Assessment of Pollution Hazards of Shallow Well Water in Abeokuta and Environs, Southwest, Nigeria

Abstract

Problem statement: Pollution of well water, either from point or non-point sources, has become a thing of health concern both in urban and rural areas. Approach: This study aim at assessing the pollution hazards of groundwater resource by sampling some shallow wells from urban and peri-urban area of Abeokuta. Collected samples were analyzed for water quality parameters using standard procedures. The parameters determined were: Static water level, color, turbidity, temperature, Electrical Conductivity (EC), pH, Total Dissolved Solids (TDS) Total Suspended Solids (TSS), Total Solids (TS), total hardness, cations {potassium (K) sodium (Na), Calcium (Ca), magnesium (mg), Manganese (Mn), iron (Fe)}, anions ﴾Chloride (Cl^-), Nitrate (NO₃), Sulphate (SO₄), Phosphate (PO₄)}, heavy metals {lead (Pb), Zinc (Zn), Copper (Cu)} and microbiological parameters {Bacteria count and Total Coliform count (TC)}. Results: Results were subjected to statistical evaluations using SPSS 15.0 for descriptive statistics and Analysis Of Variance (ANOVA). The mean values of TDS, TS, EC and PO4 were higher in well water collected from urban areas compared to peri-urban areas during wet season. It was also observed that during the dry season, TDS, TSS, TS, EC, Mg, Fe, Cl^-, PO₄ and total hardness were also higher in samples collected from urban areas relative to peri-urban well water samples. Conclusion: Water quality parameters such as Fe, Pb, NO₃, EC, Bacteria count and total coliform have mean values greater than World Health Organization maximum permissible standards for drinking water. Elevated values of these parameters are of great concern to public health when the water from these wells is consumed by people without treatment.