PHYSICOCHEMICAL CONSTITUENTS OF GROUNDWATER AND ITS QUALITY IN CRYSTALLINE BEDROCK, NIGERIA

The chemical composition of groundwater depends greatly upon rocks in contact with groundwater. The percolation of groundwater through subsurface rocks provides close contact with the lithologic environment, and this result in the dissolution of soluble minerals as it transports till it reaches an equilibrium point between dissolved and undissolved minerals. The principal water quality problem result from high salinity, enhanced iron, elevated SO42-, high nitrate concentration, excessive Ca2+ and Mg2+which renders the ground water unsafe for various purposes. This study assesses both chemical and physical constituents of shallow wells in Iresa-Apa with a view to determining its quality and suitability for domestic, industrial, and agricultural purposes. Twenty four shallow well (water) samples were analyzed for different parameters based on standard laboratory procedures. The parameters include; temperature, Electrical Conductivity (EC), power of Hydrogen (pH), Total Dissolved Solids (TDS), Total Hardness (TH), turbidity, alkalinity, Total Suspended Solids (TSS), Total Solids (TS), Mg2+, Ca2+, K+, Na+, Fe2+, Cl-, NO3-, SO42- and PO43-. The results showed that the abundance of the cation and anion in the area occurred in the order Ca2+> Mg2+> Na+>K+>Fe2+ and Cl->NO3->SO42->F->PO43- respectively. The mean values of some parameters exceed the permissible level of World Health Organization standard while some are close to the threshold line. It is affirmed that the shallow water in Iresa-Apa is satisfactory for irrigation use, but unfit for domestic, industrial, and livestock management without treatment