Groundwater Salination in Different Aquifers - A Case Study

Investigations to Identify the Extent of Depletion and Deterioration in the Quality of Groundwater Resources in Three Different Aquifers -Alluvial, Ramanathapuram and Vanur and Cuddalore Sandstone - in and around Pondicherry Region Indicated Groundwater Samples of the Southern Region to be highly Contaminated with Sea Water. Large Scale Development of Groundwater for the Combined Needs of Agriculture, Industry and Population along with Intermittent Lack of Monsoon Recharge and Non-receipt of Water by Surface Storage Reservoirs has Caused the Reversal of Hydraulic Gradient Resulting in the Intrusion of Sea Water. The Extent of intrusion Varies from Site to Site. In the Southern Part of Pondicherry (site I), where Groundwater is extensively Used for Agricultural Irrigation(upt0 60%), the extent of Reversal of Hydraulic Gradient is 5.5 to 6 Km from the Coast.

In Thc Urban Part (site III), high levels of abstraction of Groundwater for Human Consumption has Contributed for Sea Water intrusion Upto 2 Km Distance from the Coast. At Site IV, the Rapid Pace of Industrialization has Resulted in the Depletion of Groundwater table leading to Sea Water intrusion. the Unplanned Urbanization, indiscriminate irrigational Practices Resulting in large scale abstraction of Groundwater leading to Sea Water intrusion is a Warning to be Taken note of.