Composting from unplanned settlements: Stellenbosch Municipality

Waste was being pilled up near an unplanned settlement (Enkanini) in Stellenbosch Municipality. An alternative food waste treatment method was piloted in Enkanini in partnership with Stellenbosch Municipality and Probiokashi (Pty) Ltd. The method used bokashi substrate to treat food waste with microorganisms. Bokashi composting is an anaerobic process that relies on inoculated bran to ferment kitchen waste, including meat and dairy, into a safe soil builder and nutrient-rich tea for your plants.

This was then processed further into compost through the sheet mulching method and by black soldier fly Stellenbosch University   iv (Hermetia illucens) larvae. The outcomes were assessed according to the environmental, social and economic sustainability of this method of waste processing and indicated a positive impact in all three of these categories.

WHAT WORKED WELL

The right environment, infrastructure and capital for the composting methods described above, as well as the anaerobic digester and the BSFL were not available. Bokashi though, seemed to fit the constraints of the project, because of the following advantages:

• It allowed participants to collect their food waste over a longer period of time without the food waste started to emit foul odours and hence attracting pests.
• It was also very easy to use, and foul odours are an indication of pathogens.
• Stellenbosch University did not require heavy infrastructure for participants to process once it had been collected.
• Additionally, there was the convenience factor of not needing to separate food waste into further subcategories such as cooked waste, animal protein and acidic food waste, that are uncomplimentary to some other food processing methods, such as vermicomposting and anaerobic digestion.

LESSONS LEARNED

• The microorganisms present in bokashi also prevent pathogens from breeding, which was a great positive for this project as the processing required a lot of handson work and it was also often a messy job. The bokashi allowed us to handle food waste without having to be concerned about pathogen risks.

WORKING GROUP

• Stellenbosch Municipality
• Probiokashi (Pty) Ltd