Groundwater quality assessment of wells in Ifewara, Osun state

Abstract

Study was carried out in Ifewara, Osun state with an objective of evaluating the quality and suitability of local groundwater for domestic purposes. Twenty six groundwater samples from hand dug wells and one borehole sample and were subjected to physicochemical analysis. Results from the study shows that the cationic and anionic concentrations vary as follows: Na⁺(0.2-3.5 mg/l), K⁺ (0.1-15.1 mg/l) Ca²⁺ (16-96 mg/l), HCO₃ ^- (16-176 mg/l), Mg²⁺ (3- 104 mg/l), NO₃ ^-(0.18-11.43 mg/l), SO₄ ^2-,(1.24-21.3 mg/l), Cl^- (2-52 mg/l), and PO₄(0.01-0.75 mg/l).The study also shows that the water is fresh with TDS value (avg. 93.8 mg/l) and a neutral pH (avg. 6.8) within the permissible range (6.5-8.5).Hydrogeochemical evaluation of the groundwater reveals that it is predominantly of the CaHCO₃ type while others belong to the Mixed CaMgCl type. The water chemistry was observed to have been influenced by the dilution and weathering processes at shallow depth.

KEYWORDS: Groundwater quality, fresh water, hydrogeochemical evaluation,