What to Know About Municipal Ice Melt Methods

We are nearing salt season, the time of the year when municipalities and state transportation departments throughout the country work to make roads passable no matter the weather. For many locales, that means spreading road salt.

Why Salt?

Salt (sodium chloride, specifically) lowers the freezing temperature of water. Normally, water freezes at 32 degrees F or 0 degrees C. In many locations in the U.S., temperatures drop below these in the winter months. Spreading salt or other ice removal solutions will cause accumulated ice on roadways to melt, making the roads safer for driving.

Why Not Dump Salt Constantly?

Salt is not a cure-all for winter driving. As temperatures drop toward 15 F, salt can’t effectively melt ice quickly. As temperatures drop even further, that salt can melt a thin top layer of ice. But then, according to the Michigan Department of Transportation, “it may cause wet pavement to refreeze.”

Worse yet, salt is corrosive. It tends to cause rust on steel, so cars driven frequently in salt can get rusty. It’s a bigger concern for those transportation departments that are already spreading the salt. Many bridges and overpasses are constructed of steel, so overuse of salt can cause long-term damage to these critical structures.

Further, road salt can negatively impact our environment. When the ice melts, the salt washes away with the water. It runs into the soil along the roadways and into waterways.

Per the New Hampshire Department of Environmental Services, the high chloride levels in that runoff can, among other things, threaten the health of food sources for wildlife and aquatic creatures. Deer are also attracted to the salt, which means they’re creeping closer to roadways. That can lead to dangerous and sometimes deadly impacts.

What Are the Alternatives?

One common alternative to traditional road salt is distributing sand atop the ice. It never melts but gives a grit to the ice, aiding in traction. Sand also can collect in drainage areas, requiring removal in the spring.

Other chemicals like magnesium chloride, calcium chloride, calcium magnesium acetate and potassium acetate often work better than traditional road salt. These may have a lower melting temperature and come with varying degrees of corrosiveness.

The big concern for cash-strapped municipalities is cost. These chemicals cost significantly more than road salt, which can be a problem if winter weather extends into spring.

What About Brine?

Road crews can fight to keep ice from sticking to the road with a brine of water and salt sprayed on roadways in advance of an incoming storm. The water helps the salt stick to the dry road surface, and the salt impedes the formation of ice.

Some municipalities experimented with innovative solutions. One Wisconsin county worked with byproducts of the region’s most famous export — cheese. They sprayed the salty brine leftover from cheese-making on the roads ahead of storms. Others have tried beet juice, beer waste and even pickle brine. These organic solutions are likely at least a little better for wildlife.