Salting our roadways: A necessary evil
Hold the salt! Too much is as bad for the environment as it is for our bodies.
Wednesday, January 13, 2010 - 10:55
Doctors have been warning us for years that too much salt in the diet can have negative effects on our bodies. Hypertension and high blood pressure have both been linked to excess sodium levels. What many of us may not realize, however, is that too much salt may also have a negative effect on our environment. When the winter season hits, most states that witness snow have to salt their roads in order to keep them passable and safe. Road salt has the potential to corrode roadways, vehicles, bridges and other steel structures. With that in mind, one has to wonder what road salt can do to our planet.
When salt is applied to our roads, the mixture, which contains dyes and other chemicals, often runs off into nearby waterways, changing the chemistry of streams and lakes and causing minerals to leach out of the soil. It has been known to kill trees, and increase the acidity of water, exhibiting similar effects to acid rain. Lakes near major salted roadways have up to seven times the normal amount of chloride, which can allow heavy metals to enter the water from the soil and poison anything living. Though road salt can have a negative effect on the earth in many different ways, the most important thing to note is that road salt can negatively affect an area long after winter has passed.
According to the EPA, more than 13 million tons of salt are applied to our roadways every year in order to combat icy winter conditions. The West Virginia Division of Highways has already used more than 1,000 tons of road salt this season, which is more than it normally does this time of year. While salting roadways certainly increases safety for drivers, it is not necessarily safe for streams or plant life and many states have been looking into alternative de-icers such as calcium magnesium acetate and brine.
West Virginia, as one of the most ecologically diverse areas outside of the rainforest, has a responsibility to protect the ecologically sensitive areas of the state. Calcium magnesium acetate, or CMA, is considerably more expensive than road salt, but is far less corrosive and offers fewer negative environmental effects. West Virginia's Division of Highways already uses CMA in environmentally sensitive areas like the New River Gorge. CMA is biodegradable, and has poor mobility in soils, which means it is less likely than salt to reach ground water. On the downside, though CMA is not as damaging as road salt, like any additive it's not exactly great for the environment, either. If CMA does make its way into local water sources, it will reduce the water's ability to hold dissolved oxygen and may strangle living creatures if oxygen levels get too low.
The West Virginia Division of Highways has also been looking into the use of brine, a bi-product of natural gas drilling. Unlike salt, which lowers the freezing point of water, brine is applied to roadways before any moisture occurs and prevents ice from forming on the surface. It is cheaper than rock salt, and leaves significantly less residue. Though much more research is necessary to find the best method of de-icing our roadways, we must give kudos to West Virginia for considering the options when it comes to keeping their drivers safe without causing irreversible environmental damage.
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