Saturday, February 25, 2017

Landfills


                For my first post, I will be discussing one of the most common forms of waste management in the world, the collection of trash in landfills. Ever since the 1800s, people in cities had the habit of disposing of trash by throwing it out their windows. Once medical knowledge advanced, the correlation between the presence of trash in the streets and the spread of deadly diseases. By the late 1800s, many cities gathered trash in horse drawn carriages and disposed of it in dumps or even in the sea. The first modern landfill was developed in 1935 and it consisted of a hole that trash was dumped in and periodically covered in dirt. Then, by 1959, the American Society of Civil Engineers set the standards for a sanitary landfill.

                Nowadays, there are strict regulations on the composition and location of landfills. Sanitary landfills must be lined with multiple layers of organic and inorganic substances. The top layer is just a layer of soil to serve as a base for the garbage, then a geotextile layer that filters out large pieces of trash, then some filtering gravel with a plastic layer that collects all water and hazardous materials. Finally, a layer of clay lines the bottom to collect any contaminated water that has seeped through the other layers. These layers of protection are very important to the prevention of hazardous materials leaching into ground water and polluting drinking water sources. Additionally, landfills cannot be placed in areas that could allow damage to occur, such as a wetland, a floodplain, or on a fault zone. Landfills are often not placed near neighborhoods or suburbs because many people do not want the smell or the possibility of groundwater contamination.

                Like any system, there are pros and cons to sanitary landfills. Landfills are one of the cheapest options for waste management because they do not require to transport of materials to places very far away. Additionally, they are one of the safest methods when taking worker safety into consideration. There is little to no risk of harm on workers in landfills like there is in other waste management situations like incinerators. Conversely, there are many problems with landfills. They take up lots of space and change the land cover of an area. There is also the potential of ground and surface water contamination if the linings in the landfill fail. One of the largest downfalls is that they produce a lot of methane gas into the atmosphere. When wastes breakdown, they produce methane which is flammable and can cause problems if ingested. Also, methane is a very potent greenhouse gas that contributes to global warming and ozone destruction.

Stay Sustainable,
     Shelby



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