Groundwater vulnerability assessment using SINTACS model

Groundwater has been treated as an important source of water supply due to its relatively low vulnerability to pollution in comparison to surface water, and its huge storage capacity. Because of the known health and economic impacts associated with groundwater contamination, steps to measure the vulnerability of groundwater must be taken for sustainable groundwater protection and management planning. Susceptibility of groundwater refers to the intrinsic characteristics that determine the sensitivity of the water to being adversely affected by an imposed contaminant load. The SINTACS model is the most extensively used method for identifying the areas where groundwater supplies are most vulnerable to contamination. The SINTACS model uses seven environmental parameters (water table depth, effective infiltration, unsaturated conditions, soil media, aquifer hydrogeologic characteristics, hydraulic conductivity and topographic slope) to characterize the hydrogeological setting and evaluate aquifer vulnerability. In this paper, the SINTACS model is applied for a part of Kancheepuram district, Tamil Nadu, India to generate a small-scale map of groundwater vulnerability to contamination. The whole area is classified as very low, low, moderate and high susceptibility to pollution. The model is validated with ground water quality data and results have shown strong relationship between SINTACS specific vulnerability index and nitrate-as-nitrogen concentrations. The ground water vulnerability map is developed by using the SINTACS model in a computer-based geographic information system (GIS).