The purpose of this module is for you to learn about leachate generation from a municipal solid waste landfill. You will study leachate quantity and quality and the factors that influence leachate. You will have a practical understanding of leachate treatment.

Municipal solid waste leachate is a complex and highly concentrated wastewater. The characteristics of leachate vary over time as the waste degrades; quantity of leachate is impacted by climatic condition changes over the year. Leachate is captured by a leachate collection system required for modern landfills. Early in the life of a landfill, leachate tends to be high in biodegradable organic material. Over time, the concentration of ammonia, chloride and recalcitrant organics increases, however when low permeability or impermeable covers are placed on the landfill, leachate volume declines. Thus, the mass of contaminants declines. These variabilities create significant challenges in treating the leachate. Frequently, the leachate is co-treated with domestic wastewater. When treated on-site, generally a combination of chemical, physical, and biological treatment processes is required.

By completing this leachate generation and treatment module, students will be able to:

1. Discuss landfill water balance
2. Understand challenges of leachate treatment
3. Present liner and leachate collection system (LCS) design information
4. Describe landfill covers and their design and performance