Hydrochemistry of Shallow Tubewell Water, Northern Dinajpur District, Bangladesh

The present study aims at determining the quality of groundwater samples from six Shallow Tubewells (STWs), with special emphasis on drinking and agricultural uses in the northern part of Dinajpur District. The physiochemical properties of water samples were analyzed in order to measure its quality and suitability. Physical analyses involved the measurement of pH, EC, T C, Total Dissolved Solid (TDS), Dissolved Oxygen (DO), Redox potential (Eh), Arsenic (As), while the chemical analyses included determination of the concentration of selected cations (Ca2, Mg2, Na, K, NH 4, Mn 2, Fetotal) and anions (Cl–, CO–3, HCO–3, SO–24, NO–3,NO–2, PO–34). Among the cations, the concentration of calcium is highest, and among the anions, bicarbonate concentration is highest. Besides, B, F–, I– were determined. Correlation with different guideline values for water use for drinking and public health purposes shows that the groundwater is suitable for the purposes. The groundwater of this area is moderately hard and requires little softening. Plot of analytical values in the Piper Trillinear diagram shows that alkaline earths exceed alkalies, strong acid exceeds weak acids and non-carbonate hardness (secondary salinity) exceeds 50%. Integrated effect of two properties, viz., EC and Sodium-Adsorption Ratio (SAR), shows that the water is of low alkali hazard and low to medium salinity hazard, and the Permeability Index (PI) also indicates that the water is good for irrigation