« Response #1 | Main | Prompt #3 »

Prompt #2


Winter is just something you learn to deal with if you are a resident of Minnesota. Everyone understands just how bad the roadways are especially in the middle of a storm, but many things are done to help keep the roads safe for motorists. Do we truly understand the implications of our actions? Many people would be incredibly upset to see someone dumping garbage on the side of the road, yet completely ignore the plow truck dumping salt onto the road in the lane next to them. Have we ever really explored what might be affected as a society, or is it to be ignored simply because the government is doing the damage and not just a simple citizen with a couple bags of trash.

In my experience few individuals have questioned this common practice. Being the land of 10,000 lakes you hear many objections about pollution of water from littering, fertilizers and pesticides, but road salt has stayed in the background ever since it’s inception into common use in 1941. When you consider that the US distributes about 8-12 million tons over the roadways every year, the question becomes where does all that salt end up? Simple, either our water or the ground, both of which is ultimately harmful to us all.
lakesalt.jpg

Road salt or sodium chloride (Na+ Cl-) is the most common
method of deicing roads. When the solution dissolves in
water the molecules separate and the sodium ions are
attracted to molecules found in the soil while the chloride
permeates and contaminates the ground water.
“Approximately 55% of road salt chlorides are transported
in surface runoff with the remaining 45% infiltrating through
soils and into groundwater aquifers� (Janis Keating article).
There has also been research that shows a direct correlation
between salt content in water supplies to amounts of salt used
on roadways. This affects the taste of our drinking water along
with leading to increased sodium in our diets, one cause of
hypertension disorders. When stored, sodium ferrocyanide is
commonly added to the salt which reacts with water to produce
cyanide which is toxic to marine life. “Prolonged retention of salt
in streambeds or lakebeds decreases dissolved oxygen and can
increase nutrient loading, which in turn promotes eutrophication�
(Janis Keating). Many of our lakes and streams already have
problems with mercury and pollutants that prevent society from
enjoying them, chloride poisoning will be added to the list unless
our practices are changed.

It also affects the plants and wildlife both inside and outside of the city. Salt can disable bacteria found in soil and lead to erosion, while creating difficulties of water obsorbtion in plants and preventing root growth up to 200 meters from the road. Cattails can be a sign of areas polluted by too much salt since they thrive in this environment, while tell tale signs on trees include the browning of evergreens. Wildlife are also drawn to the salt but do not know how to regulate their intake and will eat until they reach toxic levels. This leads to more animal/vehicle collisions in the process.
It also affects the plants and wildlife both inside and outside of the city. Salt can disable bacteria found in soil and lead to erosion, while creating difficulties of water obsorbtion in plants and preventing root growth up to 200 meters from the road. Cattails can be a sign of areas polluted by too much salt since they thrive in this environment, while tell tale signs on trees include the browning of evergreens. Wildlife are also drawn to the salt but do not know how to regulate their intake and will eat until they reach toxic levels. This leads to more animal/vehicle collisions in the process.
The corrosive nature of salt creates direct problems aside from the damage to vehicles, salt can penetrate concrete and corrode the metal supporting structures in bridges, parking ramps and numerous other facilities costing the city additional money for repairs.
There are numerous other alternatives to keep the roadways clear although the biggest obstacle is price. Both calcium magnesium and potassium acetate have comparable abilities and offer less harmful effects. A company based in Wayzata has introduced a new paving product, SafeLane, that helps deicers stay on the road up to 10x longer, so less is needed to be effective (www.popsi.com). By continued research into other alternatives we can help prevent road salt from becoming the next environmental problem that no longer has a solution. We need to keep salt on the table instead of on our roads. saltshaker.gif
Information & Pictures (www.forester.net/sw_0107_environmental.html)