On the surface, snow removal sounds like a pretty simple process. You get yourself some snow. Then you remove it. For smaller areas, such as sidewalks and driveways, it is often a relatively easy process; one that can be handled with a sturdy shovel, a couple scoops of elbow grease, and the occasional well-placed swear word.
What about bigger jobs, though? What about parking lots? What about streets and roads? As it turns out, the ability to efficiently and safely remove significant amounts of snow from large and/or busy locations is often a matter of science.
Depending upon the timing and severity of an impending storm, it is possible to take action before it hits to make the snow removal faster and cleaner. You may already know that salt is common for helping to melt ice. While water freezes at 32 degrees, salt brine can stay liquid down to about 15 degrees, thereby helping to thwart some icing issues.
In an ideal world, we wouldn’t have to worry about temps below 15 degrees. Sadly, our world just doesn’t work that way. When the temps drop below 15 degrees, there is a surprisingly natural source that can help: beet juice, which actually acts as a anti-bonding agent.
That’s right. Beet juice from sugar beets, when combined with salt, can help keep ice from forming on roads even when the temps drop well below zero. Not bad for an all-natural product. It’s for this reason that, in some cases, snow removal crews may get out on the road before a storm to spray roads with the beet juice / salt brine mixture. When done at the right time, it can actually help to prevent snow from sticking to the roads, which make the eventual plowing faster and easier.
Speaking of faster plowing…
The Need for Speed
Whether it is in a parking lot or on the roads, it can be a little surprising to see plow trucks—some of them quite large—tearing through snow at speeds that might seem excessive.
In actuality, speed plays a key role in clearing lots and roads.
First, with snowy conditions, it can be difficult to maintain traction when the resistance of the snowing pushing back against the truck increases. By driving through the snow at an optimum speed, it increases the likelihood of not getting stuck in particularly difficult spots.
The next reason for that speed is simple physics. The more speed the plow has when it hits the snow, the greater the transfer of energy to the snow becomes. This results in snow that is thrown farther. This is especially important when plowing streets and roads, as it prevents narrowing that creates a tunnel-like effect as the season progresses.
A Swiss Mathematician, A Chinese Postman, and Algorithms
Actual driving speed is just one way to help ensure that everyone is getting the snow removed as quickly as possible. Another key factor is efficiency—more directly: How do we determine a snow removal route that requires the least amount of backtracking.
Interestingly enough, this type of problem is known as a route inspection problem and it falls squarely in the realm of mathematics known as “graph theory.”
An original example of this problem was posited by Swiss mathematician, Leonhard Euler in 1735. He was trying to devise a way to cross seven bridges in Konigsberg (now Kaliningrad in Russia) exactly once without backtracking. The catch, however, is that it only worked in areas where every intersection featured an even number of roads. Just one T-intersection and the whole thing falls apart.
In 1963, Chinese mathematician, Meigu Guan, brought out Euler’s problem with even and odd intersections. The challenge, as he put it forth, was to imagine a postman who had to deliver all the mail in a city, but needed to do so without doubling back.
Sounds a little like our road plowing issue, doesn’t it?
In 1973, American computer scientist, Jack Edmonds, intrigued by the problem, we able to develop a set of algorithms that were efficient enough to solve the problem of, what he endearingly referred to as,”The Chinese postman problem.”
In short, the solution lies in first discerning the most efficient routs among intersections that have an odd number of streets, because those are the ones that would force you to backtrack. Once you find the most efficient paths between those intersections, you can then combine those routes with the even intersections to create the most efficient overall routes to cover as much ground as possible in the least amount of time.
Of course, this doesn’t account for things like driver hours, truck deployment locations, and some other human elements, but it’s a foundation on which those factors can be figured.
Are Pooping Robots the Future?
So there you have it. From beet juice to Chinese postmen, the science behind snow removal gives you something to think about next time you’re wondering if you’ll be able to get around following a storm. While all of this is interesting to contemplate, it still won’t be as fun as a Japanese robot that eats snow and poops snow bricks. But we work with what we have.
Finally, if you find yourself in need of commercial snow plowing services, give us a call E.P.M LawnScape and Supply a call at (517)-990-0110, today.
While the snowfall for the 2018-2019 season is still (hopefully) a little ways off, snow removal companies like us are in the process of ordering salt and other supplies so that we are ready to roll when the snow flies. And if you have not heard yet, we are facing a critical salt shortage for this upcoming winter. There are a variety of reasons for this, which we will break down. In any given year, each of these reasons, alone, will have an effect on the price of salt. All of them, in combination, is a perfect storm for the price of salt this season.
Trouble in the Mines
Each year, the average salt usage for a winter snow removal season in our region is about 10 million tons. Some years, less will be used. Some years, more will be used. Still, 10 million is a good baseline number. During the course of the last year, however, three main factors have lead to the shortage:
These last two points are projected to leave us several million tons short this winter.
Filling the Gap
While we are running short in our part of the world, there is plenty if salt in other parts of the world. To address the shortage, salt has to be imported from places like Egypt and Chile. While the price of imported salt may be similar to the price of domestic salt, the cost of transporting it to the Detroit docks raises the acquisition price of that salt to 2-3 times what domestic salt would cost.
The Pecking Order
Once the salt buying process begins, government offices get first dibs. This season many state and local governments are buying 10 to 20% more salt than last year, despite already being aware of a shortage. This is likely because their reserves were depleted last year and/or they are preparing for another long winter this season and don’t want to have to buy again later in the year when the prices will likely be even higher.
After government agencies get their bids in, it moves to large contractors and brokers. At this point, there is more scarcity than before, so the price goes up for the large contractors and brokers.
Finally, smaller contractors/landscapers get a chance to order. By now, you can see where this is going. More scarcity = even higher prices.
The End Result
The compounding effect of the scarcity increases price and necessitates that more salt be imported… and importing salt costs even more. So what do the prices actually look like? In the 2017-2018 season salt prices averaged $62 per ton. This season, the price is at $125 per ton—more than double. Municipalities should be safe, which means it shouldn’t have much effect on their budgets and, by extension, your taxes. It’s consumers, however, who will wind up footing the bill for whatever differences their snow removals contractors are unable to absorb.
To learn more about snow and ice removal, as well as how the current cost of salt could effect your organization, feel free to contact us online or give us a call at (517) 990-0110.
Dutch Elm Disease was first discovered in 1921 in the Netherlands by Dutch phytopathologists, Bea Schwarz and Christine Buisman. The name, therefore, refers to its identification origin. It’s not actually a disease confined only to the Dutch Elm Hybrid. While it was first noted in the U.S. in Ohio in 1930, by the 1980s, you could find it widely spread through most of the United States. This wilt disease is caused by the fungus Ceratocystis ulmi. While it poses a very real threat to American Elms everywhere, there is still no known cure despite decades of study on the disease.
How to Spot It
Unlike some other diseases that can take months—or even years—to fully manifest, symptoms of Dutch Elm Disease present rapidly over the course of 4-6 weeks following a tree’s leaves reaching full size. The initial symptom is called, “flagging.” When this happens, the leaves will start to yellow, then turn brown as they wilt. The flagging doesn’t effect the whole tree at once, however. It starts with one branch first. As the leaves from that branch drop, the disease spreads to nearby branches and then, eventually, the entire tree. The final result is that the tree wilts and dies. While the initial symptoms present quickly, the spread of the disease throughout the rest of the tree can take a whole season or, in some cases, a few years. That said, the only conclusive way to diagnose Dutch Elm Disease is through a lab test to confirm the fungal pathogen.
The Life Cycle
The Ceratocystis ulmi fungus depends upon insect-vectored transmission to cover long distances tree by tree. In North America, there are two insect vectors for this fungus: The European Elm Bark Beetle and the more common American Bark Beetle. These beetles get under the bark of living, or recently dead, elm trees and logs to feed and multiply. As they do this, they carry the spores from the fungus in infected trees to new, healthy trees. The life cycle of the insect vectors, then, dictates the cycle of infection by the fungus. Mature beetles can fly up to 1/4 mile when looking for new trees in which to feed or reproduce, but they can also be carried across further distances by wind. In addition to being spread by beetles, Dutch Elm Disease may also be spread from a diseased tree to a healthy one if the roots systems of the two trees overlap via a root graft.
1. There is no cure for Dutch Elm Disease. That said, the first step in caring for a tree is to look for the aforementioned flagging. If you see it, cut down a few small branches and check the sapwood for brown streaking. If that streaking is present, you should seek out a lab test to confirm whether it is actually Dutch Elm Disease. In some cases, other canker and wilt pathogens in elms can present similar symptoms. Knowing what disease you have is key in treatment strategy.
2. Keep the tree as healthy as possible. This means plenty of fertilizer and water, but be careful not to apply too much. In some (mild) cases, if there is less than 5% of the tree infected, the tree may respond to simply removing the diseased section(s) of the tree. Additionally, you need to control the insect vectors to limit spread. One proven option is to inject systemic fungicides every 1-3 years. If you consider this option, you should consult with a tree specialist (arborist) first to ensure the right amount of application for your situation.
3. Tree removal. Nobody likes to remove trees, but in some cases, it is necessary to preserve the health of neighboring trees. That said, the wood from the removed tree should not be stored for firewood. It needs to be chipped in order to completely destroy the beetle’s breeding grounds. Also, as mentioned, the disease may be spread through root grafts of neighboring trees, which may require the mechanical severing of those root grafts to help slow the spread if it can be done before the fungus spreads from an infected tree to a healthy one. That said, destruction of the root graft may not always be a pragmatic option in a home setting. Again, this is a time to consult with a tree specialist.
4. Replace the trees. The final, and perhaps most obvious option, is to replace the trees. If you like the look of elm trees, there are still some elms that are resistant to Dutch Elm Disease. One option, with a shape that is quite similar to the American Elm, is the Japanese Zelkova. Another option is the Chinese Elm (Ulmus parviflora), which is often noted for its multi-color bark. Remember, while both trees are resistant to Dutch Elm Disease, that does not mean they are immune to it.
More and more, homeowners are looking for organic options for a variety of different reasons. That said, options 1, 3, and 4 mentioned above are organic. Further, option 2, sans the fungicide, is also an organic option for combating Dutch Elm Disease.
At E.P.M LawnScape and Supply, we offer a host of professional tree and shrub care services. If you have concerns about your trees and/or landscaping, feel free to contact us online or call us at (517) 990-0110 today.