I pass these piles of salt (?) on my way home from work. How is it they do not melt with rain? Or is this sand?

Me too, salt. Me too.

Appropriate username

Does rain make a big difference in dissolving this pile away?

We really, really need a big ole blizzard soon! It’s been way too long! ❄️

It's all salt. It develops a hard crust and then very little dissolves. Once winter ends, they will cover with a tarp.

Better luck next year

Welp now that you've jinxed us!