Avaliação das concentrações de nitrato nos poços tubulares da estação Engenheiro Francisco Távora em Alagoinhas Bahia

Abstract

In the current conjuncture of water resources, problems of water quality and availability are increasingly evident. In the evaluation of the nitrate in the wells of the Engineer Francisco Távora’s Station, in the city of Alagoinhas-BA, there were anomalous concentrations in 4 of the 11 wells in operation. Taking into account that this is the main supplying station in the city and that nitrate might be a risk to the population’s health, the study proposed mitigating aspects to minimize, in the short and long term, the ion indices in the distributed water and in the tubular wells. This study also allowed checking that the water delivered to users was under drinking water standards, showing a concentration of less than 10 mg / L, according to stablish Portaria 2914/11 of the Ministry of Health. This station is located in the urban area of the municipality, in which, the number of inhabitants has increased in the mediations of the station in the last decades and, because it does not have a sewage collection network, septic tanks are used for the disposal of their excrements, because they contain nitrogenous compounds, they are oxidized by the biogeochemical cycle of the nitrogen, forming also the nitrate ion, that infiltrates in the ground and causes contamination of the underground water. From this process, it can be verified that the factors determining the pollution as result of the 24 septic tanks found, contributed significantly to the occurrence of nitrate and its elevation in the wells water.