Innovative methods are key to encouraging reuse of treated wastewater in India by building trust

Ambitious plans to tackle water scarcity with reuse of treated water face infrastructural and societal challenges

India has a bold plan to reuse half of its treated wastewater from operational sewage treatment plants (STP) by 2025 and all of it by 2030. This ambitious goal aims to address a growing issue: Dwindling freshwater resources. However, realising this vision will not be easy.

The current infrastructure is inadequate to handle the task. Many STPs are overloaded and unable to treat wastewater to the high levels required for reuse. Additionally, India’s wastewater collection systems are often inadequate, hindering the efficient channelling of wastewater to treatment facilities. 

Even if these hurdles are overcome, another challenge remains — public perception. Concerns about the quality and safety of treated wastewater often lead to resistance and a reluctance to use it. 

This is in stark contrast to India’s history of wastewater reuse.  As early as 1964-65, 20 per cent of wastewater from the textile industry was repurposed without pre-treatment, reducing costs. The Air India building in Mumbai pioneered the treatment of toilet black water for reuse in air conditioning systems. Since the 1970s, Chennai has used wastewater to irrigate.

Despite these early examples, current reuse practices frequently demonstrate an important point: Wastewater use is often driven by necessity rather than choice.  Farmers in Alwar, for instance, use treated wastewater to grow vegetables that are being sold to mandis (markets). They do, however, use fresh water for their own consumption.  

While this approach saves money and makes use of a scarce resource, farmers may not trust the water for their own consumption. This emphasises the importance of bridging the gap between using treated wastewater out of necessity and fully trusting its quality.

Another example in Kanpur is treated urban wastewater (TUW) from the Jajmau STP, which is used for agriculture despite the treated water’s poor quality. However, due to contaminated groundwater, the villagers must rely on canal water for irrigation in the absence of any other source. 

During a study by Delhi-based think tank Centre for Science and Environment (CSE) across northern and southern India, several social factors hindering the reuse of treated wastewater were identified. These are: 

  • Perceived health risks: Concerns about potential health risks deter many from using recycled water, despite meeting safety standards.
  • Stigma and social acceptance: Social stigma linked to recycled water being seen as “dirty” or “contaminated” can hinder its acceptance.
  • Doubts about safety: Public doubts about the reliability and safety of recycled water can impede acceptance.
  • Perception of inferiority: Viewing recycled water as “second-rate”” contributes to societal taboos against its use.
  • Aesthetic concerns: Negative reactions to the appearance, smell, or taste of recycled water may persist, even if it meets safety standards.

Overcoming hindrances

To overcome public resistance to wastewater reuse, it is imperative to address the underlying concerns and misconceptions while simultaneously raising awareness about the benefits and safety of recycled water. 

Consumers frequently express concerns about the direct use of treated water for drinking and agriculture due to a lack of understanding of the extensive treatment processes, which fuels misconceptions that impede recycled water promotion. Breaking societal resistance to treated wastewater reuse necessitates innovative and collaborative efforts. 

Innovative methods from around the country

Secondary treated water in Bengaluru is used to recharge shallow aquifers through natural percolation by filling lakes, thereby increasing groundwater levels in nearby wells for irrigation and domestic use. Efforts at Jodikrishnapura and Narasapura Lakes have significantly increased the groundwater table, allowing drip irrigation on 20 acres. 

The HN Valley Project uses TUW to rejuvenate 65 lakes in the Chikkaballapur, Bengaluru Urban and Bengaluru Rural districts, increasing groundwater levels and revitalising wells. Another example is an open well recharged by Sihineeru Lake, which has been raised to 10 feet and now supplies 30,104 kilolitres of water to Devanahalli for domestic use since the borewells were revived.

In Karhalli Village, releasing TUW into Chikkasagarahalli Lake recharged aquifers, reviving wells and allowing farmers to grow a wider range of crops again. 

In Delhi, treated wastewater from STPs is used to recharge lakes as part of the ‘City of Lakes’ programme. This facilitates natural percolation and recharge of shallow aquifers. This augmented groundwater source is intended to be extracted from constructed tube wells for drinking water supply after further processing.

Illustration showing reuse of treated wastewater under City of Lakes programme in Delhi

These efforts demonstrate how indirect reuse can overcome the issue of acceptance of reuse of TUW for different purposes as compared to direct reuse.

In Nasapakkam, the tertiary treated water from a 10 million litres per day (MLD) tertiary treatment unit is blended with Porur lake and is then sent to a 6 MLD Drinking Water Treatment Plant, located a kilometre away, for supplying water to households for drinking and domestic needs. 

The villages surrounding the Dhandupura STP did not accept treated water for agricultural reuse. The residents continued to heavily rely on groundwater for agriculture. However, they began to face issues due to declining water levels and availability. They were also hesitant to use canal water because they believed it contained dirty water (STP-treated water).

In 2003, the plant began a showcase model on the STP grounds, growing seasonal vegetables with treated water and inviting nearby farmers to demonstrate its agricultural safety. They shared the vegetables and demonstrated the treatment process to clear up any confusion. 

Currently, nearly 80 per cent of the treated water is used to irrigate a 6 kilometre radius of agricultural land. Around 570 small farmers use it for crops like cauliflower, ladyfingers, chilies, spinach, potatoes and livestock fodder. The irrigated area has expanded from 340 hectares in 2006 to 800 hectares by 2021.

To increase the reuse of treated water generated by Prayagraj’s Naini STP, the facility was made available to farmers so that they could monitor the quality and quantity of treated water. 

Farmers now have access to this system at any time to monitor daily water quality and quantity, which has increased their confidence and sense of ownership in using treated wastewater for irrigation. Currently, approximately 14-15 villages benefit from the reuse of treated wastewater from the Naini STP.

A farmer accessing treated water from hydrant installed in a field for agriculture in Baraichpur village, Kurukshetra district, Haryana. Photo: Faraz Ahmad / CSE

A farmer accessing treated water from hydrant installed in a field for agriculture in Baraichpur village, Kurukshetra district, Haryana. Photo: Faraz Ahmad / CSE

A planned intervention in Haryana’s Kurukshetra district repurposes treated water from the Shahabad, Ladwa and Pehowa STPs for agricultural use. The Micro Irrigation Command Area Development Authority (MICADA) has established Water Use Association Committees (WUC) in villages to maximise the use of treated wastewater.  

These committees effectively disseminate information about the initiative and its benefits, assisting in overcoming the challenges associated with using treated water. The WUCs, which are trained and guided by MICADA, play an important role in communicating with farmers and raising awareness. 

The availability of treated wastewater for irrigation benefits a total of 717 acres of agricultural land. This large plot of land grows a variety of crops and provides a living for 88 farmers. 

Innovative methods, such as those used in Bengaluru, Delhi, Chennai, Kurukshetra, Agra and Prayagraj to supplement drinking water supply through shallow aquifer recharge, monitoring, knowledge dissemination, awareness and community engagement, are critical for establishing trust and increasing acceptance of recycled water initiatives. 

By involving local communities in decision-making and ensuring compliance and quality, wastewater reuse projects can be implemented in a culturally sensitive and community-responsive manner.

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