Assessing the environmental impacts of oil exploration and production on the water quality of Osse River, Southern Nigeria

The concentrations of some physico-chemical parameters of the Osse River were studied to assess the impacts of Dubri Oil Company operations. Samples were collected between July 2000 and June 2002 from five stations: Station 1 and 2 (upstream), Station 3 (Gelegele Port/Oil Company site) and Stations 4 and 5 (downstream). The concentrations of these parameters in the river ranged from 26.1 – 33.7oC for air temperature, 25.2 – 29.1oC (water temperature); 38.0 – 225cm (Transparency); 2.3 – 58NTU (Turbidity); 42.5 – 520.20mgl-1 (TDS); 14.66 – 210.04mgl-1 (TSS); 57.14 – 701.50mgl-1 (TS); 5.55 – 7.91 (pH); 4.40 – 11.60mgl-1 (DO); 0.80 – 5.60mgl-1 (BOD5); 10.0 – 208scm-1 (Conductivity); 17.50 – 100mg CaCo3-1 (Alkalinity); 7.02 – 34.50mgl-1 (Chloride); 0.02 – 0.43mgl-1 (Sulphate); 0.04 – 0.73mgl-1 (Nitrate); 0.28 – 3.52mgl-1 (Phosphate); 0.18 – 19.1mgl-1 (Sodium); 0.11 – 6.2mgl-1 (Potassium); 1.11 – 9.62mgl-1 (Calcium) and 0.20 – 7.78mgl-1 for magnesium. With the exception of air temperature, transparency, turbidity, suspended solid, dissolved solids, total solids, biochemical oxygen demand and nitrate which were significantly different (P 0.05) in the study stations. The impacts of the oil exploration and production operations of the Oil Company on the water quality was negligible as all parameters were relatively homogenous across the study stations, and were below the WHO guidelines for domestic usage. The environmental conditions studied have been discussed in relation to the general water quality standard. Global Journal of Environmental Sciences Vol. 6 (1) 2007: pp. 1-14