Physicochemical, Bacteriological and Biochemical Assessment of Water Samples from Unprotected Wells in Lagos State Metropolis

Aims: This study presents the results of the physicochemical parameter data and water quality index use to assess the quality of unprotected well water in Lagos southwest, Nigeria.

Methodology: 20 water samples were collected from selected locations namely; PPL, Okokomaiko, Cassidy, Iba express and Iba junction and they were analyzed for 7 physical parameters (temperature of the water, temperature of air, colour, odor, turbidity, conductivity, total dissolved solids) and 7 chemical parameters (pH, iron, Total Alkalinity, Total Hardness, Chloride, organic matter and residual chlorine).

Results: The result showed that 5 (25%) samples had pH below the NSDWQ limit for drinking water quality and 10 (50%) samples had conductivity that were above the standard limit. 15 (75%) samples had Total dissolve solid that were above the standard limit. All other physicochemical parameters were within the NSDWQ. Microbiological analyses were done to assess the total plate count and the coliform count of the water samples and the results showed that 9 samples had colonies that were too numerous to count exceeding the permissible limit of 100 CFU/ml set by WHO. The coliform count of the water samples showed that the MPN per 100 ml of all the water samples were above the WHO limit by having results greater than 1. The IMViC result showed that Klebsiella species and Enterobacter species were found in 6 plates (30%), Citrobacter species were found in 7 plates (35%) and Escherichia species were found in 7 plates (35%).

Conclusions: This result highlight that the well water in these areas are not safe for human consumption without additional treatment such as boiling or addition of disinfectants, therefore there is need to enlighten the consumers around these researched study areas to at least disinfect and filtrate their well water before drinking in order to avoid outbreak of waterborne diseases. Physicochemical