I am honestly curious here. Apparently, Seattle does not use salt to melt ice on roadways because they believe " it's not a healthy addition to Puget Sound." I could understand if the salt was all washing into a trout stream or perhaps a reservoir, but isn't Puget Sound part of the ocean, which has, um, salt water? Is it a different kind of salt (e.g. calcium chloride vs. sodium chloride) that causes the problem? Or is this another typical "don't understand the math of concentration" story? Or perhaps are they using environmental concerns as cover for lack of preparation?