Spatial and Seasonal Variation in Groundwater Quality in Parts of Cuddalore District, South India

An effort has been made to evaluate the groundwater quality in parts of Cuddalore district in Tamil Nadu. This study observed an alkaline nature of water for all the samples throughout the year. Classification of water based on TDS shows that majority of the samples were permissible for drinking. A wide range of values for hardness were exhibited by the groundwaters. However, pre-monsoon samples were much harder than the post-monsoon samples. Two distinct water types were present in the study area, samples from coastal areas found to have Na-Cl and the upper reaches showed a Ca-HCO3 type of water. Results suggest that the major processes controlling the groundwater chemistry are the seawater intrusion in the eastern coastal aquifers and the rock-water interaction in western part. Most of the samples exceeded the permissible limit of sodium percentage for irrigation purposes. Fluoride and nitrate concentration were below the permissible limits. Spatial distribution maps showed a clear gradation in the concentration of water quality parameters from the hilly terrains to the coastal areas. This study revealed that the groundwater quality at the eastern boundary of Cuddalore, Kurinjipetai, Parangipettai, Keerampalayam and Komaratchi Taluks were deteriorated by the seawater intrusion.