A few of our team members were recently at the Equip Exposition in Louisville, KY, one of the largest trade shows of its kind focused on landscape professionals. One thing we heard over and over in our discussions with landscape and snow and ice pros was that they know they are overusing de-icing materials, they just don’t have the right tools to reduce their usage. The general mindset tends to be, “better to oversalt than undersalt,” right? Well, not exactly.
While many different materials can be used to remove ice from roadways (nearly all of them damaging in one way or another), for the purposes of this article we will focus on the damage common rock salt can do to the environment.
Rock salt’s impact on water supply
Okay, time for a short science lesson. Rock salt, also known as sodium chloride or NaCl, contains chlorides. Chlorides come from chemicals that have chlorine in them and also have a negative charge. When rock salt (Sodium and Chlorine) dissolves in water, a negative ion is left behind. This chloride then goes on to do all sorts of bad things, including corrode metal.
In areas where excess rock salt is used, much higher levels of chloride ions will be found in the ecosystem, which means all those chloride ions are going to eat away at meta–l from bridges to pipes– at a more significant rate.
Flint, Michigan water was found to have 8x more chloride ions than the water in Detroit. In Flint, the pipes were still built with lead. While some cities use a material to prevent corroding pipes, many cities still rely on old systems, often still with lead in them. The more corrosion, the more lead (and other toxic sludge) is going directly into the water supply, meaning more possibilities for water crises like in Flint, MI.
Rock salt’s impact on wildlife and vegetation
Beyond the direct impact to humans, the increasing level of salt on the roads is affecting entire ecosystems. Plants have evolved to thrive in specific environments with a specific salinity. When this gets unbalanced by excess road salt runoff, native plants are often going to be affected fairly rapidly. Even if the plants can survive, the animals that eat them may not be able to handle the increased salt in their diets. Salt also has been known to increase the risk of erosion, meaning habitat loss for aquatic animals, bugs, amphibians, and more, all who are important to our local ecosystems. Increased salinity of the water is also shown to kill off insects and stunt growth in young fish, which in turn affects the rest of the food chain that relies on them.
The good news?
1) We have a much better understanding of how these materials can hurt vegetation, water supply, and wildlife than we did a decade ago, 2) We know how much material will suffice for particular de-icing jobs, and 3) We have access to the data to guide us in making those decisions. By looking at pavement temperatures, predicted conditions, and grip forecasts, we can salt precisely when and where it is needed to make a difference, while minimizing our negative impact on the world around us.
Interested in tapping into better data to control your environmental impact? Reach out to us at email@example.com or fill out the form below.
Sources in this article include: EPA, Pacific Standard, Corrosionpedia, Scientific American