Approximate cost functions for solid waste treatment facilities.

Cost estimation is a basic requirement for planning municipal solid waste management systems. The variety of organizational, financial and management schemes and the continuously developing technological advancements render the economic analysis a complex task, made more complex by the scarcity of real cost data. The objectives of this paper were: (1) to explore the problems arising in getting cost estimates from scattered and limited published data; (2) to suggest a procedure for generating cost functions relating initial set-up cost and operating cost with facility size; and (3) to present such cost functions, relevant to European states, for selected types of solid waste treatment and disposal facilities. Regarding the problems of available scarce data, one needs to deal with cost figures which correspond to facilities with variations in size, technology, year of construction, working conditions, level of technological automation, environmental impacts, social acceptance, capacity utilization rate, composition of inflowing waste, waste management policies, degree of compliance with quality standards, etc. The paper addresses this issue and discusses the proper use of statistical analyses in such cases of fragmented data; moreover, it points out some usual misuses of statistics by analysts and the danger of getting erroneous results. The suggested process for generating cost functions acceptable to the decision-makers is pivoted around the question of acceptable approximation level. Finally, approximate cost curves are suggested for waste-to-energy facilities, landfilling facilities, anaerobic digestion facilities and composting facilities.