A number of private and public organisations have asked the civic body to supply them recycled sewage water for non-potable use.
This follows the Brihanmumbai Municipal Corporation (BMC) asking commercial users to curb consumption of water for non–potable use, and its plan to hike the existing 15 per cent water cut across the city to 30 per cent, most likely after Diwali.
So far, Mahalaxmi racecourse, Chembur’s golf club, the dumping grounds at Gorai and Deonar, three botanical gardens, and the Naval colony at Colaba, are among the organisations that have asked for this water.
With this, Mumbai joins cities like Sydney (Australia), Tucson, Arizona and St Petersburg, Florida, (US) which are putting recycled water to constructive use in an urban setting.
Mumbai generates about 2,600 million litres daily (MLD) of sewage, of which about 1,600 MLD is treated at its seven marine outfalls, to meet environmental standards, before being discharged into the Arabian Sea.
“These private players have written to us for treated water. We will lay pipelines for them at our own cost, and they’ll have to sign an undertaking that they will buy it from us for the next 15 years,” said D.L. Shinde, deputy municipal commissioner (Special Engineering), BMC.
He added that the water will be treated to a secondary level before selling to these buyers, for uses including gardening, washing, flushing and maintaining lawns.
According to BMC data, over 75 per cent of Mumbai’s daily fresh water consumption is for non-potable use.
Rashtriya Chemicals and Fertilizers (RCF), at Chembur, has been buying 23 million litres of treated sewage water daily for over a year now.
With these additional private and public players buying treated water, over 65 million litres (ML) of fresh drinking water will be saved daily (amounting to 650 water tankers). The BMC will charge Rs 10 per kilolitre (1,000 litres) of such treated water.
“The contractors at Deonar and Gorai dumping grounds will commit to buying this water for 25 years,” Shinde added.
Mumbai has seven marine outfalls were sewage water is treated — at Versova, Colaba, Worli, Malad, Ghatkopar, Bandra and Bhandup.
Shinde added the BMC has written to the Centre to fund a Rs 1,400 crore plant to treat sewage water to a tertiary level. Also planned is an upgrade to the Colaba outfall, with commitments drawn from local hotels to buy water from this treatment plant.