An Appraisal of Groundwater Contamination : A Case Study of Shallow Wells In Agbowo Community, Southwestern Nigeria

Abstract

Abundant as it may seem in Nigeria, access to clean and potable water is a great challenge. Hence the reason for determination of the physico-chemical properties of the groundwater in Agbowo community in Ibadan, Oyo state Southwestern Nigeria for domestic uses. Water samples collected from thirty-four (34) shallow wells with varying depths were subjected to chemical analysis. The water quality parameters were analyzed in accordance to standard methods. The groundwater analysis reviewed includes pH, electrical conductivity, total dissolved solids (TDS), others include Ca<sup>2+</sup>, Mg<sup>2+</sup>, K<sup>+</sup> Na<sup>+</sup>, Fe<sup>2+</sup>, NO<sub>3</sub>, Cl<sup>-</sup> SO<sub>4</sub><sup>2-</sup> and HCO<sub>3</sub><sup>- </sup>The results indicated that the parameters analyzed have some falling within the limits and some above the maximum permissible limits in accordance to Nigeria Industrial Standard (NIS) and World Health Organization (WHO) guidelines for drinking water. In general, the data revealed that maxima and minima concentrations of the priority physico-chemical water quality parameters examined in the thirty-four (34) water points were mostly within the Target Water Quality Range (TWQR) for domestic use with little exceptions at some points. However, high nitrate concentrations and Total Dissolved Solids (TDS) above the permissible limits in some of the well water sampled are causes for serious concern. Poor construction, lack of maintenance, proximity to sewage tank and stream, as well as indiscriminate dumping of refuse are suggested as the major causes of this development. The overall implication of this observation call for sustenance and improved water resource management strategy for the area in order to prevent the deterioration of the water sources quality, which may pose associated health risks and environmental hazards.