Apartments in Bengaluru get nod to sell 50% of treated water from STPs

Karnataka government has for the first time allowed treated water from localised Sewage Treatment Plants (STPs) inside apartment complexes and gated communities to be sold on commercial basis.

On March 22, Bangalore Water Supply and Sewerage Board (BWSSB) issued an order allowing residential communities to sell 50% of treated STP water they produce on commercial basis. The treated water has to be compliant with standards set by the National Green Tribunal (NGT), and can be used for any purpose except in food and medicine industries.

This move comes amidst the board banning the use of potable water — both Cauvery river water and borewell water — for non-essential purposes, mandating the use of treated water for construction and other purposes.

300 MLD treated water up for grabs

Presently, the rule mandates that all apartments with over 20 flats built after 2016 should have an STP. According to a study by Bangalore Apartments’ Federation (BAF), there are over 3,500 such STPs in residential communities in the city, which add up to 720 Million Litres per Day (MLD) capacity to treat sewage water every day. “After using treated water for flushing and gardening purposes within the communities, our estimates suggest that at least 300 MLD of water is being wasted, and can now be used effectively,” said Satish Mallya, Vice-President, BAF.

Total number of decentralised STPs in apartments and gated communities: Around 3,500

Total Installed Capacity of these STPs: 720 Million Litres per Day (MLD)

Treated water (as per NGT standards) available to be sold: Over 300 MLD

Earlier, there was a zero discharge policy. A big part of treated water was wasted by being let into Storm Water Drains (SWDs) where it mixed with untreated sewage before entering nearby lakes.

“To prevent this, BAF had been lobbying hard with all political parties to allow us to take the treated water out of our communities, to put it to some good use. It found a mention in the Congress manifesto for the 2023 Assembly polls. Given that the party came to power, we had been pushing for the same. It has now been implemented at an opportune time when there is a water crisis in Bengaluru,” Mr. Mallya said.

BAF in talks with CREDAI, BWSSB to facilitate

BAF is holding talks with Confederation of Real Estate Developers’ Association of India (CREDAI) - Bengaluru to see if they would buy the excess treated water from residential communities.

BWSSB has banned the use of potable water for construction, and has also issued an order commandeering all borewells at construction sites. However, several builders complain that STPs of the BWSSB — 36 of them — are far off. The logistics of fetching treated water from them are challenging. In this context, BAF hopes, the 3500 STPs spread across Bengaluru can come in handy for construction projects.

While BWSSB sells 1 kilolitre of treated water for ₹10, BAF is yet to decide on a price.

V. Ram Prasath Manohar, Chairman, BWSSB said the board will partner with BAF, and will facilitate the process of sale of treated water. “Presently, the best use for treated water from residential communities is to supply it to construction projects nearby. We will facilitate this,” he said.

BWSSB and BAF are also in talks over using treated water from these STPs to fill nearby lakes. “We won’t be able to pay for treated water to fill lakes. But BAF is ready to provide us treated water for free to fill lakes nearby. The details are being worked out,” Mr. Manohar said.