Fertilizing the market

Biowaste reuse in South-east Asia by Joost C.L. van Buuren and Tran Thi My Dieu Urbanization in developing countries is beset by significant problems in solid waste management. As in other parts of the world, cities in South-east Asia must find ways of diverting biowaste from landfills and find or perhaps stimulate markets for biowaste by-products. During 2005 and 2006, a European Union-funded Asia Pro Eco project entitled ‘Biowaste Reuse in South East Asian Cities’, which included research groups from the Philippines, Thailand, Germany and the Netherlands, simultaneously mapped problems and opportunities in and around three cities: Ho Chi Minh City (Vietnam), Bangkok (Thailand) and Metro Manila (the Philippines). Research from this project can now be examined to reflect on broader issues in the management of biowaste in developing cities. This article focuses in particular on Ho Chi Minh City and compares findings with research undertaken in other large cities in the Far East and Europe. Waste management in Ho Chi Minh City Ho Chi Minh City (formerly Saigon) is situated in the south of Vietnam. Its population is growing rapidly and is now estimated at 8 million, one tenth of the country’s total population. The generation of municipal solid waste (MSW) has reached 6000 metric tonnes per day, of which 5000 tonnes are delivered to landfill. Waste generation is increasing at 6% annually. Despite important recent improvements in collection rate and the performance of landfill, existing landfills are filling up rapidly. Space for new sites is hard to find and uncollected solid waste is polluting land, sewers and waterways. There are currently no incentives for minimizing waste. The city’s expenditure on solid waste management is high and rising, but apparently still insufficient. Similar problems are found in other South-east Asian cities, particularly in Bangkok and Metro Manila. South-east Asian scientists and policymakers have become vividly aware of the approaches to solid waste in Europe based on a waste hierarchy, where priority is given to waste minimization, recycling and reuse over incineration and landfilling. They ask themselves: what has to be set in motion in order to divert biowastes from landfill and process them into attractive products? Could the model used in countries such as Germany and the Netherlands, implying at-source separation of biodegradable wastes and the production of high-quality compost products, be implemented under the constraints of South-east Asia? Opportunities for biowaste reuse The activities of the Asia Pro Eco biowaste reuse project were structured according to the biowaste-processing chain: waste segregation at source biowaste processing biowaste reuse in agriculture. In theory, this chain of waste handling should be supported by a management system that includes a regulatory and policy framework, institutions, technical infrastructure and financial instruments. The project’s objective was to formulate mechanisms to enable viable biowaste-reuse chains within the South-east Asian context. And through international collaboration, the partners undertaking this work sought to learn in detail from the different approaches in each other’s countries. The processes envisaged for biowaste treatment (leading to biowaste ‘reuse’) include windrow and aerated static pile composting, and anaerobic treatment followed by aerobic post-treatment. Through the production of biogas, the anaerobic process has the added advantage of producing energy; in other words, potentially the system could offer a net production of renewable energy. In the short term at least, however, the principal focus will naturally be on the production of compost. Demand, production and use of organic soil conditioners Moving from theoretical reuse to practical application, Vietnam is an agricultural, tropical country and, as a consequence, agriculture is the main generator and recycler of biowastes - in the form of manure, crop residuals and agro-industrial wastes. Is there room on the market for soil conditioners produced from urban biowastes on top of the organic farm wastes and commercial organic fertilizers already used? This question was addressed through an analysis of agronomic need and actual use of organic fertilizers. The cultivated area in the south-east region amounts to 1.62 million hectares and is planted with vegetables, maize, peanuts, sweet potatoes, rubber, cashew and fruit trees, among others. Cultivation has increased strongly, primarily driven by the use of inorganic fertilizers. This has led to deterioration in the long-term soil fertility. On the basis of the present organic-matter needs of various soil-crop combinations, experts estimate the total agronomic need at 25.8 million tonnes of organic fertilizer per year. Actual use of various kinds of organic fertilizers was studied by means of interviews with 542 farmers of vegetables and perennial crops in different agricultural zones across the region. The study showed that vegetable farmers use on average 50% of the recommended rate of organic fertilizers, but in other crops the usage was much lower. The overall annual use of manure (2 million tonnes/year) and commercial organic fertilizers (0.25 million tonnes/year) in the region was estimated at 2.25 million tonnes, which is less than 10% of the recommended amount. Commercial organic fertilizers constitute a supplement to farm manure and their market is growing. At the moment there are 15 organic fertilizer firms in the south-eastern region that surrounds Ho Chi Minh City, with an estimated output of 700 tonnes/day (250,000 tonnes/year). Their inputs include peat, manure, rice husk, coconut fibre, soybean residue, septage and inorganic fertilizers, and the products are sold at 25-175/tonne. In general, these firms make a profit. A problem in this sector is the increasing scarcity of one of the main raw materials: peat. Some leaders in the sector have shown interest in using good-quality compost from municipal biowastes as an alternative input in their production processes. This could be of great importance as organic fertilizer firms know their markets and could therefore facilitate the introduction to agriculture of large quantities of urban-waste-based compost. In the past, Ho Chi Minh City had a 250 tonnes waste/day composting plant, but this plant had to be closed in 1987 due to technical and waste-quality-related problems. In other regions of Vietnam, eight firms produce compost from mixed municipal wastes with a total input of 1240 tonnes waste/day. Five of these were surveyed during the project. They all use the static pile forced aeration method. The general conclusion is that these firms produce compost of a reasonable quality and that their know-how is an asset to the future ventures in the processing of municipal biowastes Nevertheless, the product is not very attractive to farmers due to the presence of debris (plastics, glass and even syringe needles), which clearly demonstrates the origin of the compost. The composting firms obtain revenues from gate fees (€0.8-1.25/tonne waste delivered) and from sales of soil conditioners, whose price (€7.5-50/tonne compost) depends upon the content of value-enhancing additives. Astonishingly, these prices in Vietnam are higher than compost prices in Europe. For example, IGEAN (the inter-municipal regional development organization for Antwerp, Belgium) sells compost from its plant in Brecht for €2.5/tonne. Whilst the Vietnamese composting firms are capable of sustaining the running costs they nonetheless operate at a loss, if capital costs and depreciation of assets are taken into account. As in the Netherlands, the experience of composting in Vietnam highlights the necessity of segregating biowastes and non-biowastes at source, particularly since the composition of the wastes is changing to larger fractions of non-biodegradable material. Only by improving the quality of the input wastes will the product quality become attractive to farmers. Compost made at Thuy Phuong plant. Photo: Centema Click here to enlarge image The maximum future production of compost in Ho Chi Minh City is estimated at 192,000 tonnes annually (525 tonnes/day), assuming a collection of 2100 tonnes of source-segregated biowaste per day (42% of total collected wastes and 70% of the biodegradable wastes), a 60% biodegradable waste content and a conversion rate of waste to product of 4:1. On the basis of this estimate, it is inferred that this future compost production constitutes only a small fraction of the actual use of organic soil conditioners in Vietnam’s south-east region (2.25 million tonnes per year) and a very small fraction of the agronomic demand (25.8 million tonnes per year). Plastic separation in Ho Chi Minh City. Photo: Centema Click here to enlarge image At interviews, many farmers indicated that they would use suitable urban-waste-based compost if the quality were good and the price reasonable (that is, about €15/tonne). Therefore, it seems justifiable to conclude that there is ample scope to enlarge the organic fertilizer and soil conditioner market in the surroundings of Ho Chi Minh City. Such an enlargement calls for an attractive compost quality, but it will also require a major effort to position municipal-waste-based compost in the market and make farmers overlook their past negative experiences with compost made from commingled wastes. Towards segregated collection and disposal According to international practice, municipal biowaste reuse should be based on source-segregated biowaste as the input to biological treatment plants. Although the supporting legal framework in Vietnam is still incomplete, several leading players at city and district level are setting course for a waste-collection system in which the generators separate three streams: recyclables, non-biowaste and biowaste. At the moment, Ho Chi Minh City has a collection system for mixed waste. Households put their wastes in the street in plastic bags or in collective containers. As most streets are very narrow, the primary collection is carried out using one-compartment pushcarts. The collection is carried out by informal private (80%) and public collectors (20%) who bring the waste to transfer points where it is loaded onto trucks heading for the landfills. During this primary transfer, the collectors separate the recyclables from the bulk of the wastes. This practice adds significantly to their income and is the basis of a considerable waste-recycling industry. Stakeholder meetings organized within the project have shown the need for improvements with regard to the collection rate, equipment, logistics, legal guidance, division of tasks among responsible institutions and financial management. A special concern of the city administration is to better control the private collectors. Informal private collectors belong to the poorest strata of the city and often are people who have migrated from the countryside. They receive their payment directly from the households they serve (about €0.50/household/month), but their performance often does not meet the requirements of the management system. In one district the informal private collectors have been organized into teams and are now managed by the wards (the city’s lowest administrative level). They are given a permit for their job, have successfully reorganized the collection routes and their performance now seems more reliable. After several smaller projects in source separation, a demonstration project commenced in the spring of 2006 encompassing 17,000 households in District 6 of Ho Chi Minh City. As before, this project did not include the separated treatment of the collected fractions. The households were provided with green and grey bins for biowaste and non-biowaste respectively, and schools received 240 litre containers for biowaste. Monitoring during the early months showed a gradual increase in the number of households that separated their wastes well. About 80% of the households participated in source separation and 40% of the waste was well separated. In 2007, however, this separated collection was stopped as the expected structural support from the city and processing of the biowaste were not forthcoming. The stakeholder dialogues have brought to light that the private collectors are not looking forward to waste separation at source. They believe that they will lose income, due to decreasing access to recyclables. In the city’s plans to extend waste separation at source to 1.3 million inhabitants, the collection of non-biowaste, which contains the valuable recyclables, will be transferred from the private to the public collectors. In addition, collectors expect that once householders embark on separating wastes they will sell the recyclables themselves, and fewer recyclables will therefore remain in the collected waste. It is clear that the districts have to win over the private collectors to the cause of segregated collection and take measures to compensate them for possible losses. Biological treatment of wastes Despite the start of segregated collection in Ho Chi Minh City, the city as yet has no facility for the treatment of the collected biowastes. This is vital, not least because it is imperative that households see the benefits of their separation efforts and gain experience in marketing the new by-products. Encouragingly, several foreign and national companies have recently proposed solid waste treatment projects to the administration of Ho Chi Minh City. To date, Vietnam Waste Solutions (a daughter of California Waste Solutions), Vietstar (established by Lemna from the US), Saigon Earthcare (also from the US) and Tam Sinh Nghia from Hue City (Vietnam) have won contracts to process in total 1500 tonnes of wastes per day. The first two companies have recently begun the construction of plants, while the Tam Sinh Nghia plant is in the design stage. The contracts of the American-Vietnamese companies assume the treatment of mixed wastes. Mechanisms to achieve viable biowaste-reuse chains The main innovation required is a practical collaboration between those active in the field of solid waste management and those in organic-fertilizer production and agriculture. In the Vietnamese context, such an alliance calls for both a high-level administrative centre for biowaste reuse to initiate and co-ordinate the collaboration throughout the chain, and decentralization of the management of collection system to lower government levels. The Asia Pro Eco project’s analysis coupled with dialogues between stakeholders resulted in recommendations for an adequate legal system and financial instruments, stakeholder participation in planning and decision-making, infrastructure development and public communication. Two aspects can be highlighted: the quality of the biowaste products and the financial future of the solid waste management system. In line with European experiences, it is believed that a reliable quality assurance system supported by government institutions and the compost sector itself will be crucial to the successful marketing of compost from municipal biowastes in Asia. Quality assurance requires appropriate legislation and institutions that can regularly monitor the performance of the compost factories and certify their products. Existing regulations in Vietnam cover compost-like products made from wastes enriched with micro-organisms and inorganic nutrients, but adequate regulations for soil conditioners made from municipal biowastes are lacking. An important task for the country’s Ministry of Agriculture and Rural Development in collaboration with the Fertilizer Management Agency will be to develop a compost quality assurance system so that, in the future, farmers know what material they are buying and product quality starts to be the leading aim of compost producers. Expenditure on solid waste management in Ho Chi Minh City was €16.8/tonne in 2004 (€30.5 million in total), which can be broken down as €8/tonne for collection, €6.2/tonne for transport and €2.6/tonne for landfilling. If all hidden costs are taken into account, landfilling would cost around €15/tonne of waste, bringing the full handling costs to €29.2/tonne. Modelling of the costs and revenues of a system based on source separation, with partial composting of biowastes and landfilling of residual wastes, showed that the overall waste-handling costs would rise slightly to €29.9/tonne of waste. Municipal waste collection in Ho Chi Minh City. Photo: Centema Click here to enlarge image Therefore, the new system would incur more or less the same financial burden as the present system. Currently, the waste generators pay only €4.7/tonne of waste (about €0.5/household/month), leaving the brunt of the expenses (75%) to the city budget. Though politically difficult, the Asia Pro Eco project advised an increased recovery of waste management costs from the generators, based on the argument that the city budget should be invested in items that provide a better yield than solid waste management. In the long run, citizens would benefit more from such investments than from continually sinking money from the city budget in the disposal of solid waste. Comparison with Thailand and the Philippines So far, the situation in Ho Chi Minh City has been highlighted but, as the Asia Pro Eco project included parallel studies in Bangkok and Metro Manila, interesting comparisons between the different cities can be made. In each of the cities, the fraction of municipal biowaste processed and reused in agriculture is negligible at the moment. However, in several respects the situation in the Philippines turned out to be quite different from Vietnam and Thailand. With its Ecological Solid Waste Management Act of 2000 (Republican Act 9003), the Philippines are definitely ahead of the other two countries in the field of legislation and policy. This law puts emphasis on waste minimization, recycling and reuse. It prohibits the opening of new dumpsites, gives clear guidelines for sanitary landfills and prescribes 25% recycling and reuse of all collected solid wastes including mandatory segregation of wastes at source, which had to be achieved by 2005. Solid waste management and the implementation of this law are delegated to the eight municipalities of Metro Manila (11 million inhabitants), while waste collection and recycling activities are the responsibility of the smallest administrative units, the ‘baranguays’, which each have a population of the order of 10,000. The responsibility for the handling of solid waste in Metro Manila is therefore much more decentralized than in Vietnam and Thailand. As a consequence of the Philippine policy, every baranguay or cluster of baranguays in Metro Manila should have a material recovery facility for the handling of separated waste streams, including biowastes. As yet, the implementation of RA 9003 is still a long way from reaching its targets. By 2006, about 40% of the baranguays were practicing segregation at source and segregated collection of household wastes. In addition, many baranguays now have a material recovery facility, mainly processing valuable recyclables. Happy-Soil rotating drum composter in Manila. PHOTO: CONSTANCIO DE GUZMAN Click here to enlarge image However, food and kitchen wastes are in most cases disposed of with the residual waste and taken to landfills. The various facilities produce no more than 4 tonnes of compost per day. Its quality is poor and the cost-effectiveness of compost production at this scale is very low. It is evident that there are opportunities for increased treatment and marketing of compost, but a proper management of the biowaste-reuse chain is absent and perhaps composting can only become successful at a larger scale. In Thailand, policies to enhance recycling (paper, cans, etc.) have existed for about a decade and the recycling rate has steadily grown to 3.1 million tonnes per year on a country-wide waste generation of 14.3 million tonnes (2005). There are small-community composting projects in villages and at schools, and a plant at the Si-Moom-Muang wholesale-market in Bangkok. In Rayong City, a full-scale anaerobic digestion plant processing 17 tonnes per day of source-separated waste is struggling to survive. It seems that official support for the composting of municipal biowastes is in practice smaller in Thailand than in Vietnam and the Philippines. Conclusions In summary, activity linked with the processing and reuse of municipal biowaste was not found to be significant in any of the South-east Asian countries studied in this project. The existing limited supply of compost products is beset with problems of uncertain quality, high prices and an inefficient retailing organization. In Vietnam, about 150,000 tonnes/year of compost are produced from mixed MSW and the authorities in Ho Chi Minh City are wrestling to implement their first biowaste-reuse chain, based on the source separation of waste. Thailand has seen the recent failure of several large-scale composting plants and the momentum for biowaste reuse, at city scale at least, seems to have dwindled. The Philippines’ solid waste management system is decentralized and has made interesting advances in source separation, but here the scale of composting operations is simply too small to make a difference. Most of the recommendations of the EU Asia Pro Eco project are of course specific to the local conditions but, in general, an institutional change is necessary that facilitates joint action of waste managers and agricultural parties. Stakeholder dialogues could boost such action as they have the power to reveal hidden problems, find shared solutions and create strengthened momentum. Ho Chi Minh City works at plans to commence segregated collection in not less than 6 districts simultaneously. The project points, however, at the scarcity of agents of change at district level and recommends to direct all efforts towards making the biowaste-reuse chain run initially in one district, or even in only a few wards. Most obviously this would be District 6, where investments in segregated storage have recently been made. Joost C.L. van Buuren is Senior Lecturer at the Sub-department of Environmental Technology, Wageningen University, the Netherlands. Tran Thi My Dieu Dieu is Senior Lecturer at the Department of Environmental Technology and Management, Van Lang University, Ho Chi Minh City, Vietnam.e-mail: Joost.vanBuuren@wur.nl For more information about the project visit www.biowastereuse.org