Landfill leachate is a liquid that forms when rainwater or other liquids percolate through waste materials in a landfill. This process can dissolve various substances, resulting in a mixture that may contain harmful chemicals, heavy metals, and organic compounds. The composition of leachate can vary depending on the type of waste and the age of the landfill. Proper management of landfill leachate is crucial to prevent environmental contamination. Treatment methods include physical, chemical, and biological processes to remove pollutants before the leachate is released into the environment. Effective management helps protect groundwater and surface water from potential harm.