Groundwater Quality in the Hard Rock Area of the Gadilam River Basin, Tamil Nadu

Hydrogeochemistry of the groundwater has been determined by various analytical method in the hard rock area of the Gadilam river basin. The data obtained are used to determine important quality parameters and ratios. High TDS is found in groundwaters of gneissic and granitic aquifers. Based on the salinity and sodium hazard for irrigation quality, C5 S2, C5 S3 and C5 S4 are the quality classes found not suitable for even salt tolerant crops in the study area. The quality parameter of the groundwater samples has been matched with ISI standards (1991). High amount of nitrate pollution is found in and around the villages of Kattusellur, Totti Kunjaram, Kuchipalayam and Parikkal. Analyses of trace metal constituents in a few selected groundwater samples has indicated the presence of antimony, and mercury in the study area.