Hydrogeochemical Characterization and Groundwater Quality Assessment in Chengalpattu District, Tamil Nadu, India

Groundwater is a major natural source of water. Groundwater pollution can occur due to the overuse of fertilizers and the specific geography of the area. The objective of this study was to assess the hydrogeochemical characteristics and overall quality of groundwater and its suitability for both irrigation and domestic purposes. Groundwater samples were collected in the Chengalpattu District using the grid method, and sampling locations were determined using GPS in this study. The key parameters, including pH, electrical conductivity (EC), total dissolved solids (TDS) and major ions, are determined for water quality. The indicators such as Sodium Adsorption Ratio (SAR), Sodium percentage (Na%), Residual Sodium Carbonate (RSC), Residual Sodium Bicarbonate (RSBC), Magnesium Hazard (MH), Kelly’s Index (KI), Permeability Index (PI) and Potential Salinity (PS) were estimated for assessing the irrigation and drinking suitability of the groundwater samples. The spatial map was drawn to illustrate the distributions effectively. The Gibbs plot indicates that the interaction between rock and water serves as the primary mechanism governing groundwater chemistry within the study area. The water type was determined through the application of Piper’s plot analysis. The US Salinity Laboratory diagram showed that most of the samples were C2S1 or C3S1, which means they had low sodium content. This means that the groundwater is good for irrigation. The Wilcox diagram illustrates the water samples for autumn across all classes, with the majority of samples indicating excellent to permissible quality. The study concluded that the water from the area is acceptable for both domestic and agricultural usage.