Safer Salt for Slick Streets

We need this, but don't have it quite yet

Between our house and town--around 4 miles--the back-country roads pass through some "northy" places in the shade of white pines or high ridges and don't get much direct sunshine for very many minutes a day.

Those are the places we know to slow down after an ice storm, but also know to expect those bits of roadway to be hazy-white with salt residue--sometimes even a day ahead of the anticipated ice event. And we're appreciative of VDOT's efforts on the behalf of winter drivers who can use all the traction they can get between home and the grocery store.

But driving first-car behind a highway department salt spreading truck last week, I wondered yet again what are the long-term consequences of salted roads; and if there are better alternatives to the usual "rock salt" sodium chloride that is mined by the ton from thousand-foot-thick domes and veins. Morton knows a thing or two about that: Salt Production and Processing - Morton Salt if you want to see where the salt on your chips comes from.

But to my point and question: are there costs to salting winter roads; and do better alternatives to sodium chloride exist, that are less harmful to the environment?

🧂 THE COSTS and CONSEQUENCES OF SALT

• The costs of road treatment include aesthetics, corrosion and physiological effects. The former is relatively trivial, but you can always tell cars on the interstate that are from the Snow Belt states— chalky white like a drizzled donut. Road ice also impacts the nearest vegetation along the roadway, killing and discoloring it. I read that the long-lasting impact on soil is minor and short-lived. But I wonder.

• Volume of usage in winter equals 20 million tons just in US snow belt cities in US, Canada and Europe, and it is reported that 23 billion dollars in auto damage occurs yearly from rust and corrosion.

• Corrosion is a serious matter--for metals, asphalt and concrete. It can be serious enough to cause catastrophic failure. The 2012 collapse of the Algo Centre Mall in Elliot Lake, Ontario was the result of rusting from years of water and salt penetration—steel support beams eventually collapsed from the damage.

SALT IN SURFACE AND GROUND WATER

• Road salt biological consequences are greatest on water resources. Salts enter groundwater, which is an especially important consideration from places like Floyd County where there are no surface water containments, and most of us pull our water out of the ground below our yards, farms and near or distant roads.

• Salty water can lead to reduced oxygen in aquatic environments and can stimulate algal (cyanobacterial) growth. Dead zones and algal blooms are a high price to pay for keeping ice off our roads.

• Smithsonian Magazine explains that approximately 40 percent of the country's urban streams have chloride levels that pose a threat to aquatic life, largely due to road salt. Canada has even gone so far as to categorize road salt as a toxin.

• A 2014 geological study even discovered elevated levels of harmful chemicals from roadside sediment. Radium, strontium, calcium, and sodium were all found in dangerous amounts; radium is particularly alarming because of its radioactive and carcinogenic properties.

AN ALTERNATIVE WORTH ITS SALT?

Looking around for less expensive and less damaging alternatives to rock salt, there are four categories of choice:

• 1.) Mechanical slip-and-slide reducers that increase friction. These are best used on a small scale--on your front walk, for instance. All carry the promise to end up on your living room carpet. No free lunch.

  • Cat liter: (unused)

  • Sand

  • Ashes (clinkers from furnace slag or wood stoves)

  • pea gravel / stone grits

  • coffee grounds (but the carpet!)

• 2.) Other salts and brines

  • salts of calcium, magnesium, potassium, all with their own characteristics and costs. See these explanations:

  • BREAK THE ICE (comparison of Ice Melting Chemicals) – Peters Chemical Company

  • Rock salt alternatives are better for infrastructure and the environment

• 3.) Food and other Waste substances that lower freezing point of water

  • Urea used in fertilizer production where that is widely active

  • Beet juice (is high in sugar)

  • Potato juice -- A waste product of vodka and rum distillation, potato juice has found a use as a de-icing agent in the snowy mountain roads of Tennessee. Marketed as Magic Salt, it’s mixed with traditional salt brine and can be effective at lower temperatures than the state usually receives. It’s also far less corrosive to vehicle metals than salt alone.

  • cheese brine; garlic salt; pickle brine -- all have low freezing points but carry risks associated with the sugars or acids they contain

  • WHAT!? The liquid waste from gas extraction by hydraulic fracturing (fracking) is rich in chemicals, including salts. [And are there not also radioactive elements therein?] In the state of New York, this waste water is used to de-ice roads. Because it has a risk of contaminating water and soil, it can only be used with permission from the state’s environment department.

• 4.) ⭐️ And finally, the most innovative (and likely far-off) possible alternative to road salt: New potential exists for synthetic bio-antifreeze chemicals based on the internal compounds produced by Antarctic toothfish, some insects and spiders, the ocean pout, winter flounder, yellow mealworm beetle, spruce budworm moth and snow flea.

  • To make less-harmful road salts, we're studying natural antifreezes produced by fish

  • This research hopes to create long proteins like those employed in creatures that are naturally adapted to survive severe cold. These long organic molecules bind to ice crystals and prevent formation; they are long lasting, effective and produce few known side-effects.

So the take-home is : choose your poison. All road treatments for ice control that are currently widely available have their down-sides. So we should be looking earnestly for safe, affordable, sustainable replacements—or designing roads in a way or with a material that does not allow ice to form on the roadbed in the first place.

Meanwhile, drive to town behind the salt truck, cover your slickery walkway with coffee grounds or cat litter (or save all your pickle juice), and take off your boots at the door.