Wastewater Recycling – Bengaluru Study Highlights Major Water-Saving Opportunity

Wastewater Recycling – Urban water reuse could become a crucial part of Bengaluru’s long-term strategy to manage recurring shortages, with a new international study estimating that the city could recycle a substantial share of the wastewater it generates each day.

Bengaluru Water Management Potential –

Researchers said the city could safely reuse between 473 million litres and 1,187 million litres of wastewater daily for non-drinking purposes. Such treated water could be used for toilet flushing, landscaping, construction work and cooling systems, reducing pressure on freshwater supplies.

The study was carried out by researchers from Swiss Federal Institute of Aquatic Science and Technology, Georgetown University and Bengaluru-based Water, Environment, Land and Livelihoods Labs. It examined how decentralised wastewater treatment systems could help the city address its growing water needs.

Limited Use Despite Extensive Infrastructure –

Bengaluru has more than 3,000 decentralised wastewater treatment and reuse systems, believed to be the largest concentration of such facilities in any city worldwide. Despite this network, only around 47 million litres of treated wastewater is currently reused each day, the researchers found.

The study reviewed water-related policies introduced over the past two decades and included interviews with government officials, technical experts and residents. The team also inspected 22 decentralised sewage treatment plants, most of them located inside apartment communities.

The findings indicated that many of these systems were not operating as intended. Researchers reported that more than 80% of the facilities examined had compliance-related concerns, including treated water that showed visible colour, odour or turbidity.

Operational Gaps Affect Treatment Quality –

A major concern identified in the study was the shortage of trained personnel to manage wastewater treatment plants. In several housing complexes, security staff or housekeeping workers were found to be handling treatment systems that require technical supervision and regular monitoring.

The researchers said this lack of skilled operators can affect the quality of treated water and reduce confidence among residents in using recycled water. Proper operation is essential because treated wastewater must meet required standards before it is supplied for non-potable uses.

The assessment also found that more than 80% of the inspected plants were not using treated water for every non-drinking purpose required under existing regulations. This meant that even facilities with treatment infrastructure were not fully reducing their dependence on freshwater.

Coordination Issues Across Government Agencies –

The study pointed to fragmented administration as another major obstacle. Water supply authorities, environmental regulators and urban development agencies often work through separate systems, creating delays and gaps in implementation.

Researchers said stronger coordination between these bodies could improve oversight, ensure that treatment plants follow standards and help residential communities make better use of recycled water.

Clear responsibilities, regular inspections and technical support for apartment associations could help improve the performance of decentralised treatment systems across Bengaluru.

Water Pricing Reduces Incentive for Reuse –

The report also highlighted the role of water pricing in limiting wastewater recycling. Subsidised piped water and easy access to low-cost groundwater have reduced the financial motivation for apartment complexes to invest in reliable reuse systems.

When freshwater remains comparatively inexpensive, many communities may not consider wastewater recycling a priority, even during periods of water stress. The researchers suggested that policy measures and better enforcement could encourage wider adoption of reuse practices.

Bengaluru’s wastewater recycling capacity could play an important role in improving urban water security if operational standards, governance systems and financial incentives are strengthened.