EVALUATION OF HYDRO GEOCHEMISTRY OF NORTH CHENNAI COASTAL AQUIFER TO ASSESS THE GROUNDWATER SUITABILITY FOR DRINKING AND IRRIGATION PURPOSES

Pressure on groundwater is increasing for domestic, agricultural and industrial requirements and the water level has fallen drastically. In coastal aquifers, the extraction of groundwater by overpumping leads to seawater intrusion. The present investigation focuses on the evaluation of hydrogeochemical parameters of groundwater of North Chennai area foritssuitability for various purposes. 33 groundwater samples collected from different locations in Araniyar and Kosasthalaiyar river basin in the North East coast of Tamil Nadu were analyzed according to APHA standards. Total Hardness, Sodium Absorption Ratio, Chloride Bicarbonate Ratio, Permeability Index and Kelly’s Ratio values were calculated from major ionic concentrations of Na, Mg, Ca, HCO3 for its suitability for drinking and irrigation purposes. Based on the parameters studied it was found that groundwater in most of the locations in the study area is not good for drinking and irrigation purposes. From this study, it is inferred that groundwater is undergoing quality deterioration near coastal areas. Continuous monitoring of groundwater quality is essential in coastal areas to control saline water intrusion and mange the aquifer from further damage.