Urban Waste And Rural Farmers: Enabling Low-Cost Organic Waste Reuse In Developing Countries
Dr Christine Furedy
York University and Furedy Research and Advising Inc.
24 Astley Avenue, Toronto, M4W 3B4 Canada
Ph: 1 416 924 2484
Fax: 1 416 962 4253
This paper was delivered at the 6th World Congress on Integrated Resources Management in Geneva in early 2002.
Compost making, promoted as a waste reduction strategy, has had little impact on the quantities of organic wastes at dumpsites in developing countries. In addition, the most immediate, numerous, and needy of organic waste reusers--peri-urban farmers--cannot afford the products of compost plants.
Asian farmers' customary use of low-cost organic matter from garbage dumps has declined steeply with contamination of refuse. Design of organics-rich disposal areas and recovery from less contaminated levels at dumps could rejuvenate peri-urban waste reuse.
Key words: organic wastes, compost, solid waste management, garbage dumps, farmers
Reuse of organic wastes is considered desirable, in general, for resource management, while reuse is seen as a way for urban authorities to substantially reduce the amount of waste requiring disposal and treatment. Controlled composting is the safest way to produce high quality products for soil amendment. But the amounts produced in compost plants in developing countries are, to date, insignificant and have had little impact on municipal solid waste management (MSWM). Solid waste quantities continue to mount, creating chronic crises for MSWM. An approach that looks beyond urban entities' management needs to the peri-urban farmers who want organic wastes for soil amendment would seek ways to increase urban organic waste reuse while lowering costs.
Compost production: a limited solution to organic waste needs
It is undeniable that composting (controlled decomposition of organics) is the preferred method of processing urban organic wastes for reuse. The experience with compost plants, however, has been fraught with multiple problems of: feedstock; plant operation; the quality and price of the product; marketing; consumer understanding, and institutional support (Rosenberg and Furedy 1996). Most of the large mechanical plants installed in Africa, Asia and the Middle East in the 1970s and 1980s did not survive more than a few years; those that remain are not operating optimally.
In response to the municipal failures, small undertakings and private enterprise have been promoted. In the 1990s, international agencies and urban organizations began experimenting with small-scale, little-mechanized, and neighbourhood-based composting and vermi-composting (producing from .5- 6 tons per day). There have been numerous pilot projects of this kind, in, for instance, Kenya, Indonesia, India and the Philippines (Mockler 1998; Hoornweg et al. 1999; WASTE 1998, 1996-; Harrison & Paumard 2000; Dulac 2001a; Davies et al. in preparation).
While there are few detailed assessments of these undertakings, small community plants are unlikely to be significant in urban waste reduction or to satisfy the demand for organics. Many will not be viable in the long run. The main problems have been lack of incentives for waste generators to consistently separate wet and dry wastes, problems in obtaining required quantities of waste, and inability to market the products at a price necessary to make a profit (Lardinois and Furedy 1999). Analysing data from Bangalore, Kathmandu and Manila, Lardinois and Marchand concluded that small plants are too expensive to operate and produce too little compost. When all expenses are calculated, the costs can be enormous. For instance, the cost of compost produced by the Centre for Environmental Education pilot plant in Bangalore was $US 1514 per ton, with a hidden cost of another $US 724 (Lardinois and Marchand 2000).
Currently there is progress in public-private partnerships for compost plants, with a city supplying the wastes and sometimes the site for a private company (Hoornweg et al 1999, Chakraborty 2000, p. 32). Some countries have recently brought in national or regional rules on SWM encouraging or requiring composting for waste reduction (see, for instance, India Supreme Court 1999; Patel forthcoming). Any progress with composting is commendable. Still, the impact upon MSW reduction from profitable compost plants is, as yet, insignificant.
An inevitable and important consequence of the high cost of compost products is that compost companies seek special customers: plantations, expensive hotels, golf courses, and farmers growing very profitable crops. Successful companies find their markets through extensive, even international networks. Unless the special customers are close by, little compost is sold locally.
This selective dispersal of locally generated wastes is a dramatic change from the time when organics were largely reused in the urban hinterland. Researchers of farmers' needs now argue for a broader view of waste reuse that looks beyond the profitable compost plant to ways in which local farmers--the most immediate, the most numerous and the most needy of potential reusers--can access urban organic solid waste.
Peri-urban farmers' needs
Projects geared to peri-urban resource management and the demand for compost from MSW in India and West Africa have examined farmers' access to organic matter and their perceived needs. All farmers recognize the need for organic soil amendments and most prefer organic matter (even if derived from municipal waste) to chemical fertilizers (Brook and Davila 2000, p. 121; Uni. Birmingham et al. 2000; Furedy and Kulkarni in prep'n; Dulac 2001b). But the small and marginal farmers cannot afford compost and cannot acquire sufficient organic wastes regularly. Even wealthy farmers in India, growing profitable crops such as flowers and costly vegetables, say they cannot afford the products of private compost plants (Uni. Birmingham et al. 2000; Furedy and Kulkarni in prep'n).
In comparison to the cost of Rs 1500-Rs 5000 per tonne (US$ 32-106) for compost made from MSW, Indian farmers acquiring waste from dump sites pay about Rs 300-Rs 500 (US$6-11) per tonne for organic material to fields (taking into account price, 'lifting fee,' amount of rejected material, and costs for transportation and sorting). Compost (even when made from MSW) costs at least four to five times as much as decomposed garbage1.
The inability of farmers to afford the cheapest compost has been documented in Mali (Dulac 2001b).
The current experience is that the products of compost plants (whether from separated or mixed wastes) are far too expensive for the majority of near-urban farmers in most Southern countries. Even if compost is subsidized (an idea floated more often nowadays) it is unlikely that most farmers could afford it. Hence experts in peri-urban resource management argue that urban waste reuse policies must include local farmers as stakeholders.
Low-cost organic waste processing and reuse
Farmers and animal husbanders in poor countries have acquired and continue to access urban organic wastes and to process and use them in various ways. Green wastes obtained from fruit and vegetable markets are used for animal fodder; food wastes from hotels, canteens and food processing industries are fed to pigs and goats; slaughterhouse wastes are processed for poultry feed (Furedy et al. 1999).
The organic fraction of mixed municipal waste was widely used on farmland in Asia in the past. The agricultural use of decomposed organic matter in municipal solid waste can be traced back to the origins of town garbage dumps in India (for instance, use of Calcutta's waste for farming was envisaged at the time an official garbage dump was set up in the 1860s (Furedy and Ghosh 1984).
Farm uses include:
- application to fields of decomposed MSW that has been manually sorted on site or at disposal areas
- on-farm co-composting of urban animal and agricultural wastes (which also applies to 'backyard farms')(Birley and Lock 1999:139)
- cultivation of dumpsites (closed or operating)(Furedy and Ghosh 1984; Drescher 1994).
While the ways farmers access municipal waste are usually 'informal,' it is notable that a number of Indian cities and towns allow farmers to remove waste from dumps for a fee (e.g., Autonagar dump, Hyderabad, Davies 1998), or, until recently, auctioned waste at the dump site (see Box 1).
Box 1 Recovery of decomposed MSW from dumps in India
Until 1997, the Hubli-Dharwad Municipal Corporation sold waste at the Dharwad dumpsite in an annual auction for farmers. The solid waste department prepared heaps and pits at the dump to receive waste and supplied labour to turn the pit contents from time to time. Waste was sold by the pit, with pit volumes varying from 15 to 50 tonnes. Pits fetched from Rs 450 - Rs 2000 (US$11-$50). Farmers who purchased pits supplied the labourers to dig up the contents and truck them to the farms. There was no charge for waste t the Hubli dump and no heap or pit organization. Well-off farmers supplied their own tractors to transport the waste, while poorer farmers would jointly hire tractors. The farmers are from villages from 3 to 25 km from the dumps.
The auction system was stopped at the Dharwad dump because, although it garnered up to Rs 100,000 yearly for the municipality, restrictions on hiring labour meant that workers could not be spared to prepare the pits. Subsequently, waste was sold by tractor load at Rs 30 per 1.5 - 2 tonnes load.
A local composting company, Hubli Biotechnologies, also removes waste, employing labourers at the dump to sort out much of the non-degradable material. It is not known whether the company pays the municipal corporation for this privilege.
The most recent report is that farmers rarely remove waste from dumps now, saying it contains far too much plastic.
The practice was common in Hyderabad, Andra Pradesh until recently. There, truckers paid a fee to dump managers to access the dumpsites but did not pay for waste. Similar arrangements existed in Bangalore in the 1990s. On the eastern fringes of Calcutta, farmers pay municipal collection crews to deliver waste directly to their farms.
Sources: Nunan 2000; Uni. Birmingham et al. 2000; Nunan 2001; Davies 1998
The practice of using MSW is growing in West Africa. It has been estimated for Kano, Nigeria, that in the 1990s, 25% of the fertilizer needs of near-urban farmers was met by using municipal waste (Lewcock 1994; Brook and Davila 2000). In Mali, poor near-urban farmers growing vegetables and cereals send women and children to municipal waste transfer points and dump sites around centres like Bamako, Ouaga or Conakry and, after some initial sorting, carry back loads of garbage with are further sorted on the farm. Those who are somewhat better off pay municipal garbage truck drivers to unload waste near to their fields (Dulac 2001b).
A variant on removing MSW from dumps is the 'mining' of dumpsites, that is, the extraction of decomposed matter from levels of waste deposited some years before or from closed dumps (see Box 2). At Beijing's main dump in the 1990s, the municipality encouraged such removal by supplying rotating drum sieves to replace the simple wood-frame ones of near-by farmers (Shi 1992).
Box 2 'Mining' of organic wastes
Bombay's Deonar dump has been receiving waste for over a hundred years. The municipal corporation of Bombay allows the removal of waste for a fee of Rs 100 a ton plus a weighing fee. At least two agrochemical companies have been accessing the waste since the late 1980s. Labourers (men, women and children) dig for waste between four and 12 years old, using simple tools. The material is left to dry in the sun and then thrown against A-frame wire mesh screens. Up to 30 tons of screened material is removed per day being made into a soil conditioner product with cow dung, neem seed residue, dolomite and gypsum. Analysis of a sample of the waste removed showed only small amounts of non-compostable manufactured material (such as plastic, glass, metals), constituting about 3% of total weight.
Large quantities of decomposed organics were 'mined' in Yangon, Myanmar, in the 1990s. The deposit of market waste across from the city's large green market for some 60 years had created a hill about 20 metres high on 1.5 ha. site. By 1995 most of this hill had been sifted and removed as compost. Within a couple of years the whole site was flattened. City authorities turned a blind eye to the mining operations when they realized the removal of the hill would free up the site for building a new market. In the Yangon case, the decomposed matter was not highly contaminated with inorganics, since most of the waste came directly from the market across the road. Some of the mining was aimed at reaching the late 1940s' level of dumping, where valuable metals from the Second World War were to be found. Metal and organic miners worked side by side with shovels and simple screens.
Sources: Scheu and Bhattacharya 1995; Furedy 1995.
The use of recently disposed organic waste is under threat, especially in Asian cities, because the waste now contains numerous contaminants: plastics, broken glass, metal fractions and biomedical wastes. In India today, only 50%-35% of MSW of major cities is organic. Consequently, the cost to farmers of sorting the MSW at the farm has increased. Even farmers growing profitable crops, who can afford to hire workers for sorting MSW, are rejecting the practice because both farm labourers and draft animals are liable to injury. Many workers refuse to work on farms receiving MSW. Further, the farmers note deterioration of their soils after some years of application (Furedy and Kulkani in prep'n). Similar problems have been noted in Ghana (Brook and Davila 2000, p. 140). The informal use of organic waste is also affected by the increased cost of transportation from the city to the farms, especially as motorized vehicles are replacing bullock and donkey carts.
Potential for improving low-cost reuse
Can disposed urban waste again be rendered acceptable to near-urban farmers? Is there any potential for reviving the traditions of low-cost recovery and reuse that are declining due to contamination?
Mandating separation of organic wastes 'at source' by households would reduce contamination. However, there is little prospect, at present, of securing large amounts of urban organic wastes by source separation in most of Asia and Africa. Source separation projects have not been successful over a long period, and they have included small numbers of waste generators (Lardinois and Furedy 2000).
National and regional policies to reduce amounts of thin plastic film in urban waste streams could help ameliorate that specific form of contamination, but no developing country has made progress in this direction (see Patel forthcoming).
Industrial waste minimization and urban source separation require considerable changes in product design and waste-generator behaviour, accomplished through legislation, education, monitory and enforcement. Managing waste disposal and access requires change on the part of far fewer people and entails much lower costs. Two approaches are worth trying:
- A. Managing dumps for organic waste recovery
- B. Mining old waste deposits.
A. The quality of some disposed MSW could be improved if sites at a dump (pits or heaps) were designated to receive the least contaminated waste -that collected from green markets, parks, and residential areas producing the 'best' waste (i.e., that containing the most organics). Wastes from hospitals and toxic industries would have to be deposited well away from the waste-sale areas. (Ideally, every dump should have special, isolated, cells for hospital waste). Farmers would be permitted to buy decomposed wastes from the designated areas. As noted above, some Indian cities have experience with organizing disposal with a view to recovery of the waste.
The solid wastes of towns may be less contaminated than that of cities, and municipal managers should study the quality of dump wastes and promote the sale or removal of decomposed organics to near-urban farmers, if there is no practice of such waste recovery in the area.
B. The advantages of mining old dumps or old levels of current ones are that they contain few toxic and manufactured contaminants and the organic material is thoroughly decomposed and stable. The organic matter would be easier to sift on site, considerably reducing transport costs compared to that for unsorted, recent waste.
A proposal has been made in Calcutta to mine a garbage hill, created by dumping operations 40-50 years ago when there were few manufactured inorganics in the city's waste (Som 1998). Just how many suitable old dumps exist that could be exploited in this way is not known. In many cases, closed dump have been built upon or converted to farmland, and most cities and towns have not kept records of where waste has been dumped.
Other factors could limit the use of MSW directly from dumps. Ensuring less contaminated areas at dumps requires both good solid waste collection and consistent management at the disposal site. Reaching lower, 'purer,' disposal levels at dumps on any scale would require equipment that poorer farmers would not possess.
Nevertheless, farmers are highly motivated to reuse organic matter. Ways to allow them access to low-cost organics is a topic that warrants the attention of public officials and aid agencies.
Conclusion: Looking beyond urban concerns
The reuse of urban organic solid wastes can be promoted in a number of ways. There is a justification for subsidizing reuse, if it can be shown that such reuse reduces the costs of solid waste disposal: diversion credits can be based on avoided costs. There is a role for well-managed compost plants, based on public-private partnerships, to supply compost products to affluent farmers and plantations, even if these markets are not local. Some small-scale, community-based operations may find niche markets (for instance, urban nurseries, 'star' hotels, or parks). Source separation should be promoted, even if on a small-scale initially. The costs of separate collection should be assessed in terms of ultimate savings for routine solid waste management.
These current approaches arise from urban management concerns. The use of organic wastes for local food production should also be an important consideration in developing countries. Composting in cities will do little for near-urban farmers. Effective national and regional action for waste minimization can contribute to less contaminated waste streams, but such action seems a long way off. Maximum use of urban organic wastes, as Fiona Nunan argues, requires that "existing markets are recognized and understood" (Nunan 2000). In many areas, needy peri-urban farmers form the largest market for low-cost organic material. Enabling farmers to obtain the least contaminated solid wastes at dumpsites may be the easiest and cheapest way to meet their urgent needs for soil amendments and fertilizer. This requires cities, regions and national governments to take a broad view of waste reuse, one that looks beyond cities' wish to contain solid waste management to promote organic waste reuse by peri-urban food producers.
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