The objective of the paper is to present sustainability indicators for municipal solid waste management (MSWM). Sustainability implies environmental, economic and social acceptance. The complexity of the system-in-focus requires the employment of a systems (or cybernetic) approach: Acceptance implies clear objectives, from a specific point of view (here, the viewpoint of the municipal administration is taken), over a time horizon covering at least two generations, a life-cycle consideration, clear evaluation criteria for alternative MSWM systems, and finally specific and measurable indicators of the degree to which the objectives have been met. A software package is presented for computing sustainability indicators; given a city of specific size and socio-economic and waste generating characteristics, the model computes indicators for existing MSWM systems or for alternative system scenarios. Each scenario, consists of three basic waste management sub-systems: (1) Temporary Storage, (2) Collection & Transport and (3) Treatment, Recycling and Disposal. A number of specific environmental indicators (abiotic depletion, global warming, human toxicity, acidification, eutrophication, etc.), economic indicators (cost per ton or per household, revenue from recovered material and energy, MSWM system cost as % of GNP of the city, cost per capita as % of minimum wage, subsidies per person, etc.) and social indicators (odour, visual impact, convenience, required or used-up space, noise, system complexity, etc.) indicators are suggested for measuring the performance of MSWM systems. The assessment model is used to analyze a real case (city of Xanthi, Greece) with the following specifications: a) Population: 45000 inhabitants, b) waste generation: 338 Kg/cap/year, c) MSW process options: collection, including mixed waste collection and source separation of bio-waste and/or mixed dry recyclables (paper, glass, metals, plastics), incineration with energy recovery, anaerobic digestion of bio-waste, mixed dry recyclables sorting and landfilling. Some of the major results are: The MSWM system, that includes anaerobic digestion of bio-waste and sorting of mixed dry recyclables, causes the higher environmental relief. The minimum and maximum total annual cost correspond, respectively, to landfilling and incineration of mixed MSW. The cost of temporary storage, collection and transport corresponds to 25-68% of the total MSWM system cost, depending on separation-at-source arrangements and treatment processes.
