Friday, January 13, 2017

Ice and Salt, A Good Solution Sometimes...

Wisconsin winters have been becoming increasingly challenging to deal with regarding rapidly changing weather.  We have seen an increase in the number of weather events involving snow and rain followed by rapidly freezing temperatures.  The results are a mess, literally.

Bellevue has trained staff knowledgeable in the science of salt application and how to effectively apply it.  The applicators have been calibrated with settings to apply the right amount of salt to melt the ice and remove it before refreeze.  The road temperature is a significant factor in how much and how fast ice melts, but also the wind, amount of sun, amount of traffic, the length of time it is in active solution, the type of road surface, and the amount of shade.

Generally, salt needs some liquid to activate and break the ice bonds.  The Village sprays a brine solution to the salt as it is being spread to jump start the melting process.  This pre-wetting of the salt also prevents salt from bouncing to the curb and allows the salt to stay in the travel lanes where it can do the most benefit.

There is a point where road temperatures and the amount of ice accumulations make it ineffective to
apply.  Usually this temperature is around 15 degrees.  Compared to 30 degree pavement temperatures, you need 7-8 times more salt to melt the same amount of ice at 15 degree pavement temperatures.  Often times staff is looking at the extended forecast to determine if it makes sense to apply the salt.

Placing abrasives on the road is not always the end all solution to low temperatures.  When applied, the Village will typically place the material near the approach to intersections, curves, and hills.  The problem with using abrasives is that they sometimes melt into the ice, scatter to the curb with moving traffic, require more frequent applications, and are environmentally more hazardous than salt applications.

Wisconsin winter weather will result in some roads not having bare pavement for quite a while.  Bellevue will continue efforts to provide safe roads while being environmentally.  Please be aware that it may take more time to accomplish this goal, but it is always our goal to provide this service.