For decades, India has largely viewed wastewater management through the lens of treatment: collect sewage, build treatment capacity, meet prescribed standards, and discharge the treated water safely.
That approach is changing.
As cities grow, industries expand, and freshwater sources come under increasing pressure, the question is no longer only how much wastewater India can treat. It is also about what happens to the water after treatment.
Can it be used again? Can it reduce dependence on freshwater? Can industries use it in place of groundwater? Can cities create reliable markets for recycled water? And can wastewater treatment plants evolve from disposal-oriented facilities into resource recovery centres?
These questions are increasingly shaping India's water policy and infrastructure planning.
In the latest development, the Central Public Health and Environmental Engineering Organisation (CPHEEO), under the Ministry of Housing and Urban Affairs, and the Japan International Cooperation Agency (JICA) signed a three-year technical cooperation agreement on October 3, 2026, to strengthen India's institutional and technical capacity for the circular use of treated wastewater. The proposed work includes a national manual on treated wastewater reuse, capacity building for urban local bodies, sharing of good practices and recommendations on policy and implementation. The applications being considered include industrial, agricultural, civic and ecological reuse, as well as groundwater recharge and aquifer storage and recovery. The development is significant. But it is also a reminder that India's wastewater reuse journey is still being built.
From treating wastewater to using it again
India's water sector has already come some way toward reuse.
The government reported in 2026 that around 6,535 MLD of treated water was being reused by states for applications including industry, horticulture and agriculture, while another 1,931 MLD of recycling and reuse capacity had been approved under AMRUT 2.0. The same programme has also established Water Resource Recovery Cells in 25 States and Union Territories to plan and monitor resource recovery interventions.
Several states also have examples of reuse. A government review has highlighted initiatives in Gujarat, Delhi, Indore, Karnataka, Tamil Nadu and Maharashtra, covering applications ranging from industrial use to agriculture, horticulture and greywater management.
These examples show that wastewater reuse is not theoretical. It is already happening.
The larger challenge is scale.
India generates enormous quantities of sewage, but treatment capacity, actual utilisation, treatment performance and reuse do not always move together. A recent CPCB summary reported sewage generation of about 61,754 MLD against installed treatment capacity of 22,963 MLD, illustrating the continuing gap between sewage generation and treatment infrastructure.
This is where the next phase of India's water story becomes more complicated.
Building an STP is only one part of the solution.
From compliance to water quality
The traditional objective of wastewater treatment has been compliance: treat the wastewater to the required standard before discharge.
Reuse introduces a different question:
Is the treated water fit for its intended purpose?
Water intended for industrial cooling cannot necessarily be treated in the same manner as water intended for horticulture. Agricultural reuse, toilet flushing, construction, industrial processes and groundwater recharge each have different requirements.
The treatment train therefore depends on the end use.
This distinction matters because the term "treated wastewater" can create a false sense of uniformity. Treatment is not a single endpoint. It is a process that must match water quality requirements and the risks associated with a particular application.
The government's Safe Reuse of Treated Water initiative reflects this sectoral approach. Uttarakhand, for example, notified a policy in 2026 covering non-potable applications such as industrial processes, construction, irrigation of parks and green spaces and other urban uses. Policies for several other states were reported to be at different stages of development.
For the industry, this creates an important opportunity—but also a responsibility.
The objective should not be to sell additional treatment technology simply because reuse is becoming fashionable. The objective should be to establish the required water quality, reliability and monitoring framework first, and then select the appropriate treatment process.
The STP is becoming more than a treatment plant
The language around wastewater infrastructure is also changing.
A conventional sewage treatment plant is largely seen as an environmental infrastructure asset. A water resource recovery facility is expected to recover value from what enters the plant.
That value may include:
- Reclaimed water
- Biogas and energy
- Nutrients
- Reusable sludge or biosolids, where appropriate
- Other recoverable resources
This does not mean every STP can immediately become a profitable resource recovery facility. Economics, wastewater characteristics, land availability, energy costs and local demand will determine what is practical.
But the direction is clear.
The more valuable question is no longer simply "How do we dispose of treated wastewater?"
It is "What resources can responsibly be recovered from it?"
For municipalities, this could reduce pressure on freshwater sources. For industries, it could provide an alternative source of process water. For utilities, it could potentially create new revenue streams.
But those benefits will materialise only where the entire chain—from collection and treatment to conveyance, offtake and monitoring—is planned together.
Technology has a role, but it is not the whole answer
Wastewater treatment is becoming increasingly sophisticated.
Advanced biological treatment, membrane systems, tertiary filtration, disinfection, online monitoring, automation and data-based plant management can improve the quality and reliability of treated water.
Digital systems can also help operators identify changes in plant performance, manage energy consumption and monitor water quality.
But technology should not replace basic infrastructure and sound operation.
A sophisticated treatment system cannot compensate for inadequate sewer connections. An advanced STP cannot create demand for recycled water where there is no assured offtake. Nor can automation solve a business model that does not provide sufficient funds for operation and maintenance.
India's wastewater sector therefore needs to avoid a technology-first approach.
The right question should be:
What is the required outcome, and what is the most appropriate technology and operating model to achieve it?
That approach will be particularly important as smaller cities and urban local bodies begin considering reuse projects.
The missing link: economics
Perhaps the most important question surrounding wastewater reuse is not technical.
It is economic.
Who will pay for recycled water?
Freshwater may already be subsidised or supplied through existing infrastructure. A recycled-water project, by contrast, may require tertiary treatment, pumping, storage, and a dedicated distribution network.
Without understanding the economics, a city can build a technically sound reuse project that struggles to find sustained users.
This is why developing markets for treated wastewater deserves as much attention as developing treatment plants.
Industries are likely to be among the most important users because they often have predictable and substantial water demand. Power plants, manufacturing facilities, construction activities, horticulture and other non-potable applications can also create demand.
Long-term purchase agreements, appropriate tariffs, reliable quality and clear responsibilities can help establish confidence on both sides.
The public sector may also need to consider whether to price recycled water based on production cost, the value of the freshwater source it replaces, or a combination of factors.
No single answer fits every city.
India's water realities vary significantly by geography, climate, industrial base, and the availability of freshwater and groundwater. A reuse model that works in Chennai may not necessarily be appropriate for a smaller inland city.
Reuse must also be safe
People tend to describe wastewater reuse as inherently sustainable. It can be—but only when properly planned and managed.
The quality of the incoming sewage, treatment performance, monitoring frequency, storage conditions and end use all matter.
Emerging contaminants and industrial pollutants also make source control increasingly important. A treatment plant should not be expected to solve every pollution problem after contaminants have already entered the sewer network.
For industrial wastewater in particular, segregation and pretreatment at source remain essential.
The same principle applies to agricultural and environmental applications. Before large-scale adoption, we need to understand the quality of reclaimed water and the long-term implications of its use.
This is where regulation and monitoring become critical.
Reuse should build confidence in recycled water, not undermine it.
India needs a market for treated water-not just more treated water
The next stage of India's wastewater journey will therefore require a shift in thinking.
Treatment is necessary. Reuse is the next step.
But reuse cannot be achieved simply by announcing targets or building additional treatment capacity.
Cities need:
Reliable collection → Effective treatment → Fit-for-purpose water quality → Reliable conveyance → Assured users → Sustainable pricing → Continuous monitoring
If one link is weak, the entire system can struggle.
The recently announced JICA–CPHEEO project is therefore important not only because it focuses on technology, but because it brings institutional capacity, technical guidance, training and policy implementation into the discussion.
That broader approach is essential.
India does not need to choose between freshwater conservation and wastewater treatment. It needs to connect the two.
Every litre of treated wastewater that can safely substitute for freshwater represents an opportunity to reduce pressure on rivers, reservoirs and aquifers. But the substitution has to be technically sound, economically viable and environmentally responsible.
The road ahead
India's wastewater sector has reached a point where the conversation is gradually moving from "How much sewage can we treat?" to "How much treated water can we put to productive use?"
That is an important shift.
The opportunity is substantial, but so are the challenges. Treatment plants must perform consistently. Distribution infrastructure has to reach users. Water quality must match the intended application. Industries need confidence in supply. Urban local bodies need sustainable operating models. And citizens need assurance that reuse is being undertaken safely.
The real water revolution, therefore, will not come from a single technology.
It will come when cities plan wastewater as part of their overall water balance.
India has spent years building the foundations of wastewater treatment. The next decade could determine whether those treated flows become a dependable second water source.
The objective should not be to make wastewater disappear.
It should be to make every safely reusable drop count.