Clean Lake Tip: Reducing Sidewalk Salt

What not to do: salt doesn’t need to be a visible layer, or “crunch” underfoot, for a sidewalk to be safe. Photo by Laura Pratt.

Salt is the ubiquitous solution to icy roads and slippery sidewalks, but it isn’t the only way you can keep from slipping during the winter. Excessive use of salt damages plants’ ability to absorb nutrients, and can affect aquatic life if it’s washed into a water body. Click here to read LCC's previous article on how municipalities use targeted application to reduce salt runoff. 

There are several ways you can reduce your salt runoff impact at home. The first, and most important thing you can do is to shovel as soon as possible after a weather event occurs. By removing the snow and slush right away you can prevent new ice from adhering to the pavement.

You can also shop around for commercial salt alternatives, such as calcium magnesium acetate and potassium acetate. Acetates are biodegradable, and don’t cause the corrosion and plant damage that salt does. They are valued for their effectiveness during extremely low temperatures, ranging from 20°F to -75°F. However, acetates are far more expensive than salt, and contain high levels of nitrogen and phosphorus that cause their own water quality problems. Nutrient pollution is the leading cause of cyanobacteria blooms in the Lake Champlain watershed. If you do use acetates, you might consider adopting storm water management practices like planting a rain garden, or using permeable pavers.

Sand is another popular alternative to salt, but it can only provide traction and does not actually melt the ice. It has also been known to clog storm drains and harm water bodies through sedimentation, and can actually be more harmful to aquatic life than salt.

In addition to trying new commercial products, there are several homemade de-icers that you can experiment with. Sugar beet juice (or even regular cane sugar) can be sprinkled over the ice to melt it. Sugar beet juice is also known to work well when mixed with salt brine (a mixture of 23% salt and 77% water) – it lowers the freezing point of the brine below the typical 15°F limit, and helps the salt stick to the pavement. If you can’t find beet juice in your fridge, pickle or cheese brine might work just as well! Alfalfa meal (or a similar fertilizer) is another product you may already have in your home, which can both melt the ice and provide traction. Alfalfa meal contains a relatively low percentage of nitrogen, and when used in moderation could pose less of a risk to water quality.

If you do need to use salt, a little can go a long way. A brine solution of 23% salt and 77% water can be sprinkled on the sidewalk before a storm, and acts to prevent ice from adhering to the pavement. Wetting salt also makes it more effective at melting ice that’s already there. This should only be used in temperatures above 15°F, as lower temperatures run the risk of freezing the brine itself. Leave some sections of the sidewalk brine-free for extra safety, and shovel right away to make the most of the brine solution.

No matter which approach you decide to take, it’s important to test new methods out on a smaller, less-traveled section of pavement. Safety is the most important thing to keep in mind when it comes to clearing your sidewalks in the winter. Studies in the Great Lakes region indicate that most of the non-point source pollution of fresh water from chlorides (salt) originate on private land and parking lots. By simply being mindful of your salt usage this winter you can make a positive difference in the Lake Champlain watershed.