When the snow and ice from winter storms arrive, people always look for the easiest, most efficient way for melting the ice. Historically, salt has been the most frequently used product for melting ice. This article discusses the potential damage from salt and non-salt products with regards to both the local vegetation and the area’s ecosystem.
Being environmentally conscious is a good thing that everyone should consider important even though many people are still debating the subject. Publicity from these debates has led to a proliferation of new ice melting products that make all kinds of claims, such as: “Green”, “Earth Friendly”, “Environmentally Safe”, “All Natural”, “Biodegradable”, etc. Because these product claims are not regulated by any official organization that is recognized universally, many ice melt buyers are very confused.
The simple truth is that caution must be taken when products are used to melt ice, regardless whether the products contain salt or don’t contain salt. When used improperly, all ice melters will cause damage to vegetation and animals. The correct question to be asked is which products pose the least risk and which products are the easiest to control.
Risk and control of salts used to melt ice:
When high concentrations of salt build up alongside pavement on which an ice melter has been applied, there will be temporary damage to the soil resulting in vegetation loss or inhibited growth. The vegetation damage comes from the dehydration of plant cells when moisture is extracted by the various salts. The good news is that Mother Nature’s rain quickly dilutes this salt, which eventually allows the soil to return to a healthy state. Taking precautions to avoid throwing the salt product on vegetation during application or plowing, should allow the spring rain and snow melt to wash away the build-up from the winter.
When it comes to melting ice on pavement, the following two categories of salts are used:
1) Inorganic salts – The inorganic salts all contain the chloride ion (Cl). Most people believe that the chloride content in the soil and its effect on the ecosystem is negligible because chlorine is one of the most abundant elements on the surface of the earth. A few researchers are still trying to prove that high concentrations of chloride can cause degradation of the organic matter in soil and some woody plants. Examples of these inorganic salts include: Sodium Chloride (NaCl), Potassium Chloride (KCl), Magnesium Chloride (MgCl2), and Calcium Chloride (CaCL2).
2) Organic salts – The organic salts contain acetate (AC) which is less aggressive on soils than inorganic salts. Acetate is capable of decay (biodegradable). This natural decay process is generally thought to be good for the environment. Acetates generally have low biological oxygen demand (BOD) values, and, therefore, are not a major contributor to fish kill. See the discussion below regarding fill kill. Examples of these organic salts include: Sodium Acetate (NAAC), Potassium Acetate (KAC), and Calcium Magnesium Acetate (CMA).
Risk and control of non-salts used to melt ice:
The common non-salt materials used to melt ice are urea, glycols, and fertilizers. Research has shown that the use of these materials can be very damaging to an ecosystem unless properly controlled. Run-off into storm sewers from lawns and pavements ends up in the rivers and lakes of the ecosystem.
Non-salt products like fertilizer, glycol, and urea with high biological oxygen demand (BOD) values tend to promote excess nutrients. These nutrients generate excess plant growth reducing the dissolved oxygen of our natural waterways leading to fish kill. This fish kill propagates throughout the ecosystem as birds/animals that use fish for their primary diet also die.
Urea (high nitrogen substance that primarily comes Whole Melt Extracts from the urine of mammals) and ethylene glycol (liquid deicer with high BOD) are used primarily at airports to melt ice because these materials do not rust metal. Airports are better able to control the run-off of these products to avoid severe damage to the ecosystem in the area.
Fertilizers containing nitrogen, phosphorus and/or potassium are primarily used to promote plant growth. Though fertilizers and urea are not very effective when used to melt ice, these materials are often found in ice melting blends marketed as “Green”. When used to melt ice, the recommended application rates for fertilizers are ten times the rate used to promote plant growth. This fact, along with the fact that weaker ice melters are often over applied mistakenly to get better results, compounds the fish kill issue described above.