India’s rapid urbanization and population growth have made food security a high policy priority and is putting significant pressure on the agriculture sector, where poor and marginal farmers especially suffer from high fertilizer prices. It is therefore imperative for India like other developing countries to explore alternative nutrient sources. With changing resource flows to cities, urban waste offers a variety of options for resource recovery. While closed-loop processes are promoted across the globe, farmers in the states of Karnataka and Andhra Pradesh, as well as other parts of Southern India, are already using fecal sludge from urban on-site sanitation facilities (Verhagen et al., 2012; Srikantaiah, 2012). The informal sector has turned widespread lack of treatment facilities for sludge derived from septic tanks (CSE, 2011, 2012) from a serious environmental burden into an agricultural asset. The sludge comes straight from the septic tanks, and instead of being dumped into rivers, is dried ("treated") on farms before use, mostly on plantation crops. Considering the declining global phosphorus reserves (Cordell et al., 2009), treated fecal sludge, and in particular urine, can constitute a significant sources of phosphorus for crops. However, the practice is not without environmental risks. To advise authorities on options for how to safeguard human and environmental health (Drechsel et al., 2010) while also looking at the potential benefits, data are needed to understand the current scale of reuse, its potential benefit, environmental tradeoffs and limitations, and a sensitive approach for moving an informal sector activity into the formal sector.
The latter challenge is currently being addressed by an already-funded IWMI project in Karnataka, in close collaboration with WHO, which will support the establishment of business models for sludge reuse, safe reuse guidelines, and Sanitation Safety Plans through stakeholder dialogues. This PEER Science project will feed data into the dialogue and contribute at the international level to the National Science Foundation (NSF)-funded network on “Coordinating phosphorus research to create a sustainable food system” (NSF award CHE-1230603) under the leadership of ASU, which will backstop the activities and assist in knowledge dissemination. A longer term impact is expected in view of food security and environmental protection, including empirically based recommendations for addressing the looming crisis of dwindling phosphorus reserves. Phosphorus recovery from otherwise wasted resources is important for sustainable land management and food security. Introducing cost recovery options into the sanitation service chain would have positive spill-over for community, public health and the environment, as uncontrolled use of fecal sludge is a major source of water pollution and a key public health threat.