Untreated wastewater discharged from Karuvadikuppam STP into canal meant for carrying rainwater in violation of norms

The discharge of untreated grey water is one of the starkest cases of pollution and official apathy, rue environmentalists

The continuous discharge of untreated wastewater from the Karuvadikuppam Sewage Treatment Plant (STP) into a canal meant originally meant for carrying rainwater in Lawspet, in gross violation of rules, poses a serious risk of contamination of water sources downstream and significant threat to environment and health of residents, environmentalists say.

Untreated greywater frothing and foaming at several points of the rainwater canal near the Narikoravar colony and adjacent to the Puducherry Airport remain a common sight.

The unchecked pollution by the STP maintained by the Drainage Division of the Public Works Department (PWD) goes against the claims made by the department that there is no illegal discharge of sewage in the city.

The discharge of untreated grey water is one of the starkest cases of pollution and official apathy, rue environmentalists.

According to Probir Banerjee, co-founder of PondyCan, a civil society organisation and member of Alliance for Good Governance (AGG), “The canal was supposed to carry excess rainwater during the monsoon. But the canal has now become an easy location for the authorities of the STP to conveniently dispose of their untreated grey water. Thick foam is visible at many spots along the canal and the untreated water has been triggering a foul smell. This grey water meanders to the city to eventually flow out into the sea. The situation is similar all over the city and the authorities are using the ocean as a garbage dumpsite and ponds for sewage water to flow.”

Mr. Banerjee added, “The practice of discharging untreated grey water into the canal must be immediately stopped and authorities must ensure that this colossal amount of water being wasted is retreated and reused for various purposes. The grey water gushing out and forming into a white frothy stream discharged is highly toxic. The possibility of toxic chemicals, causing foam to catch fire like what happened in Bellandur lake in Bengaluru cannot be ruled out here.”

Tests conducted by the Environmental Monitoring Service, a testing and research laboratory for water, soil and food products in Auroville last year had revealed that the biochemical oxygen demand (BOD)—a marker for organic pollutants in the wastewater discharged into the canal was found to be a whopping 3,192 mg/litre as against the permissible standards of 30 mg/litre on inland surface waters and 100 mg/litre for marine coastal areas.