Evaluation of Water Quality Index of Damodar River for Drinking Purpose Using Computer Programming

Abstract

The objective of the study is to evaluate and compare the water quality of river Damodar for drinking purposes using Water Quality Index (WQI) and Sensitivity Index (SI) respectively. WQI gives information about spatial and seasonal variations of pollution load and to classify river water into five classes: Excellent, Acceptable, Slightly polluted, Polluted and Heavily polluted for drinking purposes. However, SI gives an idea about whether quality of water is increasing or decreasing at same point during subsequent monitoring. Both were estimated using two separate computer programs; written in Clanguage based on the eleven water quality parameters such as pH, DO, BOD5, TDS, TSS, Cl $^-$ , NO $_3^ -$ - N, SO $_4^{2-}$ , THARD, T-alkalinity, and T-coliform. A total 76 water samples were collected from 19 sampling points of a stretch D/S Tenughat dam to D/S Barakar river in mid-upper Damodar Valley to estimate spatial and seasonal variations in water quality for the year 2010. The values of WQI were found in the range of 66.2-75.6 in summer, while it was 55-76.0 in winter, affected mainly due to high values of total coliform, TSS and pH, exceeded the tolerable limits of IS:10:500 (1993) at almost all the sampling points. The results indicate that all sampling points were falling in the Acceptable (C2) to Slightly polluted (C3) range, except at Garga Nalla [Polluted (C4) category]. This study demonstrates the application of WQI using computer programming tool for quick assessment of water quality of any water body and also can be used for effective water quality management.