must Use Salt: Apply it Early, but Sparingly ~ Remember what your Mom may have told you at the dinner table: "A little salt goes a long way." The recommended application rate for rock salt is about a handful per square meter treated (after you have scraped as much ice and snow as possible). Using more salt than this won't speed up the melting process. Even less salt is needed if you are using calcium chloride (about a handful for every three square metres treated - or about the area of a single bed). If you have a choice, pick calcium chloride over sodium chloride. Calcium chloride works at much lower temperatures and is applied at a much lower rate.

 

Sources:
Cryotech
Envirocast
Environment Canada
Hackensack Riverkeeper
Peace and Environment News
The Sault Star

Additional Information on Road Salt and De-Icers:
During winter thaws, some streams have salinity levels just under those found in the ocean - Globe and Mail article.
Assessment Report: Road Salts
- Environment Canada's comprehensive five-year scientific assessment looking at how road salts pose a risk to plants, animals and the aquatic environment
Deicing Salt: Still On the Table - A great in-depth article on deicing salt and its alternatives
Low Salt Diet
- A road salt resource; a campaign to prevent road salt contamination of rivers, groundwater and drinking water sources, and threats to aquatic and terrestrial biodiversity
Pet Owners Warned Over Road Salt - A brief CBC article cautioning about the dangers posed to pets by road salts

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