The poor condition of Grand-Bassam’s boreholes and the drinking water wells of the local population led to an assessment of their hygienic quality. Several data analysis approaches were performed on 4 boreholes and 17 well water samples. Indeed, physico-chemical and bacteriological analysis, as well as Water Quality Index and Principal Component Analysis were used to differentiate the characteristics of borehole and well water in order to determine the level and origin of water pollution. The results showed that all chemical borehole water quality was poor, while of 35% and 65% of well chemical water quality were good and satisfactory, respectively. Owns to soil nature, the iron and manganese contents were 0.73 ± 0.23 mg.L-1 and 0.1 ± 0.07 mg.L-1, respectively. The high presence of fecal streptococci, salmonella and shigella in the borehole water, as well as Escherichia coli, total coliforms and fecal coliforms in the well water, thereby underscoring the poor microbiological quality of water (90,53% of borehole and 92% of well), which is contaminated by septic tank water. Furthermore, the high presence of Salmonella in borehole water suggests that it may contain hydrogen sulfide, which is responsible for its unpleasant odors.