13. Water Quality Index Is an Important Tool of Groundwater: A Case Study

As commonly known, qualitative and quantitative assessment of groundwater poses substantial challenges toward determining the best use to maintain the balanced aquifer at any point of time for the fulfillment of the needs of society. Hence, for a certain location at a given time, the overall quality of water can be represented by a number called Water Quality Index (WQI). In the present study, 480 numbers of samples were collected during the monsoon and post-monsoon seasons from twelve different wards of Borough X located under the Kolkata Municipal Corporation (KMC) in the state of West Bengal, and analyzed as per the APHA guidelines to assess the suitability of groundwater as drinking water. WQI for these samples revealed that about 34% of groundwater samples were categorized as “excellent” and 46% as “good” during monsoon period, whereas 30% of groundwater samples were categorized as “excellent” and 55% of these as “good” during monsoon period. Clearly, groundwater quality of the post-monsoonal samples was moderately better compared to that of the monsoon season. This study also revealed that the three water quality parameters,, namely, chloride, hardness, and iron were found to be greater than the permissible level. This also revealed that the TDS value increases. However, this may be owing to the intrusion of salt water in this region. This paper attempts to describe the water WQI of KMC area and its reliability.