Mumbai societies will have to treat sewage before releasing it into Mithi river
To control the flow of sewage into the river, the state will introduce decentralised wastewater treatment for large housing societies along Mithi.
The Maharashtra Pollution Control Board (MPCB) said it will direct housing societies that generate more than 20,000 litres of sewage daily to install sewage treatment plants (STPs). The MPCB has identified 70 drains that discharge untreated sewage into the 17.8-km-long river. A year-long survey revealed that the river carried waste consisting 90% domestic sewage and 10% industrial effluents.
“In the past two years, we have shut down more than 700 small-scale industries along Mithi to curtail chemical discharge. But to control domestic waste, different departments need to work in tandem. The process to identify commercial and residential establishments generating large quantity of sewage and treating it at source has begun,” said P Anbalagan, member secretary, MPCB, adding that notices will be issued from February. “Majority of the societies are located in the western suburbs at areas such as Goregaon, Andheri, Santacruz and Kurla, among others.”
After notices are issued, the societies will get 90 days to set up an STP on their premises. MPCB officials said the Brihanmumbai Municipal Corporation (BMC) will install STPs for slums. “It is a complex procedure and will take time. However, the same setup will be replicated along Dahisar, Oshiwara and Poisar rivers simultaneously,” said Anbalagan.
In an order issued on August 16, 2017, based on a petition filed by NGO Vanshakti, the Supreme Court (SC) directed the state to deposit Rs50 lakh for Mithi’s restoration and constituted a joint team comprising of experts from Indian Institute of Technology Bombay (IIT-B) and National Environmental Engineering Research Institute (NEERI) — convened by the state environment department — to control pollution in the river and begin restoration.
“This is the most feasible solution to improve Mithi’s water quality,” said Satish Gavai, additional chief secretary, state environment department, who heads the committee. “A master plan is being prepared by our department and will be submitted in the Apex Court during the next hearing. Last week, the municipal commissioner said tendering process for new STPs in slum pockets has started.”
BMC officials said consultants for the project have been appointed and the tendering process for setting up STPs in slums has commenced. “Construction of an STPs at Filter Pada, near Aarey Colony, has started,” said LS Vhatkar, deputy municipal commissioner (environment), BMC.
Experts welcomed the move and said it will improve the water quality along the city’s shoreline. “The process has been a success at housing societies in Bengaluru. Similar to adopting composting, housing societies will take some time but the end result will benefit all,” said Almitra Patel, Swachh Bharat national expert and member of the committee that drafted Municipal Solid Waste Management rules, 2000.
“Complying with the process should not affect Mumbaiites spending large amounts as maintenance cost already. However, we have to see how MPCB plans to implement in on-ground sequentially so that all streams and nullahs are covered,” said Shyam Asolekar, professor, IIT-B.
However, the NGO said the MPCB plan was unfeasible and sewage should be treated at centralised facilities. “Decentralised wastewater management has been a failure in Mumbai even after regular monitoring by the MPCB. Treating sewage at societies individually, will be time-consuming and waste of money. Considering the space constraint in Mumbai, the plan will fail. As an alternative, clusters of large societies should send their waste to one large STP, thus making the treatment process less complicated,” said Stalin D, director, NGO Vanahsakti.
“There is no doubt that decentralised approach is the only solution to improve water quality in urban areas. This should have been a priority rather than an order from the court. The municipal engineering norms in India till date do not encourage decentralised waste treatment, even though it is a norm abroad. Accurate implementation differs from city to city, but it is essential to recycle water for non-potable use after treatment rather than sending it back to the river,” said Suresh Kumar Rohilla, programme director – urban water management, Centre for Science and Environment, New Delhi.