TEMPORAL ANALYSIS OF WATER QUALITY IN LIMOEIRO STREAM AND PIRAPOZINHO RIVER IN THE STATE OF SAO PAULO, BRAZIL

Abstract

The limnological study verified the water quality in a inland section of the Limoeiro stream, in Presidente Prudente, and in a section of the Pirapozinho River, in Pirapozinho Both belong to the Santo Anastacio river basin, located at the Water Resources Management Unit in Pontal do Paranapanema - UGRHI-22 in the western region of Sao Paulo State. The limnological monitoring occurred from 2006 to 2015, and we investigate the behavior of water bodies when they stopped receiving domestic sewage in natura from urban areas of these municipalities. We selected sample sections at points located after the urban influence areas of Presidente Prudente and Pirapozinho. We monitored water temperature, pH and dissolved oxygen using portable digital devices, and we used protocols of evaluation by Standard Methods for Examination of Water and Waste water 22nd Edition (2012) to monitor sedimentary sludge, ammonium nitrogen, chemical oxygen demand, biochemical oxygen demand, total coliforms and Escherichia. Results indicate an improvement in water quality in both sections. From 2008, the streams recovered their water quality standards in accordance with the framework classes, advocated by the Brazilian environmental legislation.