O custo de oportunidade do aterro sanitário de Ituiutaba, MG: componentes e repercussão econômica em longo prazo

Abstract

Solid waste has been highlighted in the face of increased generation, the consequences of improper disposal and conflicts over the space for disposal. The conventional evaluation of disposal costs in landfills has shown a constant increase of these expenses, besides being based on the linear model of the economy, of the extraction of the raw material at disposal. In contrast, alternatives with technological and economic feasibility, based on the circular model of the economy, promote change in the evaluation of costs, involving economic, environmental and social aspects. The objective of this study was to evaluate the cost of opportunity of the landfill, in comparison to the investment alternative in the selective collection of solid urban waste (SUW), by means of a case study in the municipality of Ituiutaba, MG, Brazil. The study uses combinations of qualitative and quantitative research methods for costing, estimating the disposal losses and the benefits generated by the use of recyclable, dry and biodegradable waste for selective collection. The data were collected from 2007 to 2016, with the projection of another five years referring to the life cycle of the landfill. The study uses the integrated approach between geography, environmental / circular economics and integrated solid waste management, promoting a broader view of complexity, broadening the analysis of the parts and understanding the whole, with the interactions and interdependencies being evidenced. The results point out political / legal, cultural, social, ecological, technological and economic aspects that are part of the diagnosis and possible solutions, with suggestions presented in the text. The recyclable wastes accounted for 80% by mass and volume of MSW for the landfill. The estimated cost of opportunity is a loss of 146 million reais for the 15 years of analysis, with the investment in landfill of recyclables, showing that it is necessary to change the way of calculating costs. The selective collection proved to be more advantageous than the disposition process in the landfill, providing a financial return of R$1.11 for each R$1.00 spent by the municipality in the period from 2011 to 2016. In addition, the selective collection commercialized 7,756.5 T of waste, generating a revenue of R$3,366,685.55 and volume savings in the landfill estimated at 33,442.8 m³, corresponding to 8.71% of its capacity (384,000 m³), representing a useful life gain. The selective collection recovers less than 4% of dry recyclables with a potential of 30.0%, and in these conditions each year of the selective collection it gains almost 1.0% of volume in the landfill. The waste marketed by the selective collection represented savings of R$1,213,820.33 with the collection service and the operation of the landfill. The dry recyclable waste destined for the landfill represents a loss of R$28,328,223.92. The loss with biodegradable was estimated at R$26,382,102.84. These are resources that, instead of returning to the economy, benefiting society, are being buried. The investment in the alternative to the landfill represents a reduction in the creation of environmental liabilities, reduction of negative environmental and social externalities, besides providing the collection of taxes and social security contributions.