Why did you decide to write yet another document about UDDTs, and how long did it takeYou?
When we started this work, we were not planning a new publication but merely wanted to update an existing publication by GTZ (now GIZ) called “Technical Datasheet of UDDTs”, which was written in 2005.We worked on revising this document over the course of 2009 and 2010, but realized that a major overhaul was needed. This took us another two years (2011 and 2012) to complete. The end result is a completely new document which has undergone an intensive, International review process. The names of the International reviewers are listed in the Acknowledgement section.
How much practical experience do the authors have with building and maintaining UDDTs?
Christian Rieck’s practical experience with UDDTs stems from the time he worked in Nairobi for the GTZ Water Sector Reform Program (2006 to 2010), on a project funded by the European Union and Sweden, where UDDTs were built for 10,000 users in rural areas and schools. More than 1000 double-vault UDDTs were implemented via CBOs and the Water Services Trust Fund in South Nyanza, Western Kenya and other provinces of Kenya. One of the other authors, Heike Hoffmann, has extensive experience in building UDDTs in Peru
Where about 800 have been built under her guidance in the Coastal, Andean and Amazon regions. She works for a private company called Rotarian do Brasil and the consulting company AKUT. Currently, AKUT is working within a GIZ program which is working together with Peruvian water and sanitation utilities. She is responsible for the integration of service model for “dry sanitation” into the urban sanitation management, with the aim of offering an adequate sanitation service in urban areas without sewers as well.
Who in particular would benefit from reading this document?
The target audience for this publication is engineers, NGO staff, local government, staff, consultants, trainers, lecturers and other persons possessing some basic technical background, who wants to:
• Obtain an overview of the function, design and operational requirements of UDDTs;
• Understand how a UDDT may provide a possible sanitation solution for a given context and
• Finance or implement sanitation systems and wish to discuss UDDT options with consultants and suppliers in an informed manner.
4. The photos are very nice – are we allowed to copy them for our own documents or presentations?
How is this document different to previous documents about UDDTs?
There were four main flaws with many previous documents on UDDTs which we wanted to overcome:
• Too much “propaganda”: UDDTs are often represented as the “magic bullet” for sanitation, the “one and only” solution, and as a system that can easily achieve complete pathogen kill. We stress that UDDTs are only one amongst a range of sanitation options with certain areas of application; that one should not expect a “complete” pathogen kill; and that a multi-barrier approach is needed to achieve a high level of safety for users and service staff.
• Too much emphasis on reuse: Often, UDDTs are described as a sensible solution only when coupled with re-use activities. We emphasize that re-use is in principle good and desirable but that there are also other reasons for building UDDTs which are not necessarily connected to any plans for reuse (mainly reduced odour and easier handling of the dried faecal matter).
Confusion about the differences between single vault and double-vault UDDTs: Unlike previous documents, our document gives very clear guidance on the advantages and disadvantages of “single vault” versus “double vault UDDTs”, and explains why there is a greater need for post-treatment for the single vault systems.
• No consideration of up-scaling and of sustainable service provision at a large scale (see also next question).
Where do you see the challenges of UDDT implementation in the future?
UDDTs have become better known of late and are now closer than ever to becoming “mainstream“. On the other hand, there is still lack of knowledge about them, while prejudices and controversies over technical details prevail even among experts. Also, the number of UDDTs realized so far is still small and often only in isolated, heavily-subsidized pilot projects. Therefore, we wanted to analyze in a “neutral” way the status quo and the required directions for up-scaling of UDDTs. A critical point for up-scaling of UDDTs is how to offer sustainable service models for their management, particularly in urban areas. What we need now is a
broad acceptance of UDDT technology, mainly at the political and institutional levels (we all know stories of mayors promising flush toilets and sewers for all, even if it makes no sense for financial and technical reasons!). The decision for or against UDDTs in a specific area, and the organization of suitable management and emptying services, should no longer be seen as the responsibility of households or NGOs, but needs to be organized and supervised by the local government authorities. It is critical that service providers begin to include ‘dry excreta management’ options in their list of services, including the supply of cover material, removal and sanitization of xcreta, and the sale of fertilizers from post-treatment procedures. Another challenge is to make use and maintenance of UDDTs simpler and thus more acceptable. The difficulty of adjusting toilet habits should not be underestimated, and may be best approached with intuitive toilet designs and comprehensive user training.
Dense urban areas present a number of impediments for UDDT construction, including limited space and unclear land ownership. Consequently, UDDTs with single vaults and interchangeable containers, or even mobile UD solutions, may be better options and subsidies may be required.