As the pore water chemistry- has been considered as one of the prominent base parameters to infer the impact of coastal mining in introducing environmental deterioration, a study in pore water chemistry is planned here along the beaches for a length of 35 km from Poompuhar to Nagoor, Central Tamil Nadu, India. The parameters such as pH, conductivity, sodium, potassium, calcium, lithium, aluminium, copper, manganese, iron, zinc, lead, cobalt, chromium, nickel and molybdenum have been analysed. During the period of study, the event of tsunami has changed the concentrations of studied parameters and so post-tsunami waters have also been analysed. The distinct shift in the heavy metal concentration during post-tsunami is observed. Further, the trend between pre-and post-tsunami concentrations enables to recognize the beaches undergoing erosion and deposition. The potassium and calcium maintains a normal distribution in both the conditions whereas sodium presence in overwhelming concentration during post-tsunami.