Sewage pollution of Cooum, groundwater depletion raise alarm

A report suggesting measures to mitigate sewage pollution has been submitted to the Tiruvallur local body and district administration. An official said the contracting firm has been advised to build a temporary bund downstream of the work site as the Chennai Peripheral Ring Road project across the river would not adversely impact groundwater.

Officials noted that advanced soil biotechnology is being deployed to improve the quality of treated sewage discharged into the river, though the article states the plant capacity was not inadequate. A report on mitigation measures was submitted to authorities.

Residents said several representations had been submitted requesting measures to arrest untreated sewage flow into the river and to restore the waterway as a groundwater source.

Residents note that water diverted through Puduchatram and Korattur check dams eventually reaches the Chembarambakkam drinking water reservoir, making upstream pollution and river health relevant to Chennai’s water source.

A resident cited that groundwater levels in Manavala Nagar and surrounding areas have declined after parts of the riverbed were dried up for bridge construction. A resident also stated that groundwater has depleted by about 20 feet in areas including Vengathur, Putlur, and Manavala Nagar.

Residents note persistent sewage pollution near the Putlur check dam, with concerns that rapid urbanisation outpaces sewer infrastructure. They point to the drying of portions of the riverbed for bridge construction as part of the Chennai Peripheral Ring Road project, linking pollution to reduced river activity and potential groundwater impact.