Chennai groundwater study finds one-third of samples unsafe

A study conducted by researchers from the Vellore Institute of Technology has found that nearly one-third of groundwater samples in Chennai are poor, very poor, or unsuitable for drinking. The assessment, published in the journal Applied Water Science, evaluated 39 wells using 12 quality parameters including nitrates, fluoride, and total dissolved solids.

In the Taramani area, the Water Quality Index (WQI) reached nearly 700, more than double the maximum safety threshold of 300. Researchers identified severe seawater intrusion along coastal stretches, driven by heavy extraction and sewage ingress, as a primary cause of high electrical conductivity. The study noted that natural recharge is limited by hydrogeological conditions, while human activities such as unchecked extraction and untreated sewage further degrade the water supply.