Assessment of groundwater quality around a petroleum tank farm, in Ifie Community and environs, Warri, Southern Nigeria

Abstract

Investigation of the physical and chemical properties of groundwater around a Petroleum Tank Farm was carried out between January and August, 2015 to assess the suitability of the borehole water for drinking and other domestic uses. The results show that pH of water was acidic with values ranging from 4.62 to 6.87, EC (33.00–206.00 µs/cm), TDS (15.00–115.00mg/L), DO (2.13 7.10mg/L), and BOD (0.71–2.28mg/L). Anionic concentrations varied thus: HCO₃ (2.42-15.11mg/L), SO₄^2- (0.67-10.54 mg/L), NO₃^- (0.15-4.71 mg/L), PO₄^-  (0.04-0.81 mg/L) and  Cl^- (8.03-35.82 mg/L). The cations had very low values:  Ca²⁺ (1.29-10.17 mg/L), Mg²⁺ (0.19-4.82 mg/L), Na⁺ (0.16-2.81mg/L), Cu²⁺ (0.02-0.20mg/L), Zn²⁺ (0.02-0.61mg/L) and Fe (0.02-0.31mg/L).  Water Quality Index (WQI) revealed very poor water, suggesting that the heavy vehicular movements and gas flaring at the Petroleum Tank Farm impacted negatively on its surrounding groundwater with increased levels of pH, DO and BOD. Based on the findings in this study, the quality of the borehole water is unsuitable for drinking without adequate treatment. Improved energy efficiency performance of all utilities such as in means of transport and behavioural changes to reduce green house gases through the adoption of renewable energy should be encouraged and advocated.

Keywords: Borehole, Groundwater, Water quality, pH, BOD, Warri