Monitoring of the Santos Submarine Outfall, São Paulo, Brazil, 10 Years in Operation

Abstract

This summary is based on several reports accompanying the performance of the Emissary in operation since 1979 that are analyzed together with the operational data of the Preconditioning Station of Santos Sewer, State of São Paulo, Brazil. The choice of the pre-treatment system and the emissary was made due to the regional absence of areas ample enough to install a complete conventional sewage treatment plant and to the fact that the economical studies showed the advantage of the construction of an outfall sewer taking into account the difference in cost between primary and secondary treatment of waste. The efficiency of the dimension of the minimal extension adopted is verified for the various trajectories of the maritime currents and their predominant cycles. The principal physical, chemical and biological parameters were collected from 14,309 analyses of the last four campaigns (1976, 1979, 1982 and 1986). They are analyzed together, permitting the verification of the efficiency of the oceanic sewage disposal. The results of the campaigns generate recommendations and conclusions, contributing with details for future projects and also permitting other countries of the Americas to evaluate and compare the operational performance of their emissaries.