Most rural communities in East Africa do not generate a lot of waste, and over 80% is organic material. Any inorganic waste produced is generally burnt. In urban areas there is a waste collection service that is ultimately disposed of at a landfill. In some cities, such as Kampala, this service is provided by the private sector, with fees being administered for collection and transportation. For many schools this is a costly and unsustainable solution. Efforts should be made as far as possible to minimise waste production and ensure that waste disposal is hygienic, safe and sustainable. With some creative thinking it is possible to turn rubbish into a resource.
The waste hierarchy indicates an order of preference to reduce and manage waste. The aim is to extract the maximum benefit from products while generating the minimum amount of waste.
Waste management strategies in order of preference are prevention, reduction, reuse, recycling, incineration and disposal to landfill. Preventing or reducing the production of waste is achieved through making smart consumer choices to avoid single use products and excessive packaging. Reuse is prolonging the usable life of a product through selling, donating or upcycling items which are no longer needed. Recycling is the breaking down of a product into something entirely new, a local example being the blending of plastic waste with sand and aggregate to make pavers.
The Appropriate Technology Centre has constructed a toilet block out of recycled plastic bottles.
The Waste Hierarchy
Under aerobic conditions, organic waste such as kitchen scraps or plant material can be recycled into a nutrient rich fertiliser called compost.
Composting is an aerobic method of recycling organic material otherwise regarded as waste, to produce a soil conditioner or compost. At its most simple, composting involves disposing of organic waste in a pit and turning the waste periodically with a spade to keep it aerated. Earthworms may be added to further aid aeration and speed up the composting process. It is essential that waste is properly segregated to avoid compost becoming contaminated with plastic or glass.
Clinical or hazardous waste, such as sanitary pads should be disposed of via incineration to avoid the spread of harmful pathogens.
Incineration is a hygienically safe waste treatment process for hazardous materials such as hospital waste and sanitary products. Hazardous waste should be incinerated at very high temperatures of a least 850 ºC to ensure pathogens are destroyed without causing excessive pollution through incomplete combustion. The incineration by-product is ash which should be disposed of in a lined ash pit. The construction of incinerators at schools is an essential feature of schools' sanitary and hygiene management.
Grey Water Recycling
Grey water from hand washing and showering can be separated at source and either treated and stored or diverted directly for simple drip irrigation.
Waste water from wash hand basins or showers is not as contaminated as black water from toilets or kitchen sinks. This grey water can be diverted for treatment through reed beds, UV or carbon filtration. Treated water can be used for flush toilets, washing clothes or watering plants. Alternatively, grey water can be diverted in a direct use system for immediate drip irrigation. Grey water recycling significantly reduces water consumption, particularly where there are water flush toilets in place.
Greywater can be poured directly into a greywater tower for the safe irrigation of fruit and vegetables.
Surface water drainage channels should be constructed to divert storm water that collects as a result of local rainfall.
East Africa experiences heavy and sustained rainfall at various periods throughout the year. Drainage channels should be built to divert this excess water to existing municipal storm water drains where present. Open channels are preferable to make them easier to clean. In order to limit the volume of surface runoff generated, hard surfaces should be limited and grass should be planted to aid infiltration of some of the would-be surface runoff.