Environmental Assessment based on microbiological indicators of balneability in Palmas, Tocantins, North Brazil / Avaliação ambiental com base em indicador microbiológico de balneabilidade no município de Palmas-TO

Abstract

UHE Lajeado reservoir is located in the central region of Tocantins State and it has favorable conditions to recreational activities. The margins of the reservoir exhibit a high recreational potential, thus, the sanitary conditions must be ensured to allow safe primary contact with waters. Balneability indicators should be assessed in environments with recreational purposes aiming the prediction and also to prevent adverse effects on human health and aquatic biota. The present work assessed the indicator parameter of fecal contamination, Escherichia coli, in order to establish the balneability of four beaches, which are: Cajú, Prata, Graciosa and Arnos, in the capital of Tocantins State, Palmas. The detection and counting of Escherichia coli used the chromogenic substrate technique of samples taken at five weeks interval during the period of 2012 and 2015. Escherichia coli counting were low and allowed the classification of the beach waters to be very good to excellent based on legal requirements CONAMA Nº 274/2000. Hence, this work contributes to build an important database about microbiological conditions of the waters of Lajeado reservoir.