Murphy, K. (2014). Crews load salt into a plow truck in Salt Lake City on Nov. 13.[Photograph].http://www.usatoday.com/story/news/nation/2014/12/13/kostigen-ice-road-technology/20239695/
Jeremy Chaitin, BCT. Brennah Beaupre, Wildlife . Dakota Horton, Horticulture.
What Happens To Road Salt Come Winter’s End?
Science reporter Joseph Stromberg (2014) said, “It’s estimated that over 22 million tons of salt are scattered on the roads of the U.S. annually- about 137 pounds of salt for every American” (p.1). Just like Stromberg (2014) we propose the question, Where does it go after that? When looking at road salt as a product it seems so harmless, all it does is melt ice for our convenience and safety. Besides its convenience, what about when the salt is washed away come springtime and the salt ends up drifting into the water and wetlands? Doesn’t 137 pounds per person seem a bit excessive and wasteful? According to Ramakrishna & Viraraghavan (2005) “[A]pproximately 9 to 10 million tons of sodium chloride, 0.3 million tons of calcium chloride and 11 million tons of abrasives are used annually. Highway salting rates range from 400 to 800 pounds of salts per mile of highway per application, and many roads annually receive more than 50 tons per mile” (Ramakrishna,D.M. & Viraraghavan,T. (2005), p 50). Those numbers make it clear that road salt is used in large, excessive quantities.
The department of public works in your respected city, county,or state executes snow removal in your area. Their job is to clear roadways and make them safe for public access before, during, or after a storm. Sometimes there is so much snow that the snowfall begins to affect homes and not only the roads.
Snow Removal Is A Hard Task
Weather is fairly unpredictable and so are its severities, which can make snow removal a difficult task. Severity of winters is an important consideration in snow removal practices; it decides how much money we need to put into snow removal In some places snow is becoming such a huge problem not only on roads but on peoples’ homes. If actions are taken on roads then soon we can work to take actions for snow removal in other areas, high and low. Writer Eric Russell (2015) talks about the snow getting so excessive that roofs are in danger and people need to now hire people to clean off their roofs. He discusses the difference between houses in the area by saying, “Most houses in Maine, whether they are one-story ranches or two-story capes and colonials, have pitched roofs that help keep snow from piling up.” (P.1) He talks about when people have flat roofs its still too dangerous to go up there and try to get most of the snow down. With homes being severely affected it puts into perspective the idea that sometimes too much snowfall is something that can’t be cleared without extensive amounts of time. This information about snow on roofs is an important example to think about in regards to snow removal on the roadways. It shows that while
Using Too Much Salt Is Expensive
The way we execute snow removal is a major problem. With the population of the U.S. being recorded at 318.9 million and the information above it is clear to people that the use of salt is extremely excessive. Salting isn’t the only problem we have found; snow removal requires many trucks or ATV’s with plows to clear the snow efficiently. Taylor Pfeiffer (2013), writer for BOSS Snowplows claims on “The Snowplow Blogger” that each of these plows ranges from three thousand to five thousand dollars depending on the material, size, and shape of the plow (p.1). Financing for snow removal has many factors, they need to pay the workers that work late hours to clear the streets as well as fund all the vehicles, repairs, and plows necessary to clear snow and distribute the calcium chloride necessary to melt the ice.Questions about snow removal only come about when there are problems existing in the current system. The problem tends to erupt when absurd amounts of snowfall impact communities and the time that it takes to clear the snow is too long.
The direct effect on the environment from road salts is the increased salinity in the water. This increase in salinity is a “growing threat that [can increase with] climate change” (Arguelles et al., 2013, p. 157). The main idea in the study by Arguelles et al. (2013) is the secondary salinization of bodies of water; all the extra salt placed on roads is a much heavier load for the rivers to take than the natural load. Arguelles et al. (2013) claim that over salinization leads to a “reduction in trait diversity”(p.157) for most animals because the salt “produces changes… in terms of density, species richness, and functional aspects” (p. 157). The effects on wildlife in the waters that are becoming over salted are detrimental to the continuation of species. Mahrosh et al. (2014) state that “Controlled episodic exposure to road salt [throughout] fertilization resulted in reduced swelling and less percent egg survival [of Atlantic Salmon].” (p. 331) The over salting of roads is extremely unnecessary and harmful towards marine wildlife. Certainly we survived for many years and hopefully there are many more to come following, but there is room for improvement.
Municipal Departments of Public Works should reduce the negative impacts of road salt on wildlife and water quality by replacing salt with eco-friendly alternatives, more efficient distribution of these alternatives, and the assistance of snow removal through energy efficient machines.
Salinity Effects on Aquatic Animals
Road de-icing materials generally used are salts, calcium chloride, and sand. Accumulation of these materials can lead to harmful effects on the environment that can impair both us as humans and the organisms around us. The reduced quality of our groundwater is something we should all be seriously concerned with. Cañedo-Argüelles (2013) says that human contamination is an increasing threat that may cause a reduction in biodiversity, and jeopardize the resources we receive from the beautiful lakes and rivers of the world (p. 158).
Information from a 2010 study in the Wisconsin area shows dramatic amounts of chloride in watersheds. “…[A] Milwaukee stream was sampled from 1996 to 2008 with 72% of 37 samples exhibiting toxicity in chronic bioassays and 43% in acute bioassays, [Bioassays are studies that find the purity of a biological substance]. The maximum chloride concentration was 7730 mg/L” (Corsi, Graczyk, Geis, Booth, Richards, 2010, p. 7376). The authors then claim that in the acute toxicity assessments, 55% of their findings exceeded the United States Environmental Protection Agency (USEPA) limit in chloride concentrations, and 100% of the chronic toxicity assessments were higher than USEPA’s regulations (Corsi, et al., 2010, p. 7379). Increased levels of chloride in water sources cannot be healthy for us, or animals, to ingest.
In order to survive, freshwater animals need to have internal salinity greater than the salinity of the water in that they live in. If the water is higher in salt content than the fish, they have to spend an incredible amount of energy in order to produce ions that allow them to keep water inside their bodies. This is a huge stress on the animal. All of the energy being produced to maintain osmosis damages the cells and can even cause death (Cañedo-Argüelles, et al., 2013, p. 159). Mahrosh et al. (2014) claim that de-icing salt is toxic to the developmental stages of Atlantic salmon eggs. In their experiment, they exposed salmon eggs to road salts during their developmental stage. They found that the road salts reduced swelling of the eggs as well as the amount of survival ( p. 331). Swelling of the fish eggs is an important step in the fertilization process. Without swelling, the embryo doesn’t have enough space to expand, development is restricted, and deformities can occur (Mahrosh et al., 2014, p. 334).
Salinity on the Ecosystem
Salinization can also degrade natural ecosystem processes. Cañedo-Argüelles et al. (2013) claim that the high amount of saline can cause important particles to settle on the bottom of streams. This affects periphyton growth, which is a mixture of algae and microbes that serve as an important food source for aquatic animals. Salinization can also increase the growth of different types of harmful algal blooms. (p.160). The high algae growth and bacteria population will decrease the amount of freshwater plants and essentially take over the environment. Cañedo-Argüelles et al. (2013) claim that high salt concentrations can reduce species diversity and density (p. 160).
Using Road Salt Effectively and Efficiently
Replacing road salts all together would be the ideal alternative but at this point there is not enough research and availability behind these alternatives. So we accept that road salt cannot be completely replaced, and we now look for what we can do to mitigate effects of road salt on environmental quality, particularly water quality, wildlife and vegetation. The goal is to use less salt overall. In order to do that we need to make sure the salt used is being put to work efficiently and effectively. A method to use less road salt overall is to spread it before a storm. As reported by Howlett (2003), “spraying roads with a brine, or salt solution, before a storm — could save each state up to $81 million over 20 years”(p.1). The Idaho Transportation Department explains that spraying a de icer before a storm prevents ice and snow from sticking to the roads. “[Deicer is] applied prior to snowfall to prevent snow and ice from bonding to the pavement. Because it is easier to prevent a bond from forming than it is to break a bond that has already formed, anti-icing techniques are more effective and require less volume of chemical spray.” (“Emerging Technologies” 2006, p.1).
Another important way to use less salt is to use energy efficient machines in snow removal. Municipal Departments of Public works can look in to replacing old, gas guzzling trucks with new ones that have better fuel economy. According to the US Department of Energy (2015), the most fuel efficient pickup trucks are the Chevrolet Colorado, GMC Canyon, Toyota Tacoma, and the Ram 1500 (“2015 Most” 2015). These more energy efficient pickup trucks should be used for plowing. More efficient snow removal technology can assure that we are using the least amount of chemicals as possible to get the job of clearing roads done. One technological advancement that should be used widely over the United States is Road Weather Information Systems(RWIS).
RWIS helps maximize effectiveness of snow removal. This technology helps to tell operators in real time what kind of snow removal product to use (liquid brine in dry conditions or dry salt in freezing rain). It tells operators if the temperature is too low to use road salt. If the temperature is too low other deicers like calcium chloride, magnesium chloride, or potassium acetate can be added to the road salt mixture so it is more effective. RWIS also allows for information on wind strength and direction with aids with the actual distribution of deicers on roadways. With RWIS technology less road salt and other chemicals are needed because this technological advancement allows for the deicers to be used more efficiently.
(“Emerging Technologies” 2006 p.4).There are many different technologies out there and ways to go about using less chemicals. Municipal Departments of Public works around the country should implement these methods so that they are releasing the minimum amount of chemicals into the environment.
There are alternatives to salts that we could use to create safe driving conditions during the winter. One option is Verglimit. The Michigan State Government (“Current Deicing…”, n.d., Verglimit) says that it is;
a patented bituminous concrete pavement that contains calcium chloride pellets encapsulated in linseed oil and caustic soda. The pellets remain inactive until the roadway surface wears under traffic. As the pavement wears, the exposed particles dissolve by attracting and absorbing moisture from the air, creating minute pores in the pavement. When a pore becomes full, the spillover dampens surrounding pavement. These many damp spots create a surface on which it is very difficult for ice or packed snow to adhere. (p. 18)
Although calcium chloride is in Verglimit, it has very little environmental impact. Michigan State Government maintains that when it does reach the environment, it is a minuscule amount that is in a diluted form. It is about 33 times more expensive than asphalt, however savings would be seen by the reduced amount of car accidents and road salts used, along with the dwindling costs of highway and vehicle corrosion. (“Current Deicing…”, n.d., p. 19). The next option is a magnesium chloride solution. “Magnesium Chloride is less toxic than baking soda or salt…Tests have shown that proper application of magnesium chloride produces no negative effects on groundwater, surface water, or vegetation” (“Magnesium Chloride,” 2014). Magnesium chloride is a better choice than cheaper salt and sand because magnesium chloride is more cost-effective. Using magnesium chloride is a better choice because “…it is less corrosive and works better than other chemicals. It reduces environmental impact, bridge corrosion and vehicle damage” (“Magnesium Chloride,” 2014). A third alternative that is used somewhat, but not widely, is CMA, or calcium magnesium acetate. This chemical is effectively used on Zilwaukee Bridge in the state of Michigan since it was built in 1988. The bridge was selected for this because it is near a river, so addition of regular sodium chloride would be harmful to the environment (“Emerging Technologies” 2006, p.3). The Michigan State Government also states that, “Because it is biodegradable and exhibits poor mobility in soils, it is less likely than road salt to reach groundwater” (“Current Deicing…”, n.d., p. 16). Another great thing about CMA is the ability to reduce the amount of destruction to vehicles, bridges, and roads, due to its lack of corrosive materials (“Current Deicing…”, n.d., p. 16). It’s set at a high price,the costs would equal out because there will be less money spent on fixing corroded bridges. It costs a lot less to spend the extra money on CMA in a few areas than it does to replace an entire bridge when it is too corroded. An option for using CMA would be to only use it in areas that will be greatly impacted, such as roads right next to bodies of water or wildlife protected areas.
Some may be skeptical of alternative methods to de icing roads. One argument against these alternatives may be that road salt is the most effective method and other methods do not work to de ice roads as well. That statement is simply not true, rock salts are only effective up to -9°C(16°F) and after this temperature point they only melt 10% of the snow and ice (Ramakrishna,D.M. & Viraraghavan,T .p. 50). Think about it, 16°F is not very cold for a snowy January night in New England. “At 30 degrees, one pound of salt will melt 46.3 pounds of ice, but at 0 degrees, the same pound of salt will melt just 3.7 pounds of ice” (“Snow..” (n.d.), p.1). One eco-friendly solution for deicing is the sugar beet juice method. Mixing sugar beet juice with small amounts of salt brine helps to melt the ice at much lower temperatures. The Missouri Department of Transportation uses this method, and states that this beet juice and salt brine mixture will work to de ice roads at temperatures approaching 0°F, which is clearly better than the 16°F that sodium chloride alone achieves (“Snow..”,p.1).Another rebuttal may be about the costs of alternative methods. Particularly for sugar beet juice, it is not an additional cost. We manufacture sugar beet juice as a by product when making table salt (“Snow..”,p.1). According to Ali (2014) writing for the United States Department of Agriculture, sugar beet juice costs on average $34.20 per ton (p.1). Cranson (2014) for the Michigan Department of Transportation states that road salt currently costs $65.81 per ton. So it is clear that sugar beet juice is much less expensive to purchase than road salt, but most are unaware of this alternative. States only have a limited budget for winter deicing and adding sugar beet juice and other alternatives in with road salt may stretch that budget much farther. The goal with de icing of roads is for general safety of drivers. Replacing some of the road salt with sugar beet juice allows for more roads to be cleared of ice, and more ice to be cleared off of those roads, lasting up to much lower temperatures. The taxpayer is getting more for their dollar, and the negative environmental effects are mitigated by using less salt.
So Why Should You Care?
Road salt when released into the environment surrounding the roadways causes damaging effects. Wildlife in the area are exposed to road salt and the chemicals that are in them, this can be life threatening and sickening to many different species. That road salt and chemicals get into the groundwater and is very expensive and hard to remove; humans ultimately ingest this groundwater when it comes above ground once again and so do wildlife. Overall, there are better ways to go about removing snow and ice from the roadways. Some presented methods like sugar beet juice, Calcium Magnesium Acetate, and Magnesium Chloride are more environmentally friendly and should be more widely used. Putting some research into implementing more efficient ways to go about using salt is a very important next step in reducing these negative environmental effects. RWIS technology should be more widely used along with other methods like salting before a storm and using the proper decier for specific weather conditions.Overall road salt is terrible for the environment and different options are available so less of it can be used.
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Corsi, S. R., Graczyk, D. J., Geis, S. W., Booth, N. L., & Richards, K. D. (2010). A Fresh Look at Road Salt: Aquatic Toxicity and Water-Quality Impacts on Local, Regional, and National Scales.Environmental Science & Technology, 44(19), 7376–7382. doi:10.1021/es101333u.
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Howlett, D. (24 December 2003). States try new ant-icing methods. USA Today. p.03a. Retrieved from: http://web.a.ebscohost.com/ehost/detail/detail? vid=7&sid=3ccc063a-9fe6-41cb-814f-2683830d68ae %40sessionmgr4001&hid=4104&bdata=JnNpdGU9ZWhvc3QtbGl2ZSZzY29wZT1zaXRl#db=a ph&AN=J0E054847130403
Mahrosh, U., Kleiven, M., Meland, S., Rosseland, B. O., Salbu, B., & Teien, H. (2014). Toxicity of road deicing salt (NaCl) and copper (cu) to fertilization and early developmental stages of atlantic salmon (salmo salar). Journal of Hazardous Materials, 280(0), 331-339.doi:10.1016/j.jhazmat.2014.07.076
Pfeiffer, T. (2013, July 31). What Everybody Ought to Know Before Purchasing a Snowplow. The Snowplow Blogger, 1. Retrieved from http://info.bossplow.com/Blog/bid/150788/What-Everybody-Ought-To-Know-Before-Purchasing-a-Snowplow
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Russell, E. (2015, February 12). With snow piling up, is it time to hit the roof? Portland Press Herald. http://www.pressherald.com/2015/02/12/time-to-hit-the-roof-shovel-or-rake-in-hand/
Snow, Ice, Freezing Rain…MoDot has it Covered!.(n.d). Missouri Department of Transportation. Retrieved from: http://www.modot.org/KansasCity/winter_driving/sugarbeets.htm