An Assessment of Trace Elements in Surface and Ground Water Quality in the Ebocha-Obrikom Oil and Gas Producing Area of Rivers State, Nigeria.

Abstract

This study presents the impact of surface and ground water quality on the environment in Ebocha-Obrikom oil and gas producing area of Rivers State, Nigeria. Specifically, the study examined the relationship between the physico-chemical parameters, determine the quality of surface and ground water in the study area as compared with national and international standards for drinking water, assess the quality of borehole and well water in the study area, and determine the relationship between gas flaring sites and physico-chemical parameters. This study adopted both field and laboratory experimental analysis of physical and chemical parameters. The water samples were analysed for Physico-chemical parameters using standard procedures. Physico-chemical parameters analysed for were pH, DO, BOD, TDs, Conductivity, Turbidity, Salinity, Total Hardness, Total Alkalinity, Temperature; cations and anions and TPH, Iron, Copper, Chromium, Manganese, Nickel, Lead and Zinc. The results show that ground water contained high amounts of turbidity (21.5NTU, 23.00NTU and 19.0NTU in the borehole water and well water), iron (5.3mg/l in the ground water and 6.98mg/l in the borehole water), biological oxygen demand (3.80mg/l in the surface water) and pH of all water samples were acidic in the study area. These results show that ground waters including borehole; well waters and surface water of the study area had acquired reasonable levels of pollution. Apart from these specific cases, other values were found to be lower or above and corresponded to the approved maximum permissible level (i.e. maximum permissible limits for drinking water set by NAFDAC and WHO). Pearson correlation coefficient also indicated that there was a significant correlation among the studied physico-chemical parameters in both surface and ground water. The ground waters therefore, were more impacted upon by chemical parameters than surface water. This study, recommends for the continuous monitoring of water quality in the oil producing areas to protect man and the environment. Also, there is need for bio-physico-chemical assessment extension to other new areas of the Niger Delta region of Nigeria.

Keywords: water quality, trace element, oil and gas producing area