Reuse of Treated Wastewater Can Help Ease Growing Urban Water Crisis: CSE Report

Patna: The ongoing global warming has been affecting water resources in India like elsewhere, but the country can reuse treated wastewater for climate resilience.

According to a latest report of New Delhi-based think tank, Centre for Science and Environment(CSE), reusing treated wastewater can help ease India’s growing urban water crisis.

The report titled, Waste to Worth: Managing India’s Urban Water Crisis Through Wastewater Reuse, highlighted that India treats only 28% of the wastewater it generates; 72% remains untreated – once treated, all this wastewater can be reused.

"Of the total urban wastewater and sewage generated in India, a mere 28 per cent (20,236 million litre per day or MLD) undergoes treatment, leaving a substantial 72 per cent untreated and allowed to flow into rivers, lakes and land. All this treated water – and the remaining untreated amount if treated – holds an opportunity within itself: the opportunity to ease India’s urban water crisis", says the report.

Sunita Narain, director general, CSE, said: “India faces significant water scarcity challenges due to rapid urbanisation, industrial growth, population expansion – and most importantly -- climate change. Wastewater reuse can be a key part of the strategy to address these concerns and promote water circularity and sustainability.”

“In fact, there is an opportunity for turning wastewater into water again, and this is what our report’s title – Waste to Worth -- is referring to,” Narain added, in a release.

Rajiv Kumar Mital, director general, National Mission for Clean Ganga, was quoted as saying that “using and disposing treated water, without harnessing its potential, means we are losing out on utilising an important resource. The challenge is to scale up and ensure that the work we do in this sector is impactful.”

Subrata Chakraborty, senior programme manager, water programme, CSE, said the Jal Shakti Ministry had mandated that cities must recycle and reuse at least 20% of the water they consume.

“This is in line with the belief that promoting a circular economy is essential for achieving a sustainable and climate-resilient future, and for managing the ever-growing demand for freshwater,” she added.

The CSE report further said that the gap in total sewage water generated and its treatment was the highest in Uttar Pradesh, followed by Maharashtra, Karnataka, Rajasthan, Tamil Nadu, Delhi and Haryana.

The report also highlighted good examples -- cases of states that have introduced policies to encourage treated wastewater reuse.

Maharashtra, for instance, mandates industries in urban areas to use treated wastewater. Gujarat targets 100% reuse with applications in agriculture and industry, and Tamil Nadu promotes reuse for industrial and urban greening projects.

At the national level, the National Urban Sanitation Policy and the Namami Gange Programme emphasise wastewater management and reuse as key components of water security initiatives, the report added.

Cities like Nagpur, Bengaluru and Chennai have taken the lead in implementing wastewater reuse practices. Nagpur supplies treated wastewater to power plants, significantly reducing freshwater usage, while Bengaluru utilises it for agriculture, lake revival and groundwater recharge. Chennai has adopted treated wastewater for industrial applications, urban landscaping and groundwater recharge.

Sumita Singhal, programme manager, water, CSE, said: “Upscaling wastewater reuse faces challenges, including infrastructure gaps in sewage treatment and distribution, quality assurance to meet reuse standards, public resistance due to cultural beliefs, and the high operational costs of treatment facilities.”

She added, “The data implies that 28 per cent (20,236 MLD) treated water is immediately available for reuse. Aligning policies with urban planning and industrial needs can enhance adoption, while advancements in decentralised and cost-effective treatment technologies can address infrastructure deficits.”

The CSE report points out that public-private partnerships can help mobilise investments for scaling up reuse projects, and capacity-building initiatives can improve awareness and acceptance among urban managers and communities.

The writer is a freelancer based in Patna, Bihar.