Quality Assessment of Groundwater in Parts of Niger Delta, Southern Nigeria using Metal Pollution Index and Factor Analysis

Abstract

The Niger Delta is the operational base of major oil producing and servicing companies in Nigeria. The various human activities domiciled in the area have negatively impacted on the groundwater quality in the region. A total of 75 groundwater samples were collected and 11 heavy metals were analysed and used to assess the potability of the groundwater for domestic use. Water quality index, factor analysis and metal pollution index were employed in the study to ascertain the extent and level of heavy metal enrichment in the groundwater systems in the area. The pollution ranking of the analysed metals are in the order of: very highly polluted (nickel), highly polluted (cadmium and lead), moderately polluted (cobalt, chromium, copper, iron, mercury and zinc) and lightly polluted (arsenic and manganese). Factor analysis revealed three factors, which signify three possible sources of pollution, with contributors to each factor having the same source. The study identified oil spill, gas flaring, industrial effluents, acid rain, agrochemicals and indiscriminate dumping of refuse as the factors responsible for the deterioration of groundwater in the area. The local geology of the area which is characterized by high porosity and permeability provide the conductive pathway for easy movement of metals under acidic condition into the shallow groundwater system. Due to the monumental and devastating effects of hydrocarbon pollution in the area, the need to eradicate gas flaring and minimize oil spills as well as clean-up of contaminated sites in the area is advocated.