Groundwater Quality for Irrigation Purposes and Classification for Hydrochemical Facies in Parts of Southern Ijaw Local Government Area, Bayelsa State, Nigeria

As a result of economic development and rapid growth of the population in Southern Ijaw Local Government Area of Bayelsa State, Nigeria, there have been clear changes in the use of land, resulting in increased demand for water for various uses including agricultural activities. This study examined groundwater quality and classification of hydrochemical facies of communities in the study area. Fifteen (15) communities within the LGA were selected and groundwater from hand-dug well (HDW-15 samples) and borehole (BH-15 samples) was sourced during the wet season (July) and dry season (March) and analyzed for seasonal variation, irrigation purposes and hydrochemical facies classification using a standard method. Based on Sodium Adsorption Ratio (SAR) classification scheme, all groundwater sources in the area are excellent for irrigation purposes because they all have SAR values <3. This implies that SAR values of <3 will not threaten vegetation. The value of sodium percentage (Na%) ranges from 29.81% to 66.13% and 23.30% to 71.89% for hand dug wells in both wet and dry seasons. Similarly, the value of Na% ranged from 3.57% to 16.32% and 3.38% to 19.60% for borehole water in both wet and dry seasons. The groundwater hydrochemistry facies analysis indicated that there was an adjustment in groundwater chemistry during dry season while