Watershed-friendly Deicing

Did you know that runoff containing de-icing chemicals can damage our rivers and streams?
Watershed-friendly Deicing - News

Updated: January 30, 2017

Watershed-friendly Deicing

Melting snow with deicing salt. Photo: V Jedlicka, Nebraska Extension

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 also minimizing pollution to our waterways.

Precipitation includes ice, snow and rain, and all carry pollutants into our waterways. The only difference is how long it takes the snow and ice to melt and run off. Melting snow and ice flows across the land, washing deicer and other harmful pollutants into streams and storm drains.

Your walk or driveway may not cause much harm individually, but think about all the deicing compounds applied throughout the area. All that runoff adds up to large amounts of salt and nutrients entering local waterways.

Freshwater ponds, lakes, streams and rivers are especially vulnerable. Salt is often toxic to animals living in fresh water and can also harm plants in your yard and along the roads.

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

  • Rock salt (sodium chloride) is the most commonly used but contains cyanide, as an anti-caking agent that can be toxic to underwater life, and is the most harmful for plants.
  • Calcium chloride is considered a better choice than rock salt, because it does not contain cyanide, however, it can also harm plants. Calcium chloride costs about three times more than rock salt, but you only need to use about 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.
  • Calcium magnesium acetate (CMA) is considered the best overall 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.

Even rock salt can be applied in a way does the job while causing the least amount of harm. Here are some tips for applying deicer:

  • Spread deicer before snow and ice start to accumulate.
  • Remove as much snow and ice as possible before applying deicer.
  • 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.
  • Don't use rock salt within 5-10 feet of salt-sensitive plants.
  • Once you establish a dry, safe route to the house, block off slippery areas you won't be walking on!

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

  • Warm water mixed with table salt or water conditioning salt
  • Sand to improve traction on slippery areas
  • If you can anticipate the forecast, cover small areas (such as your steps) with heavy, waterproof plastic or a tarp.

Authors

Diane Oleson, M.S.