Environmental Hazards Essay Example for Free

Environmental Hazards Essay If someone was to ask you, â€Å"What is an open dump? † What would you say? Would you know what to tell them? An open dump is abandoned piles of household garbage, bags of yard waste, appliances, old barrels, used tires, and demolition debris can threaten the health of wildlife, the environment, and humans. They can cause such health, environmental, and safety issues as fires or explosions, the inhalation of toxic gases, injuries to children playing in or around the dumpsites (I have personal experience of cutting my foot on broken glass as a child playing in an open dump), diseases carried by flies, rodents and mosquitos, and other hazards. Open Dumps, 1996 – 2011). Early Landfill Believe it or not, landfills go way back in history. Of course, back then they were called â€Å"garbage dumps. † For instance, early American settlers used to deal with their garbage by dumping it over the back fence, burying it in their back yards, or dumping it in rivers. They also would burn their garbage. (Amsel, 2005 – 2013). We can go even further back in history with this subject. Case in point: Did you know the cause of the bubonic plague (14th century) was too much garbage in the streets? Allow me to explain. The bubonic plague, also called, the â€Å"black death,† spread through Africa, Asia, nd Europe, killing 75 million people. What these people did not know at the time was they had too much garbage in their streets. There was so much it was in piles. These piles of garbage in turn attracted rats. The rats had fleas. The fleas carried the disease. With rats carrying the disease from place to place, the lack of sanitation made it the worst epidemic in human history. (Amsel, 2005 – 2013). Many of the early landfills were made in wetlands. These wetlands were thought to be wasteland at that time. These landfills leaked into lakes and rivers and built up gases, such as methane. As garbage rots, it gives off a flammable gas, called methane. Because of this many garbage dumps would catch fire or explode! The first garbage burning plant was built in 1885 in New York on Governor’s Island. It was called an â€Å"incinerator. † There were 300 incinerators burning garbage in the U. S. by 1914. (Amsel, 2005 – 2013). Leachate – The most serious problem with landfills is groundwater contamination. As water percolates through the ground (like water does in a coffeemaker), chemicals can be released in the ground and get carried along in a process called leaching. The resulting water with the various pollutants is called leachate. As the water percolates through Municipal Solid Waste (MSW), a noxious leachate is generated that consists of residues various decomposing organic matter mixed with various metals from rusting items in the landfills. This can funnel directly into the groundwater without correct precautionary measures. (Wright, 2011). Methane – Municipal Solid Waste is about 2/3 organic material. Because of this, it is subject to natural decomposition. Buried wastes are anaerobic, meaning they decompose without oxygen. A major by-product of this process produces a combination of about 2/3 methane and 1/3 hydrogen and carbon dioxide, called biogas. This is a highly flammable mixture. This has caused homes to explode at up to 1000 feet away and has caused some deaths. Also, gases seeping up to the surface have killed vegetation by poisoning their roots. (Wright, 2011). Incomplete Decomposition – Commonly used plastics resist natural decomposition because of their molecular structure. Microbes are unable to digest them because they are polymers of petroleum-based compounds. There have been biodegradable plastic polymers developed from other sources, such as cornstarch, lactic acid, cellulose, and soybean protein, as well as petroleum. Wright, 2011). Settling – Finally, as waste compacts and decomposes, it settles. This problem was recognized from the beginning and there have been no buildings built on landfills. Settling creates shallow depressions that collect and hold water. These can also be deep holes. This can be addressed by continuous monitoring and filling to restore it to a level surface. (Wright, 2011). Modern Landfill Modern landfills are designed to address the previous mentioned issues. The EPA (Environmental Protection Agency) has upgraded requirements for landfill siting. New landfills are to be sited well above the water table on high ground. The floor is contoured so water drains into a tile leachate collection system. The sides and floor are covered with a plastic liner and at least two feet of compacted soil. This allows any percolating leachate to drain into the leachate collection system and be treated as necessary. Layers of refuse are positioned so the fill is built up in the shape of a pyramid. It is then with at least 18 inches of earthen material and then seeded. This cap and the pyramid shape help the landfill in shedding water. The entire landfill site is surrounded by groundwater monitoring wells and periodically checked. This checking must go on indefinitely. (Wright, 2011). Mariannhill Landfill, South Africa I chose the Mariannhill Landfill, South Africa for innovative practices in making it more productive and reducing its environmental impact. In reading the description of this landfill, it seemed more like a recreation area and less like a landfill. I could tell a lot of thought and planning went into this. This landfill contains several â€Å"cells† to hold waste. Soil from the landfill area is removed and put in storage. The resulting hole is the cell. Once the cell is full the soil is replaced. Vegetation is also removed and placed in a large holding nursery on the site. This is called Plant Rescue Unit or PRUNIT. There is a barrier system in each cell to prevent harmful waste by-products from seeping into the environment. Leachate is treated on site. This is done by a biological primary treatment with sludge followed by a â€Å"polishing treatment† by a reed bed. The Mariannhill site treats landfill water to reduce leachate until the water is reusable. Mariannhill has also set up a landfill gas extraction scheme. It has been operational for four years as of 2008. It also has a bird hide and conservation area with nature trails that link up with existing green space in the metro. (Mariannhill Landfill Conservancy, 2008). This has been a truly eye-opening assignment. Little did I realize as a child that some of the areas I was playing in were so dangerous. I’m not sure if my parents knew, but they always told me to stay away from places like that. I am so thankful these places (older landfills and â€Å"dumps†) are practically figments of the imagination now. We need to take better care of our planet! Let’s all chip in!