Soon, the volume of treated sewage reaching city waterways will be reduced.
As part of its eco-friendly efforts, Chennai Metrowater will start supplying tertiary treated sewage, which is an advanced process that produces high-quality water, to industries.
Metrowater will soon own the first-of-its-kind tertiary treatment units in the State. Plans are afoot to set the facilities up in the Kodungaiyur and Koyambedu sewage treatment plants.
This month, tenders will be floated for the facility in Kodungaiyur that will treat 45 million litres a day (mld).
As part of the process, sewage will be treated again to reduce the level of total dissolved solids and made fit for industrial use.
With more water-intensive industries mushrooming in the Manali-Ennore and Manali-Minjur belts, the water agency expects the demand for treated sewage to increase in the next few years.
Now, nearly 36 mld of secondary treated sewage — wherein only micro impurities are removed — is supplied to 68 industries in north Chennai and an annual revenue of Rs. 15 crore is generated. Sources in Metrowater said work is on simultaneously to set up the tertiary units in Koyambedu and Kodungaiyur.
With similar capacity, the units will produce recycled water, which can be used for non-potable purposes such as gardening. This will ease the burden on use of fresh water resources.
The new facility in Kodungaiyur will come up on seven acres at a cost of Rs. 255 crore and will be ready in two years. This is expected to provide recycled water for 34 industries. A proposal to add a tertiary treatment unit at the Perungudi sewage treatment plant is also in the pipeline, the sources said.
