Seawater intrusion up to 700 m inland from Adyar to Muttukadu on ECR now
Posted on: 30/Oct/2019 10:13:09 AM
The important piece of news that has come out now is the indiscriminate pumping of ground water by the residents along with inadequate recharge has resulted in sea water intrusion up to 700m inland from Adyar to Muttukadu on the ECR now. This has been revealed by some researchers belonging to Anna University of Chennai.
It is known that development usually comes with a cost and here in ECR the cost is water intrusion. It must be noted that the researchers studied more than 30 wells on the 20 km stretch and the results showed the presence of total dissolved solids or TDS ranging from 2500 to 3000 parts per million or ppm. The upper limit of TDS in water is 500 parts per million and this is as per the BIS.
The seawater intrusion has been indicated by the presence of chloride and sodium ions in the ground water. Several places like Thiruvanmiyur, Besant Nagar, Palavakkam, Uthandi, Akkarai etc were badly affected by this sea water intrusion.
As per Mr. Elango, professor of Geology, Anna University or AU, it is very clear that seawater has been entering aquifer due to the presence of more buildings and excessive pumping of ground water. He then explained about how TDS has been increasing though the groundwater is present at the shallow pits. The point to be noted is if the metro water provided residents piped water supply then pumping would reduce. By means of recharge, the quality of ground water could be restored.
A paper titled ‘Seawater intrusion and submarine groundwater discharge along the Indian coast’ has been published by the researchers. Additional steps needed to improve the quality of groundwater were also suggested by the researchers. These additional measures includes moving bore wells away from the sea, increasing aquifer recharge through a row of fresh water wells parallel to the sea, pumping out salty groundwater and sending it back to the sea etc.
It is worthy to note that many residents of ECR complained that groundwater could not be used for cooking and drinking as it was saline. They mentioned about how three decades back the groundwater was not contaminated.
