Analysis of Major Ion Constituents in Groundwater of Amassoma and Environs, Bayelsa State, Nigeria

E. Oborie[1] , H.O Nwankwoala[2]
Page No. 1-13

The present study focused on the hydrochemistry of groundwater in Amassoma and neighbouring
communities to assess the quality ofgroundwater for determining its suitability for drinking and
agricultural purposes. Groundwater samples werecollected from fourteen stations in the study area
and were analysed for physico-chemical parameters such as pH, EC, TDS, sodium, potassium,
calcium, magnesium, chloride, sulphate, carbonate,bicarbonate, nitrate and iron. Comparison of
the analysed parameters with World Health Organization (WHO, 2006) drinking water standards
shows that groundwater in the area is satisfactory for drinking purposes.The results also show that
calcium concentration in two stations exceed permissible limits while iron concentration in more
than 60% of the locations sampled were seen to exceed acceptable levels as per WHO standards
with maximum up to 0.84mg/L. Piper trilinear diagram was plotted based on the results of the
analysis for characterization of the hydrogeologic systems and classifying the different water types.
Groundwater samples in the study were classified into two groups – the predominantly Calcium
bicarbonate water type and the Magnesium sulphate, sodium chloride calcium bicarbonate water
type based on their hydrogeochemical characteristics. In the second class all ions appear to be
reasonably present in close proportions. Water of this composition is generally acceptable for
domestic and industrial purposes, provided the TDS are within tolerable limits. The calcium
bicarbonate waters are generally hard. The piper diagram also shows that alkali earth metals
(Ca²⁺ + Mg²⁺) exceed alkali metals (Na⁺+ K⁺) while weak acids (HCO₃^- + CO₃^2-) were dominant
over the strong acids (SO₄² + Cl^-). Lastly, the groundwater chemistry was analysed to determine its
suitability for agricultural purposes. The calculated values for Sodium adsorption ratio (SAR),
Residual Carbonate and Percentage sodium derived from the hydrochemical data suggest that
groundwater is of sufficient quality for irrigation in the area.
Keywords: Groundwater, hydrogeochemistry, major ion, water quality, Amassoma, Bayelsa State