With winter in full swing, Virginians are thinking about choosing a deicer to purchase for that next winter storm to make icy sidewalks and driveway surfaces less hazardous. You may not have considered the environmental impacts of products containing “salt,” when you rush to buy a deicing solution before a snowstorm. Is salt the best solution for snow and ice management? And even if you’ve chosen a more environmentally friendly product, what about your neighbors or your homeowners’ association?
Salt is a common name for Sodium Chloride (NaCl), which comes in several forms, including fine-grained table salt and a coarser version, known as rock or road salt. While table salt is a popular seasoning used to enhance the flavor of food, rock salt is often used to help manage the melting and freezing of snow and ice. Sodium chloride and other chloride-based salts lower the freezing/melting point of water from 32° F.
Many people choose chloride-based salts (calcium chloride, magnesium chloride, potassium chloride, sodium chloride) because they’re cheap and available.In Virginia, VDOT uses these compounds to prepare for snow and ice on Virginia’s highways and byways. Calcium magnesium acetate (CMA) is one alternative recommended by the Virginia Cooperative Extension. It is a formulation of dolomitic limestone and acetic acid and is effective down to 5 degrees Fahrenheit and particularly useful in environmentally-sensitive areas. CMA can also be applied in a liquid form to roads and bridges before a storm to prevent snow and ice from bonding to the road surface.
Deicer salts are especially corrosive to metal and concrete. For many years, snow and ice melt products containing sodium chloride, were used on sidewalks, roadways, bridges, airport surfaces, and other hardscape infrastructure to help melt snow and ice, so traffic could continue to move along our roads and highways. But over time, it became obvious that salt and other chlorides react with and damage concrete, steel, vehicles and other materials and equipment. The cost of large-scale application of salt deicers is high. Washington State University estimated that the U.S. spends several billion dollars on removal of snow and ice from major highways each year, not to mention the other associated costs, including damage due to corrosion.
Deicing salts can cause damage, decline and death of our landscape plants and trees. Salts can be absorbed by plant roots, causing dehydration and displacement of other mineral nutrients by the sodium chloride ions. Typical plant symptoms of salt damage include dried up and brown needles and leaves, loss of foliage, buds and branches, reduced or distorted leaf or stem growth that looks like a chemical burn. This damage initially appears mostly on the side of the plant facing the road or sidewalk. Sodium causes clay particles in soil to expand, increasing soil compaction, reducing water infiltration, making it harder for roots to grow which can result in premature plant death. Managing sodium buildup in the soil has many effects on plants and is very challenging.
Salt and deicing solutions find their way into ground water, negatively impacting water quality and contributing to contamination of natural waters, both surface and groundwater. Chloride in high amounts reduces oxygen levels in water and can be toxic to fish, aquatic bugs and amphibians. In addition, runoff from nutrient -based deicers such as urea pollute local waterways, as well as causing toxic algae blooms that are harmful to aquatic life, people and pets.
If you are only concerned about melting snow and or ice, traditional ice melt products containing salt usually prove very effective in most climates. If you do use a salt product, use it sparingly, apply according to the label and at the right temperature. Target areas where icing is most hazardous. Remove snow first and sweep up any leftover salt grains for use later in the season. Here are more tips on how to become “winter salt smart”. Remember, more is not better! It only takes one teaspoon of salt to pollute 5 gallons of water.
However, as a thoughtful, knowledgeable steward of our environment, you probably are already using an alternative deicer, like CMA, or are ready to start. Products containing CMA can be found at local garden and lawn retailers. If you are unable to obtain CMA or it is too expensive, consider using a non-chemical option, like sand or bird seed, that provides good traction.
When comparing costs against investments in caring for your property, it makes sense to try a product that has been proven to lower risk of damage to your plants, landscape and groundwater. This is especially the case for many of us who have spent many hours, if not years, nurturing our gardens and yards!
Need more information? Review the pros and cons of using salt for snow and ice melt from these blogs on rock salt damage to plants and trees, alternatives to using salt, and melting snow and ice with salt.
This is wonderful! Thank you Michael.