Investigation of hydrocarbon contaminant levels and groundwater quality assessment in parts of Bonny Island, Rivers State of Nigeria

This study investigates the environmental impact of a recent oil spill incident in Bonny terminal using groundwater media. The objective was to establish the presence of Contaminants of Concern (COC), determine, quantify and model spilled volume IEEE Transactions on Components, Packaging and Manufacturing Technology and ascertain potential health risk associated with the spill incident. The COC included Total Petroleum Hydrocarbons (TPH), Polyaromatic Hydrocarbons (PAH) and BTEX compounds. Groundwater was sampled in the vicinity of the spill incidents and further away into the surrounding communities. Groundwater assessment showed that TPH ranges from 9.04 to 20.60 μg/L with a mean value of 2526.90 ± 6392.40 μg/L. Apart from four boreholes, all others had TPH values exceeding DPR target value of 50μg/L. PAH was recorded only at three boreholes, with values: 0.13, 1.07, and 0.25μg/L, respectively. Meanwhile, BTEX compounds had concentration (5910 μg/L) that exceeded Directorate of Petroleum Resources (DPR) target value of 0.8 μg/L over 7000 times. The BW-3 is most deteriorated in water quality. These contaminated borehole-sampling locations are positioned at the vicinity of tank farm, at higher hydraulic heads and hence, might not pose much health risk to the surrounding communities. Groundwater movement in the area is towards the Bonny River at the southwestern part of the area. This study, therefore recommends remedial actions be taken immediately to prevent health risk in the tank farm area.