EFICIÊNCIA DE INTERCEPTORES DE ESGOTO SOBRE A QUALIDADE DA ÁGUA: UMA CONTRIBUIÇÃO AO PLANEJAMENTO URBANO APLICADO À CIDADE DE JABOTICABAL-SP

The sewer is one of the most relevant environmental factors which contributes to loss of life quality in the urban areas. Usually, the sewer final destiny is in the watercourse-bound, since it´s production is inevitable. It demands studies and techniques to be developed and duly applied so that its harmful influence on water quality is avoid, making it as close as possible of its natural conditions. The construction of sewer collection throughout watercourses and its further forwarding to the sewer treatment stations have been considered the most recommended technique. In this study we tried to analise the effectiveness of the application of this technique to reestablish the water quality in two watercourses which drain the river basin where Jaboticabal city is placed. The study was based in Cerradinho and Jaboticabal streams and in water quality characterization. The samples of the water were collected monthly during a year, throughout the watercourses, both in the urban and in the rural areas - near the headwater, in the urban area upstream and after the confluence of both, at the urban area downstream. The main aspects, which were analyzed, were the following: temperature, pH, DO, COD, nitrite, nitrate, total-N, total-P, BOD, total coliforms and fecal coliforms (Escherichia coli). Analyses of cluster and main components were used to evaluate the effect of hidrical parameters in the collect stations. The results of the research showed that there was increase of hidrical pollution from the riverhead to the outfall of Cerradinho and Jaboticabal streams and that the isolated practices of sanitation (collection of the urban sewer) improved the water quality but it was not enough to return these streams to the non polluted condition.