The Value of Treated Wastewater

India’s G20 presidency is a unique opportunity to promote a circular economy in water. For promoting circularity in wastewater management in leading emerging economies like India, it is important to assess the market value associated with the reuse of treated wastewater. About 11,622 million cubic metres (MCM) of treated wastewater were available in India for reuse in 2021, considering that the treatment capacity was fully utilised

India’s Urban 20 (U20) cycle has laid emphasis on cities being drivers of the circular economy, with ‘ensuring urban water security’ being a key priority area. Growing populations and rapid urbanisation combined with climate change-induced adverse impacts on water resources have increased the pressure on already scarce freshwater resources, leading to the need to explore alternative sources of water. These factors are common drivers for governments globally that are taking steps to shift from a linear to a circular economy approach, with mainstreaming the reuse of treated wastewater as one of the interventions.

India is no exception to the imminent water scarcity issue. According to an analysis by the Council on Energy, Environment, and Water (CEEW) using the Central Water Commission (CWC) estimates, 11 out of the 15 major river basins will experience water stress by 2025, with annual per capita renewable water availability below 1,700 cubic metres. While various water supply augmentation and demand interventions are being explored, the reuse of treated wastewater is receiving increased traction of late, given that India generates over 72,000 million litres of wastewater per day (MLD) in urban areas alone (CPCB, 2021). Out of this, only 28 per cent, or less than one-third, is actually treated. The remaining untreated wastewater is discharged into freshwater bodies. This is one of the main reasons for high levels of pollution in many of the major Indian rivers, especially concentrated in the river stretches passing through urban areas.

Class I cities, having population above 1,00,000, and class II cities, with populations of 50,000–99,999, which represent a major share of about 72 per cent of the total urban population in the country, produce an estimated 38,254 MLD of sewage, of which only 30 percent is treated (CPCB, 2021). Various reports suggest that many STPs don’t function at maximum capacity, and others don’t meet prescribed effluent water quality standards. In some cases, STPs are underutilised since the sewerage network doesn’t cover unauthorised colonies and sub-urban areas. Further, many urban utilities are unable to scale up wastewater treatment capacity as the capital and operating costs of building infrastructure are high.

In addition to treatment, the reuse of treated wastewater is also low, even in major urban agglomerations. For instance, it is 49 per cent in Chennai, 19 per cent in Delhi, and 6 per cent in Hyderabad (IWA, 2018).

Wastewater treatment capacity & economic growth

Cities are key propellers of economic growth, with the majority of global GDP generated in cities (World Bank, 2020). Correlating the sewage treatment capacity (as a percentage of total sewage generation) with the per capita GDP in the G20 countries can indicate whether wastewater treatment is a strong function of economic development. Our analysis shows that most of the G20 countries with high GDPs also have high wastewater treatment capacities (Figure 1 ). The coefficient of correlation is 0.65. Thus, major growth in sewage treatment capacity is expected in leading emerging economies, including Brazil, India, China, and South Africa.

Market value of reuse

For promoting circularity in wastewater management in leading emerging economies like India, it is important to assess the market value associated with the reuse of treated wastewater. About 11,622 million cubic metres (MCM) of treated wastewater were available in India for reuse in 2021 (CPCB, 2021). As per the CEEW estimates, this will become 15,288 MCM by 2025 and 35,178 MCM by 2050. We estimate that the market value of the total treated wastewater (TWW) available in 2021 would have been over 630 million had there been a mechanism in place for the sale of TWW for reuse. The market value would substantially increase to over 830 million in 2025 and `1.9 billion in 2050 (Bassi et al., 2023). Hence reusing treated wastewater can be a financially viable proposition too.

Reusing TWW in irrigation

India’s irrigation sector, with its predominant water demand, offers a substantial opportunity for TWW’s reuse. As per our analysis, nine times the area of New Delhi can be irrigated with the treated wastewater currently available in India for the irrigation sector. Further, about `966 billion would be the revenue generated from the agricultural yield produced from this area of land. There are also environmental benefits associated with reusing TWW in the irrigation sector.

Recommendations

Despite its potential, reuse of TWW has not yet become mainstream in India. Only a few Indian states have framed policies and guidelines to promote treatment and reuse. The National Framework on Safe Reuse of Treated Water (NFSRTW) was launched as recently as January 2023 with the broader vision of bringing water into a circular economy framework. It will act as a guiding document for the formulation of state-level policies based on respective needs and demands. However, the successful implementation of these policies is directly linked to the economic feasibility of reuse projects. Here, we make some recommendations to enable the implementation and scaling up of reuse projects in India.

First, we need a paradigm shift in ideology for wastewater to be considered an integral part of all water resource management-related policies, plans, and regulations. A common enabling factor in the successful implementation of reuse projects globally is the adoption of a comprehensive national policy framework on wastewater treatment and reuse. The focus now should shift towards effective implementation of the recently launched NFSRTW.

Second, robust institutional arrangements need to be put in place to ensure effective collaboration between the centre and states. At city level, urban local bodies should be empowered to formulate and adopt long-term, city-level wastewater reuse plans.

Third, we need to promote the financial viability of reuse projects by adopting supply-side and demand-side interventions in synergy. On the supply side, appropriate PPP models need to be promoted for effective responsibility and risk sharing. Learnings from global experience suggest that blended finance can go a long way in ensuring the financial viability of reuse projects. On the demand side, freshwater needs to be priced to create demand for TWW in the first place. To enable a shift towards treated wastewater reuse for non-potable purposes, freshwater needs to be priced to reflect its scarcity, which means that its price should be higher than that of treated wastewater.

Fourth, we should have a sector-based dynamic pricing mechanism for TWW that considers different categories of users and their paying abilities. One of the major barriers to implementing reuse projects for local urban authorities is cost recovery. The collection of user charges for urban infrastructure services has been promoted in the Union Budget 2023. It will help recover the wastewater treatment cost and contribute towards making reuse projects commercially viable. For instance, local authorities can provide secondary TWW to industries at rates lower than industrial water tariffs paid otherwise. Lastly, investment in public outreach through effective information, communication and education activities is required to build public confidence and encourage behaviour change towards using reclaimed water. Public acceptance is a crucial factor in successful implementation of reuse policies. STPs have been rebranded as Nirmal Jal Kendras to remove stigma associated with wastewater.

Incorporating wastewater management as an essential urban service is important. India has taken comprehensive steps to address it through national missions such as AMRUT and initiatives for river-sensitive urban development such as Namami Gange programme. As the host of the G20 this year, India has the unique opportunity to develop an action plan and framework for tackling wastewater in the Global South, thereby driving long-term impact towards sustainable water management.