The use of treated wastewater in agriculture is essential for addressing water scarcity and promoting a circular economy. In this blog, Arsha discusses the potential of treated water to enhance agricultural practices and the importance of educating farmers on its safe and effective use.
CONTEXT
India, classified as a water-stressed country, holds 17% of the world’s population but only 4% of its water resources. Agriculture is the largest water-consuming sector, accounting for around 85% of total water consumption. With water scarcity and climate change posing serious challenges, it’s crucial to manage water demand efficiently. The traditional open-loop system of linear economy needs to be replaced with a circular economy. In the linear model of take-make-use-dispose,” water is extracted, used, and then disposed of as wastewater into water bodies without proper treatment, exacerbating freshwater scarcity and pollution.
UNDERSTANDING THE CIRCULAR ECONOMY
A Circular Economy (CE) is a closed-loop system focused on reusing, recycling, and regenerating resources to minimize waste and environmental impact. Unlike the linear model, CE maximizes resource efficiency and extends the life cycle of materials. CE is based on three principles: Eliminate waste and pollution, Keep products and materials in use, Regenerate natural systems. The 9R strategy—refuse, rethink, reduce, reuse, repair, refurbish, remanufacture, repurpose, recycle, and recover—represents the most comprehensive and detailed set of strategies currently available.
One key aspect of CE is wastewater treatment and reuse. Treated wastewater has significant potential for agriculture, yet public concerns about safety, health, and quality have hindered its widespread adoption, especially for edible crops.
TREATED WATER IN AGRICULTURE
The public perception regarding the use of treated water for gardening (non-edible crops) and landscaping is positive up to an extent. However, its application in edible crops is not very well received due to concerns about contaminants like pathogens, heavy metals, or chemical residues. Such concerns are of a serious nature, as even a slight alteration of the water used for irrigation could impact the safety of the produce, impacting the health of consumers. Edible crops like leafy vegetables, which are consumed raw, are more susceptible to heavy metal contamination, while non-edible crops pose significantly fewer concerns.
Vegetables grown using treated water in Municipal Sewage Treatment plant
in Dombivli, Maharashtra
In my own research conducted at the Tata Institute of Social Sciences as part of my Master’s programme, I found that cases where treated water is used for irrigation of edible crops are very few compared to non-edible crops. Two cases of each are explained below (Box 1).
| Box 1: Case Studies
Treated Water for Edible Crops — STP Dandhupura, Agra Treated Water for Non-Edible Crops — HDIL Residency Park, Virar, Mumbai |
Primary treatment tank of a Sewage Treatment Plant in Dombivli, Maharashtra
The Central Pollution Control Board (CPCB) of India has established water quality standards for various uses, classifying water for irrigation, industrial cooling, and controlled waste disposal under Class E. Recently, the CPCB released draft guidelines for using treated sewage water, which also meets Class E standards, ensuring that the quality of treated water remains uncompromised.
However, the current operating capacity of Sewage Treatment Plants (STPs) in India raises concerns about the effectiveness and quality of treated water. According to the National Inventory of Sewage Treatment Plants, India generates an estimated 72,368 litres per day (MLD) of sewage daily, yet the country’s sewage treatment capacity is only 18.6%. As a result, only 37.1% of the total sewage is treated. Many of these plants fall short of meeting even the basic Class E requirements, highlighting significant issues with the effectiveness and coverage of sewage treatment.
HOW TREATED WATER CONTRIBUTES TO A CIRCULAR ECONOMY
In a circular economy, resources are maintained in use for as long as possible, extracting their maximum value before recovering and regenerating them at the end of their life cycle. The agricultural sector supports this model by repurposing treated wastewater, ensuring that water—a vital resource—is continuously cycled rather than used once and discarded. This also closes the loop on nutrient cycling. Nutrients like nitrogen and phosphorus in treated sewage are redirected from potential pollutants into valuable resources that enhance soil fertility and support crop growth. This practice decreases reliance on synthetic fertilizers, which are energy-intensive and environmentally harmful.
The government currently providing power subsidies for farmers to pump water has led to increased groundwater use and subsequent depletion, bearing significant environmental costs. Treated water offers a better alternative. It is more cost-effective than freshwater, especially in water-scarce areas, and its nutrients reduce the need for expensive synthetic fertilizers. Reliable access to treated water can also boost crop yields and allow for crop diversification, enhancing agricultural productivity and sustainability.
Current Status of Treated Water Reuse
India generates about 72,368 million litres of sewage per day but has an installed treatment capacity of only 31,841 MLD, with only 37.1% of sewage being treated. The majority of treated water is used for industrial, gardening, or environmental purposes, with limited adoption in agriculture due to quality concerns.
IMPORTANCE OF BEHAVIOURAL CHANGE COMMUNICATIONS IN PROMOTING TREATED WATER USAGE
Adopting treated water in agriculture requires not only technological solutions but also a shift in perception among farmers. Behavioural change communication plays a crucial role in this process. A study in Sivakasi, Tamil Nadu, involving 397 farmers, revealed that willingness to use treated water increased significantly when farmers were educated about its economic benefits, such as reduced fertilizer costs.
A similar study carried out in the Mid-Atlantic and Southwestern regions of the United States showed that farmers preferred practical demonstrations and workshops when new practices, like treated water use, were introduced. Extension professionals, acting as trusted intermediaries, can effectively influence farmers’ decisions through targeted education and transparent communication about the safety and benefits of treated water.
A study in Almería, Spain, demonstrated that initial negative perceptions of treated water among farmers shifted positively after education and hands-on experience. Farmers emphasized the need for public administration to ensure water quality and reasonable pricing, which further underscores the importance of consistent monitoring and government support.
The UNDP-World Bank document “Reuse of Wastewater in Agriculture: A Guide for Planners” outlines best practices for reclaiming wastewater in water-scarce regions. This guide serves as a valuable resource for extension professionals to educate farmers on the safe use of treated wastewater in agriculture.
The U.S. Environmental Protection Agency (EPA) had released a comprehensive manual that provides guidelines for water reuse, including a dedicated section on agricultural applications. This manual will also serve as an excellent resource for extension professionals, offering in-depth information on water quality and best practices for integrating water reuse into agricultural systems.
WAY FORWARD
Looking ahead, the potential of treated wastewater to transform agriculture is immense, provided there are full-capacity STPs in completely functional conditions. Continuous monitoring and transparency of the water quality will be vital in maintaining the trust of the farmers.
It’s important to address the concerns and misconceptions that farmers might have about using treated wastewater. Education and training programs are essential to convince the farmers that they need to adopt this practice. Through workshops, seminars, and hands-on training, farmers can learn about the advantages of using treated wastewater, the safety protocols in place, and how this method contributes to long-term sustainability.
The government should be ready to provide incentives to farmers for adopting treated water irrigation. With the amplifying impact of climate change, treated water can be a consistent and reliable source, unlike freshwater. This approach will contribute to a circular economy by turning waste into a valuable input for food production. Through the benefits of treated wastewater, we can make a significant positive impact on agricultural productivity, environmental sustainability, and economic resilience.
Arsha Ashly is a Research Officer with the Centre for Research on Innovation and Science Policy (CRISP), Hyderabad, India and recently completed her Masters in Water Policy and Governance from the Tata Institute of Social Sciences (TISS), Mumbai, India. She can be reached at:ashlyarsha20@gmail.com
Congratulations to Arsha Ashly for the blog on use of treated wastewater in agriculture, emphasizing its crucial role in promoting a circular economy and addressing water scarcity in India. This blog has effectively opened up a critical conversation on the need to rethink our water use practices in agriculture. This blog provides a valuable perspective on the role of treated wastewater in fostering a circular economy in agriculture, particularly in a water-stressed country like India. The emphasis on using treated water to mitigate water scarcity and reduce dependence on freshwater resources is both timely and necessary, given the increasing challenges posed by climate change and population growth.
Your detailed discussion highlights not only the potential benefits of using treated water but also the barriers to its widespread adoption—such as public concerns over safety, health, and quality. This balanced approach is commendable, as it underscores the importance of building trust among farmers and the general public regarding the use of treated wastewater for edible crops.The case studies presented in the blog provide valuable real-world examples of how treated water can be successfully integrated into agricultural practices, enhancing soil fertility and crop yields. They also illustrate the economic advantages, such as cost savings on synthetic fertilizers and improved cost-benefit ratios. These examples can serve as an encouraging model for other regions facing similar water constraints.
Research Studies by CWRDM on the use of domestic wastewater in agriculture demonstrate its potential to enhance crop and water productivity while minimizing environmental pollution, thereby contributing significantly to a circular economy. CWRDM studies also showed that the integration of treated water into agricultural practices not only enhances soil fertility and crop yields but also reduces dependency on synthetic fertilizers, thereby supporting sustainable farming. However, the successes of this approach hinges on educating farmers and reduce the misconceptions about the safety and quality of treated water. By fostering awareness and ensuring consistent water quality, we can unlock the full potential of treated wastewater, making it a key resource for sustainable agricultural growth in a water-stressed world.
Further research is needed to explore the long-term impacts of using treated wastewater on different soil types, crops, and ecosystems. Investing in research and development will provide more data to support the safe use of treated water, particularly for edible crops, and can help develop innovative treatment technologies that address current challenges. Clear policies and guidelines need to be put in place for the use of treated wastewater in agriculture, aligned with international standards. These policies should focus on ensuring water quality, safety, and sustainability while providing a supportive framework for farmers and stakeholders.To maximize these benefits, it is crucial to prioritize behavioral change communication strategies that focus on educating farmers about the safety, advantages, and best practices of using treated wastewater. Expanding extension services to provide continuous training, practical demonstrations, and workshops tailored to local needs will be essential. Drawing on successful examples from other regions, can offer a valuable roadmap for scaling up these efforts effectively.
Keep up the great work in promoting sustainable water management practices, and thank you for shedding light on this important issue.
Thank you so much for your kind and encouraging words. I’m really glad that the blog connected with you and sparked meaningful conversations on such a critical issue.
Congratulations to Ms Arsha Ashley for presenting the need and scope of using treated water for agriculture. She gave some suggestions to improve the use of treated water for producing edible crops which definitely need acceptance from both farmers and consumers. The consumers in most of the urban localities are not aware of the source of water being used for vegetables they purchase from the local markets. One can notice in peri urban areas farmers use mostly untreated drainage water to grow vegetables, other edible crops and fodder grasses. One can imagine the serious health hazards these vegetables and milk pose to the consumers of these products. Imposing regulatory measures to ban the use of untreated waters help the consumers at the cost of the livelihoods of per-urban farmers and it is not practicable in our country.
Ideally treated water only must be permitted for irrigation. But the methods to establish treatment plants are not cost effective. In addition to make the farmers and consumers aware about the serious health consequences of using untreated water for agriculture, it is also necessary to come out with cost effective treatment plants. Data is also lacking on the quantities of hazardous elements like heavy metals, pathogens etc in untreated water in different locations and their presence in vegetables and milk.
Thanks to AESA for publishing this blog of public health importance.