Watershed-friendly Deicing

Everyone deals with snow and ice removal in the winter. One popular approach is to apply chemical deicing materials to clear sidewalks, stairs, and driveways. There are many ways to keep walkways safe while minimizing pollution to our waterways.

Precipitation includes ice, snow, and rain, which all carry pollutants into our waterways. The only difference is how long it takes the snow and ice to melt and runoff. Melting snow and ice flows across the land, washing deicer and other harmful pollutants into streams and storm drains. These deicing chemicals can cause a multitude of problems for the environment.

Your walk or driveway may not cause much harm individually but think about all the deicing compounds applied throughout the area. The individual chemicals used will all combine and concentrate in bodies of water. All that runoff adds to large amounts of salt and nutrients entering local waterways.

Deicers come in several forms. Consider the best choice for your area.

• Rock salt (sodium chloride) is the most used but contains cyanide as an anti-caking agent that can be toxic to underwater life and is the most harmful for plants due to its high chloride levels.
• Calcium chloride is considered a better choice than rock salt because it does not contain cyanide. However, it can also harm plants because of chloride. Calcium chloride costs about three times more than rock salt, but you only need to use approximately one-third as much.
• Magnesium chloride is considered the least toxic deicing salt because it contains less chloride than either rock salt or calcium chloride, making it safer for plants and animals. Still, it has levels of chloride that can cause issues.
• Calcium magnesium acetate (CMA) is considered the best choice for safely melting ice. It is less toxic than deicers containing chloride but can cost considerably more than rock salt.

Never use fertilizer as a deicer. Nutrients in fertilizer and urea-containing deicers can run off your property, polluting local waterways.

Best management practices for deicing chemicals:

• Spread deicer before snow and ice start to accumulate.
• Remove as much snow and ice as possible before applying the deicer.
• Apply deicer only to areas where people or vehicles will be traveling
• Follow the label directions. If only a handful of rock salt per square yard is needed, using more isn't more effective, just more expensive.
• Grains of salt should be roughly 3 inches apart from each other
• Sweep up extra salt to reuse
• Don't use rock salt within 5-10 feet of salt-sensitive plants.
• Store in a waterproof container to prevent leaks or spills

If you are unsure how much deicer to use, then you can utilize an application tool to help

Deicer is not the only choice. Alternatives for small areas or thin areas of ice include:

• Warm water mixed with table salt or water conditioning salt
• Pickle brine solutions
• Sand
• Kitty litter
• Bird seed
• If you can anticipate the forecast, cover small areas (such as your steps) with heavy, waterproof plastic or a tarp.

Make sure to use all deicing chemicals and alternatives in as small quantities as possible. Even the environmentally friendlier options will still pose problems if used in large enough quantities. Be sure you constantly monitor your use of deicers to reduce environmental impacts.

Resources:

SeaGrant Program: Reducing Use of Deicing Salt for Homeowners

New Hampshire Department of Environmental Services: Road Salt and Water Quality (WMB-4)

Carroll County Environmental Advisory Council (EAC): Guide to Salt Management for Homeowners: Deicing and Water Softeners