Ending Chennai’s wait of nearly 25 years for a tertiary treated reverse osmosis (TTRO) plant, Chennai Metrowater plans to commission two such plants in Koyambedu and Kodungaiyur, either later this month or early next month.
Using domestic sewage as raw material, the proposed TTRO plants will, initially, have the capacity to handle 45 million litres a day (MLD) each. Eventually, they can go up to 60 MLD each. By the middle of this month, the proposed plants will have trial runs.
A senior Metrowater official said the plants would formally be inaugurated by Chief Minister Edappadi K. Palaniswami. Once they are operational, freshwater of at least 60 MLD would be conserved which would, in turn, be made available for the public water supply.
Even in the mid-1990s, a 100-MLD plant was proposed in Kodungaiyur with the assistance of a Japanese agency. It was meant to take care of water requirements of industrial units in and around Manali on the northern fringes of Chennai. But in March 2001, the State government decided to scrap the project and asked Chennai Metrowater to scale down the capacity of the plant to 50 MLD. It took more than 10 years for the government to get convinced again of the importance of the TTRO and sanction two such plants at a total cost of around ₹816 crore. In late 2014-early 2015, Central assistance was sought and both projects were covered under the Atal Mission for Rejuvenation and Urban Transformation .
Industrial demand
The Koyambedu plant will take care of industrial units in Irungattukottai, Sriperumpudur and Oragadam, all in Kancheepuram district. At present, the units, located at parks set up by SIPCOT, are getting water, thanks to the infrastructure created by the Tamil Nadu Water Supply and Drainage (TWAD) Board. Their water demand is expected to touch around 50 MLD this year, according to a 2018 document of Metrowater.
The Kodungaiyur plant will take care of demands of entities in the Manali-Minjur belt. Even now, some companies in north Chennai are getting 30 MLD of secondary-treated water. They also get freshwater supply from a seawater desalination plant in Minjur. Once the TTRO starts functioning, Metrowater is planning to divert water from the desalination plant to public water supply.
