Winter is coming; so is salt. It’s time to develop new weapons in the war against icy roads

30 Oct 2023 5:39 AM | Smart About Salt (Administrator)

Winter is coming; so is salt. It’s time to develop new weapons in the war against icy roads | Opinion |

HERE IT COMES. Another Northern Ontario winter nears, and with it the perils of driving on ice and snow along with the remedy, namely road salt and all the damage that it brings. After all this time, why hasn’t Canada — presumably a winter expert — figured out an alternative to the road salt products that ruin our vehicles and harm much of our environment?

It turns out that some jurisdictions have done just that with impressive results. First, though, some history.

Road salt initially appeared in the United States when New Hampshire began to experiment with granular sodium chloride in 1938. By the winter of 1941-42, the state began using salt on local roads and highways. Eventually, other states caught on and began using salt to treat their roads, as did Canada.

Water freezes to form ice at zero degrees. Road salt lowers the freezing temperature of the water and stops the formation of ice, but the colder it gets, the higher the concentration of salt that is needed.

Reduced winter highway maintenance in Northern Ontario by private contractors, in part acting on less stringent provincial standards and with fewer resources, has led regional municipal associations to demand more attention sooner after snowfalls as accident rates grow and highways are closed in storms. And so, they poured on more salt.

Today, the United States uses between 10 and 20 million tons of road salt each winter. Canada, with one-tenth the population but just a quarter of the kilometres of roads, uses roughly five million tons of salt products annually.

Writing in the Smithsonian Magazine, Joshua Rapp Learn noted an increasing amount of research showing that road salt gets absorbed into roadside plants, licked up by wildlife or accumulates in aquatic ecosystems — sometimes with devastating consequences. “All that saltiness can help invasive or even toxic species spread, not to mention (ironically) increase traffic danger due to deer and moose drawn to salt-covered roads.”

Among the effects on wildlife, salt runoff into waterways can reduce the size of rainbow trout hatchlings, kill off zooplankton — the minute, abundant organisms that form the baseline resource for entire ecosystems, and even affect gender ratios of frog populations.

Milkweed tends to absorb high concentrations of roadside salt runoff, altering the development of monarch butterflies that feed on it and killing those exposed to the highest levels even as efforts are underway to try and reverse their decline.

Emilie Snell-Rood, an associate professor in ecology, evolution and behaviour at the University of Minnesota, says that since salt is often limited in the natural world for creatures, it can act as a super stimulus when they do encounter it.

“Road salt is kind of like potato chips for animals,” she says. By attracting some species to roadsides, salt can put animals in danger from getting hit from passing cars. Canadians are well acquainted with this phenomenon, some violently so, as moose and deer amble onto highways to lick up salt. Across North America, researchers say there are approximately 45,000 reports of wildlife-vehicle collisions each year.

Salt of course moves from roadside ditches to creeks and rivers and into water tables and lakes, sources of drinking water. High levels of chloride can produce health issues with people on low-sodium diets due to diabetes or other illnesses. The increase in cyanobacteria — also called blue-green algae, which have been growing in number in Thunder Bay district — can also put toxins into lakes people and dogs swim in.

ROAD SALTING has changed over the last 10 years from using rock salt to a heavy wetting agent, or brine that is designed to stick to the road, but conversely also sticks to your vehicle. This new agent “is heavily laden with magnesium chloride which is tremendously caustic to any type of metal,” says Pierre Leger, president of Krown Rust Control. So it’s more important than ever to wash your vehicle after every storm where salt brine is applied to roads.

Even with that, and annual rustproofing, brine will eventually creep into auto body nooks and crannies and begin to rust metal from the inside out. It’s inevitable, but there are ways being found to prevent it.

There are enough harmful effects, including early deterioration of concrete bridges and parking structures and their steel innards, to have prompted some jurisdictions to look at alternatives to road salt.

The Minnesota Department of Transportation has been experimenting with potassium acetate on some of the most heavily used bridges, tunnels and traffic routes near downtown Duluth.

Chris Cheney, maintenance operations superintendent for the department’s Duluth district, said the chemical has shown some promise. It’s better at melting ice in cold temperatures, he said.

Potassium acetate is a liquid solution and costs about three times as much as road salt, Cheney said. But crews are using much less of it than they do road salt, so the cost ends up being about the same. Unlike chloride, the chemical eventually breaks down in the environment.

Following Calgary’s lead, the City of Winnipeg has used beet juice to help lower the amount of salt used on its roadways since 2020, and according to a city spokesperson, it can improve the “adhesion of the sand and salt to the roadway surface at colder temperatures.”

“Beet juice can make up to 60 per cent of the solution we are applying to the roads and is combined with a traditional sodium chloride-based brine. This lessens our chloride loading on infrastructure and the environment while producing a good quality melting solution effective to temperatures below -30 C,” a spokesperson told CTV News.

Yes, the beet juice solution — a waste byproduct of beet sugar refining — does leave the roads stained with red and brown, which can be unappealing. That being said, Laval, one of the earlier adopters of this solution, has started to use the juice from white beets to avoid the mess.

Williams Lake, B.C., began to experiment with Beet 55, a slightly sticky mix of sugar-beet juice and saline. It’s brown and doesn’t stain.

SO WHILE SALT is the cheapest method of winter ice and snow control, it’s also the most damaging. Those withered conifers you see beside highways are brown for a reason.

“We’ve been dramatically increasing the amount of salt per mile since the 1970s, even in places where we don’t have any substantial increases in the amount of road miles,” says Rick Relyea, a professor of biological sciences at New York’s Rensselaer Polytechnic Institute. “The answer isn’t really in alternative salts but in less salt.”

Hilary Dugan, a freshwaters scientist at the University of Wisconsin-Madison, agrees that using less salt is the answer in many cases, and that educating people about the amount they use on their driveways and sidewalks could help. “You can maintain safety by using a lot less road salt,” she says.

Charlottetown uses common-sense ideas to reduce its use of road salt. Sidewalks will not be salted when snow can be scraped to reveal mostly bare sidewalks, when sunny weather conditions and rising temperatures are forecast for after the snow has been plowed, another weather event is expected in the next 24-36 hours, or temperatures are too low for salt to be effective.

The “Superior-By-Nature” City of Thunder Bay, other regional municipalities and the Ontario Ministry of Transportation need to start doing winter differently. Consider the deleterious effects of road salt. Follow the lead of others. Settle on alternatives to protect life. It works.

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