The Sanitation Centre

The Indlovu Project Sanitation Centre was envisioned as a decentralized, experimental facility within Monwabisi Park, C-Section “Redevelopment Seed” that embodies the principles of sustainability and resource conservation. The Centre employs solid waste composting, urine collection, and grey water purification systems in order to reduce its footprint within the community while reusing by-products as agricultural resources.

The current site blueprint was designed to accommodate a user load of approximately 200 Community Centre patrons and surrounding residents in a gated perimeter facility abutting the new Community Centre. The facility will include a dry composting toilet scheme, a laundry station, improved taps, hand washing sinks, and a grey water management system, all continuously monitored and maintained by a carefully selected and trainedfacility caretaker.

The work of Worcester Polytechnic Institute project teams over the past two years provided a firm basis for the design of the facility layout and the identification of priority components. The 2007 IQP team succeeded in engaging with the Indlovu Project, an aspiring “eco-village” parented by the local Shaster Foundation, to develop a sustainable community laundry facility. From there, the 2008 IQP team furthered communications with the Shaster Foundation, neighboring community members, and local street committees to understand the water and sanitation needs of the residents, and the 2009 MQP team continued to develop their recommendations into a preliminary sanitation facility design. The work of these project teams, in collaboration with the University of Cape Town, has proceeded to win international attention in the form of the 5,000 Euro Mondialogo Engineering Bronze Award.

Certain aspects of the Sanitation Centre plans were left underdeveloped, however, including the underlying sanitation system. This year’s project focused on the many possibilities for this important aspect of the facility, particularly with regard to the evaluation of waterborne and dry system options (see discussion below). These efforts resulted in the development of novel waste composting and grey water purification schemes, and the integration of these systems into a comprehensive Sanitation Centre contingent on extensive research into system efficacy, product quality, and social acceptability. 

System Components

1. Toilets, Urinals, and Primary Waste Management
2. Composting & Pasteurization
3. Improved Taps
4. Hand Washing Station
5. Laundry Station
6. Grey Water Management Scheme
7. Caretaker Office
8. Facility Perimeter
   

Design Considerations and Specifications

• Target Usage: 200 users
• Operated by: Caretaker under cooperative Indlovu Project and City supervision
• Collaborators: Shaster Foundation, City of Cape Town, University of Cape Town, EcoBeam
• Location: “Redevelopment Seed”, C-Section, Monwabisi Park
• Funding: Capital funding by Indlovu Project and WPI/UCT Mondialogo funds

Operational Plan

• Hours of Operation: 6 a.m. – 10 p.m.
• Management Plan: Multiple local and City caretakers, potential City funding and salaries

Experimental Research Recommendations

• Testing
  • Determine social acceptability of facility. Understand what residents like and dislike and make changes accordingly.
  • Determine level of social integration. Evaluate behavior of users to understand if residents are embracing key ideas.

Background Research and Discussion

Choosing a Method of Waste Disposal

A critical decision that we had to consider before designing the sanitation facility was what method of waste disposal would be used; the traditional flush toilet or a dry composting system. The flush system is clearly the most desirable toilet by the community as there is minimal contact with waste; simply flush and forget. This decision, however, could not be made solely on the desires of the community as there are several other aspects that we had to weigh. Most importantly, Monwabisi Park has no municipal sewerage infrastructure with which to connect flush toilets, so any system developed must operate reliably on a decentralized basis, fit into a densely populated area, and emanate little odor, noise or other public nuisance.

The decision to pursue a composting option also included the views of collaborating partners. The Indlovu Project embraces composting as a permaculture practice to turn waste into resources and has informally tried various composting systems in the past including homemade worm composting toilets, an Enviro-loo, and an AfriSan; although no testing has been done on these toilets to determine pathogen removal. Some of these toilets were found to work well while others were removed due to unsatisfactory performance. The University of Cape Town has similarly expressed interested in creating an experimental model in order to collect data regarding the waste and waste processing methods of informal settlements. The conceptual simplicity and eco-friendly nature of composting toilets allows for data collection at various stages and will allow researchers to better understand how to deal with the sanitation issues in informal settlements.

Wet Sanitation

We first set out to understand each system. A great deal of research was done on both the wet and dry systems. Research was done on both wet and dry systems, through which we understood that the best potential method of waterborne sanitation for this location would be the Anaerobic Baffled Reactor (ABR). The ABR has no electrical requirements, low land space requirements, is fairly inexpensive to install and operate, and employs locally available construction materials (UNEP, 2002). Our concept for ABR application was to develop a closed-loop system requiring no use of potable water for operation. Instead, we investigated a novel approach that aimed to recirculate treated black water back as toilet water. This approach, if properly researched, understood, and planned, is worth exploring further for other areas of Monwabisi Park. This site would also need to be set up as an experimental facility in order to collect data throughout the sanitation process. Below is a table summarizing the key advantages and disadvantages of wet systems.

Dry Sanitation

While researching wet systems, we simultaneously investigated dry composting sanitation as another possible solution. Dry composting offers the option to conserve water in a water scarce environment and it avoids many of the problems posed by a flush system. In addition, there is a great deal of information available on how to build, use, and maintain dry composting systems. Some important advantages and disadvantages of the dry composting system are shown below.

Commercially Available Dry Sanitation Systems

While pursuing dry sanitation, we researched commercially available systems as shown by the table below. If a commercial unit is found that can meet the needs of the sanitation facility, it would offer advantages over a “do-it-yourself-system”, primarily that a commercial unit has already been tested so problems may be minimized. The centre is also designed to allow experimental testing of potentially viable commercial composting systems.