December 24, 2007
Eco-Friendly Alternatives to Salt
By Joe Lamp'l
Sometimes it's not an easy choice between our safety and the safety of our plants and soil. If I lived alone, I'd give the nod to the latter. But, I must be prudent to protect my family and guests from winter perils, namely an icy slick sidewalk or driveway.
If you live in an area where this can be a problem, you know that de-icers are a common way to eliminate slickness. But too often we don't use de-icers properly. Their job is to loosen ice from below making it easier to shovel or plow, not remove ice completely.
Improper or over use of de-icers is detrimental to plant life and the environment. Most de-icers are chemicals containing high concentrations of salt. Excess salts build up in the soil, just as they do with the overuse of chemical fertilizers. They impede the uptake of moisture and nutrients. Others cause leaching of heavy metals which eventually make their way to water supplies.
Although you may not see the damage to plants under a blanket of snow, you will by spring. Symptoms include stunted growth, wilting, desiccation, and burned leaf tips or margins. It can also cause permanent root damage.
The following list includes some of the most common ingredients used to battle ice and snow each winter:
Sodium chloride, commonly known as rock salt, has been the most used de-icer since the 1940s. Millions of tons are used each year on roads in the United States and Canada.
Calcium chloride is produced in flakes, pellets and as a liquid. It is sometimes sprayed over rock salt to lower its melting temperature, which further increases plant and soil exposure to salt damage. Even though it is considered to be practically non-toxic to aquatic life, it does increase algae growth which poses a problem for our waterways.
Potassium chloride occurs naturally in the mineral form of Sylvite and can also be extracted from salt water. Ok, that's a clue -- more salt. It is also used as a fertilizer (muriate of potash) and as a salt substitute.
These chloride salts, although common choices, present their own set of problems.
As a group they are corrosive to metal and concrete, damaging to plant material, a harmful skin irritant and potentially lethal to pets. Please be sure to read the label before purchasing.
Some people broadcast common household fertilizer like 10-10-10 onto the ice, thinking they are feeding their plants and lawn while providing a more benign solution. It's not! Synthetic fertilizer can have a lot of salt plus nitrogen and phosphorus. Excessive run-off of these materials is capable of harming lakes and streams.
Here are some eco-friendly alternatives:
Covering key areas with plastic before a storm, and removing it before it has a chance to freeze in place is a good preventative measure that is certainly a more environmentally sensitive option. Spreading sand or gravel over slick spots will not melt the ice or snow but offers some traction.
The choice to opt for salt-free alternatives provides for pets' safety as well. Salt build-up from de-icers accumulates on an animal's paws and coat causing mild to fatal illnesses as they attempt to lick themselves clean. One alternative salt-free de-icer I found during my research is guaranteed not to be harmful to humans, pets or the environment. It is trademarked under the name of Safe Paw.
Another option being tested is calcium magnesium acetate (CMA) made from dolomitic limestone and acetic acid, which we know as vinegar. This salt-free melting agent is being studied as a substitute in environmentally sensitive areas. Although it is expensive, so far research has shown that it has little impact on plants or animals.
So while it may be necessary to use melting agents at times, it doesn't seem to me we should risk harming our pets, soil or the water supply any more than we have to.
Joe Lamp'l hosts "Fresh from the Garden" on the DIY Network and "GardenSMART" on PBS.