January 23, 2014

Can black ice be green?

I detest black ice as much as any driver, but I was puzzled when I saw those squiggly lines on our local roads before the snow arrived. I had heard of brining turkeys but never brining roads. So I wondered just how much of this salty compound was put down whether the snow arrived or not. Is anti-icing or pre-wetting preferable to de-icing after the snow falls?

Then I read that Hampton City Public Works crews had applied more than 400 tons of salt and more than 100,000 gallons of brine solution on their roads alone. Add in what I saw on James City County roads and the Chesapeake Bay will still end up with an onslaught of salty water entering its waterways when that snow melts and the next rain occurs. Hope those crabs and oysters like a saltier environment.

Traditional salt brine is usually a 23 percent salt solution, derived from rock salt. But I discovered that alternate sources of brine include agricultural by-products such as beet juice, and even cheese making leftover liquids in Wisconsin. Love those cheese heads!

I admit that rock salt trucks of olden days may have put down even more salt on the roads. Perhaps four times as much. At least that is what the brine enthusiasts say. A New York State study reported that using salt brines before anticipated snowfalls was more effective and cheaper than using solid rock salt. And the brines are more effective in lower temperatures too, although 15 degrees seems to be the limit. Since our local temperatures have dropped below that threshold this week, black ice has still been a problem.

So is salt brine a greener option than rock salt? Perhaps a tad but still a threat to the Chesapeake until local governments truly address rainwater runoff.