QUALITY ASSESSMENT OF UNDERGROUND WATER IN WAMBA TOWN OF WAMBA LOCAL GOVERNMENT AREA, NASARAWA STATE, NIGERIA

The research was carried out to determine the quality of underground water in Wamba town of Wamba Local Government Area, Nasarawa State. Physico-chemical parameters of the borehole and well water samples were determined using standard methods. Heavy metals (Al, Cd, Cu, Pb, Ni, Fe and Zn) were quantified using Graphite Atomic Absorption Spectrometer (GAAS). Borehole and well water pH (7.00 + 1.0 - 7.30 + 0.30) were slightly alkaline.The levels of temperature, acidity, total solids(TS), total dissolved solids(TDS) , total suspended solid (TSS) , total alkalinity, total hardness, dissolved oxygen( DO) and bio-chemical oxygen demand(BOD) in borehole water were higher during the dry season, except for electrical conductivity (EC). Levels of physico-chemical parameter during the dry and wet seasons in borehole water were significantly different (P< 0.05), except for pH, temperature, EC, TS,and DO. Heavy metal concentrations in borehole waterwere generally higher during dry season than the wet seasons. Cu and Ni concentration were highest. Fe levels were below detection limit in dry season. Al and Fe concentrationswere not significantly different (P < 0.05) in borehole water. Inwell water the levels of EC, and TDS were higher during the wet seasons.Acidity, TSS, total alkalinity, total hardness and BOD in well water were significantly different (P < 0.05) for both seasons. Heavy metal concentrations in well water werehigher in wet season compared to dry season, except for levels of Ni and Zn. Concentrations of Cd (1.04+ 0.003mg/L) was the highest levels in well water. Heavy metals levels in well were significantly different (P< 0.05), except for Al. Higher concentrations of heavy metals were recorded in well water compared to water from the boreholes. Physico-chemical and heavy metals level were within the acceptable limits for drinking and domestic water except for the levels of aluminum and cadmium.(WHO, 2011.Appendix A and B).The water physico-chemical quality index (WQ1) and heavy metal pollution index (HQI) for both borehole and well water in the dry and wet season were less than 100 and 1, which indicated that the water samples were good for drinking (WHO, 2011.Appendix