Decentralised Treatment of Wastewater and its Bulk Reuse

India’s urban water crisis is no longer a looming threat; it is a lived reality.

According to the NITI Aayog’s Composite Water Management Index

• About 600 million Indians face high to extreme water stress.
• Nearly 0.2 million (two lakh) die every year due to inadequate access to safe water.
• By 2030, the country’s water demand is projected to be twice the available supply.
• 21 cities, including Delhi, Bengaluru and Hyderabad, are at risk of running out of groundwater.
• Indian cities already lose 30-50 per cent of their supplied water through leakages, theft and inefficient distribution
• Only 28 per cent of urban wastewater is treated.

Conventional approaches — drawing more from rivers, aquifers, and inter-basin transfers — are reaching ecological and economic limits, while climate variability makes rainfall increasingly unreliable. In this context, water and sludge reuse are not merely efficiency measures; they are structural necessities. Decentralised and modular treatment systems offer an opportunity to treat wastewater closer to where it is generated and enable its fit-for-purpose reuse for applications such as flushing, landscaping, cooling, industrial processes and other non-potable uses. Similarly, treated sludge and other treatment-derived solids can potentially be recovered and reused as compost, soil amendments, energy feedstock or sources of nutrients and other resources.

However, the availability of technologies alone does not ensure their wider adoption. Questions remain around technology performance and readiness, treatment and reuse standards, building bylaws, regulatory approvals, monitoring, quality assurance, institutional responsibility and long-term operation and maintenance. There is also a need to examine whether existing technical guidelines and regulatory frameworks are keeping pace with emerging treatment and resource-recovery technologies.

THE ROUNDTABLE WILL, THEREFORE, BRING DIFFERENT STAKEHOLDERS TOGETHER TO ADDRESS THREE BROAD QUESTIONS:

Where are we today?
What technologies and approaches are currently available for in-situ treatment, liquid reuse and solid/ resource recovery?

What enables or constrains adoption?
Do existing standards, bylaws, policies and institutional arrangements adequately support decentralised treatment and reuse?

What needs to change?
What technological, regulatory, institutional and implementation changes are required to move from individual projects and pilots towards safe, viable and scalable decentralised treatment and bulk reuse?

FOR MORE INFORMATION, PLEASE CONTACT:

PRADEEP KUMAR MISHRA
Deputy Programme Manager
Water Programme, CSE
Mobile: 8085443793
Email: pradeep.mishra@cseindia.org

SUBRATA CHAKRABORTY
Programme Director
Water Programme, CSE
Email: subrata.chakraborty@cseindia.org