India’s water challenges are multifaceted and multiplying. The country is ranked as the world’s 13th most water-stressed country by the World Resources Institute’s Aqueduct Water Risk Atlas. Given that both surface water and groundwater in India are highly exploited, the concept of recycling and reuse of wastewater has started gaining significance. The huge volume of untreated water can be effectively treated and used for various non-potable purposes such as gardening, flushing, construction, etc.
State governments have either adopted or are moving forward with treated wastewater recycle and reuse policies that seek to reduce dependency on freshwater resources. The government’s policy aims to reuse 70 per cent of the treated wastewater by 2025 and to achieve 100 per cent reuse by 2030. Further, the policy is directed at widespread and safe reuse of treated used water in India, which reduces the pressure on scarce freshwater resources, reduces environmental pollution, alleviates risks to public health and achieves economic benefits by adopting a sustainable circular economy approach.
In this context, the Nagpur Municipal Corporation recycles more than 90 per cent of its generated sewage and is in the process of increasing the capacity of its treatment plants with the aim of recycling 480 million litres per day (mld) of wastewater. Delhi is also aiming to achieve 80 per cent wastewater reuse by 2027.
In November 2019, the Haryana government approved a policy to treat wastewater for non-potable purposes, aimed at alleviating the stress on ground and surface water resources. In January 2020, the Telangana government announced the launch of a sanitation hub. It is an incubator to promote start-ups and innovations in water, sanitation, sewage water management and wastewater recycling. A seed fund of Rs 250 million was earmarked for the initiative.
Meanwhile, the Chennai Metropolitan Water Supply and Sewerage Board has formulated a set of service standards, mandating accelerated wastewater reuse and zero liquid discharge (ZLD). All stakeholders, including government authorities, the private sector and citizens are mandated by a set of regulations and by-laws to ensure maximum reuse of wastewater adhering to safe quality standards. ZLD is a water treatment process, involving steps such as ultrafiltration, reverse osmosis, crystallisation and fractional electrode ionisation. After the process, the entire treated wastewater is fit for recycled use.
Industries are also taking initiatives to enable recycle and reuse of wastewater. In 2019-20, Indian Oil Corporation Limited recycled 41.35 billion litres of wastewater to reduce its freshwater requirement. Recycled wastewater accounted for 30 per cent of the company’s total operational water consumption. Following a similar trend, the percentage of wastewater recycled/reused/recirculated by Hindustan Petroleum Corporation Limited in 2019-20 amounted to nearly 60.2 per cent. It has undertaken the installation of water-efficient fixtures and recycling of wastewater through effluent and sewage treatment plants.
In another development, the Welspun Group has set up a 30 mld sewage treatment plant at its Anjar factory in Gujarat, which recycles sewage wastewater from neighbouring areas. This initiative has led to zero intake of freshwater for manufacturing processes. Besides, Grasim Industries acknowledges water as a scarce natural resource and as a responsible corporate, the company has implemented the 3R (reduce, reuse and recycle) principles across all its units. In Kanpur’s Jai Narayan School, a new recycling system has been set up. The school is saving approximately 3,000 litres of fresh water every day. They are reusing laundry wastewater to flush toilets in the boys’ hostel.
There are various challenges faced in the implementation of wastewater reuse projects. Of these, financial challenges include insufficient access to capital, high operation and maintenance costs, and limited research on market viability. Institutional challenges such as lack of coordination among authorities, absence of a proper regulatory framework and limited data availability also hamper these projects. Besides, insufficient treatment and distribution infrastructure, limitations of treatment technology and lack of water quality monitoring hamper the growth of wastewater reclamation and reuse in the country.
The road ahead
As India’s population grows, it is outstripping the available water supply. The booming population is placing unsustainable demands on the country’s already stressed water resources. Groundwater wells are declining and 21 major cities – including Delhi, Bengaluru and Hyderabad – are soon expected to run out of groundwater, affecting water access for nearly 100 million people. Going forward, it is imperative to develop a robust regulatory paradigm specifically meant to address the issue of water reuse. It is essential that all stakeholders integrate their efforts to enable the recycle and reuse of wastewater.