Despite global warming, snow still falls in winter on much of the nation, ice still forms on highways and road department trucks still spread salt on the problem.
According to the Salt Institute, a trade association in Alexandria, Va., the Snow Belt consumes 10 million tons of rock salt in an average season, as much as 18 million tons in a severe winter such as 1994-1995. (The winter of 1995-1996, especially snowy on the East Coast, used up 14.4 million tons.)
The use of salt is anathema to many environmentalists, who contend that runoff into rivers and streams kills fish and aquatic plants. They say roadside plantings are also affected.
"Salting the roads affects every facet of the surrounding environment," said Zev Ross, conservation coordinator for the River Alliance of Wisconsin.
The Pennsylvania Department of Environmental Protection says that much of the damage is caused by runoff from improperly stored salt stockpiles.
"There is a potential for water supply contamination," said Andrew Briscoe III of the Salt Institute, which urges storage under a roof on an impermeable asphalt or concrete pad, with all runoff channeled into a catch basin.
Health officials say highly saline drinking water, with salt concentrations above 250 parts per million, posed a danger to the 15 percent of Americans who both are sensitive to salt and have high blood pressure.
Until recently, most complaints about salted roads centered on the corrosion they caused to cars and trucks. But modern vehicles offer far better undercarriage protection from road salt than their predecessors had, and the salt controversy has largely become an environmental concern.
Still, despite the complaints, salt remains king in the New York City metropolitan area, its use dictated largely by its effectiveness in melting ice and by simple economics. (It costs $30 a ton, compared with $675 a ton for calcium magnesium acetate, a less corrosive substitute that is used on some bridges in Michigan.)
Sand is even cheaper, at only $5 a ton, but it doesn't melt ice, and, maintenance officials say, it requires costly and time-consuming cleanup operations come spring.
Joe Doherty, program manager for snow and ice control of the New York State Department of Transportation, says that in an average winter the state spreads 600,000 tons of rock salt, mixed with liquid calcium chloride so it forms a solution and stays in place, on 42,000 miles of icy roads.
"We're aware of the environmental problems, and we have cut back," Doherty said. "We use just enough to do the job."
New Jersey uses the same chemical mix, said John Dourgarian of the state Department of Transportation. "We use the salt only when it's absolutely necessary, when our pavement-temperature monitoring tells us of the potential for icy conditions," he said.
Connecticut mixes two parts of salt with seven parts of sand and uses 300 pounds of the mixture for each mile of two-lane road.
"We've had some complaints about auto corrosion and environmental damage," said Michael Turrano, transportation maintenance director for the Department of Transportation. "Now we're experimenting with liquid magnesium chloride, which does less damage and saves a lot of cleanup time because it's a liquid."
The experimental liquid sells for 85 cents a gallon.
Ross of the River Alliance says some states are experimenting JTC with environmentally benign alternatives that also are agricultural byproducts.
Pub Date: 12/01/96