| The current goal in solid waste engineering is to create a system that is sustainable, meaning that it must satisfy sustainability requirements both financially and environmentally for both the present day and many generations to come. In an effort to provide economically and environmentally informed choices for the solid waste industry to push further toward the goal of sustainability, a detailed assessment of different types of solid waste treatment/disposal methods is presented. The array of solid waste treatment methods ranges from a relatively inactive large encapsulated fill with virtually no resource recovery to various material conversion processes resulting in valuable end products and many times more site life for a given landfill footprint. In order to evaluate the various treatment methods, three options were quantified; (1) the conventional "dry tomb" landfill, (2) the bioreactor landfill, and (3) a smaller landfill with a materials recovery facility (MRF) and an anaerobic digester coupled with composting operations. Models were created for each option in order to evaluate the economics and environmental impacts of each. The models take into account the site life, the generation of methane gas for the production of energy, fugitive greenhouse gas emissions, construction and maintenance costs, post-closure costs, and beneficial end products. The models allow these three alternatives to be evaluated for their environmental impact and their levelized cost expressed in present (2010) U.S. dollars per ton of waste. An overview of each technology is presented with a detailed cost summary throughout the life of each option applied to a landfill of average footprint size in the Western United States. The technical and regulatory challenges of each option are discussed and potential solutions to these challenges presented. |
