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Smart salting: maintaining safe roads and keeping our water clean

When conducting snow and ice control, the city’s priority is maintaining safe, drivable roadways. This activity is balanced with many other concerns such as:

  • Public safety
  • Personnel (crew) safety
  • Past, current and future weather conditions
  • Cost
  • Environmental protection
  • Priority routes (roads with high volumes of traffic need extra attention) 

Salt use causes irreversible damage to our surface waters (ponds and lakes) and groundwater. Once salt from deicing activities is dissolved in water, there is no natural or cost effective means of removal. In surface waters, chloride levels can become too high to support aquatic life or to use on turf for irrigation. Chloride can also impact groundwater and drinking water supplies through infiltration of stormwater. 

For example, although Eagle Valley Golf Course typically recycles stormwater runoff to water the grass following storms, elevated chloride levels after winter maintenance prevent the water from being used immediately in the spring without significant rain events.

Additionally, while still well within acceptable state surface and drinking water standards, chloride concentrations are elevated in both Bailey Lake and shallow groundwater monitoring wells. The cause of this chloride level is most likely infiltration of stormwater runoff that has high levels of dissolved road salt.

In order to combat these challenges and reach the goal of achieving safe roads with less salt use, the Streets Division purchased an anti-icing vehicle, with 30 percent of the cost covered by a grant from the South Washington Watershed District. Anti-icing involves the application of alternative chemical products to the roadway before a winter storm even hits. The chemical acts as a bond-breaker between the pavement surface and the snow and ice layer. The snow melts more quickly and reduces the chance that ice will form and bond to the surface.

Public Works will be testing the effectiveness of the anti-icing unit on typical problem areas, such as the Lake Road/I-494 and Tamarack Road/I-494 interchange bridges. The material will be applied before storms. After initially applied, the anti-icing material appears that a vehicle is leaking fluid on the roadway. Once dried, the anti-icing material will change to a white color.

What can residents do?
When considering salt use on your own driveway and sidewalks this winter, do your part by following these simple tips:

  • Shovel. The more snow and ice you remove manually, the less salt you will have to use and the more effective it can be.
  • 15 degrees (F) is too cold for salt. Most salts stop working at this temperature. Use sand instead for traction, but remember that sand does not melt ice.
  • Slow down. Drive for the conditions and make sure to give plow drivers plenty of space to do their work. Consider purchasing winter (snow) tires.
  • Apply less. More salt does not mean more melting. Use less than four pounds of salt per 1,000 square feet. One pound of salt is approximately a heaping 12-ounce coffee mug. Leave about a three-inch space between granules. Consider purchasing a hand-held spreader to help you apply a consistent amount.
  • Sweep up extra. If salt or sand is visible on dry pavement it is no longer doing any work and will be washed away. Use this salt or sand somewhere else or throw it away.
  • Act locally. Support local and state winter maintenance crews in their efforts to reduce their salt use.
Learn more on the MPCA's website

See more winter safety tips