One of several ways to process garbage we create everyday, a landfill, or sanitary landfill, is where garbage is dumped underground, compacted by bulldozers. It is covered with clay (when full), and soil is placed over the clay. Please observe below:

As you can see, the layers of a landfill are protected by protective liner, that protects the surrounding soil and environment from being contaminated by the garbage. The compacted garbage (between soil cover) will biodegrade naturally. The leachate pump's function is to contain leachate (mixture of rainwater and garbage liquids) that will be pumped out and streamed to sewage treatment plant for processing of their own.

It's said that this way of disposal is the cheapest. And the top of the landfill can be planted with trees and plants, too, creating greenery. However to build a really safe landfill needs excellent technical design (to prevent surrounding contamination), good funding (to ensure quality) and good location. Location of a landfill should not be in area where natural instabilities are common, and not too far from urban or community area. Other name for landfill is closed dumping, or buried dumping, as an alternative to the open dumping that risks many hazards.

One main problem of landfill is the rapid filling of landfill as many people like us contribute much and much more disposals everyday. This makes the authorities push some efforts to find another areas for another landfill as fast as possible.