Rather than using rock salt on icy sidewalks, look for nontoxic ice-melt products. Kitty litter also works. / Ricky Flores/The Journal News
Q: How can I keep my icy sidewalks clear without harming my pets or the environment?
A: Ice-melt products work by creating a brine solution that has a freezing point lower than water. The brine then travels between the surface and ice layer, loosening the bond for easier removal. For an icy driveway, sidewalk or deck, many homeowners rely on rock salt (typically sodium chloride) to solve the problem. However, this practice is not ideal for several reasons.
Rock salt is carried by storm water runoff (which is untreated) and makes its way directly into our reservoirs, streams and lakes, polluting them and damaging our ecosystem. Urea or other fertilizers should never be used to de-ice for the same reason. These chemicals damage or kill many plants, and the damage is made even worse when foot traffic and heavy snow banks compact it into the soil.
If you have young children or pets, ice-melt products can cause eye and skin irritation. There are several options for concerned homeowners. First and foremost, be sure to promptly clear sidewalks, decks and driveways after a winter storm. You can improve traction on any existing ice by sprinkling kitty litter (be sure to use the non-clumping brands, otherwise you will have a mess on your hands).
Lastly, there are several non-toxic ice-melt products on the market. Check your local hardware, nursery or pet store, and be sure to follow the labeled directions carefully. If you absolutely must use rock salt, apply only enough salt to do the job after you remove the snow. The Department of Horticulture at Cornell notes that calcium chloride-based salts cause less damage than sodium chloride.
What to do with the areas that did get too much salt? In well-drained soils, spring rains may leach the problem away. If the soil is poorly drained, organic matter can be incorporated into the top 6 inches. Re-seeding directly into a salt-contaminated soil won’t work. Seedlings are quite susceptible to its toxicity.
— Elaine Trainor, Pearl River, master gardener with Cornell Cooperative Extension of Rockland