Sunday, October 24, 2010

Figuring out Salt DeIcers for commercial properties

The use of salt as a deicer on townhome roads and sidewalks is the preferred method to promote safe motor vehicle and pedestrian travel during winter months. The most commonly used deicing salt is sodium chloride (NaCl). Sodium Chloride effectively depresses the freezing point of water to melt ice. But what are the impacts of salt applications to drinking-water supplies and watershed ecosystems?
The application of NaCl and its environmental consequences have come under scrutiny by the environmental and scientific communities as well as regulators and legislators.
There is growing concern over plant habitat, wildlife kills, and water-quality issues. It is estimated that the United States applies 8-12 million tons of salt on the roads annually. Living in Minnesota, we certainly get more than our share of this total. The question is, how much damage to the environment is caused by dumping the equivalent of 20 pounds of salt on the ground for every man, woman and child in the U.S. each year?
Environmental Fate
Soil with high salt concentrations affect biotic communities, hinder plants ability to uptake nutrients and reduce root growth.



Wildlife
Damage to vegetation hurts wildlife habitat by destroying food resources, shelter, and nesting sites..There have even been reports of bird kills. The thinking is that birds might not be able to distinguish between salt crystals and the grit their diets require. Salt can be an irritant to dogs and cats too.
Infrastructure Impacts
In addition to the public health and environmental problems associated with chloride deicers, the corrosivity of road salt adversely impacts motor vehicles and infrastructure. In vehicles, corrosion can affect critical vehicle parts, such as brake linings, frames, and bumpers, and of course, surface rust on the body. Townhome sidewalks receive a lot of damage each year.
“Pet Safe” products
Many bags of salt promote the fact that they are pet safe. In practice, most pet safe salts have a blend of different chemicals, some of which can be an irritant to pets. Magnesium Chloride and CMA are more “pet and environmentally friendly” than Sodium Chloride, but there still may be other salts in the blend.

So, what is the solution for townhome associations and condos?
1.review your winter maintenance contract. Does your contract call for auto salting by the contractor whether the site needs it or not? Although the numbers vary widely, most snowfalls in the Twin Cities don’t require salting. If we have 20 snow events in a season, Maybe 4-7 need salt. So salting 20 times is not only damaging your property and the environment, but you’re throwing dollars out the window as the contractor has built in the cost of the 20 saltings in your contract.
It’s better to have your board or manager determine when and where salt is applied on your property. Since the board lives on site, you’ll have a constant watch of your sites conditions.
2. Even if a site requires salt, many times putting the proper amount of salt on intersections, hills and underground parking ramps are all that is needed. That alone will save at least 50% of the salt applied.
3. Temperatures matter! At 30 degrees, one pound of salt melts 40 pounds of ice, while at 20 degrees, one pound of salt melts only10 pounds of ice, a 400% difference! And the air temperature is a minor part of the equation. Does your contractor apply varying amounts of salt to your property at different temperatures? Do the varying amounts show up when they bill for salt, or does it always seem to be “2 tons” every time?
4. Barrels of salt/sand. 10 years ago, we were applying mixtures of 80% sand and 20% salt as THE standard application for townhomes. The salt was in there basically to keep the sand from freezing solid in the spreader. Nowadays, sand is rarely used on private lots, but there is still a place for sand. Your contractor can usually provide sand barrels for your association. They’ll place them next to hills and parking ramps, or wherever you want them. It’s that same 80/20 mix of sand/salt. They’ll provide a cover and a scoop for residents to use whenever needed. When a barrel runs low, call the contractor and he’ll refill it. At the end of the season, the contractor picks up the barrel and stores it.
Road-Salt Alternatives
Calcium Magnesium Acetate
CMA is relatively harmless to plants and animals, noncorrosive to metals, and nondestructive to concrete and other highway materials. CMA is very expensive and is required by customers with raised parking decks or concrete parking areas. Because of it’s expense, it’s use as a parking lot deicer is limited, but can be found in bagged salt as a blend to be used on sidewalks. CMA acts more slowly and is less effective than salt in cold conditions.
Magnesium Chloride. Another good choice if you’re concerned about pets and the environment. Magnesium Chloride also melts ice at much lower temperatures than Sodium Chloride.

1 comment:

Eric said...

Great article Steve. I read it in Community Association Living too!