Salting the roads – and water, and fields …

Bill Knight column for Thursday, Friday or Saturday, Dec. 14, 15 or 16

There are always trade-offs, it seems.

In “Inherit the Wind,” the Henry Drummond character (Spencer Tracy in the film version) sums it up: “Progress has never been a bargain; you have to pay for it. Sometimes I think there's a man who sits behind a counter and says, ‘All right, you can have a telephone but you lose privacy and the charm of distance. Madam, you may vote, but at a price; you lose the right to retreat behind the powder puff or your petticoat. Mister, you may conquer the air, but the birds will lose their wonder and the clouds will smell of gasoline’.”

As winter arrives next week, people need snowy streets and roads cleared to travel safely and get to work. However, the main tool is road salt, which dissolves in water and runs off into ditches and lakes, streams and sewage-treatment plants, potentially affecting plants and animals. It also can seep into groundwater, where it can remain for years and accumulate from previous seasons and enter wells and other supplies of drinking water, which can affect taste and people on restricted-sodium diets.

First used in 1938, road salt is relatively cheap and effective. It lowers the freezing point, so snow melts until temperatures drop to, say, 0 degrees instead of 32 degrees, before freezing. Illinois was one of the states examined in studies showing road salt cuts snowstorm wrecks by 88 percent, according to research by Marquette University, and the negative economic cost of road closures is costlier than snow removal, says a report by the consulting service IHS Global Insight.

Road salt has three costs: the salt and labor to use it, indirect expenses for repairs or replacements for corroded concrete, bridges, vehicles and equipment, and long-term remediation of removing salt from water. Salt prices are variable; most counties pay about $55/ton, down from $95/ton in 2014.

Salting roads undoubtedly saves lives, but environmental consequences can be the most expensive.

“Like most chemicals, too much salt is toxic,” wrote William Schlesinger and Stuart Findlay of the nonprofit Cary Institute of Ecosystem Studies. “And humans are inadvertently increasing the salinity of freshwater resources through routine road-salt application. If salt continues to accumulate at its present rate, in our region many surface and well waters will be unhealthy for humans and wildlife by the end of this century.”

Salt pollution, measured by the concentration of chloride (road salt is sodium chloride), is substantial, according to the U.S. Geologicl Survey, which found that 84 percent of northern U.S. streams have toxic levels of chloride, highest in winter, when road salt is prevalent.

The results can hurt freshwater species, soil, vegetation and wildlife, which can be lured by the artificial “salt licks” where animals near rural traffic can become road kill.

Of course, an ideal approach to snow removal hasn’t been perfected, but there are innovations: adding abrasives such as cinders or sand, “pre-wetting” salt for better control and adherence; monitoring weather forecasts to apply salt just before accumulation; and supplementary substances such as (biodegradable) sugar-beet juice, cheese brine (used in Wisconsin), pickle juice (used in New Jersey) and potato juice (used in Tennessee).

“Research indicates that we can achieve safety while being more efficient and careful with our road salt,” according to the Cary Institute. “By combining efforts to improve efficiency in road-salt use with alternative chemicals in targeted areas, we can make a difference and improve conditions for ourselves and future generations.”