High levels of nutrients recovery can be achieved with source control sanitation - technologies are already available. Separation toilets for example separate urine that can be used in agriculture with some crop restrictions as a fertiliser after about 6 months of storage. The grey water has very low loads of nitrogen and can be treated in different combinations of biological and physical treatment and reused. Faecal matter with flush water from the separation toilet can be discharged into Rottebehaelter (an underground pre-composting tank) that retains solid material and drains liquid to a certain extent. Investigation of Rottebehaelter in the different sites and laboratory experiments showed that retained faecal material still contained a high percentage of water. However, odour was not noticed in those Rottebehaelters that have been examined. One of the major advantages of this system over other forms of pre-treatment as the septic tanks is that it does not deprive agriculture of the valuable nutrients and soil conditioner from human excreta. It has to be stated that maintenance is a crucial factor. As an intermediate result of the intensive research of Rottebehaelter it seems that these systems are rather a way of solids retaining, de-watering and long-term storage before the contents are further treated.

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