CHENNAI: Recycling of wastewater is predominantly seen as a measure to safeguard the environment. However, the Chennai Metropolitan Water Supply and Sewerage Board (Metro Water) has proven that this recycling process is also economically lucrative.
Since 2020, the ‘water manager’ has generated an income of Rs 550.56 crore by supplying tertiary treatment reverse osmosis (TTRO) water to industries in Manali, Sriperumbudur, Irungattukottai and Oragadam.
As per government data, as much as 74,249 million litres of fresh water has been saved from 2020, which is equivalent to two months of present water supply to the city. Metro Water supplies around 1,200 million litres of water per day.
Metro Water sells TTRO water at rate of Rs 80 per kilo litre to industries in Manali and `65 per kilo litre to industries in the SIPCOT industrial parks in Sriperumbudur, Irungattukottai and Oragadam. It makes Rs 7.63 crore per month by selling TTRO water and Rs 1.80 crore a month by selling secondary treated water, which is being used for gardening and landscaping purposes by civic bodies.
Metro Water operates two 45 million liters per day (MLD) capacity TTRO plants at Kodungaiyur and Koyambedu that were constructed at a cost of Rs 235 crore and Rs 396 crore respectively. “At present, only 13% of the treated sewage is being utilised by industries and local bodies. In 2019, only 6% treated sewage was utilised,” an official said.
The ‘water manager’ has 20 sewage treatment plants with a total sewage treatment capacity of 957 MLD but only 763 MLD is being utilised due to various reasons. Of the total treatment capacity, 412 MLD was brought into operation after July 2022. Also, new plants with a treatment capacity of 64 MLD are under construction.
According to data, the Greater Chennai Corporation generates around 900 MLD of sewage. “The existing sewer network was laid 25 years ago. In order to strengthen the sewage collection network, four major locations at Nesapakkam have been identified, DPR prepared, and tender is being floated under ADB funding,” the document added.