What is the purpose of using a vacuum system in landfill gas (LFG) collection?

The purpose of using a vacuum system in landfill gas (LFG) collection is to create a negative pressure gradient within the landfill, which enhances the extraction of LFG from the waste mass and prevents its uncontrolled migration. Landfill gas is produced by the anaerobic decomposition of organic waste and consists primarily of methane and carbon dioxide. Without a vacuum system, LFG will migrate through the landfill along paths of least resistance, potentially escaping into the atmosphere, causing odors, posing explosion hazards, and contributing to greenhouse gas emissions. By applying a vacuum to the LFG collection wells, a pressure differential is created, drawing the gas towards the wells and into the collection system. This active extraction method is more efficient than relying on passive gas migration and ensures a higher percentage of LFG is captured, which can then be used for energy production or safely flared. For example, a vacuum system ensures that LFG is drawn from the entire waste mass, even areas with lower gas permeability.