The MobiSan Project: Pooke se Bos Settlement, Cape Town

The MobiSan Project: Pooke se Bos Settlement, Cape Town

On November 3, our team conducted a site visit to the MobiSan Project in the Pooke Se Bos settlement of Athlone, Cape Town. This pilot program, sponsored by a Dutch consortium and supported by the City of Cape Town, consists of a dry compost sanitation unit designed to accommodate a community of roughly 500 people. Since its installation in April 2009, the facility has been estimated to service closer to 400 users.

During our site visit we had the opportunity to speak with David Castellano, a Dutch representative who has periodically monitored the system since its inception. He was able to provide invaluable insight into the system’s functionality, the community’s reactions, and the improvements suggested for the future. Some of the most important information gleaned from his guided tour of the facility included:

• Design aspects: The MobiSan unit features a total of 13 toilet stalls, all designed and subsequently labelled specifically for gender and age. Standard toilets were provided for men, while both extended-plate urine divergent toilets (“women’s urinals”) and standard toilets were provided for women to control the liquid content of the waste tanks. The primary waste tank was accessible for maintenance and bulking agent addition through a narrow passageway within the container and a small door on the container’s exterior, and waste could be transferred from the primary tank to the secondary tank through the manual cranking of a gear system connected to an internal auger. Two urine-divergent children’s toilets were also provided, with “potty seats” available in the stalls to be placed over the toilet seats. In addition, a row of 12 standard men’s urinals was installed along the rear of the facility, and the urine collected from all toilets and urinals was held in a separate tank with a transparent volume meter. Three sinks and a simple “soap-on-a-rope” were also affixed to the outside of the container, directly below the caretaker office window for optimal supervision. Rainwater run-off was controlled by a simple gutter, while standpipe wastewater was directed away from the facility through a buried pipe. The entire facility, constructed out of a steel shipping container that was moved as a single unit and lowered onto a concrete slab, could be illuminated by one raised streetlamp, and was surrounded by a ten-foot gated metal fence to be locked by a caretaker after hours.
• Caretaker: Discussion on the MobiSan Project’s caretakers highlighted some important challenges for this vital facility element, including community politics, personal responsibility, and the key project component of education. The help of the City and external players like David seemed to greatly reduce the tensions often arising from community relationships or personal grudges; however the introduction of community members to the program was still considered vital to its sustainability. The caretaker’s role in enforcing hygienic practices and proper facility use, supported by various instructional posters, was also declared a major factor in the facility’s success thus far. Perhaps most important, however, was the caretaker’s role in achieving community acceptance of the project as an improved alternative to the previously available facilities, despite the absence of the generally preferred “flusher toilets”.
• Composting Procedures: The general conditions in Pooke se Bos are very similar to those in Monwabisi Park, including a relatively high liquid content in solid waste due to the poor, unvaried diets and common diarrhoeal infections among the residents. Woodchips were added to the solid waste tanks of the MobiSan unit as a bulking agent and carbon source to aid the dehydration process and boost the carbon content of the end result. In addition to the difficulty of dehydrating the waste, the system requires manual movement of the waste from one tank to another after a six month period. Though the included crank system moved much of the waste from one tank to another, some human contact with the partially composted waste was still necessary and strong, volatile odors were only partially controlled. If possible, this movement process should be avoided.  Finally, though the City was charged with the removal and off-site treatment of the waste at the time of our visit, full composting and end product use would require another method of waste handling and extensive testing for compost safety.

To learn more about the MobiSan Project, click here [PDF 1.21 MB].