Главная > Реферат >Остальные работы
Landfills Infrastructure Essay, Research Paper
THE LANDFILLS INFRASTRUCTURE
What is the largest construction you can think of? Does a landfill come to your mind? Probably not. One of the largest buildings on the face of the earth is the Pyramid of the sun, constructed in Mexico and covers approximately thirty million cubic feet of space. Now if you think that is big just imagine an even larger structure: a landfill that occupies over seventy million cubic feet of biosphere, we are talking about the Durham Road landfill, outside San Francisco. It is a sad monument, indeed, to the excesses of modern society [Gore 151].
One might assume such a monstrous mound of garbage is the largest thing ever produced by human hands. Unhappily, this is not the case. The Fresh Kills Landfill, located on Staten Island, is the largest landfill in the world. It sports an elevation of 155 feet, an estimated mass of 100 million tons, and a volume of 2.9 billion cubic feet. In total acreage, it is equal to 16,000 baseball diamonds [Miller 526]. By the year 2005, when the landfill is projected to close, its elevation will reach 505 feet above sea level, making it the highest point along the Eastern Seaboard, Florida to Maine. At that height, the mound will constitute a hazard to air traffic at Newark airport [Rathje 3-4].
A modern state-of-the-art sanitary landfill is a graveyard for garbage, where deposited wastes are compacted, spread in thin layers, and covered daily with clay or synthetic foam. In a landfill there are four major sections: The bottom liner (layers of clay or synthetic flexible membrane), a leachate collections system (collection of badly contaminated water from landfills), a cover (it is an “umbrella” that covers the landfill preventing water to get inside), and the natural hydrogeologic system (the actual terrain surrounding the landfill). The modern landfill is covered with impermeable layers of clay, sand, and plastic before any garbage is put into it. This liner prevents liquids, called leachates, from going into the groundwater. Leachates result from rainwater mixing with fluids in the garbage, making a highly toxic “juice” containing inks, heavy metals, and other poisonous compounds. Ideally, leachates are pumped up from collection points along the bottom of the landfill and they are sent to liquid waste disposal points or put back into the upper layers of garbage, to resume the cycle. The aim is to avoid any hydraulic (water-related) connection between the wastes and the surrounding environment, particularly groundwater [The basic of landfills]. Unfortunately, most landfills have no such pumping system [Miller 527]. Until the formation of the Environmental Protection Agency by Nixon in 1970, there were almost no regulations on the construction, operation, and closure of landfills. As a result, 85 percent of all landfills existing in this country are unlined (covered with impermeable layer). Many are located in close proximity to aquifers or other groundwater features, or near geologically unstable sites. Many older landfills are leaching toxins into our water supply at this very moment, with no way to stop them. For example, the Fresh Kills landfill leaks an estimated one million gallons of toxic ooze into the surrounding water table every day [Miller 527].
Pros and Cons
Sanitary landfills do offer certain advantages. The daily cover of clay or other material dramatically reduces offensive odors, the mainstay of the old city dump. Vermin and insects, both of the terrestrial and airborne varieties, are denied a free meal and the opportunity to spread disease, by the daily clay layer. Furthermore, modern landfills are less of an eyesore than their counterparts of yore.
Nevertheless there are more disadvantages in this system, although we have to take into consideration that without this structures, god knows where would all this garbage be floating. The daily compacting and covering of the garbage deposits effectively squeezes the available oxygen out of the material. Whatever aerobic bacteria are present in the garbage can not survive for very long and so decomposition stops. Anaerobic bacteria, by their very nature, are not present in appreciable numbers in our biosphere. What few manage to enter and survive in the garbage deposits are slow-acting and perform little in the way of breaking down the materials. In other words, rather than the giant compost heap most people imagine, a landfill is actually a huge mummification center. Hot dogs and bananas, decades old; have been recovered from landfills, still recognizable in their mummified splendor [Rathje 111-12]. What little decomposition does occur in landfills generates vast amounts of methane gas, one of the significant greenhouse effect gasses. Landfill gas consists of naturally-occurring methane and carbon dioxide, which form inside the landfill as the waste decomposes. As the gases form, the pressure builds up inside a landfill, forcing the gases to move. Some of the gases escape through the surrounding soil or simply move upward into the atmosphere, where they drift away. [Landfills are Hazardous to Humans]
In today’s landfills, decomposition is negligible. Most of the actual short-term rotting is from scraps of prepared food. Plastics do not biodegrade at all. Biodegradable plastic is an oxymoron at best; the most unstable plastic requires intense sunlight to decompose, and sunlight is denied in a sanitary landfill. Newspapers from before World War Two are still readable; they have, in fact, they are used to relate how long has the garbage been seated there. It is also noticed that the left over of a product and the actual product creates the same hazard when they become garbage and end up in a landfill.
If burning garbage and dumping garbage at sea are unacceptable, what are the alternatives? Of the landfills, sanitary and otherwise, open for business in 1979, 85 percent are now closed [Miller 527]. Where is all the garbage going? Some municipalities are shipping garbage to other cities, or even other states, a costly proposition. Larger metropolitan agencies have even taken to shipping garbage to third world countries, which cannot depreciate the so valuable dollar, because of their economic problems. This, of course, only transfers the problem from one population to the other, making a hole to fill up another.
Recycling really is making a difference. Newspapers now represent almost no problem. They used to make up 25 to 40 percent of the garbage volume of a typical city and now they are being disposed in the right way. Aluminum can recycling has become a profitable business. Construction waste is now barred from landfills in most locales; this high volume material is now recycled or put to Earth-friendly uses, such as making barrier reefs. Recycling has been very useful especially that man is constantly consuming, burning up, wearing out, replacing and disposing at alarming rate. We have to take care of what we consume since even though recycling is helping our environment it has been proof that is expensive and government usually have to step in and help. Plans for the safe incineration of refuse to generate electric power have presented some highly contentious issues. It would also help us to know what may happen in the future when t a new landfill is being projected. These questions can lead to a better understanding of the future outcomes of a projected landfill:
o How big will the landfill be in acres?
o What is the depth of the landfill in feet, and what will be the height of the highest point of the cap after the landfill is closed?
o How much of the acreage will be filled with garbage?
o How much of the acreage will be used for the buffer zone?
o How much of the acreage will be unused?
o What is the maximum tons per day they will accept?
o Does the contract have a minimum tons per day quota (often called put or pay clauses)? If it does who is responsible for finding the additional tonnage or the money in lieu of the tonnage?
o What type of garbage will it be filled with:
municipal solid waste
low level radioactive waste
below regulatory concern (brc) waste
special waste (often incinerator ash)
industrial solid waste
o Will they be putting recyclables in the landfill (glass, aluminum, tin, paper, etc.)?
o Will they be putting clean organic compostables in the landfill (for example, yard wastes)?
o If they are putting recyclables and organic compostables in the landfill will they be putting them in separate cells?
o In tons per day, how much of the garbage will come from your town, county, state, out-of-state?
o How many years will the landfill be in operation?
o Will it be lined and capped? If so what will these be made of?
o How long will the operators be responsible for it once it is closed, often referred to as the post-closure period?
o Who will be responsible for it once the post-closure period is over?
[The basic of landfill]
We will probably have to deal with the same problem for some more time because clear-cut answer is probably non-existent. Several effective programs, and everyone having the right information about our environment, probably will lead us to success.
Gore Senator Al. Earth in the Balance. New York: Houghton, 1992.
Miller, G. Tyler, Jr. Living in the Environment. Belmont CA: Wadsworth, 1998.
Landfills are hazardous to humans. http://www.filpside.org/vol12/week4/se98w406.htm
Rathje, William and Cullen Murphy. Rubbish!. New York: Harper, 1996.
The Basics of Landfills. http://www.enviroweb.org/enviroissues/landfills
- Kobe Earthquake Essay, Research Paper The January 17, 1995 Kobe Earthquake ... in significant losses to the local economy. Other Infrastructure The electrical and telecommunications ... , much of the industry is concentrated near the port on landfill or very ...
- Three Georges Dam Essay, Research Paper The United States, China and the Three Gorges Dam ... by encouraging more ecologically sound infrastructure projects in developing countries. ... instruments, process controls, sanitary landfill liners, and inexpensive but ...
- Canadian Water Conservation Essay, Research Paper The importance of protecting our water ... , or indirectly from the leaching of chemicals from landfills, or pollution from ... that can be used for infrastructure renewal and replacement and protection ...
- Composting And The Grocery Industry Essay, Research Paper The following bulletin was prepared ... and retailers, and the development of the supporting infrastructure. Composting can handle ... in order to reduce the landfilling of grocery industry wastes. ...
- Privitization Of Airports Essay, Research Paper Privatization of Airports By: Maiea E- ... –commercial aviation–and represent essential infrastructure with a near monopoly. Qualified private ... of soil to cap landfills on a site. The city of Austin needed ...