Following the Flow: Where Wastewater goes

The rapid rate of population growth and urbanisation that has been taking place domestically has made it difficult for India's infrastructural developments and regulations to keep pace. 

Autor*in RESET , 04.10.13

The rapid rate of population growth and urbanisation that has been taking place domestically has made it difficult for India’s infrastructural developments and regulations to keep pace. 70 to 80 percent of all water that is supplied for domestic and industrial use in India, emerges again as wastewater, 60 to 70 percent of which flows untreated.

It is estimated that by 2050 nearly 85 crore people will be living in cities, which will make India decidedly peri-urban, rather than rural in character. This also means that city planners have some planning to do, and supplying water for domestic and industrial use alike is a top priority

Water scarcity is a serious concern for India’s cities. “[Planners] need to have a strategy on how to best utilise various water resources, including untreated, partially treated and fully treated wastewater”, finds the International Water Management Institute’s (IWMI) in their recently published report on ‘Urban Wastewater and Agricultural Reuse Challenges in India’.

By looking at national data, as well as case studies from Ahmedabad, New Delhi, Hyderabad, Kanpur and Kolkata, the IWMI assessed the current status of wastewater and how it is being used and beneficial to agriculturalists. The undertaking of such a research is difficult, given the limited information available on how much water is being discharged, what the quality of this discharged water is and how much agricultural land is being irrigated, usually informally, by this wastewater.

The government’s concerted efforts to reduce surface water pollution are being hampered by untreated wastewater. The Centre of Science and Environment (CSE) has estimated that 80 percent of the pollution of surface water is created by the roughly 160 latrines and septic tanks nationwide.

With slight variations across cities, the IWMI found that the wastewater generated in India’s urban areas is 60 to 70 percent greater than the capacity of the established treatment facilities to process it. Furthermore domestic and industrial wastewater is, in the majority of cities, not being separated.

Wastewater is being used for aquaculture, to grow cereals such as rice, as well as horticultural and fodder crops in India. The data also demonstrates that instances where domestic wastewater does not mix with industrial wastewater show higher financial benefits from farming with wastewater than with freshwater-agriculture. However, in cities such as Kanpur and Ahmedabad, where the level of industrial pollution is high, the wastewater quality poor, as is the quality of the crops it feeds.

The IWMI report recommends a more holistic analysis of wastewater that includes household expenses like health and food, and considers both direct and indirect costs and benefits of wastewater. Of crucial importance is learning how hazardous contaminants effect water, soil and crops in the short and long term, and what the health risks associated with using wastewater is for farmers.  

To move forward, the IWMI advises “further investments to be made to increase treatment capacity for septage collected from on-site sanitation units, and in particular for industries to avoid interference in the domestic and industrial waste stream”.

It was found that 1.1 million hectares of land, that is 11 000 million m², could be irrigated with wastewater if it was appropriately treated. Needless to say recycling and reusing wastewater offers not only greater protection for the environment, but also great opportunities for India’s agricultural economy.

Author: Kirsten Zeller/ RESET editorial

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