Economic and financial evaluation of waste water management systems of domestic origin in housing projects

Abstract

The purpose of this study is to evaluate the economic and financial viability of domestic wastewater management systems in housing developments of social interest. These are two compartmentalized anaerobic / aerobic / anoxic vertical systems for removal of carbon and nitrogen. The economic-financial analysis of the pilot project of the compartmentalized systems was composed by Cost Present Value, Equivalent Annual Uniform Cost, Breakeven Box Inputs, Sensitivity Analysis and Monte Carlo Simulation. The result of the traditional analysis considered the best result the assumptions "With Reuse and Without Initial Investment". According to Breakeven cash inflows, the higher the cost of capital, the greater the cash inflow required to make the project viable. For the Sensitivity Analysis, the cost of the project to Present Value decreases as the cost of capital increases, thus reducing non-viability. In the Equivalent Uniform Annual Cost, in the assumptions "without initial investment" and "with initial investment" the higher the cost of capital, the lower and higher the CAUE, respectively. In the Monte Carlo Simulations performed, the analyzes based on the interpretation of traditional indicators were extremely optimistic, but they do not represent reality, so that the probability of occurrence is less than 1%.