For long limited by logistic bottlenecks and unfavourable perceptions, Bengaluru’s treated wastewater could find new takers as researchers and civic stakeholders start to look at it as a viable solution to the city’s freshwater concerns.
A grey-to-green project by the Centre for Social and Environmental Innovation (CSEI), in association with the Karnataka State Pollution Control Board (KSPCB), is on cue. The project envisions use of treated wastewater generated in apartment buildings for greening medians and parks. The pilot, done in the Yelahanka zone, involved a survey of around 70 parks.
Shreya Nath who leads CSEI’s Green Cities initiative said only 25% of the surveyed parks have storage facilities. “We expect to submit a Detailed Project Report to the BBMP soon. The project, in its initial phase, will focus on the medians,” Shreya told DH.
CSEI estimates that the Bangalore Water Supply and Sewerage Board’s centralised sewage treatment plants (STPs) and decentralised STPs installed in apartments and other buildings together generate 1,265 MLD (million litres per day) of treated wastewater in Bengaluru, of which 720 MLD is unused and discharged into drains and lakes.
Speaking at a workshop on wastewater reuse in Bengaluru last week, KSPCB member-secretary Srinivasulu said the adoption of treated wastewater could help replace substantial amounts of freshwater put to non-potable use.
Supply awaits demand
Tankerwala — the mobile app startup which helps people book freshwater through tankers — has also been supplying treated water to the construction industry for the past three months. The company now delivers about 1 MLD of treated water sourced from apartment STPs to its customers.
It conducts its own tests on the water’s quality before it contracts partners for transporting it. The company also runs its own fleet of tankers. Shravanth Donthi, co-founder and CEO of Tankerwala, said an official certification for prescribed standards of treated water is a missing link. While top builders work with treated water generated from their own STPs, there is not enough awareness on its potential.
“With greater awareness, the demand will increase; the supply is already in place. We are building a database on treated water available with the apartments,” Donthi said.
The Bangalore Apartments’ Federation (BAF) collaborates with CSEI on the grey-to-green project. “The cost of compliance makes it tougher (for STP installation in apartments). These apartment associations spend Rs 60 to Rs 70 per litre as treatment costs. Instead of getting incentives for these efforts, they are penalised,” Vikram Rai, general secretary, BAF, said.
He said a lack of clarity in policy-making regarding standards to be followed and inconsistent adoption of technology provided by various service providers are challenges that need to be addressed before treated wastewater finds greater acceptance.