206 CHRISTINE FUREDY
Vermicomposting
Compost composed largely of worm castings from worms fed organic wastes has a
greater fertilizer value than aerobic compost from organics and can usually be sold at
a higher price. A number of pilot projects have been undertaken with solid wastes
(Spiaggi et al., 2000; Yasmeen, 2001), and private fertilizer companies have adopted
this technique (for example, Terra Firma Bio-Technologies in Bangalore). The NGO
undertakings, however, are too small to be significant in city waste treatment, and
there are unresolved health issues (see section 9.5 below). It seems likely that, leaving
aside its incorporation in some commercial operations, vermiculture using urban
organics will be confined to demonstration projects to serve mainly educational
purposes or to small undertakings where there are niche markets with customers
willing to pay a higher price than that of compost. For instance, squatter families
lacking solid waste collection might persist with vermicomposting after pilot work, if
they can also sell the worms for fish bait or poultry feed (cf. Spiaggi et al., 2000). The
pilot project in Hyderabad is an example of a subsidised project that has yet to develop
a secure market for its product.
Waste generator co-operation with organic waste management
To produce compost acceptable in quality and price to buyers, on the scale that can
significantly reduce urban organic solid waste, would seem to require large-scale
‘separation at source’. That is, the organic wastes are kept separate or segregated by
waste generators and are separately collected for processing. Source-separated
organics originate from two main sources in a city: residential consumers (mainly
households) and bulk or single-source generators (food processing plants, wholesale
market terminals, green markets, large hotels, large restaurants, large institutions,
parks). In many cities of developing countries, the available separated organic wastes
are in high demand and are extensively exploited through informal networks (Furedy,
1995). To date, cities have had limited success in gaining residential waste generator
co-operation in separating organics that have hitherto been put out for collection
mixed with other wastes. Reports on pilot schemes have highlighted many barriers to
compliance, although householders may express willingness to separate when initially
questioned (Lardinois and Furedy, 1999; Asomani-Boateng, 1999; Pitot, 2001; Le,
1995). It is important to note that in addition to waste-generator cooperation, the
separate collection of residential organics on a large-scale requires radical changes in
existing solid waste management systems and the unit costs are very high (Lardinois
and Furedy, 1999: 187,195). An approach that does not demand complete waste
generator compliance with separation is doorstep sorting by waste collectors. This can
be implemented where collectors receive wastes from door-to-door and immediately
sort organics from inorganics. It is being applied in projects for small-scale neighbour-
hood composting (Dulac, 2001).