Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB), popular as Metrowater, plans to increase sewage treatment capacity by 450 MLD. The agency’s plants have the capacity to treat 745 MLD, but treat only 599 MLD. “This gap will be plugged after interventions and by adding infrastructure this year,” said executive director Akash P. The agency will also lay pipes in areas unconnected to main sewage lines.
Jayaram Venkatesan, convenor of Arappor Iyakkam, an anti-graft NGO which conducted an audit on all STPs in 2017, said maladministration was the reason for the plants not run ning to full capacity. “The agency should first admit that the sewage generated is more than 650MLD. It claims it supplies 850 MLD of drinking water and that only 80% of it returns as sewage. But it doesn’t acknowledge that two-thirds of the city’s water comes from borewells. This means 1,300MLD of groundwater is drawn daily, increasing the sewage generated to 1,500 MLD-1,800 MLD. With the present 550 MLD capacity, the actual raw sewage entering water bodies will be five times more,” he said. This is based on ‘Domestic Sewage consumption in Chennai,’ a study by A Vaidyanathan and J Saravanan which found only one-third of the city uses Metrowater’s 850MLD and the rest uses borewell water, bottled water or own water.
Many STPs are reeling under maintenance issues and in several places along the Adyar and Buckingham canal, raw sewage is let out from main pipelines for months when repair work takes place.
Activists call for sewage and water supply to be headed by different officers for more efficiency. “Metrowater needs to strengthen the sewage wing and bring in a separate official to ensure it gets the same focus,” said Jayaram Venkatesan.
Senior Metrowater officials said proposals with information and field inspection reports to ensure there is no delay due to protests for STPs were drawn. Shiv Das Meena, principal secretary of municipal administration department, promised to come up with solutions to the sewage problem.
Move to bar discharge of untreated water
The Metrowater plans to double its tertiary treated water capacity from 30mld to 60mld to make the city water positive by reducing pressure on water resources. While industries still remain skeptical to purchase treated water from the agency, they plan to tie up with the PWD and the corporation to let out treated water into lakes and tanks. Metrowater has also planned a series of tertiary treatment ultra filtration plants at Nesapakkam and other locations. “This water will be treated using ultra filtration method and can be used for commercial and industrial purpose. And it won’t pollute lakes but only improve their water storage and ground water table,” said a metro water official adding that with not many resources to tap drinking water remaining in the city, this will help the future drinking water demand.