Abstract

This study was conducted to assess the quality of groundwater in Okitipupa (Okpa), the head quarter of Okitipupa local government area of Ondo State, Nigeria. Physico-chemical parameters were determined using standard methods while metals were determined using Atomic Absorption Spectrophotometer. The pH range (Mean ± SD) are 8.5- 11.2 (10.1 ± 0.9), the Electrical Conductivity range are 1095- 1932 (1503 ± 211) µSCm-1, the TDS range are 657 – 1159 (902 ± 126) mgL-1, the chloride concentration range are 220- 299 (276 ± 18.5) mgL-1, the Sulphate range are 80.7 – 260 (201 ± 53.5) mgL-1 and Nitrate range 10.1-92 (35.1-19.6) mgL-1. The metal index (MI) was used to assess the level of metal contamination in comparison with WHO maximum acceptable concentration (MAC). The calculated MI values of metals (Fe, Cr, Pb, Cu and Ni) ranged from 1.47- 46.3. The results show that the overall quality of water decreases as MI >1 is a threshold of warning. Improved sanitation and treatment of groundwater meant for drinking is necessary.

Key word: Groundwater, Okitipupa, metal index, anions, Ondo State.