An application of Water Quality Index (WQI) and multivariate statistics to evaluate the water quality around Maddhapara Granite Mining Industrial Area, Dinajpur, Bangladesh

Abstract Background Pure water is an absolutely necessary component of the earth not only for life but also for sustainable socio-economic development of today’s civilization. The aim of this study was to analysis the quality of water resources and to investigate the influences of mining activities on water quality around the Maddhapara Granite Mining area, Dinajpur, Bangladesh. Result 31 samples from surface and groundwater were collected from this selected area to assess their hydrochemistry, suitability, and their possible sources of contamination. Consequently, in the case of physico-chemical analysis, the 24 parameters such as PH, Electrical Conductivity, TDS, TH, Ca2+, Mg2+, K+, Cd2+, Cr3+, Cl−, $${\text{SO}}_{4}^{{2{ - }}}$$ SO 4 2 - , $${\text{PO}}_{4}^{3 - }$$ PO 4 3 - , $${\text{NH}}_{4}^{ + }$$ NH 4 + , $${\text{NO}}_{3}^{{ - }}$$ NO 3 - , $${\text{HCO}}_{3}^{{ - }}$$ HCO 3 - etc. were analyzed in laboratory. Multivariate statistical methods were adopted for determining the water quality and their sources of contamination. The Gibbs ratio plot suggests that most of the samples fall in the rock dominance fields and some are in the precipitation dominance field. Cluster analysis confirms that three main groups of water samples where cluster I includes 70.97% of water samples, cluster II and cluster III includes rest 22.58 and 6.45% of the water samples respectively. Factor Analysis/Principal Component Analysis (FA/PCA) illustrates five factors extracted which explain 75.89% of the total variance. Conclusion The collective results of multivariate analysis and Water Quality Index implies that most of the areas around the mining area are dominated by the good to excellent quality water for different purposes. In addition, the results of this research will then be helpful to estimate the major sources of contamination in different areas within the framework of activities intending to improve the quality of water.