|
Chemical De-Icers a Mixed Blessing
 Snow-melt
products can be a good-bad thing. They can make walking safer on
our sidewalks and driveways, but they can also damage concrete
surfaces, plants, grass and can be a potential pollutant for
creeks and lakes.
The problem comes when we over-apply them
around our home, just to make sure the ice and snow melts.
Excessive use leads to an accumulation of the active
ingredients. This can damage concrete surfaces, harm plants and
grass and be carried away to stormwater drains when the ice and
snow melts. Pollutants entering the stormwater drains are
deposited in Omaha metro creeks and lakes. De-icers can cause
raised levels of chloride in creeks and lakes which is harmful
to aquatic life. That is why it’s still best to remove the ice
and snow by hand when you can and use only moderate amounts of a
snow melt.
The five major ingredients offered in the
different brands of chemical de-icer each bring advantages and
disadvantages:
Calcium chloride – the traditional
ice-melting product that continues melting ice in temperatures
down to about -25 degrees F. It rarely harms plants unless used
in excess, but it can create a slippery, slimy surface on
concrete and other hard surfaces.
Rock salt – the original ice melter and
the least expensive. Because it’s sodium chloride, it’s
effective down to about 12 degrees F. It can, however damage not
only concrete and plants but also soils and metals.
Potassium chloride – another chloride
formulation that can damage plant roots. Plus, it can cause
serious plant injury when washed or splashed on foliage.
Urea (carbonyl diamide) – a fertilizer
sometimes used to melt ice. It’s only about one-tenth as
corrosive as calcium chloride, but it still can contaminate
ground and surface water with nitrates. Urea is only effective
to about 21 degrees F. Urea is not recommended for use as a de-icer
where runoff can enter stormwater drains or waterbodies.
Calcium magnesium acetate (CMA) – is
made from dolomitic limestone and acetic acid (the principal
compound in vinegar). CMA does not form a brine as the salts do,
but rather helps prevent snow particles from sticking to each
other or the road surface. It has little effect on plant growth
or concrete surfaces; however its performance decreases below 20
degrees F.
Never over apply de-icing agents and use them
only when necessary and be sure to remove the slush before it
has a chance to refreeze. Also consider mixing de-icing agents
with sand so the mixture is not so concentrated. These tips will
help to protect your property, plants and our creeks and lakes.
- return to top -
|
Archived Articles |
 |
|
