Planning and managing urban organic solid waste in an African city, linking organic solid waste composting to urban cultivation in Accra, Ghana, West Africa

Abstract

The effective management of urban solid waste presents a great challenge to cities of Sub-Saharan Africa. The ineffectiveness of the conventional approach, which is limited to the collection and disposal of wastes out of the sight of city residents, is widely known. Heaps of garbage found in undesignated sites in African cities is common; some cities in Africa were even being dubbed "cities of garbage" and "cities of mess" by the mis 1980s. Across Africa the waste collection rate is around 40 to 50 percent, and an overwhelming majority of disposal sites are poorly managed open dumps, some located in densely-populated and ecologically-sensitive areas.

The unsustainability of the conventional system on social, economic and environmental grounds has necessitated finding more effective strategies to waste collection and disposal in African cities. Agenda 21 and the Earth summit in 1992 along with Habit II in Istanbul in 1996, brought increased attention to these issues. Many international donor agencies have given priority to the provision of these services and are encouraging governments to invest in solid waste management strategies such as recycling organic solid waste in urban food cultivation, an area which has also received the attention of solid waste management experts, researchers and consultants. The abundance of organic solid waste, which ranges between 60 to 90 percent of the municipal waste stream in African cities along with the presence of large number of urban cultivators in need of organic materials for use as soil conditioner, suggest that urban cultivation has the potential to reduce the total volume of waste requiring disposal.

There is a dearth of studies into finding effective solid waste management strategies but studies into developing effective and sustained linkages between urban cultivation and municipal solid waste management is lacking, and there is an absence of models or frameworks to facilitate such integration. The research focused on how to integrate urban cultivation and municipal solid waste management through organic solid waste composting.

The main objective of the research was to explore, demonstrate, and develop effective and sustained linkages between urban farming and municipal solid waste management through organic solid waste composting as an urban management and resource conservation strategy to improve the specific objectives: (i) to examine the nature, components and current status of urban cultivation in Accra and identify how organic solid waste from the city's waste stream is currently being utilized; (ii) to examine the environmental, economic, social, institutional and cultural opportunities and constraints of recycling organic solid waste into urban cultivation in Accra; (iii) to identify farmed areas in the city that are suitable for both food cultivation and on-site composting of organic solid waste; (iv) to develop a conceptual planning and management framework which links organic solid waste composting and urban food cultivation in Accra and which might be applicable to other cities in Ghana as well as other Sub-Saharan African cities faced with similar waste collection and disposal problems. It emphasized techniques of integration and means to manage issues arising from the integration of the two sectors. For each objective, specific research questions were developed to help generate and elicit the relevant data.

This study adopted a qualitative approach using multiple data gathering techniques (eg. participant observation, semi-structured face-to-face interviews, informal discussions and conversations with local farmers, government officials, waste generators, urban management institutions users and potential users of compost to gather different kinds of information and data. The field work consisted of a socio-economic survey and a community-based source separation and composting demonstration project.

Major findings from the study were: (i) a significant proportion of the city's organic solid waste which can be composted is wasted; (ii) recycling organic solid waste into urban cultivation can divert enormous quantities of waste from the city's waste stream; (iii) the practice of using untreated waste in the form of wastewater cow and chicken manure is common and widespread; (iv) the availability of incentives, familiarity and knowledge about source separation and composting, and collection systems used impact on participation rate and the sustainability of community-based source separation and composting projects; (v) urban cultivation in Accra is an age-old and predominantly male activity undertaken by migrants and (vi) availability and security to land are major problems facing urban cultivators in Accra.

A conceptual planning and management framework linking organic solid waste composting and urban food cultivation was proposed as an outcome of the research. The framework consists of (i) a public education component; (ii) storage, collection and transportation of source-separated organic solid waste; (iii) marketing of compost using various communication channels; (iv) the creation of waste reuse urban cultivation zones; and (v) the implementation of the framework at the sub-district level focusing on residential communities and neighbourhoods.

The study concluded with policy recommendations to promote the WRUC concept emphasizing on the (a) the promotion of compost and manure use in urban civilization, (b) increased support for waste-based urban cultivation, (c) the introduction of new and revision of old municipal by-laws to accommodate WRUC practices, (d) incorporating WRUC zones into urban land use planning, and (e) the introduction of aggressive strategies to market compost.