What are the two main byproducts landfills?

The two main byproducts of landfills are methane gas and leachate. Methane is a potent greenhouse gas produced during the anaerobic decomposition of organic waste. Leachate is a liquid that forms when rainwater filters through waste materials, potentially containing harmful contaminants that can seep into the groundwater. Both byproducts pose environmental challenges that require careful management.