A Slick Idea

It’s deicing time again and there are a few things to consider apart from the obvious. The most commonly used deicers (sodium chloride and calciumicy-sidewalk-200x300 A Slick Idea chloride) are not considered particularly hazardous, but improper storage, use, and disposal of these materials can have negative environmental consequences.

Sodium chloride will, in relatively low concentrations, kill vegetation and contaminate soil for a considerable period of time. It and other commonly used materials can reduce oxygen in bodies of water, which can adversely affect aquatic life. The Chesapeake Bay Watershed is the largest in this region and many of the ills there have been attributed to nitrates from agricultural sources (in the form of fertilizers). A number of deicing products are nitrate-based and their use and disposal would contribute to the pollutant load.

The primary consideration in ice control is obviously public safety and chemical deicers are important tools. Judicious use and conscientious disposal of those materials will not only save you money, they can help save the environment. Here are a few things to consider.

*Road salt (sodium chloride) is the least costly among common agents, but it’s also among the least effective. Salt is also more detrimental to concrete than other, more effective ice melters. One mechanism of ice control is brine formation, which lowers the freezing point of water and salt brines don’t lower it by very much. Brine concentration will change with evaporation/sublimation and other factors. The result is there can be hundreds of freeze/thaw cycles over the course of a single day when temperatures are near the freezing point for fresh water. The Mid-Atlantic region experiences those temperatures more than any other part of the country. Consider products (such as calcium chloride) that exhibit better ice suppression properties, in lower concentrations.

*Try to avoid the use of nitrate-base products. In addition to increasing the pollutant load in the Chesapeake, nitrates contribute to concrete damage for reasons similar to those described above for salt.

*Properly store all materials in protected locations. Exposure to water will convert a bag of pellets into a solid, unusable lump. Many deciers are also hygroscopic and will absorb enough water vapor over time to cause clumping. If you have surplus materials from previous seasons, try to use those before new stocks.  If you have any unusable materials, consider recycling them instead of throwing them into the dumpster. Many (such as calcium chloride)have other, industrial uses and there are companies that will collect and recycle them. Search the internet for services near you.