摘要：Analytical study of boreholes water quality in both sedimentary terrain and basement complex were carried out with 16 samples from different boreholes, collected from two different States (regions) representing the lithology in South Western Nigeria. It is in no doubt that the composition of a terrain has influence on the water quality and from both terrains, it was observed that the pH ranges from 5.30 to 7.60, Iron, Nitrite, Nitrate and Manganese contents have maximum values of 2.70, 2.00, 7.30 and 0.10 mg L-1, respectively. Total alkalinity ranges from 12.00-155.0 mg L-1, total hardness ranges from 21.00-275.00 mg L-1, salinity ranges from 15.00-566.00 mg L-1, chloride ranges from 5.50-70.00 mg L-1, but sulphate is absent in all the water samples. The obtained results showed how elemental compositions vary with lithology and how water qualities in the two zones are almost suitable for use/consumption of the populace. Although, some samples from the Sedimentary basin have slight high Iron content, this calls for attention.
