Efforts to reduce stress on freshwater sources in the city may finally become a reality.
Chennai Metrowater has completed 35% of the work to set up a tertiary treatment reverse osmosis (TTRO) plants to treat sewage and supply to industries.
Tertiary treatment is an advanced process that further purifies secondary treated sewage and produce better quality water.
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The plants are coming up at Koyambedu and Kodungaiyur with a combined capacity of 90 million litres to treat sewage and make it ready for reuse.
The work is being taken up nearly five years after it was conceived after the city came under severe strain last summer with meagre sources.
Described to be first-of-its-kind facility in the State, the TTRO plants coming up in the site of sewage treatment plants will be operational by April next year.
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At present, Chennai Metrowater provides 35 million litres of fresh water to industries in the city’s peripheries. It provides another 30 mld of secondary treated sewage to Manali industrial belt. For both, the water agency charges ₹120 per kilolitre.
It has been estimated that the demand of industries in Manali-Ennore and Manali-Minjur corridors alone would go up to 70 mld by 2020.
Pipelines being laid
“We are in the process of laying a 28 km long pipeline from Kodungaiyur plant and 68 km pipeline to Sriperumbudur and Oragadam belt. The capacity of the plants can be further expanded by 30 mld for future needs. We are yet to fix a rate for the tertiary treated water to be supplied,” said an official.
However, the concept of decentralised sewage treatment, including at residential level, is yet to become popular.
Kannan Pasupathy, founder of Ecotech Engineers and Consultants, said STPs of smaller capacities, which could treat 600 to 1,000 litres a day and suit the needs of a small family, are available. But, many people are unaware of the technologies and products available that could reduce strain on sewer system and help recycle water for purposes, including gardening.
Krishna water to stop
On Wednesday, water supply from Krishna river in Andhra Pradesh reduced to a trickle at the inter-state border of the Kandaleru Poondi canal in Uthukottai, Tiruvallur.
Poondi reservoir, which stores and distributes Krishna water, received 70 cusecs on Wednesday and the water release may completely stop in a few days due to dismal storage at Kandaleru reservoir.
The water agency has to tread on a tightrope this summer as well, given the available water sources, and sustain supply of 650 mld.