Abstract:

Groundwater is a natural gift whose significance in all spheres of human endeavours cannot be underestimated. It also plays a critical role and indispensable contribution in the dilution and intake of a number of several nutritional and toxic trace elements in the body system of humans and other biological populations. This study has examined the concentration status of heavy metals in wells and boreholes of Wasinmi within Ewekoro Local Government Area of Ogun State, South-West Nigeria. The existing and functioning 25 boreholes and 25 hand-dug wells in the area were physically and chemically sampled using Ion Chromatography (IC) for anions, Nitrate, Phosphates, Bicarbonate, Chloride and Sulphate were measured after chromatography separation utilizing conductivity detectors while Inductively Coupled Mass Spectrometer (ICP-MS) and Inductively Coupled Optical Emission Spectrometry (ICP-OES) were used for heavy metals and trace elements detection. The raw data obtained from the laboratory analyses were subjected to statistical treatment using SPSS software version 20.0. Results of the analyses revealed that the concentrations of Copper (Cu), Lead (Pb), Zinc (Zn), and Manganese (Mn) were within approved guidelines including WHO and NESREA maximum permissible limits with mean values of 0.020.01mg/L and 0.040.02mg/L; 0.0040.0005mg/L and 0.00080.0004mg/L; 1.0080.37mg/L and 1.600.89 mg/L and 0.010.009mg/L and 0.040.01mg/L, respectively for boreholes and wells. The proportion of Cadmium (Cd) was also very low, with a mean concentration value of 0.00020.0004mg/L and 0.00070.0005mg/L for boreholes and wells respectively. The value of chromium and cobalt were found to be significantly low (0.00010.0003mg/L) in boreholes only and largely undetected in wells while Iron exhibited elevated concentration mean values of 0.440.34mg/L and 0.540.32mg/L respectively for boreholes and wells which is above the permissible water quality set standards. The elevated values of the identified parameters notably DO, BOD, Alkalinity, Cl−, HCO3−, Zn2+, and Fe3+ in the groundwater system of the study area that were above the set standards are major concern to the health of the consumers which necessitates a proactive response from the communities.