Dave Olson, Published January 08 2013
Metro cities' sand, salt mixtures help winter drivers get a grip
It’s a briny mixture of water and salt, with the salt content set at about 23 percent for optimum ice-fighting ability.
When sprayed on streets, the blend hinders snow and ice from bonding to the road surface, making it easier for plows to keep roads clean.
Fargo and West Fargo use brine as a way to pre-vent ice buildup, but West Fargo also applies it after snow and ice have com-pacted as a way to de-ice road surfaces.
Fargo and West Fargo also spread a mixture of salt and sand on their streets – usually about 25 percent salt and 75 percent sand – as a way to enhance traction.
In that form, however, salt is not as effective as a de-icer, said Chris Brungardt, West Fargo’s assistant director for pub-lic works.
In whatever form it is applied, typical road salt is most effective between about 20 degrees and 32 degrees Fahrenheit.
It provides little to no benefits when the mercury reaches zero and below, at which point sand and the grit it provides becomes the only useful part of a salt/sand mixture, Brungardt said.
Even when temperatures allow salt to work, melting snow eventually dilutes any mixture, lessening its impact, he added.
When it comes to apply-ing sand and salt to streets, factors like wind and tire traffic can quickly scatter the material, offi-cials say.
The city of Moorhead us-es a mixture of 10 percent salt and 90 percent sand to improve traction for stop-ping and starting on icy streets.
While the salt provides some de-icing benefits, it is basically there to keep the sand from freezing when it is stored in piles, said Chad Martin, the city’s director of operations.
Martin said the city spends about $30,000 a year on salt and sand, with most of that going for salt because Moorhead’s sand supply in recent years has largely been sand collected from past flood fights.
“We’ve probably got sand for another three years,” said Martin, who added the city will typically apply sand after a freezing rain or significant snowfall.
About a week after a heavy snowfall, Moorhead snowplows will touch up areas that might have been missed before, such as spots where parked cars prevented plowing, Martin said.
The touch-up work can cause polishing of ice in some areas and when that happens crews apply salt and sand where needed, he said.
All three cities dispatch crews to sand areas identi-fied as problem areas, officials said.
Fargo budgets about $325,000 a year for salt and sand, said Mark Williams, public works services manager for the city.
West Fargo spent about $70,000 on brine, salt and sand last year, according to Brungardt, who said crews have been applying brine to streets and running snowplows in recent days in an attempt to clear streets down to the pavement.
Readers can reach Forum reporter Dave Olson at (701) 241-5555