With water becoming a critical resource, water utilities are more conscious of the need for proper management and distribution. The Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) is making significant efforts to ensure efficient water supply in Chennai by reducing its misuse and treating wastewater and seawater. In an interview with Indian Infrastructure, Dr T.G. Vinay, Managing Director, CMWSSB, highlighted its key initiatives, the potential for wastewater recycling and reuse, the challenges faced and the future outlook. Excerpts…
What are the key initiatives taken by CMWSSB in the water and sewerage sector over the past year? What has been the progress under government schemes like AMRUT, JJM and SBM?
CMWSSB has commissioned 12 water supply schemes in the past one year benefitting a population of around 1.65 million at a cost of Rs 19.10 billion. It has also commissioned sewer schemes and constructed sewage treatment plants (STPs) benefitting a population of around 2.93 million at a cost of Rs 7.54 billion. Under the Atal Mission for Rejuvenation and Urban Transformation (AMRUT), four water supply schemes were completed in the past year at an estimated cost of Rs 16.64 billion, covering a population of 1.008 million. Additionally, eight sewer schemes were completed at an estimated cost of Rs 3.72 billion. The total number of beneficiaries is around 11.21 million. Similarly, under the Swachh Bharat Mission (SBM), CMWSSB has made efforts to mechanise sewer cleaning using state-of-the-art equipment and making the transition from manual to mechanised sewer maintenance.
How is CMWSSB providing uninterrupted water supply and promoting effective water conservation?
At present, treated water supply to the city is 1,100 million litres per day (mld) from surface water sources and desalination plants. Over the past one to two years, CMWSSB has augmented supply resources through various measures such as the commissioning of the 150 mld capacity Nemelli desalination plant, augmentation of water supply works with the ongoing work of laying a second water pipeline from the Chembarambakkam water treatment plant, and collaborations with the Water Resources Department to enhance the capacity of the reservoirs. Furthermore, the construction of the 400 mld capacity Perur desalination plant has commenced and is planned to be completed by March 2027. On its commissioning, Chennai will have a total installed capacity of 750 mld of water from its desalination plants.
What initiatives are being taken for wastewater recycling and reuse? What is the future potential?
CMWSSB is a pioneer in wastewater reuse. As early as the 1980s, its secondary treated water was being supplied to petrochemical industries such as CPCL and others. To further boost Chennai’s resilience and push the city towards a circular economy, CMWSSB has embarked on a journey to ensure the increased use of recycled water. In this endeavour, it has established two tertiary treated reverse osmosis (TTRO) plants of 45 mld capacity each at Koyambedu and Kodungaiyur to supply treated water to industries in Irungattukottai, Sriperumbudur and Oragadam, as well as the Manali-Ennore and Manali-Minjur corridors. A total of 36,350 mld of product water from the Kodungaiyur TTRO plant and 18,820 mld from the Koyambedu TTRO plant has been supplied to these industries. Currently, Chennai is the only city where 12 per cent of wastewater is being recycled and reused with TTRO for industrial purposes since 2019. In another move, CMWSSB has tested the TTRO water quality for construction purposes, ensuring it meets the permissible limits. This treated water was utilised in the construction of the 120 mld STP at Kodungaiyur, and is used by various construction units in the city.
What are the key challenges that remain unaddressed?
The key challenges faced by CMWSSB relating to water supply are the unreliability of surface water sources owing to dependence on monsoons; groundwater depletion; exponential population growth; old infrastructure resulting in frequent breakdowns and leakages; and inequitable distribution of water supply.
What are CMWSSB’s plans for the next one to two years?
CMWSSB aims to facilitate higher usage of recycled water by industries, the construction sector, etc., and to ensure equitable water supply to households. It aims to cover all the left-out areas through comprehensive water supply schemes and is taking measures to recover the costs of operation and maintenance by ensuring IoT-based management of all pumping stations (water and sewerage pumping stations included) and distribution networks, and implementing bulk metering of all water treatment plants and consumers in a phased manner. In the sewage sector, a detailed project report is under preparation for the improvement of the old sewerage system in Chennai.
