Estudo de viabilidade econômica: implantação de sistema de aproveitamento de água da chuva na nova sede do Ministério Público do Espírito Santo

Abstract

Population growth has generated a series of issues related to the conservation and availability of water resources. Therefore, the adoption and use of sustainable practices for water supply are important to ensure its availability for present and future generations. The objective of this study was to evaluate a rainwater harvesting system in order to promote rational and sustainable water use in the new headquarters of the Federal Public Ministry in Espírito Santo. The building under study comprises 11 floors, where it is estimated that 570 people will work daily, resulting in high water costs, which encourages the implementation of this type of system. Project surveys were conducted, along with verification of the sizing of the collection network, considering local precipitation, as well as a physical and financial analysis of the implementation feasibility. Based on the data and results obtained, estimates were made for the volumes of rainwater that could be used. In addition, the demand for use in sanitary basins was determined, along with the installation and annual savings values. This allowed the calculation of the payback period, given that the annual savings will be R$7.878,32 and the implementation cost of the system is R$142,322.01, resulting in a payback time of 18,065 years, below the recommended minimum useful life of 20 years. Thus, the system proves to be economically viable when operation and maintenance costs are not considered, being a good method for both cost savings and environmental benefits, given the significant amount of water collected in terms of stormwater drainage, approximately 25,000 cubic meters.