GOVERNMENT,MARKET AND COMMUNITY IN URBAN SOLID WASTE 271
Reuse and diversion of organic waste: outcomes
The reuse and diversion of urban organic waste is currently receiving a great deal of
attention in the literature as the ultimate way of reducing volumes of solid waste in
cities in Africa, Asia and Latin America. In cities with a sizeable urban and peri-urban
agricultural sector (such as Nairobi) the potential seems to be best. The findings
indicate that it is essential to make a distinction between various types of urban
organic waste: pure urban organic waste, urban organic waste mixed in municipal
waste, and compost. As far as the first is concerned, bulk generators can easily find
appropriate outlets and the municipalities do not have to interfere. Within this
category of pure urban organic waste we can further differentiate between animal
manure and food and fruit leftovers (mainly used as animal feed or for fertilizer
production). In the Kenyan capital agricultural applications of pure urban organic
waste predominantly concern animal dung, but goats are fed market wastes. In
Hyderabad both types of usage are extensive.
Mixed urban organic waste (coming from the municipal waste stream) is not much
used in Nairobi in (peri-)urban farming. Hyderabad did have a tradition of farmers
using decomposed matter from mixed municipal solid waste but it seems to have
become less popular in the past five years Many farmers around the city have discon-
tinued using this type of urban organic waste on their fields, at least in the area taken
up in our study, because of mounting negative effects (health hazards for workers and
animals, obstruction by workers, lower yields due to soil contamination). Besides,
transportation costs for this particular type of low quality agricultural resource soon
become prohibitive, implying that demand is highly localized, and consequently
restricted.
The core problem inhibiting wider usage of urban organic waste in and around the two
cities is the lack of waste separation. In the course of time this has become an increas-
ingly serious handicap because of higher levels of contamination of waste (more
non-biodegradable components, more hazardous substances entering the waste
stream). This problem also affects composting undertakings which, in both cities, are
currently dominated by small-scale units. The production of good quality compost is
difficult. It not only requires appropriate technical skills and facilities, but also
depends on the availability of an adequate uncontaminated feedstock. However, not
all composting units succeed in getting sufficient access to pure organics. This is espe-
cially troublesome for neighbourhood composting units that depend on local waste
collection efforts rather than the purer supply by bulk generators (such as markets and
food processing companies).
In both cities compost was predominantly used in specific niche markets (non-food
crops, notably floriculture and mushroom cultivation where it can successfully
compete with chemical fertilizers). The major reason for this is that most local farmers
either cannot afford the products (the small and marginal farmers) or have adequate