Influência do lançamento de esgotos na qualidade das águas do aquífero aluvial do rio Sucuru, no município de Sumé-PB.

Abstract

In Paraíba, the usage of groundwater has increased considerably, therefore, these water resources are more susceptibles to contamination, either by the discharge of untreated wastewater, or by other anthropogenic activities, above all, agropastoral activities. The main objective of this study is to evaluate the influence of the sewage discharge on the groundwater quality and the viability of these resources for various uses. For this research 9 wells along the alluvial aquifer of Sucuru River in Sumé-PB were chosen. The water quality indicators selected were: physico-chemical - bicarbonate and carbonate alkalinity, calcium, chloride, conductivity, BOD, COD, iron, magnesium, nitrate, nitrite, ammoniacal nitrogen, DO, pH, potassium, salinity, sodium, total dissolved solids, temperature, turbidity; microbiological - thermotolerant coliforms and E-Coli. Along the alluvium were indentified various fonts of anthropogenic pollution, which have influence on the aquifer water quality. Through the GOD method, the aquifer was classified with medium vulnerability level. The indicators related to salinity presented high salt levels along the alluvion, which restricts the water use to irrigation. The minimal parameters for the classification of groundwater according to the CONAMA Resolution 396/2008, have been, on most the wells, above the MVA, except for nitrate, thus qualifying the aquifer water as Class 4. Therefore it was concluded that the water from the alluvial aquifer of the Sucuru River can only be used, untreated, for least restrictive uses.