Pass the Salt

There is simply no way around it.  If you live in central Ohio during the winter, you are going to eventually be faced with the unenviable task of clearing snow and ice from your driveway and sidewalks.  Fortunately, we have many modern tools to help us with this chore.  From snow-blowers to ice melt chemicals, each year there are new innovations aimed at making winter survival just a little bit easier.  It is important to be aware though, that not all of these innovations come without some cost to the environment.

In particular, the use of ice removal chemicals has increased greatly with the addition of Calcium Chloride, Magnesium Chloride, and a host of other products to go along with the old stand-by, road salt.  Safety is paramount, so the use of such products is well-warranted, both on the roads for vehicular safety and on sidewalks for the safety of pedestrians.  This fact should not prevent us, however, from considering both what we are using to melt snow and ice and how we use it, as it relates to impacts on the environment.

The corrosive effects of road salt and other chlorides is well known.  Rust on vehicles and degraded concrete surfaces are two places where this damage is most visible.  Salts and chloride based products can also be harmful to plant material when not applied properly.  Salt sprayed directly on a plant can damage tissue and cause branch dieback and even the death of the entire plant.  Salts can also build up in the soil and cause harm to vegetation.  This build up can limit the ability of plants to take up water in the spring time; even with seemingly sufficient rainfall, a plant can die from the effects of a “chemical drought.”

Some ice removal chemicals can also harm aquatic life.  When these chemicals wash into the waterways, they deplete oxygen levels in the water, which in turn can be harmful or deadly to fish and aquatic invertebrates.  This issue is most problematic in wetlands and other water areas where there is not much circulation.

With all of these potential harmful effects to the environment, it may be tempting to abandon the use of ice removal chemicals altogether.  Where foot traffic is low, this may indeed the best course of action, but there are times and places where this would not be a good or, more importantly, safe solution.  When the situation dictates that something must be used, there are a wide range of products available.  Each product has positives and negatives.  There are no perfect options, so it is important to be aware of the advantages and disadvantages of each.

Road salt is an inexpensive and easy-to-obtain product. However, it has corrosive properties and can be harmful to plants and marine environments when overused.  Calcium Chloride is effective at much colder temperatures than road salt (up to -25 F), is less corrosive than salt, and is somewhat less harmful to plant material, but it is more costly, can still harm aquatic life, and is often tracked indoors where it can be very damaging to carpets and flooring.  Magnesium Chloride works at temperatures approaching 0 F and has very little negative effect on plants. However, it is fairly expensive and, because it is a Chloride, it can deplete oxygen levels in water resulting in harm to aquatic life.  Potassium-based products have fewer harmful environmental effects when used properly, but are not effective at temperatures below 25 F so they are of little use in our climate.  Abrasives, such as sand and sawdust, help provide traction and have few negative impacts on the environment, but they have no ice melting ability.  And then there are a host of products that blend two or more of these chemicals together.  Confused yet?!?!

The first thing that you can do to lessen the environmental impact of these chemicals, regardless of which one you use, is to use no more than necessary.  Everyone has seen the piles of salt or calcium chloride that linger on sidewalks long after the snow has melted.  This is not only wasteful, but potentially harmful when the chemicals eventually wash into the soil or waterways.  Step two, is to always begin by removing as much snow and ice as possible manually and then use the product properly.  Never throw ice removal chemicals directly on the snow without first removing as much snow and ice as you can with a shovel or snow-blower.  This will make the chemical work more effectively and you will use less of it, as well.

When possible, use anti-icing techniques.  This means putting down a small amount of salt or other chemical prior to the start of the snow or ice storm.  The initial precipitation will melt off and form a layer of water that will melt subsequent precipitation for a time.  This reduces accumulations and also helps to make manual removal much easier.  In the end, you will actually use fewer ice melting materials than if you wait until the conclusion of the storm.  Many municipalities are using this technique when they spread a liquid brine on roadways prior to a snow or ice storm.  Another step that you can take is to put down abrasives after you have manually cleared the snow and ice.  Although these have no ice melting properties, they do help with traction and thus limit the danger of slipping and falling.  Be judicious in your use of these products, too, as too much can clog up waterways and drains when it washes away.

Finally, know the properties of the products available and make informed decisions on what product to use and where it is appropriate to use it.  A little knowledge can go a long way in helping both you and the environment to get through the winter safe and sound.