ASSESSMENT OF GROUNDWATER QUALITY OF SAIDPUR UPAZILA UNDER THE DISTRICT OF NILPHAMARI FOR DRINKING AND IRRIGATION PURPOSES

Abstract

Groundwater samples collected from Saidpur Upazilamunder the district of Nilphamari, Bangladesh during dry season of the year 2012 were analyzed for its quality and suitability for irrigation and drinking purposes. To study the various chemical parameters, water samples were 25 shallow tubewell and 25 deep tubewell. Analyses included pH, EC, cations (Ca’*, Mg”*, Na‘, K*, Zn’*, Cu’*, Mn** and Fe**), anions (HCO;", NO3", SO.”", PO.*” and CI) and TDS (total dissolved solids). We also computed several variables such as SAR (sodium adsorption ratio), SSP (soluble sodium percentage) RSC (residual sodium carbonate), hardness, permeability index, permeability salinity, Kelly’s ratio and Gibbs ratio to evaluate the suitability of groundwater supply for specific use. Some correlations and compositional relations were also evaluated. Overall we found that all the groundwaters were acidic in nature (pH 6.0 - 7.7) and could be suitable for drinking and irrigation uses. According to TDS and SAR values, all samples were classed as ‘freshwater’ and ‘excellent’ categories. The soluble sodium percentage (SSP) of all waters was under ‘excellent’ and ‘good’ classes. Maximum samples were within ‘soft’ class regarding hardness with ‘suitable’ RSC. Based on Zn?*, Mn?*, Fe**, SO,””, NO3" and CI, all groundwater samples were within the ‘safe’ limit for drinking. The results also provided data for water quality of groundwater resources of study region to match national and international standards for drinking and irrigation ways.