HYDROGEOCHEMICAL EVALUATION OF GROUNDWATER IN PARTS OF EASTERN NIGER DELTA, NIGERIA

Hydrogeochemical characteristics of groundwater in parts of the Eastern Niger Delta, Nigeria have been investigated to identify the distributions of groundwater geochemistry and the hydrogeochemical evolution pattern in the area. Groundwater samples were analysed for their physical and chemical properties. Results reveal that the water is acidic on account low pH values. Because of this, Poly Vinyl Chloride materials and other non-corrosive materials is recommended for borehole construction in the area, because acidic waters can be very aggressive. The study also reveals saltwater contamination as Chloride contents in some boreholes are up to 710.00mg/l. Iron concentrations are above the World Health Organization guide value in majority of the boreholes studied, with maximum value up to 1.600mg/l. Piper trilinear diagram was plotted based on the results of the analysis for separating the different water types, classification and characterization of the hydrologic systems. The groundwater is classified into Ca – Mg-ClSO4 and Na + K-Cl-SO4 water based on its hydrogeochemical characteristics. The second water type is also influenced by NO3. This means that groundwater in the area is mainly made up of mixtures of earth alkaline and alkaline metals and predominantly Cl- - SO42-water type. Chloride is the dominant anion followed by sulphate. Most of the water samples are made up of mixtures of the two water types. The groundwater chemistry was further analysed to determine its suitability for irrigation. The Sodium Adsorption Ratio (SAR) calculated from the hydrochemical data suggest that groundwater is of sufficient quality for irrigation in the area. Beside providing an assessment of the hydrogeochemistry of and possible controls, this study  has shown that, groundwater quality problems in the study area are traceable to the lack of consistent efforts to squarely address the problems, hence the need for a regular groundwater quality monitoring and effective management strategies in the area.