Evaluation of the Physico-chemical and Bacteriological Quality of Well Water along the Tilé River in N’Zérékoré, Guinea

Abstract

Water resources used for domestic purposes require continuous quality assessment, particularly in urban areas where surface water and shallow groundwater are exposed to domestic effluents, solid waste and runoff. This study evaluated the physico-chemical and bacteriological quality of well water along the Tilé River in the urban commune of N’Zérékoré, Guinea. The investigation was based on direct site observation and laboratory analyses of water samples collected from riverside wells and the Tilé River across nine districts. A total of 180 samples were analysed, comprising 10 well-water samples and 10 river-water samples per district. The measured parameters included temperature, pH, dissolved oxygen, colour, total dissolved solids, electrical conductivity, turbidity, total coliforms and faecal coliforms. The results were compared with World Health Organization guideline values for drinking water. Well-water temperatures ranged from 25.7°C to 26.1°C, whereas river-water temperatures ranged from 27.2°C to 27.7°C. The pH showed marked spatial variation, with acidic conditions recorded in Bellevue (3.52) and a higher value in Kwitiapoulou (7.79). Conductivity and total dissolved solids were generally higher in wells than in the river, indicating stronger groundwater mineralisation. In contrast, turbidity and colour were more pronounced in the Tilé River, with particularly high values in some districts. Bacteriological results indicated contamination by total and faecal coliforms, with concentrations ranging from 4 to 2,200 CFU/100 mL in the reported samples. These findings indicate that the Tilé River and adjacent wells are vulnerable to physico-chemical variation and faecal contamination. The water should not be consumed without appropriate treatment, and regular monitoring is required to support safer local water use.