Life-Cycle Modeling of Municipal Solid Waste Landfills

Landfills that receive municipal solid waste represent a critical component of solid waste infrastructure in the U.S. and are a leading source of greenhouse gas emissions. Thus, it is critical to understand the factors that control the environmental performance of landfills. Life-cycle modeling of landfills is complex, as landfills constantly change over time. The objective of this research was to develop a life-cycle model of an average ton of municipal solid waste disposed in a “national average” landfill. The framework considers critical factors relating to the temporal changes in landfill gas generation, collection, beneficial use, and oxidation. The model calculates temporally averaged landfill gas collection efficiencies for individual waste components in consideration of the aforementioned factors. The results indicate that for mixed waste, 12 to 41% of the generated methane becomes fugitive emissions. The results also show the significant potential benefits of earlier landfill gas collection.