The Brihanmumbai Municipal Corporation (BMC) has tied up with the Indian Institute of Technology (IIT-B) for in-situ treatment of sewage in drains in the city. This pilot project will prevent coastal pollution from flowing into the sea or gulf due to sewage from 25 drains in Bandra, Andheri, Goregaon, Kandivali, Borivali and Dahisar.
IIT-B’s N-Treat technology Seven-step treatment of sewage in drains without the need of additional space, with the help of screens, gates, silt nets, coconut fiber curtains for filtration and disinfection using sodium hypochlorite uses the process.
The project is a temporary and short-term measure to comply with the National Green Tribunal (NGT), which in 2019 directed the civic body to permanently check the flow of sewage into the sea and gulf from drains and their tributaries in Mumbai . In March this year, the BMC sought a consultant to prepare a detailed project report (DPR) to examine the discharge of sewage from major drains and their tributaries and find permanent solutions to prevent such pollution. . A senior civic official said, “Several civic departments are working on this issue. While a permanent solution is being worked out to stop the discharge of sewage into the drains and later into the sea, we are working to handle the current pollution in the drain.”
The project is estimated to cost BMC Rs 82 crore and will be completed in phases over the next five years. The official quoted above said, “BMC approached IIT-B for a solution to treat sewage in the drain. IIT submitted a detailed proposal with the use of n-treat technology. This is the first time it is being used by the civic body. Tenders have been invited to appoint contractors for the project.
Storm water drains (SWDs), or popularly called rivulets, are for releasing rainwater into the sea. However, a survey conducted by the BMC four years ago found that over 75,000 properties and slums along these SWDs discharge untreated sewage into canals.
Of the 25 drains selected for the project, five are in the Bandra and Santacruz areas – Rahul Nagar Nala, Boran Nala, Behrampada Nala, and P&T Nallah in Santacruz and on Link Road; The seven are in Andheri – Milan Subway Road, Cargo Complex Road 1 and 2, Coldongri Road, Abhishek Road, Malpadongri Road and Mogra Road; Six are in Malad and around Goregaon – Dnyaneshwar Nagar, Krishna Nagar, Chincholi, Piramal, MHB in Malad and Papatarshi; And the rest are north of Kandivali – Janupada, Pancholi, Kumbharkala, Kora Kendra, Tavdem Tare Compound, and Avadut Nalla.
Stalin Dayanand from NGO Vanshakti, which had approached the NGT in 2017 for coastal pollution due to discharge of untreated sewage into the sea, said, “What the BMC is doing is minimal. It’s not enough but it’s a start. The civic body today is doing what it was told in 2018. Furthermore, all of its activities and projects are designed to look expensive, while simple measures are sufficient to achieve the same effect. ,
Ashok Mengde, chief engineer of the Mumbai Sewage Disposal Project department, which commissioned the project, said, “The project has been started and tenders have been floated… Overall, the matter is under consideration.” [In 2020, NGT fined BMC Rs 34 crore for non-compliance. The civic body challenged the fine in the Supreme Court],