WATER QUALITY EVALUATION ON SÃO JOAQUIM AND RIBEIRÃO CLARO STREAM, MICROBASIN OF CORUMBATAI RIVER, SÃO PAULO, STATE, BRAZIL.

Abstract

The water is a finite natural resource, and indispensable for all organism which made its conservation and management an priority issue for ecosystems maintenance.Given to this importance, several studies were developed on the waters quality of São Joaquim and Ribeirão Claro streams, belonging to Corumbataí river basin, located between the latitudes 22º36´S and 22º16´S and longitudes 46º36´W and 47º26´W. In this microbasin, were verified climatic geomorphologic, geological and social–demographic parameters. It was defined 5 collection points, being 2 in the Ribeirão Claro and 3 in the São Joaquim stream. The monthly collections were developed, between April and September/2002, when the weather is characterized by lower temperatures. The water samples were collected in the middle of the traversal water course at 20cm deep of the water surface. Were evaluated physical-chemical, chemical, physical and biological were variables, in the total of 16 parameters and the results were submitted to statistical analysis. According to the CONAMA 20/86 Resolution the data showed that the waters of São Joaquim stream belongs to Class 2, excepting for the values of dissolved oxygen, total coliformes, and Escherichia coli, which are above to the limit defined for the Class 3.The Ribeirão Claro stream, situated in the studied area, however, can be inserted in the Class 4, despite of its flow into the Corumbataí river. It was observed that the pollution of those waters comes from the release of urban sewer in natura.