The Environmental Research and Education Foundation (EREF), in conjunction with Ecobalance and researchers from the University of Wisconsin and North Carolina State, is nearing completion of a comprehensive 2-year project on the life-cycle inventory (LCI) of a modern municipal solid waste (MSW) landfill. Data for the model came from both primary (over 100 landfills world-wide) and secondary data sources. Partners in the project included waste management companies from North America and Europe (including Waste Management Inc., SITA and CREED). In addition to the landfill LCI model, the project also includes the development of a software tool. The final report will provide a sound basis for assessing, on a life-cycle basis, the emissions and resource consumption associated with a modern MSW landfill. The model and report can be used to assess the importance of: (1) the various stages in the life-cycle system; (2) the time horizon selected; and (3) the air and water management techniques selected.