A comprehensive investigation of groundwater quality in lagos state university, EPE, Lagos State, Nigeria

Groundwater is a major source of drinking water especially in developing countries. Continuous monitoring of groundwater quality is necessary to determine its suitability for drinking. This work was carried out to comprehensively investigate the groundwater quality in Lagos State University, Epe, Lagos State, Nigeria with a view to determine its suitability for drinking and domestic purposes. 20 different locations where groundwater samples were collected were selected and coordinated with handheld Global Positioning System (GPS) for the purpose of universal identification and visualisation. Groundwater samples were taken from boreholes in the identified and coordinated locations using 1 litre treated plastic bottles labelled GW 1 – GW 20. All the samples were analysed for physicochemical paramters such as pH, total dissolved solids (TDS), total hardness, calcium, biochemical oxygen demand (BOD), chemical oxygen demand (COD) among others. Heavy metals which include lead, chromium, cadmium and nickel and microbiological parameters like coliform and aerobic mesophilic count were also analysed usinh the standard methods for examination of water and waste water as prescribed by American Public Health association / American Water Works Association / Water bEnvironment Federation (APHA/AWWH/WEF, 2017). The results revealed that the pH values of groundwater samples investigated varied between 3.8 and 6.8 with an average value of 4.655 and a standard deviation of 0.659. The concentration of lead ranged between 0.003 and 0.15 mg/L with a mean value of 0.046 mg/L. nickel concentrations varied between 0.0068 and 0.2 mg/L with a mean of 0.053 mg/L. The average concentrations of pH, lead and nickel were above the threshold limits stipulated for drinking water quality by Nigerian Standards for Drinking Water Quality (NSDWQ) and World Health Organisation (WHO). The correlation coefficient revealed lead was positive weakly correlated with chromium, iron, cadmium and nickel while nickel was negative strongly orrelated with chromium. It was concluded that LASU, Epe groundwater is unfit for drinking and domestic purposes.