Correlation of various water quality parameters and water quality index of districts of Uttarakhand

Abstract

This study is based on hydrogeochemical and biological parameters and calculation of Water Quality Index (WQI) to assess water quality of a rural tract in five districts of Garhwal and Kumaon district of Uttarakhand, India. The drinking water quality parameters are pH, Total Hardness, Alkalinity, Turbidity, Iron (Fe), Chloride (Cl), Fluoride (F), Dissolved Solids (TDS), Sulphate (SO4), Nitrate (NO3), Calcium (Ca), Magnesium (Mg), Arsenic (As), conductivity, Total Coliform, Fecal Coliform and Total Residual Chlorine. It was observed that the physicochemical properties were as per BIS standards and found suitable for drinking purposes. However Bacteriological parameters i.e. Total coliform and Fecal coliform of some sampling sites ranged from 20 to 300 ​CFU/100 ​ml, which were higher than permissible limit (0 ​CFU/100 ​ml) as per BIS standards. Statistical analysis had been used to calculate the correlation coefficient of different parameters with WQI and the study showed significant linear relationship and the high correlation coefficient between different pairs of water quality parameters. The correlation matrix shows that total iron concentration, total coliform, and faecal coliform have a significant effect on Water quality index. Among these parameters, TDS has the highest correlation with conductivity, sulphate, and chloride ion concentration whereas turbidity significantly correlates with the presence of nitrate in drinking water.