Urine diversion

One of the goals set by the South African Government Strategic Framework for Water Services is the provision of an appropriate, effective and sustainable water and sanitation service to all South Africans (Department of Water Affairs and Forestry). The provision of adequate fresh drinking water and effective sanitation has an enormous impact on public health, limiting the likelihood of hygiene related illness in communities that have limited access to health-care, in a country where many people already have impaired immune systems.

It is the responsibility of local government to implement these goals by providing a basic level of water and sanitation services for all, irrespective of whether or not communities are able to pay for such services. Although the consumer is not required to pay for services, it is considered wise to attempt to provide a service that is affordable to the target consumers. Waterborne sanitation services are costly and add to the financial burden on both the household and the municipality, hence focus has been turned to sustainable, low water sanitation options. Two such models put forward for the provision of basic sanitation services are the Ventilated Improved Pit Latrine (VIP) and the Urine Diversion System (UD)

VIPs are supposed to be on-site sanitation systems, with the pit being relocated once full. However, in order to encourage the use of VIPs in South Africa by using status and dignity to persuade communities to accept sanitation services, VIPs have developed into having immovable brick superstructures. This precludes the VIP being moved with any degree of ease and results in pits having to be evacuated mechanically when full. Aside from mechanical evacuation not always being practical in areas with steep terrain or dense informal settlements where access for heavy vehicles is very restricted, it is also relatively costly. At present it costs between R500 and R1 500 to empty a VIP and emptying should occur approximately every four years. This is often beyond the affordability of the target communities.

When emptying VIPs large quantities of water need to be transported in order to dispose of relatively small quantities of solid waste. It is logical then to consider drying the material. Desiccation not only decreases the volume of material that requires handling, allowing it be worked with hand tools, but also reduces odour and pathogen content. This provides the potential for owner servicing, further reducing the burden on municipalities. Ecological sanitation (ecosan) systems using desiccation have been implemented elsewhere, however not under conditions similar to those found in Durban.

eThekwini Municipality realised that urgent large-scale roll out of basic sanitation was necessary, and a decision had to be made as to what form of basic sanitation would be implemented. The municipality was faced with two options: VIPs, which were impractical under the constraints faced in the areas of operation, and UD, a method that theoretically could function but was untried under the operating conditions. The municipality instituted a double vault urine diversion system and implemented it along with extensive marketing and health and hygiene education.

UD latrines separate urine and faeces by diverting the urine to a soak-away. One vault of the double vault latrine is used at a time whilst the contents of the idle vault are left to dry. Once the contents have reached a point where they are safe and not offensive to handle the vault can be emptied and a new cycle begun. At this stage eThekwini is not operating the UD latrines as ecosan systems, however they could easily be adapted at a later stage.