(CBS) — As we’ve been reporting, road crews have been using so many tons of salt this winter – their supplies are dwindling.

We wondered: what happens to all that salt after it’s on the roads?

The salt, of course, runs off when the ice and snow melt and it gets into lakes and streams and groundwater.

Mike Adam, senior biologist for the Lake County, Illinois, health department, says it’s not so much the sodium that’s a concern, it’s more the chloride. Over time, it affects small lakes.

We asked him how a lake might change over, say, decades.

“It may be more (like), one or two types of plants rather than 20-30 different types of plants. Same with the fish population. It could be less diverse than it was before.”

And drinking water from wells? Adam says the salinity in some groundwater in the Chicago area is going up ever so slightly each year.

A big contributing factor: road salt.

“The scary thing is, what’s our alternative? That’s what’s a little scary. We can do all these things to help reduce the salt, but unless we spend a lot of money on non-chloride deicers, what’s our option?”

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