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Contact person
For further information please contact:
Dr. Elisabeth von Münch
Tel: +49 6196 79-4221
Fax: +49 6196 79-804221
Email: ecosan@giz.de
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Theory - Questions and answers
| Does ecosan always use urine diversion? |
| Ecosan and urine diversion are not identical. A whole range of toilet types can be used in ecosan concepts: with or without urine diversion, and with or without flushing water – as long as they provides options for safe and sustainable reuse. Ecosan is not limited to a specific toilet type, but it is a concept. |
| What are the purposes of separating urine and faeces (urine diversion)? |
- to reduce odour: when urine and faeces are not mixed, the odour from a dry (or waterless) urine diversion (UD) toilet is much reduced. A dry toilet with UD can even be placed indoors.
- to avoid production of wet, odorous faecal sludge: Faeces collected dry, separately from urine and water, are hardly offensive, especially after an extended drying period in a faeces vault.
- to reduce water consumption
- to be able to collect urine pure so that it can – after sanitisation by storage – be safely used as fertiliser in agriculture.
For more details see our technical data sheet on urine diversion. |
| Are ecosan systems cheaper than conventional systems? |
Ecosan systems can be cheaper or more expensive than conventional systems, depending on what the conventional system is, the scale of the project, the price of water, the price of fertiliser and so on. It is therefore not possible to make a generalised statement. If a centralised sewer system and wastewater treatment plant could be avoided by using UDD toilets, then cost savings may be considerable. However, the collection and treatment of greywater, industrial wastewater and rainwater, still requires a sewer system of some sort. It is also important to not only consider capital costs but also operation and maintenance costs.
See also SuSanA, working group 2, cost and economics (link at the botton of the page). |
| What is the rate of return of an investment in sanitation? |
A recently conducted study of the World Health Organisation estimated that the global rate of return of investment into basic sanitation has a wide range, but is approximately 9:1 (Euros returned for Euros invested). Those economic benefits are mainly due to cost savings and productivity gains through health improvements.
See also SuSanA, working group 2, cost and economics (link at the botton of the page). |
| Are pharmaceutical residues a problem for urine reuse in agriculture? |
| There is the possibility that if urine is reused in agriculture, pharmaceutical residues are taken up by plants and thereby enter the human food chain. This is a risk, but a small one: a full evaluation of the potential toxic effects of pharmaceuticals ingested by humans with crops is very difficult and has not yet been done. Moreover, the risks needs to be put in perspective compared to pharmaceutical residues contained in animal manure and sewage sludge, or the risks resulting from pesticide use. Additionally, it has to be pointed out that European wastewater treatment plants are not able to eliminate pharmaceutical residues from the wastewater and the residues end up directly in our water bodies. |
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