A landfill is a site for the disposal of waste materials by burial and is a traditional form of waste treatment. Landfilling is common around the globe. There are two basic landfill operations for handling waste disposal: dry tomb and bioreactor. A “dry tomb” sanitary landfill involves burying waste and attempting to maintain dry conditions in order to minimize biodegradation, as well as leachate and biogas production. This landfill design is commonly used in developed nations. In a bioreactor landfill, controlled quantities of liquid are added and circulated throughout waste in order to accelerate the natural biodegradation of buried waste. Bioreactor landfills are present at several test locations and may replace current landfill designs. 

Read more – http://www.epa.gov/landfill/