Why Mumbai’s STP project got lion’s share of funding in this year’s BMC budget

Here’s a look at why the STP project received a major chunk of funding in this year’s BMC budget.

What is the STP project?

An STP is a treatment facility that scientifically treats wastewater for potable and non-potable uses. The STP project being executed by the Mumbai Sewage Disposal Project (MSDP) department will see seven STPs being constructed across Mumbai with a collective capacity of treating 2,464 million litres (MLD) of water daily for potable usage. In addition to this, the STPs will have a combined capacity to treat 1,232 MLD of water further for non-potable use.

Where will these STPs come up?

The STPs are being constructed at seven locations in Mumbai – Worli, Bandra, Dharavi, Versova, Malad, Ghatkopar and Bhandup. Of these seven STPs, the largest one is located in Worli, which will have a capacity of treating 500 MLD of water, followed by Malad (454 MLD), Dharavi (418 MLD), Bandra (360 MLD), Ghatkopar (337 MLD), Bhandup (215 MLD) and Versova (180 MLD).

Why is the STP project important for Mumbai?

Being an island city, Mumbai does not have any natural resources to draw its water from. Daily, the BMC supplies 3,800 MLD of water to Mumbai which comes from seven different lakes, five of which are located in the satellite districts of Thane, Palghar and Nashik. Of the total water received, around 80 per cent or 3,040 MLD is converted into sewage or wastewater after usage. Also, the water that is supplied by the BMC has a shortfall of 400 MLD since Mumbai’s actual requirement is 4,250 MLD every day.

“Our problem is that Mumbai is used to throwing its entire sewage and wastewater into the sea that would go deep by about eight to 10 km. The overall volumetric sludge of sewage collected every day is equivalent to the size of Powai Lake,” Bhushan Gagrani, Municipal Commissioner and state-appointed administrator, said in an Idea Exchange organised by The Indian Express on January 21.

Therefore, in a bid to bridge the deficit of demand and supply, the BMC mooted the STP project so that it can recycle at least 2,464 MLD or 80 per cent of Mumbai’s daily sewage water and bring it back to the city for its potable usage, which in turn will bridge the deficit of daily water supply, leading to equal distribution of water.

What is the current status of each STP?

Of the seven STP projects, Bhandup, Ghatkopar and Dharavi are set to be operational by July 2026, while the facilities at Bandra, Versova and Worli are set to be operational by July 2027. The Malad facility is set to become operational by 2028.

According to the BMC’s budget document, the highest progress of completion of 28 per cent is recorded at Ghatkopar, followed by 26 per cent at Bhandup, 20 per cent each in Dharavi and Bandra, 18 per cent at Versova, 17 per cent at Worli and 7 per cent at Malad.

Abhijit Bangar, Additional Municipal Commissioner, Projects, who is spearheading this operation, told The Indian Express, “Of the various infrastructure projects that BMC has taken up, the STP project is running well on schedule. The civil works for the Malad facility could only begin in 2024 since the process of land acquisition and environment clearances took time. Yet in this short while, we have achieved significant progress.”

“Once they are ready, these STPs will not only bridge the demand-supply gap of water supply in Mumbai by a significant margin but also will contribute towards controlling water pollution as well,” Bangar added.