Qualitative evaluation of microbiological contamination of the wells water in the Carlinda –

Abstract

This work was developed in order to evaluate qualitatively the water from wells used by people who live in the neighborhood of Bom Jesus, in the city of Carlinda, State of Mato Grosso (MT). Two water collections were carried out in the rainfall season and two in the drought season. In each of them, twelve wells were used as samples. Questionnaires were applied for the data gathering on the care concerning wells as well as the proximity of septic tanks. The purpose of this work was to determine total coliform, Escherichia coli and mesophile bacteria, in the two rainfall seasons of the year. Results show a high level of contamination of these wells in the rainfall seasons, once the level of contamination by total coliform was of 100% in all water collections. Concerning Escherichia coli, it was observed a higher level of contamination in the rainfall period (91%) in relation to the drought period (79%), with no significant difference between the observed rainfall periods. The total counting of mesophile bacteria followed the same pattern observed for Escherichia coli, where the higher concentration was found in the rainfall period (10.430 UFC/100mL) statistically different in relation to the drought period (6.390 UFC/100mL). According to the applied questionnaires, 70% of the people use the water for human consumption, and out of these, 20% boil and/or filter the water. The wells are located at an average 8m-distance from the septic tanks.