Landfills are one of two ways to bury trash. A landfill is a carefully designed isolated structure built on top of or into the ground where municipal trash can be dumped.

The danger in using landfills is that leachate (the water from rain, snow, dew, and natural precipitation that passes through the layers of trash) can leak into local water supplies. Methane gas can build up and cause fires or explosions, however, new technology can be used to trap the released methane gas and use it for energy.

To learn more, go to:

http://science.howstuffworks.com/landfill3.htm

http://ohioline.osu.edu/cd-fact/0111.html