Abstract

All the water that fills the holes, pores, and fissures inside geological formations is referred to as groundwater. This water is derived from atmospheric precipitation, either directly through rainfall infiltration, or indirectly through rivers, lakes, or canals. Groundwater quality assessment was carried out in Sakponba Community of Orhionmwon L.G.A. of Edo State with the view to examine the extent of physicochemical properties of the water in the study area. Fifteen (15) boreholes were randomly sampled with two samples obtained from each borehole, and all samples analyzed for their physicochemical properties. The physicochemical parameters were determined using standard method while the light metals and heavy metals were determined with fume and atomic absorption spectrophotometers. The analyses revealed pH ranging from 4.51 to 5.22, indicating acidity. TDS values range from 5.34 to 6.22 mg/l. Chloride concentration ranged from 13.03 to 14.13 mg/l. The lowest chloride value was recorded in sample BH10 and the highest value recorded in sample BH1. Nitrate concentration in the study area ranged between 1.54 and 2.12 mg/l, and all water samples collected fall within the limit when compared to WHO limit of 10 mg/l. Zn concentrations recorded in the study area ranged from 0.116 to 0.269 mg/l and exceeded WHO standard of 0.01 mg/l. Mn concentration ranged from 0.021 to 0.35 mg/l. Only one sample BH8 was above the limit when compared to WHO limit of 0.1 mg/l. Due to high concentration of a few parameters, water samples from some of the boreholes are non-potable water source. Therefore, the quality of the groundwater in the study area has likely been impacted by human activity (refuse dumping, sewage disposal).

Keywords: Contamination, Parameters, Borehole samples, Orhionmwon.