Zach’s Weather Whys: Science of salt, brine’s effect on winter weather

Zach's Weather Whys

CENTRAL ILLINOIS — Try not to be too salty about this, but we are going to explore why it’s important for trucks to spray salt on roadways.

Sure you see them spraying stuff on the road before winter weather strikes, but what’s in that mixture?

Peoria Public Works Superintendent Sie Maroon shows us just what’s in the solution.

“Brine is a 23 percent salt solution, that, it’s simply taking salt and water and making a liquid out of it that will, what we use is a pre-treat. We use brine as a pre-treat on the streets when they are dry,” said Sie Maroon, Peoria Public Works superintendent.

But that chemical can sometimes fail.

The freezing point of water is of course 32 degrees. And if you mix salt with water it drops the freezing point to around 15 degrees. Anything colder than that and the salt can be rendered useless, allowing ice and snow to accumulate on the pavement.

“Typically, it’s below 20 degrees when you don’t get the saltwater, the brine solution to have much effect. That’s when we convert over to the calcium chloride,” said Maroon.

When we get to the dead of winter and temps are much colder, you will see less salt being sprayed and more snow is cleared.

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