Economic Effects of Sustainable Sanitation - SuSanA

Figure 15: Logistics system for urine and faeces reuse - system B (own contribution)
6.2.2.4 Costs of the urine and faeces logistics
Case Study Kampala
The costs of this extended logistics system have also been calculated with the assistance of
the Microsoft Excel based model used in chapter 6.2.2.1 (for details regarding the model, cf.
chapter 9.3). Various assumptions have been used and different scenarios have been
calculated (cf. Table 6 and chapter 9.3).
The income for system B is generated through the sales of urine 78 and the dried faeces
fertiliser bags. The bags have a weight of 50 kg and are sold for a price of 7.13 EUR 79 for
collection.
Regarding the general framework, parameters such as project lifetime, working hours/days,
labour requirement or delimitations (exclusion of toilet facilities or property issues), system A
and B do not differ from each other. The scenarios from system B are also calculated based on
monthly N demands. The number of people served is only affected by this parameter. The
amount of faeces in turn is calculated based on the number of people living in the slum area.
A collection efficiency of 50% is used. As average amount of faeces excreted by one person
per day, 0.14 kg has been incorporated in the calculation (Vinneras, 2002, p. 37). In system B
for both types of human excreta delivered to the collection point 0.04 EUR are paid as
78 Values are the same as for system A.
79 The value of the contained urea adds up to 4.29 EUR per bag. However, due to atmospherical losses the
additional nitrogen content from adding urea is consumed again. The real nutrient level of dried, urea sanitised
faeces has to be tested in further studies (cf. Appendix B). The margin between the urea value and the sales
prices per bag covers the basic requirements for management and profit.
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