The new paradigm in sanitation must be based on ecosystem approaches and the closure of material flow cycles rather than on linear, expensive and energy intensive end-of-pipe technologies. Sanitation systems are part of several cycles, of which the most important cycles are the pathogen-, water-, nutrient- and energy cycle. In order to ensure public health, sanitation approaches primarily aim at interrupting the life cycle of pathogens. In addition, the new approach is recognising human excreta and water from households not as a waste but as a resource that could be made available for reuse, especially considering that human excreta and manure from husbandry play an essential role in building healthy soils and are providing valuable nutrients for plants. While conventional sanitation restricts health security to the in-house environment and sometimes leads to a disastrous situation in the neighbourhood or the receiving water body, the new approach is aiming at sanitizing the products instead of exporting problems and apply a health oriented multi-barrier concept of treatment, croprestriction and exposure control.
This approach, mostly addressed as “ecological sanitation” or ecosan offers an alternative to conventional sanitation. It is based on an overall view of material flows as part of an ecologically and economically sustainable sanitation system tailored to the needs of the users and to specific local conditions. It does not favour or promote a specific sanitation technology, but is rather a new
philosophy in handling substances that have so far been seen merely as wastewater and watercarried waste for disposal. It carries with it a new approach to sanitation education, a new discourse, and a new way of managing knowledge.
Ecosan systems restore a remarkable natural balance between the quantity of nutrients excreted by one person in one year and that required to produce their food (7.5 kg nitrate, phosphorous and potassium to produce 250 kg of grain) and therefore can greatly help in saving limited resources. This is particularly urgent with regard to fresh water and mineral resources – for example current estimates for phosphorus state that economically extractable reserves risk to be exhausted in the foreseeable future. Ecosan does not favour a particular technology but is rather a philosophy in recycling oriented resource management and offers modern, convenient, gender friendly and desirable solutions, in accordance with the Bellagio Principles as formulated by the WSSCC (Water Supply and Sanitation Collaborative Council) (SANDEC/WSSCC 2000a).
The core principle of ecosan is to close the loop between sanitation and agriculture, enabling and bringing about “agricultural reuse”, along with other means of closing flow cycles.