It's Curious City, where we take your questions about Chicago and the region, and investigate,

report, explore, from WBEZ.

Hi, I'm Erin Allen.

What you're hearing is a salt truck, leaving one of those large domes in Chicago where road salt is stored by the Tons.

And that word, Tons, is pretty cringeworthy for our question asker, Susan Elliott.

She's an educator, and she teaches environmental justice.

When we go to all these places like Wild Mile and the Metropolitan Water District, they always talk about

the environmental impact of road salt on our water supply and what impact it's having on

the plants and the animals.

Susan wanted to know, why does the city of Chicago still use road salt if it's so harmful

for the environment?

Let's back up for a second.

How bad is salt?

Well, it's the chloride in road salt that's doing most of the harm.

Jennifer Hammer is an ecologist with the Conservation Foundation in Illinois.

She says chloride damages concrete, metal doors, the salt. Jennifer Hammer is an ecologist with the Conservation Foundation in Illinois.

She says chloride damages concrete, metal doors, the soil around your building, your dad's 1974 pickup truck.

I mean, think about how much money it costs to replace all that once it's corroded.

Jennifer also talks about our beloved pets.

Where it gets into their paws, your dogs,

or if you're having an outdoor cat, like salt getting into their pads

and be very damaging, drying out the pads.

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