Brine vs. salt on roads - what is brine, anyway?
Posted by David Brooks | Saturday, December 24, 2011
Most of us realize that road salt is an environmental problem, rilling pants and altering the chemistry of streams when it flows off the road. New Hampshire has an entire Road Salt Reduction Initiative. We've probably also heard about "brine" as a sort of alternative that's somehow better - it sounds more natural, whatever that means. But what is brine, anyway?
Just water and salt mixed together, I discovered after stumbling across this NH Department of Transportation explanation of how to make it. (Here, in a PDF which includes the advice that 23% salt brine has the lowest possible freezing point - 0 F.) The big advantage for road application is that being wet it sticks to the road so you need to use less total salt, plus it can be applied before snow falls because it won't just bounce off. It takes different equipment to apply it than to apply dry salt or sand, which adds to the cost. (The city of Dover studied the issue (PDF here) and noted that brine can be applied during regular working hours, up to three days before a storm, reducing overtime costs.)