Contribuição à aplicação de coeficientes de consumo em projetos de abastecimento de água e esgotamento sanitário em comunidades urbanas de baixa renda do Nordeste do Brasil - estudo de caso.

Abstract

The aim of this work was to study the per capita consumption rate (q), coefficients of water consumption variation (K1 and K2) and sewage to water ratio (C) for two well-structured places, Gloria I and Gloria II, in Campina Grande city (7°13’11” S, 35°52’31” W), Paraiba state, northeast Brazil, where live 2,304 low-income people transferred from a slum (Favela da Cachoeira).Water for both places was taken from a main pipe of the Campina Grande Water Supply System at a flow-rate of 8.38L/s being 5.13L/s pumped to a 100m3-elevated reservoir for supplying Gloria I and 3.15L/s for feeding straightly Gloria II distribution system. Wastewaters from both places were sewered to a treatment plant made up of the preliminary treatment units bar screen and grit chamber and two stabilization ponds, an anaerobic and a secondary facultative one. Water consumption readings were obtained hourly, between November 2006 and February 2007 for estimating the aimed design parameters on consumption water. Measurements of sewage flow-rate taken hourly, between november 2006 and february 2007, based estimation of sewage to water ratio. The per capita consumption rate of 90L/inhabitant.day was less than that of 120L/inhabitant.day adopted for designing water supply. Estimates for K1 were 1.15 and 1.25, respectively for Gloria I and Gloria II, very close to the design value of 1.2, but the correspondent ones for K2 of 2.36 and 2.41 were higher enough compared to that (1.5), adopted for design. Estimated sewage to water ratio of 0.81 was close to that (0.85) used in the project. Due to the short period of study, coefficients obtained herein will be useful as indicators for designing future systems of water supply and wastewater collection for low-income urban populations in tropical countries.