Aquatic community protection on treated effluent disposal from waste stabilization ponds on São Lourenço River in São Lourenço da Serra from Vale da Ribeira in the State of São Paulo

DOI: 10.15343/0104-7809.200832.3.6

Abstract

The treatment of sewer pipes of small cities using waste stabilization ponds is a simple, efficient, and low cost option. Sewer pipes are
a fountain of water and ground contamination and consequently they contribute to diseases transmission, besides being a threat to the preservation
of the environment. It is thus necessary to investigate the conditions of effluents going to water courses. The present work aims to carry
out an investigation on the quality of residual waters treated by stabilization ponds of a sewer pipe treatment facility located in São Lourenço
da Serra, Vale do Ribeira, State São Paulo and examine the sanitary risks and the local aquatic community. Samples were taken for evaluating the
several anaerobic and facultative ponds of sewer pipe of the treatment facility of São Lourenço da Serra. Parameters used were pH, air and water
temperature, climatic conditions, biochemical demand of oxygen and ammoniac nitrogen, thermo-tolerant bacteria, photosynthetic pigments and
zooplanktonic community. We observed that the anaerobic and optional pond systems were efficient in the production of effluent and presented
values in accordance with the Resolution Conama nº 357, which establish limits for waste disposal in water sources. São Lourenço River is located in
an area of environmental protection, and data were compared to limits established in Class 1 and 2 and demonstrate a process of euthrophization,
putting in risk aquatic biodiversity and the health of the population.