Landfills And Their Effects On Humans And The Enviroment
Every year Americans collectively create approximately 208 million tons of municipal solid waste, which breaks down to 4.3 pounds of waste generated per American per day. In addition to this normal waste, the United States produces roughly 279 million tons of hazardous waste per year.1 All of this waste has to go somewhere. Two good methods of waste disposal, infrequently used, are incineration and recycling. However, any waste that is not recycled or incinerated ends up in America’s landfills. Landfills that are not in proper working order can pose a serious threat to humans and the environment, but ones that safely store all of their waste may possibly be helpful for the environment.
The landfills of today are nothing like the open dumps of the past, where anyone could dump any kind of materials they liked. Fortunately, open dumps have been banned in the United States due to the threat they pose to the environment. Because these dumps were open, hazardous waste was often stored there. Furthermore, precipitation would travel through the waste in the open dump and eventually end up in the groundwater, carrying any toxic materials that were in the dump. Today’s landfills are required to meet strict government standards regarding composition and structure of landfills.2 According to the Environmental Literacy Council, "modern landfills are constructed with a number of safeguards, and new federal standards active in 1993 require landfills to have liners, leachate collection facilities, and gas monitoring systems."3
The structure of a landfill involves four distinct layers. They are the natural environment of the landfill, the bottom liner, a leachate collection system, and a cover. All coincide to make up a landfill.4
Working from the bottom up, the natural setting of the landfill deals with the kind of rock that is underneath the landfill. The rock should be as nonporous as possible to stop waste from seeping into the groundwater, but one must be able to predict where the waste will go if it escapes through the liner of the landfill.5
The next layer is the bottom liner of the landfill, which can be made of one or more layers of natural or synthetic materials. The liner is the landfill's defense to keep the waste out of the environment. This liner can be made of clay, plastic, or a composite of plastic and clay soil. Natural liners, made of clays and shales, often crack and allow the waste to enter the environment. In addition, some chemicals can soak into the clay, thus causing additional harm to the environment.6 The Geomembranes, liners made of plastic, may seem like they are the best available today, but many household chemicals can break down the plastic, and it can be easily punctured.7 Thus, like natural liners, Geomembranes may also allow waste to enter the environment. Combinations of the different kinds of liners can be more effective than the use of a single...