The-Integration-of-bio-waste-and-urban-agriculture-Prospects-and-Issues1

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14. International Conference on Environmental Management of Urban Infrastructures & Industry in Asian Ho Chi Minh City, Vietnam y 11 & 12 November, 2005 14 Tchobanoglous, G., H. Theisen, S.A. Vigil, (1 993); Integrated Solid Waste Management, McGraw Hill International Editions . www.compostnetwork.info.

11. International Conference on Environmental Management of Urban Infrastructures & Industry in Asian Ho Chi Minh City, Vietnam y 11 & 12 November, 2005 11 at least the scale of institutional collaboration so that technical surveillance, product quality control and marketing could bene fit from economies of scale. Big or medium scale composting plants do not exis t yet in MM . Composting at a scale of more than 10 tons/d and especially at a scale of 100 tons/d or more would require a strong political determination at the level of municipalities and central government to solve the problems of markets, high-quality compost production and sour ce separation in a coordinated way. This determination seems to lack at the moment. A general challenge regarding biowaste processi ng is the siting on composting plants. For the same flow of wastes many small plants would take more land than a few big plants, as service buildings, storage surfaces and roads take spac e that does not shrink in proportion to the small size of the plant. Since composting plants with their storage of raw wastes could gene rate bad odours and a considerable flow of rejects and leachate, they often are laid out at the same site as landfills. In MM such sites could probably be found only at a (long) distance from the built-up environment. From a logistic point of view the best location of a composting plant would be close to the zone of waste generation, since due to the weight redu ction at composting of a bout 60%, the transport of the raw biowastes contributes much more to th e costs than the transport of the final compost product. This of course is true only if the co mpost can be utilized in the vicinity of the composting plant. Location of composting plants far from the city would considerably increase the cost of transport in the chain. Again from the viewpoint of transport costs, it can be concluded that a number of medium-scale plants is cheaper than one big central composting pl ant. One or two very big plants would lead to large transport distances and consequently high costs: the bulky biowastes would have to be transported over long distances to the plants and from thereon to the widely extended areas of compost application. A higher number of smaller plants could result in considerably smaller transport costs. The optimum number in a city would be determined by many local factors, but theoretically the decreasing cost of transport associated with sm aller plants is offset by the higher cost of processing per ton of waste in small plants in comparison to big plants. VII. TO LAND ON HIGHER GROUND In The Philippines up to now the production of compost from MSW has primarily been viewed as a method of solid waste trea tment better than landfilling. Th e pressing questio ns preceding the extension of composting capacity are however: to what extent do farmers and other potential users want biowaste-based compost from MSW? Wh at other applications than farming could be part of the chain? What qualities of compost are needed? Up to now no adequate answers to these questions have been found. Our research has shown that increase of the reuse of municipal biow astes is fraught with uncertainties. It is useless to start stepping up one link of the chain, e.g. the composting capacity, without simultaneously warrant ing a matching demand of compost product and an enhanced segregated collection. Evidently, a ll key players have to act in concert to make the chain In order

2. International Conference on Environmental Management of Urban Infrastructures & Industry in Asian Ho Chi Minh City, Vietnam y 11 & 12 November, 2005 2 As new dumpsites for the soaring flow of municipa l wastes are increasingly hard to find, or only at very large distances from the city, a national po licy of closing of material cycles has been put into place and thus recycling and reuse have become a core issu e. It was realised that huge amounts of agricultural products are taken from the land inside and surrounding MM, but that the failing re-supply of organic matter, if not of N+P+K, to these lands would eventually lead to soil degradation. A new biowas te management policy would have to help prevent this soil degradation. Here, the product resulting from the (aerobic or anaerobic) stabilisation of municipal biowastes is designated with ‘compost’ or ‘soil conditi oner’. The term fertiliser is avoided since biowaste-based co mpost is not a satisfactory fertiliser in it own right. Since 2000 the Philippine Government bases it s waste management on the Ecological Waste Management Act (EWMA). This law targets at a 25% reduction of the wastes to be landfilled/ dumped within 5 years (2005). The law prescribes mandatory waste segregation, waste recovery, composting and reuse of biowaste-based products in agriculture. The Department of the Environment and Natural Resources (DENR) a nd The Department of Agriculture (DA) are charged with respectively the technical assistance for the production of good biowaste-based ‘compost’ and the development of new mark ets for the compost (ESWMA, 2002). The EWMA stipulates that implementation of waste segr egation at source and collection be further decentralized from the higher local government units such as to the barangay level. However, at this moment due to lack of resources at the barangay level in most localities the higher local government units, provinces and municipalities, are still the main actor in solid waste management. At the same time (1998) a national program for ur ban agriculture was adopted. Urban agriculture is stimulated by means of the Integrated Rese arch Development and Ex tension Agenda Program (IRDEAP). Urban agriculture is considered impor tant as a livelihood especially for the low- income brackets of the population. It contributes to food security, though modestly in the case of Manila, and in addition could be a market fo r a certain amount of composted biowastes. Everywhere in the developing wo rld the problems of solid waste management are accumulating through the enormous per capita growth of th e waste flow, the incr easing fraction of non- biodegradable and hazardous wastes and the concomitant crisis of traditional recycling practices. While the traditional recycling practices are dwindling, most city wastes are being dumped onto landfills. Environmental authorities in Europe and the USA have realised that biowaste recycling, especially composting and reuse, in ag ri- and horticulture, remained an indispensable element in waste management. Initially, mixed waste was used as input for composting. The product of this process became gradually less attractive to farmers due to the deteriorating quality of the raw waste that co ntradicts higher quality requireme nts. For better compost quality the biowastes had to be separated from the growing fractions of other wastes, either at-source or centrally after collection. At the same time, the separation of fractions enhances the calorific value of the combustable wastes , thus facilitating waste incine ration with energy recovery. The present practice in Europe and the USA, wher e firms at a scale of 100,000 tons/yr process source-separated urban biowaste s for commercial markets, is se rving as the hopeful perspective for waste managers in developing countries. This system is feasible however, by virtue of a substantial financial contribution of the hous eholds founded on the polluter-pays-principle. In The Netherlands ( www.compostnetwork.info) the costs of the production of compost from municipal biowastes amounts to abou t 60 EUR/ton. The market value of this compost varies with

5. International Conference on Environmental Management of Urban Infrastructures & Industry in Asian Ho Chi Minh City, Vietnam y 11 & 12 November, 2005 5 Table 3 Philippine quality requirements for compost (Obcemea, 2004) Parameter FPA requirement Moisture content < 35% (wet matter) N+P+K 3-4% (dry matter) C/N-ratio 12 Total coliforms < 500/g Fecal Streptococci < 5000/g The products from Barangay Sun Valley and Smokey Mountain comply with the moisture norm. The product from Barangay Escopa II had a moistu re content of 50%, far above the requirement of 35%. According to the FPA requirements compost shoul d contain 3-4% N+P+K on a dry weight basis. Barangay Sun Valley compost ha ving a total NPK content of 7.26 % more than meets the requirement. Barangay Escopa II and Smokey Mountain produce compost slightly higher (4.26%) and lower (1.84%) than the nor m for N+P+K content, respectively. The product C/N ratio of 12, as sp ecified by FPA, is being attain ed at Barangay Sun Valley only. Considering the required final C/N ratio of 15-20 (Kayhanian and Tchobanoglous, 1993), the compost products from Escopa II (C/N=25) and Smokey Mountain (C/N=33) even did not come close to that range. This could be attributed to the application of a too big amount of sawdust/coco dust. A C/N ratio of the end product higher than 20 should be avoided since such a high ratio could have a negative impact on the plan t growth and seed germination (Ref 5). Under these circumstances micro-organisms would cont inue to degrade the materials and consume available nitrogen and oxygen in the soil, thus competing with crops. Among the 3 composting sites, Smokey Mount ain exceeded the requirement set for total coliforms and fecal streptococci, while Salm onella bacteria, indicators for the possible transmission of infectious diseases, have been detected in all samples. Salmonella species can be eliminated from compost by an exposure for 15-20 minutes at 60o C or for 60 minutes at 55oC (dela Cruz, 2003). Since the feedstock used for composting is source separated, heavy metal concentrations are low and pass the FPA requirements. In subsection 4 the experiences with the three composting enterprises serve as a basis for an assessment of the biowaste to soil conditioner chain. 3.1.3. Survey among compost producers The 13 compost producers reached by our questi onnaire survey mainly manufacture organic fertilizers based on animal manure and other agri cultural residues. Five of them were using household or market wastes as raw material. Their production capac ities averaged about 90,000 bags of 50 kg per year, sold at a price ranging from 100 – 300 P/50 kg (= 2-6 USD/50 kg). The compost products were FPA registered and cer tified. The most importa nt compost buyers are farmers, but also fish pond owners were menti oned. The principal problem in extending the compost market, according to the producer group, lies in the fact that farmers are not convinced about the efficacy of the compost.

9. International Conference on Environmental Management of Urban Infrastructures & Industry in Asian Ho Chi Minh City, Vietnam y 11 & 12 November, 2005 9 Evidently the municipal biowaste reuse chain depends on the strength of the three links: compost markets, compost production and segregated wa ste collection. At the present stage it is impossible to pinpoint something as a main weakness in this chain. The Sta Maria, Bulacan study (Lapid et al. , 1996) and our own survey among farmers show in a qualitative way that the potential compost market s would be vast under the conditions that quality be guaranteed, prices lowered and farmer s made aware of the importance of maintaining the soil organic matter content. This statemen t would suggest that chain enhancement would particularly depend on improvement of quality and price of compost. But at the same time waste segregation remains a struggle for most citi es, and commingled waste collection, though discouraged by the law, is still by far most import ant. Where waste segregation at source runs well its success depends on the participation of the people, efficient involvement of the local private sector and on the support and political will of the national and local government. Some recent experiences have also shown the political vul nerability of the chain. Simultaneous changes of political leadership and connected ad ministrative staff after elections have brought about the collapse of well-runn ing biowaste reuse schemes, though these schemes themselves never were an issu e at the elections. 5.3. Strength of the present sm all-scale composting practice Positive features of the present small composting plants are their: 1. manageability by grassroots organisations under the present conditions of limited availability of at-source segregated biowastes and uncertain markets of the end products. 2. short transport distances of the bulky biowastes. 3. low requirement of space in crowded urban neighbourhoods close to the sources of wastes. A basic assumption of the barangay-scale plants is that the transport distances of raw wastes and compost product to the users are small so that transport costs which amount to about 0.04 USD/ton km remain modest. For the present size of plants the cost of transp ort is estimated at about 10% of the cost of processing. If the number of these small plants would increase, markets at short distance from the processing plants could become scarce and transport costs would increase. 5.4. Weaknesses of the present composting practice In our survey the quality of the compost of the 3 small enterprises appeared to be unreliable and in some respects deficient. NPK content was found to be too low (< 3% dry weight) in one instance and the C/N ratio and pathogen conten t too high. Doubts about the quality of the final product were raised in a study on the 6 tons/day co mposting plant at Sta Maria, Bulacan as well (Lapid et al. , 1996 ). The quality control of the compost is a task of FPA, but the regulations are not strictly enforced. The frequency of compost analysis is low (once pe r year) and significant quality fluctuations may occur depending of the qua lity of input wastes. Also it can be observed that composts in the market often lack FPA certification.

1. International Conference on Environmental Management of Urban Infrastructures & Industry in Asian Ho Chi Minh City, Vietnam y 11 & 12 November, 2005 1 THE INTEGRATION OF BIOWASTE AND URBAN AGRICULTURE: PROSPECTS AND ISSUES Ma. Cristina C. de la Cruz 1 , Constancio C. de Guzman 2 , Joost C.L. van Buuren 3 , Bert Hamelers 3 1 Housing and Land Use Regulatory Board, Quezon City, The Philippines 2 Department of Horticulture, College of Agriculture , University of the Philippines Los Baños, The Philippines 3 Sub-department Environmental Technology, Wageningen University, The Netherlands ABSTRACT Presently, Metropolitan Manila (MM) generates about 6,000 tons of municipal solid wastes per day of which 2,800 tons is estimated to be biodegradable. Despite a legal framework and policy that aims at recycling 25% of the biodegradable wastes, presently (only) 160 tons/d of these biowastes (ca 6%) is source-separated and processed in 22 small-scale composting plants. Evaluation of the performance of 3 of these plants revealed flaws in obtaining compost with the officially required quality standards. A survey among 50 horticultural farmers showed that only 34% of them use organic fertiliser. The main impediments for increased compost application are low expectations about the yields of compost versus inorganic fertilizers, the relatively high price and cumbersome handling of the bulky product . At 25% recycling in MM an agricultural area in the order of 20,000 ha would have to apply municipal biowaste-based compost in quantities of ca 10 tons/ha/yr, which is far more than the agricultural area within the city’s boundaries. Enhancement of the municipal biowaste reuse chain in MM would require synchronous expansion of the markets, the composting and the collection of segregated wastes. In order to develop a vision on chain enhancement a research programme covering Manila and several other South East Asian megacities is proposed. A determined collaboration of the stakeholders involved in the chain, farmers, compost producers, waste generators, waste collectors and waste managers, is seen as a prime prerequisite in the development of this vision. I. THE PERSPECTIVES OF SOLID WASTE MANAGEMENT IN METROPOLITAN MANILA In developing cities solid waste management is one of the most pressing concerns. This certainly is true in Metro Manila (METROPOLITAN MA NILA, MM), the prime urban center of The Philippines. In the year 2000 Metro Manila counted about 10 million inhabitants, which is 13% of the national population, living on an area of 636 km 2 . The municipal solid waste (MSW) flow amounts to about 6,000 tons per day, which co rresponds to about 25% of the country’s MSW production and this flow is still growing fast. About 45% of the to tal flow consists biodegradable material (municipal biowaste or MBW). Waste collection and disposal are a task of Metro Manila Development Authorit y (MMDA) and the 17 local gove rnment units comprising MM. Each of these local government units is subdivided into barangays . A barangay in MM comprises a population in the range of 2,000 – 10,000 persons. The fraction of solid wasted collected in MM is estimated at 65% (JICA and MMDA, 1998). Collected commingled municipal waste is transporte d to open dumpsites. Only 2% of the wastes are disposed onto sanitary landfills or controlled dumps. Uncollected wastes are either burned or dumped in vacant lots. The many dumpsites and the uncollected wastes cause severe air and water pollution as well as cloggi ng of the drainage systems.

12. International Conference on Environmental Management of Urban Infrastructures & Industry in Asian Ho Chi Minh City, Vietnam y 11 & 12 November, 2005 12 to find mechanisms to achieve a viable and manageable biowaste reuse chain and create a supportive environment for implementation, a res earch and demonstration programme consisting of 4 main activities has been developed (Table 6). Table 6 Research agenda for enhancing the biowaste reuse chain Stakeholder dialogues Establishment of a supportive environment through assessment of needs, constraints and strengths of stakeholders Diagnostic research Analysis of ongoing waste segregation at-source activities Assessment of the technical efficiency and economic viability of existing composting ventures including regulatory framework of compost application Agronomic, financial and demand analysis of the application of fertilizers Demonstration activities Farmers Field Studies to assess the efficacy of in the produced compost Manufacturing competitive compost products from market wastes and source-separated municipal wastes Strategies for chain management Survey of international best practices in urban waste management and reuse in South East Asian Cities Identifying mechanisms to achieve a viable and manageable biowaste reuse chain The backbone of the activities is the stakeholders dialogue. The main stakeholders are users of biowaste products, compost producers, waste generators (citizens and their grass root organizations), waste collectors and waste manage rs. The dialogue brings stakeholders together, makes them familiar with each other’s needs, cons traints and possibilities and intends to create a supportive environment for coordinated e xpansion of activities in the chain. Secondly diagnostic activities in each of the li nks: waste segregation at source, composting ventures and compost market intend to find bot tlenecks and opportunities in the chain, to learn from good practices already ex isting and to contribute to a vision on chain management. Thirdly, demonstration activities in biowaste treatment and application of compost in horticulture would have to result in widely ag reed procedures to make competitive compost products and to have farmers build up a joint expe rience in the use of compost. In contrast to field studies carried out by staff of an agricultural institute, during Farmers Field Studies farmers apply the compost under their own field conditions, they themselves carry out the monitoring of the plant growth and are directly involved in the analysis of their data a nd those of colleagues. The research programme will have to result in strategies for chain management applicable under Philippine conditions. The final stage of ‘ide ntifying mechanisms to achieve a viable and manageable biowaste reuse chain’ is carried out on the basis of a survey of international best practices in urban waste management, especially in South East Asia, in addition to the lessons learned from stakeholder dialogues, diagnos tic research and demonstration studies. Since reuse of municipal biowaste reuse is a pressing problem, not only in The Philippines but in South East Asian cities in general, the proposed programme could integrate comparative studies, conducted by joint venture of local and interna tional partners, in the surroundings of Bangkok (Thailand), Ho Chi Minh City (Vietnam) and Phnom Penh (Cambodja).

10. International Conference on Environmental Management of Urban Infrastructures & Industry in Asian Ho Chi Minh City, Vietnam y 11 & 12 November, 2005 10 Disappointing quality is not an intrinsic conseq uence of small-scale co mposting, but operations at a bigger scale could more easily justify more skilled surveillance, a more professional plant lay-out and more frequent product analysis. In bigger composting faci lities of the windrow forced-aeration type the high temperature requir ed for fast pathogen re moval could be more easily attained and controlled. VI. FUTURE BIOWASTE REUSE CHAINS A significant increase of municipal biowaste reuse requires a simultaneous boost of waste separation at source, compost production and applic ation. If, in accordance to the Philippine Law 25% of the biowastes of MM would be reused in agriculture, the compost flow produced would amount to about 600 t/day and the involved agricult ural area would be in the range of 20,000 ha. If we would visualize the metropolis as a rectangle of 30 * 21 km 2 with one side bordering the sea and 3 sides amenable to horticulture, the aver age width of the peri-urban horticultural ‘rim’ would be about 3 km. Even if only a part of this rim could be cultivated, this calculation shows that transport distances of compost do not have to be very long. In terms of composting an extension of the pr ocessing capacity to 1000 tons of wastes per day would require the implementation of the following possibilities: 1. Reuse of raw biow astes by farmers. 2. Increase of home composting. 3. A high number of small-scale plants with capa cities in the order of 5 – 10 tons per day 4. A small number of medium capacity plants of 10 – 100 t/d spread along the perimeters of the Metropolitan. 5. One large-scale plant with a capa city in the order of 500 t/d. The reuse of raw at-source segregated househol d biowastes by farmers was suggested by C. Furedy (2003 ), mainly as a means to reduce the financial burden for farmers at the use of compost from municipal wastes and thereby improving the possibilities of reuse. This form of reuse is not uncommon in Asia. An important disa dvantage would be a complete lack of quality control of the end product. It could lead to enha nced hygienic and chemical risks. Most likely the option could work in rural towns where the dist ance between waste generators and reusers is small. Some form of quality control to the raw wastes would have to be implemented. Home composting is particularly feasible in ur ban areas with a modest population density (e.g. < 100 /ha) where households could cultivate vegetabl es or decoration plants in gardens or in receptacles close to the residences. Home composti ng is common e.g. in cities in Nepal (Karki, 2004) Small-scale plants with a capacity up to 10 tons raw biowastes per day are the option embarked on in MM now. The option matches with the pr esent institutional arrangements of waste collection at barangay level and with the limited market . A barangay with a population of 5,000 inhabitants would generate about 5 tons of biowastes per day. The strength and weaknesses of this option have been discusse d above on the basis of our own survey. Despite some strengths of small-scale (manageability by grassroot organisations), we believe that its weaknesses (e.g. lack of quality) plead for an increase of the scale of the plants or

7. International Conference on Environmental Management of Urban Infrastructures & Industry in Asian Ho Chi Minh City, Vietnam y 11 & 12 November, 2005 7 Table 4 Assumptions applied in scenario analysis Waste Input Municipal Solid Waste generated Biowaste fraction of MSW (w.w.) Municipal Biowaste generated (w.w.) Moisture content of MBW Organic dry matter fraction in MBW C content in MBW N content in MBW P content in MBW K content in MBW 5,350 t/d 52 % 2,780 t/d 45% 84.6% 50% 3.2% 0.08% 1.5 % Process Addition of carbon-rich material (% of wet waste) Organic matter degradation rate C-loss to environment N-loss to environment 20% 34% 34% 33% Compost (end-product) Moisture content C/N ratio Compost application rate 35% 15-20 10 t/ha/yr 4.2. Demand within the urban area As the available land to urban agriculture amount s to 262 ha, the demand would be 2,620 tons of soil conditioner per year based on an applicati on rate 10 tons per hectare per year. To this amount could be added the demand for receptacl e farming whose value however is unknown. 4.3. Supply of organic soil conditione r in Metro Manila as per 3 scenarios Recycle-All In this scenario it is assumed that all generate d biowastes, equal to 2,780 tons per day, would be collected for composting. Utilizing the wa ste characterization in MM (JICA and MMDA, 1998), this amount of waste represents a dry matt er flow of 1,530 tons and an organic matter flow of 1,294 tons per day. As indicated in Ta ble 4 sawdust or a comparable material would be added as a carbon-rich material for adjustment of the C/N-ratio at a rate of 20% of the biowaste wet weight. This mixture would amount to 3,338 tons/d av ailable for composting. Assuming the quality requirements given in Table 3, th is mixture would result in 2,374 tons/d of compost, containing 1,429 tons of dry matter, 34 tons/d of N, 2 tons/d of P and 33 tons/d of K. The sum of N+P+K = 5.8 %. This compost has 40% moisture: that is higher than the requirement. During the composting process an estimated 316 t ons of carbon (as CO2) and 17 tons of nitrogen would be lost to the environment. According to the Recycle-All scenario Metro Ma nila would generate 866,000 tons of municipal biowaste-based compost annually. This is 330 times the quantity of 2,620 ton/year required for urban agriculture. It shows that the theoretical compost flow of 870,000 tons/yr is enormous and could help in improving the soil quality of an area in the range of 80-90,000 ha provided this compost could be distri buted to these lands.

4. International Conference on Environmental Management of Urban Infrastructures & Industry in Asian Ho Chi Minh City, Vietnam y 11 & 12 November, 2005 4 III. RESPONSES TOWARD CLOSING CYCLES 3.1. Small-scale composting sites The Philippine Ecological Waste Mana gement Act stipulates that each barangay formulate and implement a Solid Waste Management Plan appropr iate to the local conditions. As of October 2002 22 small-scale composting sites had been esta blished in the metropolis. Together they treat an estimated 160 tons/d of sepa rated biowastes. (6% of the to tal 2,700 t MBW/d generated). The activities of 3 of them, Barangay Sun Valley in Parañaque, Barangay Escopa II in Quezon City, and Smokey Mountain in Manila, are appraised here with regard to technology, product quality and cost. These sites were selected to repres ent different scales a nd systems of biowaste processing (Table 2). 3.1.1. Compost–making Common to the 3 sites are the use of kitchen wast e as feedstock, employment of eco-aides to do segregated waste collection and the use of coco dust/sawdust and inocula as additions to the wastes. The inocula or bacterial activators co ntain pure strains of micro-organisms or other biological factors deemed important to accelerat e the decomposition and stabilisation of organic matter and to fix nitrogen. They are often term ed as "enzymes," "hormones," "preserved living organisms," "activated factors," "biocatalyst," etc. Coco-dust and sawdust are applied to control the moisture content and to enhance the carbon/n itrogen (C/N) ratio. Structural materials like wood chips or yard trimmings to enhance th e aeration of the biomass are not added. Table 2 Capacity and prices of packed product at 3 studied composting sites (N.C.= not commercialised) Biowaste Composting Plant Capacity (tons/ month) Compost retail Price (USD/50 kg) Barangay Sun Valley 90 4.5 Barangay Escopa II 6 N.C Smokey Mountain 50 N.C At Barangay Sun Valley, raw materials are firs t mixed thoroughly by means of a cement mixer, put into sacks and stored for 15 days to allow d ecomposition. The stabi lised materials are then shredded to reduce the size and sieved before pack ing. The compost product is sold to traders from MM and Tarlac Province The composting plant has a partnership with the municipal government of Cavite (a province just adjacent to MM) in which the efficacy of the compost is tested at a farm. Barangay Escopa II utilizes ro tating drums instead of a cement mixer to mix the materials. Wastes are mixed with inocula and sawdust, ro tated daily and left open for aeration. The materials are left in the drum for 1-3 weeks to allow decomposition and are afterwards spread on the ground for drying. At Smokey Mountain, a rota ting drum with a maximum load of 5 tons is utilized. The residence time in the drum amounts to only 4 days followed by a period of drying. The compost produced at Barangay Escopa II a nd Smokey Mountain is used for receptacle farming. 3.1.2. Quality of the produced compost In The Philippines, a standard for compost separate from that of organic fertilizers has recently been developed. Compost producers must theref ore comply with the requirements of the Fertilizer and Pesticides Authority (FPA) (see Table 3).

6. International Conference on Environmental Management of Urban Infrastructures & Industry in Asian Ho Chi Minh City, Vietnam y 11 & 12 November, 2005 6 3.2. Urban agriculture in metro manila Urban and peri-urban agriculture (UPA) is thought to play a major role in helping to close the biowaste-related nutrient cycle in that it repr esents a potential demand for compost. In MM urban field agriculture is a marginal activity, but a significant source of income for the poor. According to data published by the Bureau of Ag ricultural Research the total area cultivated within the boundaries of MM in 1998 amounts to (only) 262 ha (0.04 % of MM surface) with a total annual production of various vegetables of 3,362 tons or 1. 1 % of the vegetable demand of the city. The small fraction of urban agricu ltural land and open land available for the establishment of waste processing plants can be explained by the high need of land for more profitable purposes as reflected by increasing land prices. For comparison: in Biratnagar, a town in Nepal, 59% of the urban area is us ed for agricultural purposes (Karki, 2004). The urban farmers of MM usually do not own the land they till and often are insecure about their tenure, but they depend on farming as their ma jor source of income. For them short-term financial security is of mu ch higher concern than long-t erm environmental benefit and consequently they use i norganic fertilizers to replenish a nd support the nutrient requirement of the crops. Most respondents to our questionnaires recognize the benefits of organic materials, but see three main drawbacks: 1. Preparation of compost is time consuming and laborious, so they rather buy compost than prepare it themselves. 2. The price is high, but they would buy it if it would be cheap(er). 3. They are uncertain about the agricultural valu e, but they would buy it if it is shown to be effective. The farmers are dependent on prompt crop yield, do not like to gamble with novelties and prefer proven methods. They assess government s upport for urban agriculture as marginal. Receptacle farming is common in Manila and pr omoted by institutions like the University of the Philippines Los Baños, Central Luzon State University and Cavite State University, where compost is utilized as growing media. The use of compost for receptacle farming is believed to increase. IV. COMPOST SUPPLY AND DEMAND In order to get a picture of the required co mpost market in and around MM, the supply was estimated for three scenarios of biowaste collection. 4.1. Three supply scenarios The 3 scenarios are referred to as 1. Recycle- A ll; 2. Philippine-Law and 3. Business-as-usual. The Recycle-All scenario assumes that all compos table wastes in Metro Manila, particularly the food waste, grasses and wood trimmings fracti on could be collected and transformed to soil conditioner. The Philippine-Law Scen ario is based on the target se t forth in the Ecological Waste Management Act. According to this law about 25% of biowaste would have to be composted. The Business-as-usual scenario departs from the present recycling rate of 6% (160 t/d) of the total biodegradable waste flow. In each scenario the same set of assumpti ons is applied as shown in Table 4.

3. International Conference on Environmental Management of Urban Infrastructures & Industry in Asian Ho Chi Minh City, Vietnam y 11 & 12 November, 2005 3 quality and application. High quality compost us ed for greenhouse cultures and sports turfs may yield 30-60 EUR/ton, compost used for lands caping about 25 EUR/ton, while in regular agriculture compost can be sold at 0-5 EUR/ton (1 EUR = 1.2 USD, 2003) Table 1 Market share of compost sales in a few EU countries (Status 1999-2001) Market share (%) Belgium Germany France Landscaping 26 19 Landfill+ restoration 2 25 Agriculture 43 52 Horticulture 9 5 5 Earth works 35 10 15 Private gardens 19 14 Export 5 - Miscellaneous 4 3 9 The data presented in Table 1show that the compos t market in Europe is diversified and strongly varies across countries. The closi ng of the cycle of biowastes requi res a continuous effort to find new markets for compost and the outcome of this ma rketing effort may vary from place to place. In developing countries there are several reasons why composting still contributes insignificantly to the reduction of waste disposal onto landfills. A financial contribution from the households to biowaste processing, or any other treatment process, usually doe s not exist and is hard to realise in the near future. Consequently, compost buyers have to pay the full price of the composting process and subsequent transport, which rend ers the compost too expensive for the average farmer. In reaction, composters attempt to tap the markets of high-value crop producers. Such markets exist, but their effective demand is limited. In order to overcome the problem of the high compost price, Furedy (2003) suggests giving farmers in developing countries access to non-c ontaminated urban biowastes such as market wastes. While compost would cost in the orde r of 50 USD/ton, this raw unprocessed waste would be sold at transfer points at a modest pr ice of 1-2 USD/ton. Farm ers would additionally pay for the cost of transport and proc ess the waste at their own premises. II. OBJECTIVES AND METHODOLOGY The present study aims at elucidating the main problems of the municipa l biowaste reuse chain and included the following stages. a. The state of art of solid waste management a nd its related regulations and policies in The Philippines and MM. b. A study about the operation of 3 composting en terprises by means of interviews, field observations and chemical and microbiological an alysis of the produced compost. In addition managers at 13 compost producers were in terviewed about compost manufacturing and marketing. c. A questionnaire survey among 50 urban and peri -urban farmers mainly about their views on the application of organic fertilizers. d. Scenario studies exploring the supply and demand of soil conditioner in and around MM. e. A strengths-weaknesses analysis to appraise strategies for en hanced compost utilization. f. Formulation of a research agenda aiming at answers about the main uncertainties.

8. International Conference on Environmental Management of Urban Infrastructures & Industry in Asian Ho Chi Minh City, Vietnam y 11 & 12 November, 2005 8 4.4. Philippine law and business-as-usual scenarios Similarly to the Recycle-All scenario the Phili ppine-Law and the Business-as-usual scenario are calculated. The results are shown in Table 5. The calculations show that even the actual pract ice (Business-as-usual) where only 6% of the generated biowaste is composted leads to a s upply (142/7.2 =) of ca 20 times as high as the demand of field agriculture within Metropolitan Manila. It is evid ent, that the chain biowaste-to- soil conditioner in Manila can be enhanced onl y if reliable markets for compost are developed for agriculture outside the city and for non-field applications. Table 5 Municipal biowaste collected, compost produced, emissions and theoretical compost demand in the present 262 ha of urban agriculture within Metro Manila. Wastes Compost Production Emissions to environment Present demand within Metro Manila Scenario Biowaste Collected (%of MSW) Biowaste Collected (w.wt) (t/d) C-rich material added (t/d) Compost Produced (t/d) N+P+K (% d.m.) C (t/d) N (t/d) Compost needed (t/d) Recycle-All 100 2,780 556 2,370 5.8 316 17 7.2 Philippine- Law 25 696 139 590 5.8 79 5 7.2 Business- as-usual 6 167 33 142 5.8 19 1 7.2 V. WEAKNESSES AND STRENGTHS OF THE PRESENT PRACTICE In the ensuing analysis of strengths and weakness es of the existing practice a distinction is made between the municipal biowaste reuse chain as a whole and the composting activity as such. 5.1. Strengths of the chain The main strength of the present practice in MM is the fact that municipa l biowaste reuse chains are operating and continue to develop. This deve lopment is made possible by official supportive policies and by the environmental awareness and ac tive stance of a multitude of grassroots organisations. The ratification of the Philippine Ecological Waste Management Act in 2000 reflects the strength of the organizations, which lobbied for this law. These include NGOs in education and training regarding waste management , a local private sector dealing with waste collection under government contr acts and universities that pr omote organic and receptacle farming. These organisations together with th e local government units are the backbone of the present chain. 5.2. Weaknesses of the chain The chains exist but contribute as yet insignifican tly to the reduction of the biowaste flow going to landfills. This is the pivotal weakness of the present practice. As of 2002, the biowaste reuse in MM depended on the operation of 22 small com posting plants with a summed capacity of 160 tons/day, which represented about 6% of the tota l municipal biowaste fl ow. The small scale of the operation has its pros and cons as is explained below.

13. International Conference on Environmental Management of Urban Infrastructures & Industry in Asian Ho Chi Minh City, Vietnam y 11 & 12 November, 2005 13 VIII. CONCLUSIONS Presently, MM generates about 6,000 tons of municipal solid wastes per day of which 2,800 tons is estimated to be biodegradable. Despite a le gal framework and policy th at aims at recycling 25% of the biodegradable wastes, presently (onl y) 160 tons/d of these biowastes (ca 6%) is source-separated and processed in 22 small- scale composting plants. Evaluation of the performance of 3 of these plants revealed flaws in obtaining com post with the officially required quality standards. A survey among 50 horticultural farmers showed that only 34% of them use organic fertiliser. The main impe diments for increased compost a pplication are low expectations about the yields of compost ve rsus inorganic fertilizers, the relatively high price and cumbersome handling of the bulky product . At 25% recycling in MM an agricultural area in the order of 20,000 ha would have to apply municipal biowaste-based compost in quantities of ca 10 tons/ha/yr , which is far more than the agricultural area within the city’s boundaries. Enhancement of the municipal biowaste reuse chain in Manila would require synchronous expansion of the markets, the composting and the collection of segregated wastes. In order to develop a vision on chain enhancement a research programme covering MM and several other South East Asian megacities is proposed. A determined collaboration of the stakeholders involved in the chain, farmers, compost producers, waste generators, waste collectors and wa ste managers, is seen as a prime prerequisite in the development of this vision. REFERENCES De la Cruz, M. C. C. (2003), The Integration of Biowaste and Urban Ag riculture: Prospects and Issues, Master’s Thesis Wage ningen University. Ecological Solid Waste Management Act of 2002 (Republic Act 9003). Furedy, C., (2003), Urban Waste and Rural Farmer s: enabling low-cost organic waste reuse in developing countries; Paper for the 6th World Congr ess on Integrated Pesources Management , Geneva, 2002 ; www.cityfarmer.org Golueke, C.G. (1977), Biological Reclamation of Solid Wastes, Rodale Press (Pa) , USA. JICA and MMDA (1998), The Study on Solid Wa ste Management for Me tropolitan Manila in the Republic of the Philippines, Master Plan Report , MMDA, Philippines. Kayhanian and Tchobanoglous. 1993. Characteris tics of Humus Produced from the Anaerobic Composting of the Biodegrad able Organic fraction. OF Municipal Solid Waste , Environmental Technology. Karki, M., (2004) B., Solid Waste Management. Resource Recovery and Recycling Potential in Biratnagar, Nepal; Master’s Thesis, Wageningen University. Lapid, D.G., C.C. Ancheta, Th. J. Villareal, (1996), Composting in The Philippines, Case-study Report , Urban Waste Expertise Programme -WASTE ( [email protected]) . Obcemea, W. N. 2004. Organic Ferti lizer Standards and Requirements. Paper presented at the Seminar-Workshop on the Assessment of Trichod erma-based Compost and Organic Fertilizer Production and Utilization , July 13-14, 2004, PCARRD, Los Baños, Laguna.

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