A construction of water quality index considering physicochemical properties for drinking purposes in a rural settlement: a case study of Gajraula region, Ganga River Basin (North India)

A simple methodology based on several key variables of groundwater chemistry is used to create a water quality index (WQI), with the aim of monitoring the influence of industrial and rapid urbanization on a typical rural settlement. The applicability of the constructed indices as an assessment and communication tool is evaluated in a case study of Gajraula and its suburb of JP Nagar district in northern India. The water quality data from 2007 to 2009 were analysed for 12 different locations surrounding Gajraula for two seasons, i.e. wet and dry. Five point rating scale was used to classify water quality for each of the study locations. Rating curves were drawn based on the tolerance limits of drinking waters. In the present study, the WQI demonstrated a modest increase in wet seasons (August to November) than dry seasons (February to June) for all locations with a few exceptions. Hardness, total dissolved solids, NO₃⁻, biochemical oxygen demand, and Fe in most cases were found to be responsible for the decline in seasonal WQI for various locations. However, the WQI around Gajraula varied from 50.6 to 87.7 and was found to be satisfactory except for some locations.