Rainwater falls onto the landfill. The water trickles through the garbage. Many substances in the garbage (some of them hazardous) are dissolved into the water. The liquid that is produced is called leachate. Leachate can contaminate our drinking water. The people who design the landfill must be careful to follow rules to protect our drinking water.

• The pit must be dug away from rivers or streams.
• The pit cannot be dug close to any ground water.
• The pit must have clay along the sides and the bottom, or else it must have a special liner so that the leachate cannot escape out of the garbage and into the water system.
• Wells are dug all around the pit area. These wells will collect water. The water is checked frequently for leachate leaks.