Each year, on average, there are 105 snowstorms. Salt is driven around in millions of trucks across the country to help deice the roads to make way for safe travels. In the United States, 20 billion pounds of salt are used every year to treat the icy roads after snowstorms. Common salt, the salt almost every American has on their dinner table, NaCl is most frequently used to deice roads across the country. Salt is very cost effective and efficient when used properly, however it is causing more harm than good when it comes to the environment (Environmental Encyclopedia).
Applying salt to roads has been done for many years. It helps prevent car accidents by melting the ice on the road. People are able to get where they need to go despite the bad weather and conditions. Usually at the first sign of a snow storm the roads will get treated with salt or brine which provides a layer between the pavement and snow. The snow will get compacted by the tires onto the road. The layer of compressed snow is called a hard pack. Without the pretreatment of salt or brine to the roads the snow would form a bond to the pavement, which would be impossible to plow away, resulting in an extremely icy road.
After the snowfall more salt trucks will distribute even more salt to the street which would break the ice-pavement bond and plows would be able to clear the roads for safe driving. This process is preformed many times throughout the winter. But once the snow melts, the salty water is sprayed by the traffic onto the roadside vegetation where it will cause hard to plants and pollute the water systems (Environmental Encyclopedia). It is common knowledge that salt should be consumed in moderation. So why is salt being applied liberally to roads throughout the winter time?
Simply because it is a cheap solution to a large scale issue. When the billions of pounds of salt are poured on to the streets, some of the salt causes rust and damages cars. The salt is able to corrode steel. There are about 500,000 bridges in the United States and 40% of these bridges are considered deficient due to salt damage. This mineral may come from earth but it causes damage to natural and manmade structures (Environmental Encyclopedia). Such large amounts of salt are dumper on to roadways to make for safe travels however not much thought is given about the environment.
Scientist Xianming Shi studied the quantity of road salt that is used to deice road salt. He found that in a stretch of one mile on a four lane highway, 16 tons of salt are dumped yearly. In half a century this will add up to over 800 tons of salt in just 50 years. Salt isn’t able to break down, so 99% of it stays in the environment (The Science Teacher). Tons of salt is poured out onto the streets each winter and cars always spray slush on to the roadside vegetation. Some salt will dissolve into the melted snow which will end up as runoff in streams or rivers.
Some salt will get absorbed into the soil, while even more salt will become concentrated into drinking water (“Living on Earth”). This kills most plants; they are not accustomed to high levels of salinity. As the plants die off the melted snow tends to travel downstream with nearby water sources. This downstream water gathers so much salt that when tested it contains up to 31 times more salt that water upstream. In local states, such as Connecticut and Massachusetts well water has become contaminated with salt.
The sodium content of many wells has risen to over 20mg per liter which is the highest amount for people who have to limit their daily sodium intake. One area in Massachusetts had to put an end to the deicing of streets with salt because the drinking water supplies became contaminated with unsafe levels of salinity. These high levels on salt are harmful to humans, they are even worse for plants and animals (Environmental Encyclopedia). While new solutions aren’t getting very far, salt pollution is getting even worse. The salt gets tossed on to soil by the roadways, which causes erosion.
This also affects all plants and wildlife up to 650 feet away from the road. The salt on the side of the road also can build up over time, producing an unnatural salt lick. This salt that gets distributed into the nearby forests causes great destruction. The salt first lands on soil, drying it out. This salt is landing on plants and trees as well. The salt dehydrates the plant leaves. All of the salt on the soil absorbs most of the water. This creates desert like conditions. Then the plants in the area have a difficult time absorbing water due to the amount of concentrated salt.
This causes plant leaves to yellow and eventually die (Stromberg, Joseph). A salt lick will call attention to larger animals like deer, moose, or even elk. When the animals find the salt by the road their chances of being hit by a vehicle is increased by a lot. Many smaller animals, like birds, get attracted to the salt licks (Rastogi, Nina). Chris Swan, a scientist, investigated gray tree frogs reaction to a high salt environment by putting them in water with a high salinity level.
The frogs did not react as expected, the salt made the frogs develop much faster than sual. The increased amount of salt made the frogs feed much more than they usually would during development. The increases feeding made the frogs grow to be much larger than usual as well. It was thought that the gray tree frogs would dehydrate with the increased salinity but they were able to survive. The frogs may have survived but this change in size could have a larger impact on the food chain (“Living on Earth”). Zooplankton, a much smaller organism than the gray tree frog; the zooplankton wasn’t not able to survive in the water with high levels of salt.
If the zooplankton die out then the body of water’s algae contented would increase but not only that, the fish that feed on zooplankton would die out, creating an imbalance in the food chain. The zooplankton get stressed in the high salt environment, just like humans get dehydrated, however they are too small to handle all of the salt so they die off (“Living on Earth”). Along the Massachusetts turnpike, where tons of salt is poured onto the roadways every year, salt damaged the local plant life. In Massachusetts, the salt aided the growth of invasive species.
Salt tolerant plants began grow and kill of local species of plants because they were better suited for the environment (Stromberg, Joseph). According to the National Academy of Sciences studies, salt concentration levels in freshwater is on the rise in the northeast. This would make the groundwater in many areas undrinkable within the next century. When people can no longer drink the water plants will have a hard time surviving because the high salt levels in the soil and in the ground water will dry up some of their water supply.
The high salt levels in the water will also create stress within larger animals as well (“Living on Earth”). In 2013 the EPA reported “alarming levels of sodium and chloride in East Coast groundwater,” this is mainly caused by the over salting of the local roads and the frequent snow storms. In certain areas, undrinkable water may be more of a reality than previously thought (The Science Teacher). Many more scientists have studied the terrifying impact of salt across America. Sujay S. Kaushai from New York is studying the harmful effects of road salt pollution on nearby wildlife.
He found that in a century or two much of the surface water in the Northeast will become toxic to freshwater life. Also, in Baltimore, Maryland many streams that were close to roadways became very contaminated. Some of the streams became ? as salty as seawater. The only this can be prevented is by ceasing all salt usage in the winter because salt simply accumulates and doesn’t go away. (Reebs, Stephan). Many states across the country are aware of this hazardous pollutant being distributed into the environment, but few reliable solutions have become easily accessible or cost effective.
Calcium Chloride and Potassium Chloride have been used on roads but they are just as bad for the environment and not as cost effective as common salt (Environmental Encyclopedia). Another salt alternative that has become more available is calcium magnesium acetate. It is much better for the environment; however, it has a higher cost than salt which is making it much less accessible. Another product that has thought about using but doesn’t make the cut is Urea. It is not in uses due to the high nitrogen levels which are damaging to plants.
It also only works in temperatures as low as 19. ° Fahrenheit whereas salt is effective down to 15° Fahrenheit (Environmental Encyclopedia). In Ohio many more solutions to this issue are being tested. The most common and effective solution is using beet juice. Sugar beet juice is melted down and combined with calcium chloride and soap rind. This combination of ingredients is able to melt snow at even colder temperatures than salt. By using beets, the salt runoff from melted snow and ice will decrease tremendously. The solution of 10% beet juice mixed with the liquid salt is able to purify the process of deicing roads everywhere, says Paul Barnett.
The main issue with using beets is that they are not as cost efficient. Beet juice costs $2. 60 per gallon while salt is only $0. 04 a gallon. Also, that pouring beet juice on the roads is a very messy job and the public does not want to wash beet juice off of their cars. While the beets could be a solution to the issue, they cost too much to become a feasible solution to this issue (“Beets Part”). For now, limiting salt use will help save the most wildlife until a better and ecofriendly solution is found. Pre-wetting the salt, which aides in better application, will help limit salt application.
Closely monitoring the weather and applying salt to the roads before the storm hits will help limit pollution (Rastogi, Nina). In the United States, deicing the roadways with salt needs to be stopped. It is deeply damaging the environment. Salt is the best choice for making roads safe during the wintertime, but in a century the real impact of all this salt use will catch up to society. Billions of pounds of salt per year is adding up and the real cost will soon be discovered when local forests, animals, and water supplies become corrupted.
