ESTUDO DE VIABILIDADE ECONÔMICA PARA USO DE ÁGUAS PLUVIAIS NO HOSPITAL METROPOLITANO DE SANTA RITA

Abstract

Water scarcity has been increasing over time due to large uses, population increases and pollution. This problem generates a search for new forms of water use. One of the ways found is the reuse of rainwater. In the city of João Pessoa - PB, rainwater is considered as good, requiring simple treatments, such as sand filters, to be useful for human consumption. In this work, it was considered to study the economic viability of a rainwater reservoir as an alternative for the supply of garden watering, sanitary vessels of the support block and urinals of the Santa Rita Metropolitan Hospital, currently in execution. To do this, was calculated the reservoir to supply all the demand of annual water, reaching the valor of 1200 m³ and it was varied until it reached the value of 25 m³, what is the real reservoir of the hospital. Based on the estimation of the water consumption for these uses and the costs of construction, maintenance and operation costs, and considering different Long-Term Interest Rates (LTIR), the economic viability of the rainwater reuse project was analyzed by means of the economic parameters of Net Present Value (NPV) and Benefit / Cost (B / C), where it was estimated which reservoir would bring greater economic benefit. The average LTIR for the last years is 6.12% and for this work, the LTIR’s of 4%, 8%, 10% and 12% were considered. The LTIR increase is detrimental to the economic viability of the project. For both parameters, the reuse project is viable, however, for the NPV the reservoir of 1200 m³ is more beneficial and for the B / C the reservoir of 25 m³ presents the best economic benefit.