Urban Research · Field Study
Wastewater Reuse in Agriculture
Field Studies on Wastewater Irrigation Economy and the Health Impacts of Wastewater Use in Agriculture
The Scale of the Problem
India's sewage waters have the potential to annually irrigate approximately 1.5 million hectares of land and contribute about one million tonnes of nutrients; while supporting 130 million man-days of employment. Yet this potential is undermined by a critical failure of treatment infrastructure and the public health risks it creates.
Despite these challenges, untreated or partially treated wastewater is commonly used for irrigation due to its consistent availability; often the only reliable water source for downstream farmers.
What the Field Study Found
Through case studies, the research observed that Sewage Treatment Plants (STPs) in certain cities discharge semi-treated water, while others release untreated water directly into drains; which flows into rivers and is then used by downstream farmers regardless of treatment status.
One potential intervention identified: the separation of industrial and domestic waste at the source. This could increase the value of domestic wastewater as a resource and enable its direct supply to farmers at the farm level for safe, on-site treatment; a more realistic pathway than building city-scale treatment infrastructure.
Research Methods
The study combined multiple approaches to build a complete picture; from infrastructure tracking to community experience to satellite-level land analysis.
The study also examined the revenue of farmers utilizing freshwater versus those using wastewater; quantifying the economic stakes for communities that have adapted their livelihoods around an imperfect system.
