Landfill

The term "sanitary landfill" was first used in the 1930s to refer to the compacting of solid waste materials. Initially adopted by New York City and Fresno, California, the sanitary landfill used heavy earth-moving equipment to compress waste materials and then cover them with soil. The practice of covering solid waste was evident in Greek civilization over 2,000 years ago, but the Greeks did it without compacting.

Today, the sanitary landfill is the major method of disposing waste materials in North America and other developed countries, even though considerable efforts are being made to find alternative methods, such as recycling, incineration, and composting. Among the reasons that landfills remain a popular alternative are their simplicity and versatility. For example, they are not sensitive to the shape, size, or weight of a particular waste material. Since they are constructed of soil, they are rarely affected by the chemical composition of a particular waste component or by any collective incompatibility of co-mingled wastes. By comparison, composting and incineration require uniformity in the form and chemical properties of the waste for efficient operation. About 67% of the solid waste generated in the United States is still dumped in landfills. This corresponds to several tons of waste per landfill daily, considering 4.5 lb (2 kg) of solid waste is generated each day per person in this country. Americans will have created approximately 220 million tons of solid waste in the year 2000. The many tons of solid waste dumped in a landfill today will not decompose until 30 years from now. In order to create environmentally friendly landfills, new sites are being engineered to recover the methane gas that is generated during decomposition, and some older landfills are being mined for useful products.

About 70% of materials that are routinely disposed of in landfills could be recycled instead. More than 30% of bulk municipal garbage collections consist of paper that could be remanufactured into other paper products. Other materials like plastic, metal, and glass can also be reused in manufacturing, which can greatly reduce the amount of waste materials disposed in landfills, as well as preserving sources of nonrenewable raw materials.