Clearing ice without salting lakes, rivers
Officials look to cut sodium chloride use in creative ways
CONCORD, N.H. — Looking to strike a balance between ice-free roads and clean waterways, public works departments around the country are working to cut their salt use in winter by slathering the roads with beet juice, molasses, and even beer waste to make them safer.
Rock salt for decades has provided the cheapest and most effective way to cut down on traffic accidents and pedestrian falls during winter storms. But researchers cite mounting evidence that those tons of sodium chloride crystals — more than 20 million nationwide each year — are increasing the salinity of hundreds of lakes, especially in the Northeast and Midwest. That is putting everything from fish and frogs to microscopic zooplankton at risk.
“There has been a sense of alarm on the impacts of road salt on organisms and ecosystems,” said Victoria Kelly, a road salt expert at the Cary Institute of Ecosystem Studies in New York. “We’ve seen increasing concentrations in river water, lakes, streams. Then, scientists started asking the question: What is going to happen to the organisms living in freshwater bodies and what will happen to the freshwater bodies as a whole?”
Believed to be first used in the 1940s in New Hampshire, salt became the go-to de-icing agent as cities expanded, highways were built and motorists came to expect clear roads. More than a million truckloads a year are deployed in iceprone climes, most heavily in the Northeast and Midwest.
But many state and local agencies are seeking ways to reduce salt use as its environmental impacts are becoming more apparent.
They have turned to high-tech equipment to spread salt more efficiently, better weather forecasting to time their salting, and liquefied organic additives that help salt stick to pavement. That reduces salt use by preventing it from washing away immediately.
Agencies from New Jersey to North Dakota are using a mixture that includes beet juice; New Hampshire and Maine use one with molasses. Highway departments also have turned to beer waste, pickle brine and, in at least one Wisconsin county, cheese brine.
“Adding salt to the environment does have negative impacts, but for those of us in the Northeast, especially in rural states, where driving is the predominant way of getting around, we need mobility,” said Jonathan Rubin, director of the Margaret Chase Smith Policy Center and lead author on a 2010 report on the cost and benefits of salting Maine roads.