Sistema de reúso de águas cinzas: estudo de caso para implantação em um condomínio residencial de baixo padrão em fase de projeto

Abstract

With the population growth and world economic development, the water demanding is increasing and becoming even higher. As an alternative, the greywater reuse emerges to reduce the consumption. In this way, this paper aims to present a study case of a greywater reuse system in a low standard residential condominium, commonly constructed in the governmental social programs such as the Minha Casa Minha Vida, elaborating the design of treatments units (Septic tank and filter trench) as well as the estimate of the costs through the budgeting and the payback. The greywater reuse consists in segregate it from the bathroom sink and the washing machine and canalize it to the treatment units in order to be used for flushing afterwards. These treatment units are designed in accordance with the NBR7229 ABNT (1997b) and NBR13969 ABNT (1997a) standards for a condominium used as a reference, which is located in Bauru, state of Sao Paulo, Brazil. In parallel, a survey has been applied in this condominium in order to verify the residents’ acceptance in regard to this greywater usage for flushing. It has been pointed out that the vast majority is favorable, mainly because of the money saving. In regards to the payback, it will take about 15 months and 7 days of the system in operation so that the consumption’s reduce pays the amount invested in it, which indicates a relative little time if it be considered in relation to the real estate development lifetime, although this return not necessarily gets back to those hands which originally made the investment, such as the construction companies.