All salts pose a negative impact on the landscape, infrastructure and freshwater resources. The best practice for minimizing this impact is applying the least amount of salt necessary to provide for safe travel.

If excess salt is used, the most visible impact will be noticeable in grass, shrubs and other landscape foliage. Salt run-off from roads and sidewalks then enters the natural environment in a variety of ways:
• Splash and spray from vehicles
• Wind
• Melting of snow into the soil
• Run-off to surface waters
• Bounce and scatter from spreaders

Salt, particularly rock salt, causes dehydration, which leads to foliage damage.  Salt also harms root growth, disrupts nutrient uptake and causes injury to new seed germination, stems, leaves and flowers.

In addition to the landscape, the second most visible environmental impact of excess salt usage is damage caused to infrastructure, including roads, bridges, parking decks, sidewalks, doorways and even flooring. Chloride in salts, whether they are in a blended product or not, increase the conductivity of water and accelerate corrosion. All salts, when used in excess, can deteriorate concrete that isn’t properly cured or sealed, and can also cause corrosion and damage to reinforcing rods and structural steel, which results in compromised structural integrity.  

Although reducing landscape and infrastructure damage is vital, the most important environmental impact of salt is its effect on freshwater resources, which impacts aquatic life and drinking water.  Chloride in surface waters can be toxic to many forms of freshwater aquatic life, including fish, macro invertebrates, insects and amphibians. 

Contaminants from salt used for ice and snow management enter fresh water resources by infiltration to groundwater, runoff to surface water and through storm drains. The chlorides from salt discharged into these water systems remain in solution with no chance of removal through natural mean; only dilution with more fresh water can reduce its concentration.

It is essential that custodial managers understand what salt products to use, when to use them and how much is necessary. This will ensure safe passage for building occupants, while controlling spending and minimizing the facilities impact on the environment. 

PHILL SEXTON is the director of education and outreach for the Snow & Ice Management Association.