The USA began using salt on roadways in the 1930s. Back then we would go through about 5,000 tons in a given winter, while today we easily run through more than 20 million tons of salt according to research at the University of Vermont.
Winter brings forth picturesque landscapes blanketed in snow, but it also brings the challenge of icy walkways, driveways, and roads. The task of de-icing often involves balancing safety with environmental concerns. With numerous options available, understanding the risks and recommendations for effective de-icing becomes crucial.
What are the Options?
De-icing during winter encompasses a range of methods, each with its benefits and drawbacks. To avoid the need for a professional landscaping company to come in and repair the damage done each spring, choose your methods for snow & ice control carefully.
Rock Salt / Sodium Chloride is a popular choice due to affordability and speed in melting ice because it has a lower freezing point at 15 degrees Fahrenheit. Because it contains cyanide, it can be especially damaging to underwater life. Sodium Chloride can also pose significant risks to plants, waterways, and concrete surfaces. The highly corrosive nature is especially visible on cars after they drive down a salted roadway.
Calcium Chloride is effective in temperatures as low as -20 degrees Fahrenheit. It dissolves easily and acts quickly, leaving no residue behind. Although it is more expensive than common rock salt, about 1/3 as much is needed. It is less harmful to plants and concrete than rock salt, and contains no cyanide, but still requires cautious use as it is highly corrosive as well.
Magnesium Chloride is considered a safer alternative for the environment than both sodium chloride and calcium chloride. It melts ice effectively as low as -13 degrees Fahrenheit and is less harmful to surrounding plants and hardscapes.
Potassium Chloride is safer for plants but less effective at lower temperatures and comparatively more expensive. The melting point is 20 degrees Fahrenheit, it will act more slowly, and it has a relatively low melt volume capacity. All of this, meshed with the fact that it still causes the potential for corrosion, makes it less desirable than the other options.
Calcium Magnesium Acetate (CMA) stands out as a top choice for ice melting due to its reduced toxicity compared to chloride-based deicers. It does come at a higher cost and is typically incorporated into blends with more affordable materials like rock salt. CMA operates at temperatures around 20 degrees Fahrenheit with limited ice penetration and melting capacity. While CMA, similar to urea, poses lower risks to plants and wildlife, its high organic content can heighten biological oxygen demand in water bodies, potentially endangering aquatic life.
Urea is occasionally used as an unconventional ice melt agent due to its ability to lower the freezing point of water, with a melting point of 20 degrees Farenheit. While it’s less effective than traditional de-icers like rock salt, urea is less harmful to plants and wildlife than chloride-based products. However, it’s not commonly used for this purpose due to its cost and potential to negatively impact the environment by contributing to nitrogen runoff, which can harm aquatic ecosystems.
Safe Melting Products like Safe Paw contain no chloride, salt, or acetate. The main components consist of altered carbonyl diamide crystals, specific glycols, and accelerants in the form of non-ionic surfactants, making it safe for the environment and pet friendly.
Natural Alternatives like pickle brine, alcohol-water mixtures, and sand to provide temporary traction, offer varying degrees of effectiveness. One route that can be employed with driveways and walkways is an underground heating system, although this can be costly. While these might pose fewer environmental risks, their efficacy may be limited, and application can present a mess to clean up later.
What are the Risks?
Each de-icing method comes with its set of potential risks, some of which have already been outlined. Apart from the damage done to concrete and hardscapes, as well as the landscaping, there are some other factors to consider as well.
Certain de-icers, especially sodium chloride-based products, can be harmful to pets, causing irritation or even toxicity when ingested or exposed to paws. Dried salt can also attract animals and pets to roadways. Road salt can create such a profound impact on the environment that in 2004 Canada declared it a toxin, and instituted measures for how it is to be applied.
A study done by Science Direct found that sodium and chloride levels in the Mohawk River in Upstate New York rose 130% and 243% respectively from 1952 to 1998. A more recent study of a stream in southeastern New York done by the American Chemical Society found a similar pattern after studying the levels from 1986 to 2005. It is estimated that 91% of the sodium chloride levels are from road salting.
What are Some Recommendations?
Given the various options and associated risks, there are some general recommendations to de-ice effectively while minimizing harm.
Always use De-icers sparingly. Regardless of the type, apply the minimum amount necessary to reduce environmental impact and protect landscapes. Follow recommended application rates to prevent excessive use. Applying more than required won’t help the effectiveness in any way.
Plan ahead. When a storm is on the horizon, lay deicers before the snow starts to fall. If you are going to plant trees and shrubs, keep them at least 3 feet from walkways and 7 feet from roadways where salt may be sprayed.
Consider the safer alternatives. Magnesium chloride or potassium chloride are safer options that balance effectiveness and reduced environmental impact. There are many pet safe environmentally friendly options out there as well. Opt for deicers labeled with EPA approval.
Use a combination of different de-icing methods. Combining traction producing material like kitty litter with ice melting compounds can limit the environmental impact. For instance, combine sand for traction with non-harmful deicers to minimize damage to landscapes and surfaces.
Perform regular maintenance. Regardless of the deicer employed, it’s is always going to be essential to put in some work. Shovel snow promptly and regularly to minimize ice buildup. Preventive measures often reduce the need for excessive de-icing.
Choose surface-specific deicers. There are methods specifically designed for each surface type, whether concrete walkways, or composite decks. To reduce damage, use the appropriate deicer. Specifically, when clearing a deck, shovel parallel with the boards and use a plastic shovel.
By balancing safety concerns with environmental impact, adopting a conscientious approach to de-icing can significantly reduce damage to landscapes, hardscapes, and the environment while ensuring safety during icy winter conditions.
Winter’s beauty doesn’t have to come at the cost of environmental harm. With careful consideration and judicious use of de-icing methods, it’s possible to keep surfaces clear while safeguarding our landscapes and surroundings.