Geospatial Assessment of Groundwater Quality for Drinking through Water Quality Index and Human Health Risk Index in an Upland Area of Chota Nagpur Plateau of West Bengal, India

Groundwater quality is directly related to human health. Therefore, analysis of groundwater quality and its effect on human health in any area on a spatial scale are very important. It is even more important in an undulating area where topography, land use, human settlement and aquifer parameters vary on a short distance. Such an area is the Nituria block of Purulia district where an investigation on groundwater quality for drinking purpose has been carried. 52 groundwater samples were collected during pre-monsoon and post-monsoon seasons to estimate hydro-chemical characteristics and its suitability to human health. Drinking water suitability is analysed by a composite Water Quality Index based on standard limit of each parameter for drinking purpose set by Bureau of Indian Standard. Groundwater of this area is partially contaminated and the origin of contamination is geogenic. Different multivariate analysis of groundwater as well as piper trilinear diagram shows active cations and anions are the determinant factors to control groundwater quality. It suggests interaction of minerals with groundwater is the principal cause of water quality changes along with secondary anthropogenic contribution. The overall Water Quality Index ranges from 59.40 to 171.43. ‘Sabari’ (171.43) and ‘Purana Panchakot’ (168.21) village indicates highest Water Quality Index value during pre- and post-monsoon seasons, respectively. GIS analysis shows most of the area falls under ‘good’ to ‘moderate’ water quality zone. Human health risk due to intake of Fe and F− was assessed by following the USEPA method. Health Hazard Index during pre-monsoon period indicates that 88.46% and 94.23% groundwater samples are at noncarcinogenic health risk zone for male and female, respectively. During post-monsoon season, 69.23% and 78.84% samples were under noncarcinogenic health risk for male and female, respectively. This study identified the hot spots of groundwater contamination where remedial measures as suggested in this work can be undertaken.