Iowa DOT News

Salt brine…preserves more than pickles

Ames , Iowa – Salt Brine, water saturated or nearly saturated with rock salt, is preserving more than pickles and meat these days, it's preserving safety on the primary highway system.

The Iowa Department of Transportation (Iowa DOT) uses salt brine as a tool to help keep roads safe and passable during the winter months, when weather conditions allow. The salt brine is a simple solution of rock salt and water made at Iowa DOT maintenance garages. About two pounds of rock salt is added to each gallon of water to make the solution. When sprayed on the roadway at 50 gallons per mile, it's the equivalent to approximately 110 pounds of salt spread over a 12-foot wide roadway one mile in length.

The use of salt brine is often referred to as anti-icing. Hours before snow or freezing rain falls or frost forms, salt brine is applied to the primary highway system roads and bridges. This practice will often replace the first round of solid material (rock salt or sand) application, and gives crews a head start on winter precipitation events. While it might look unusual to see road crews spraying roads and bridges with salt brine on a day when roads are clear and the sky is sunny, these proactive anti-icing treatments can prevent a bond from forming between the roadway and precipitation precisely when conditions change.

The use of a salt brine solution has many advantages. In some circumstances, it can cut the cost of maintaining a safe road surface over conventional deicing. Brine also:

•  Can help return road surfaces to normal faster, resulting in fewer crashes and delays.

•  Jumpstarts the melting process, because salt needs moisture to begin the melting process.

•  Often carries over between storms.

•  Activate the salt to melt faster, when sprayed on dry materials as they are spread from the back of a snowplow and can help prevent dry materials from bouncing or blowing off the road surface, so they are used more efficiently.

•  Helps prevent a bond from forming between snow and ice and the pavement surface and can start working when precipitation begins or frost forms.

•  Allows crews to cover more territory during a storm.

•  Minimizes environmental concerns because materials stay on the roadway.

•  Reduces the amount of sand that is needed, saving tax dollars and natural resources. It also leaves no sand residue behind that has to be removed from storm sewer catch basins or swept up and disposed of in the spring by street sweeping equipment.

•  Provides safer working conditions for snowfighters who can travel on less slippery roads.

While brine isn't the answer to all snow and ice situations, it does give road workers one more weapon against frost, snow and ice, which will help make Iowa a safer place to drive.


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