Hennepin County has been steadily decreasing the amount of salt it uses during snow and ice removal. This is the result of improvements in technology, new equipment acquired and changes in techniques. We follow a number of a best manage practices for minimizing effects to the environment while maintaining safe road conditions for the travelling public.
To effectively restore or maintain road surfaces, crews may use any or all of the three techniques listed below.
Anti-icing
Anti-icing is the practice of pre-treating roads and bridge decks prior to any winter snow, ice or frost event. The purpose is to prevent the initial bond of snow and ice to the surface. By preventing the initial bond, less deicing material is required. The anti-icing process typically occurs one to three days prior to projected storm events for selected roads and routinely for bridges.
Common mixtures used include potassium acetate (KA) and salt brine (NaCl and water).
Pre-wetting
Pre-wetting, or adding liquids to deicers right before applying to the road surface, is an increasing common activity for the county’s snow and ice removal crews. A slushy, wet material gets applied to the road. This results in faster and more effective ice melting, because it keeps the materials on the road instead of "bounce and scattering."
Deicing
Deicing is the process used in the midst of active snowfall or immediately after a snow fall. Hennepin County most commonly uses rock salt (NaCl) for deicing. This is effective down to 15 degrees Fahrenheit. Other materials, including salt mixed with sand, may be used depending on weather conditions.