In this article we will discuss about the solid waste management in Singapore.
Singapore – An Introduction:
The island city-state of The Republic of Singapore is situated towards the southern end of the Malayan Peninsula and is connected to it by a causeway, 1.2 kilometres in length, over the straits of Johore. Its area is only 699.44 square kilometres, of which about 70 per cent is made up by the main Singapore Island and the rest by 60 other smaller islets. It receives 60 per cent of its water supplies via this causeway through a pipeline from mainland Malaysia. Situated only 135 kilometres from the equator, it is at the crossroads of world trade, air and maritime routes, between Indian Ocean and South China Sea. This strategic location has made it one of the chief entrepots and commercial centres of the world.
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The main island of Singapore is, generally, flat with gently undulating low hills of igneous granitic rocks covering about 40 per cent of the central island. Singapore has a typically equatorial climate without any clearly defined seasons. The average annual rainfall is around 236 cms. Average day and night temperatures are 26.6°C and 23.7°C, respectively.
Singapore crossed the population level of 3 million in 1990, and in 2005 it was placed at 4.35 million, of which Singapore’s citizens and permanent residents constituted 3.55 million. Now it has cent per cent urban population, and one of the highest densities in the world. Population density of Singapore in 2005 was 6,222 persons to one square kilometre. The Central DGP Region—Development Guide Plan Region—sustained a majority of the population.
In 1990, 37.5 per cent of the total population was concentrated there, though the figure came down considerably from 56.5 per cent of the total in 1980. The Central Region also had the highest population density of 9,515 persons per square kilometre in Singapore. Singapore’s high population density is engendered by a severe constraint of land that Singapore is confronted with. At the micro level, the densities touch almost 27,000 persons per square kilometre in secondary planning regions, called DGP Areas.
Constraints of land in Singapore have led to large scale levelling of low hills and reclamation of land. Singapore had an approximate area of 587 square kilometres in 1967, which has now increased by 19.2 per cent to 699.44 square kilometres in 2005, all due to land reclamation. In the long term, the Concept Plan of 1991 aims to increase this area to 730 square kilometres—a total growth of 25 per cent since 1967.
The extensive public housing programmes of Housing and Development Board (HDB) had resulted in building up of 77 million houses by 1995-96 which accommodated 86 per cent of Singapore’s population. Most of the population lives in multistorey apartments, generally having 10- 13 storeys. A very limited land supply forced HDB to adopt the high-rise, high-density approach to public housing.
Millions were spent to provide more equitable, healthy and subsidised living environment to the poor. The dwellers of the slums and squatters were resettled in different areas of the island, so that no ghettos come up again. As a result, the poor quality housing in the form of attap and zinc-roofed houses constituted only one per cent of the total occupied dwellings in 1990. Amongst the resident household, 93 per cent had their own homes in 2005.
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Singapore’s small size and absence of hinterland, deficiency in natural resources, lack of energy sources, its external dependence on food and water requirements and its small population base have been instrumental in deciding its domestic and foreign economic and political policies. As the former Foreign Minister Rajaratnam said, a small city-state with above characteristics had a near-zero chance of survival politically, economically or militarily.
Therefore, only as a ‘Global City’ could Singapore draw its subsistence from the international economic system and tap a global hinterland. Singapore has, since long, followed a policy of export based industrialization in a fully open economy. The choice of having even a slightly closed economy with import substitution based industrialization was ruled out by its scanty resources and a very small domestic market.
At the time of attaining internal self-government in 1959, Singaporean economy was seriously afflicted with unemployment and a low standard of living. Emphasis was put on industrial development, strengthening of entrepot trade, and development of tourism. By the year 1970, the unemployment problem was almost erased with the arrival of Transnational Corporations (TNCs) units in Singapore.
Singapore now began to encourage investments in high skill and technology based areas as computers, electronics, machinery and pharmaceuticals. Soon, Singapore became an epitome of export-oriented industrialisation based on highly skilled labour and high value added goods. High- skilled foreign labourers formed about 10 per cent of the total population in 1990 census.
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Since mid-1980s, efforts at diversification of economic and export base from manufacturing to business and financial services were made. Biotechnology, aerospace and computer peripherals were also targeted. It is now the world’s 12th richest economy and unemployment there is as low as 3.4 per cent. It is the 14th largest exporting country and a major investor in the Asia-Pacific region. It has been transformed from an entrepot economy to a truly ‘global city’.
The government of Singapore, only too conscious of country’s spatial constraints and lack of natural resources, leaves nothing to chance. Its response to the imperatives of the peculiar situation in which Singapore is placed is reflected in its emphasis on detailed planning, efficient execution, and sensitivity to changes in international political and economic situation, competitiveness, flexible economic policies and conservation ethics. The small size and the resultant susceptibility of Singapore has been cited as the reason to legitimise the kind of politico-administrative system it follows, with single party domination and rule of the People’s Action Party (PAP).
Oft-repeated statements like ‘Singapore has little margin for experimentation and error’ and ‘nothing can be taken for granted’ show the concern of politicians in this regard. All these factors have ensured Singapore’s survival as a strong entity in world’s political economy and ecosystem.
Urban Solid Waste Management in Singapore – Constraints and Options:
Generally, the constraints in the process of urban solid waste management can broadly be divided into financial, technological, administrative-organisational and land constraints.
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Financial constraints are amongst the chief hindrances in solid waste management. Most of developing cities have low levels of revenue generation. This has a direct bearing upon waste management infrastructure, especially the number and upkeep of waste transportation vehicles, the insufficiency of which is a common phenomenon.
Inefficiency and mismanagement of resources highly reduces the functioning strength of the existing fleet of vehicles at any point of time. Financial constraints are also reflected in an inadequate number of cleansing staff, required to clean, collect and transport the wastes. Combined effect of all these is visible in the heaps of un-cleared solid wastes in different parts of the cities.
The following facts show that financial constraints are not applicable to Singapore:
Singapore is the second largest economy in Asia after Japan and twelfth largest in the world. It is also a major exporting country, the chief item of export being highly value-added electronic goods. Due to its financial power, Singapore is able to spend heavily on solid waste management services, which came to $ 104.20 per capita in 1996. With a GDP of 194359.8 million S $ (million Singapore Dollars, at Current Market Prices) in 2005, and a per capita GDP of 44666 S$, it has become one of the leading investor countries of the world.
The expenditure on environmental management in Singapore is as high as 0.95 per cent of the GDP. National Environmental Agency (NEA) had property, plant and equipment worth 109.97 million S $ in 2004-05, while its total operating expenditure was 313.50 million S $.
Inaccessibility to efficient technology and expertise for proper and safe disposal and management of solid wastes is another major constraint in the cities. This constraint is, in a way, a function of non-availability of sufficient financial resources. Costly infrastructure, like incineration and composting plants, vehicles and sanitary landfills etc., cannot be put into place until sufficient financial resources are available. The economic well-being of Singapore is reflected in the highly mechanised solid waste management system found there.
The refuse collection vehicles (RCVs), prime movers, roll-off refuse containers and the mechanised road sweepers characterise the Singaporean system. The RCVs are fitted with mechanical waste bin lifting devices and waste compactors, which enable RCVs to collect greater amount of solid wastes. The prime-movers and roll-off refuse containers are also high-capacity, automated waste transport vehicles fitted with compactors.
These collect wastes from big bin centres (waste collection centres) and take them to incineration plants and the waste transfer stations. Incineration plants are capital and technology-intensive plants, which require sophisticated monitoring and control procedures to prevent air pollution. Singapore’s off-shore waste landfill site also uses advanced technology, and is provided with leachate collection and treatment plant, weighbridges, computerised vehicle recognition mechanism, among others.
(c) Administrative-Organisational Constraints:
These are another very significant set of hindrances, which may manifest themselves in various ways. Many cities have multiple agencies looking after collection and removal of urban solid wastes in different jurisdictions of the city. An agency looking after its area may not have waste disposal site in its jurisdiction due to intense land-use competition found there. In such case, the waste will be thrown in the street corners, or within the limits of the adjacent jurisdictions.
This is because the financial condition of the concerned agencies is not good enough to bear the high waste transportation costs to the disposal site, which are often located outside the city limits. This practice of dumping wastes in the neighouring jurisdictions often causes conflicts amongst the concerned jurisdictions. Multiplicity of agencies may also cause doubling of infrastructure in the respective jurisdictions, which is economically inefficient due to the wastage of meagre resources of the civic bodies.
Sometimes, even within the jurisdiction of a municipality, different agencies dealing with collection and removal of solid wastes may occur. Absence of a co-ordinating mechanism amongst these agencies often leads them into a conflicting situation over the removal of wastes, creating chaos and disorder.
Waste management agencies are, often enough, further hampered by ill-motivated and inefficient staff. The urban environmental management systems are also susceptible to political and clandestine influences. Thus, the influential people of the high class neighbourhood are able to ensure total cleanliness for their areas, while the poor, uninfluential class neighbourhoods get little care.
Lack of effective municipal laws, and of a comprehensive strategy for public education required to instill a sense of responsibility and caring for one’s environment—are another significant lacunae in the proper management of urban solid wastes.
The solid waste management services in Singapore have been organised in a comprehensive and efficient manner. These services come under the preview of Ministry of Environment and Water Resources (MEWR), which was reconstituted from the erstwhile Ministry of Environment (ENV), w.e.f. September 1, 2004. The new MEWR aims ‘to deliver and sustain a clean and healthy environment and water resources for all in Singapore’.
The emphasis on water is significant because Singapore is a resource constrained country, and water has strategic significance as most of the water supplies of Singapore are imported from Malaysia. The MEWR works in co-ordination with other ministries and departments like – Public Works Department; National Parks Board; Urban Redevelopment Authority; Jurong Town Corporation (concerned with industrial development); Ministries of Health, Labour and Communication; and two statutory boards, viz. Public Utilities Board (PUB) and National Environment Agency (NEA).
The Planning Division of MEWR aims at facilitation and management of Singapore Green Plan process as well as other organisational improvement initiatives. The 3P Network (People, Public and Private Sector) Division seeks to formulate and implement public education strategies to foster shared ownership of environment and water resources. It works with NEA and PUB to facilitate capability-building of environment industry and to support its growth.
The Strategic Planning Division formulates and implements strategic policies on environmental issues related to clean air, clean land and public health; and performs research and analysis on current environmental policy issues. The Water Studies Division seeks to review and formulate strategic environmental policies relating to water, wastewater and drainage issues to ensure an adequate and affordable supply of water, as well as protection and enhancement of living environment.
The PUB and NEA work closely with MEWR in order to ensure a clean, pollution-free and well- cared environment of Singapore. The PUB is concerned with providing utilities like water, sewerage and electricity. The NEA focuses on the implementation of environmental policies of MEWR, and was formulated in its present form on July 1, 2002. The divisions of Environmental Protection, Environmental Public Health and Meteorological Services work under NEA in order to ensure a quality environment for the citizens (Chart 34.2).
The Environmental Protection Division plays a major role in protecting the environment. It implements programmes to prevent, reduce and monitor pollution. It also operates refuse incineration plants and the off-shore sanitary landfill. In order to conserve energy resources and landfill space, the Division implements programmes to minimise waste generation and maximise recycling and energy conservation.
Its Waste Management Department plans, develops and manages refuse disposal facilities, including four incineration plants of Tuas, Tuas South, Senoko and Ulu Pandan; the offshore Semakau Landfill site, as well as Tuas Marine (Waste) Transfer Station. It licenses waste collectors and regulates collection of wastes by Public Waste Collectors in nine geographical sectors.
The Pollution Control Department (PCD) controls pollution of air and water; ensures incorporation of environmental factors in land use planning; and also controls hazardous and toxic industrial wastes. Planning and Development Department develops environmental protection policies and standards; and ensures that environmental considerations are incorporated into land use planning and development.
The Resource Conservation Department formulates waste minimisation and energy efficiency policies, seeks to propel public education and to encourage public participation in waste minimisation and recycling.
The Environmental Public Health Division of NEA ensures a high standard of public cleansing and public health through comprehensive ground surveillance and appropriate preventive measures; overall cleanliness of Singapore and a high standard of hygiene in the retail food industry. Its Environmental Health Department (EHD) has been restructured from March 1, 2003. The re-organised EHD seeks to – make optimum use of resources by emphasizing synergy between sanitation and vector control; and to re-orient the organisation to work more closely with the community.
This involves engaging and empowering the people sector, private sector and the public sector; and working in tandem with Community Development Councils, Town Councils, grass-root organizations and residents (Chart 34.2). The EHD works through its 5 Regional offices (ROs), which are responsible for conducting regular checks in order to ensure, inter alia, that- (i) contractors are performing satisfactorily in public cleansing services (ii) vectors like mosquito, rodents, crow, cockroach, etc., are kept under check, (iii) premises are neat and clean, and (iv) littering does not take place.
Such constraints arise because land is in short shrift in large, densely settled cities. The limited land is divided into many conflicting demands, which raises its values sky-high. In these circumstances, finding sufficient open spaces for dumping or sanitary landfilling of wastes becomes an increasingly difficult task. Existing landfill sites get filled-up in time, even as newer sites are progressively difficult to find and locate in fast-growing, densely inhabited city.
Further, the undesirability, or ‘negative externalities’, associated with the wastes evoke the detest of the people against the creation of proposed waste dumping or processing sites in their neighbourhoods as evinced by the phenomenon of Not in My Backyard (NIMBY). Another related phenomenon is that of growing slums and squatters.
Unable to pay higher rentals or to buy land/house in a high-cost, land-squeezed urban market, the poor citizens rent in cheaper dilapidated slum-type housing, or squat on public lands. These slum and squatter areas are the problem zones for provision of urban waste management services, because they are provided either partial or no services at all, due to various reasons ranging from congestion to illegality.
The main constraint in urban solid waste management in Singapore is that of land. As we saw above, Singapore’s development pattern and policies have been markedly guided by its lack of sufficient natural and land resources. Dumping of wastes has been accorded a low priority in the solid waste management strategy of Singapore. Waste dumping grounds or sanitary landfills occupy much valuable urban land, which is in short supply in the highly urbanized city of Singapore.
This is the reason why the Lorong Halus sanitary landfill site was the last such on-shore site on the main Singaporean island. Whole of the main island has been reserved for future urban expansion in the form of residential, commercial, industrial or natural land-uses. Given this situation of land squeeze, Singapore is now dumping its wastes in the Pulau Semakau offshore landfill site, situated in the sea south-southwest of the main island.
Singapore has gone out of its way and spent more than 1000 million Singapore Dollars on this off-shore project. The importance given to incineration of all combustible wastes in Singapore, instead of their straight forward dumping, has to be seen in the light of tight land constraints that it faces. This costly process of incineration is supposed to reduce their volume by upto 90 per cent.
Only the residue obtained from incineration is sent to the landfill site. Reduction, reuse and recycling of wastes are now being given greater emphasis than incineration and land filling. The former three processes not only prolong the life-span of the landfills by reducing the volume of disposable wastes, but also reduce the cost accruing on the incineration process, as well as save the precious little available land for other uses.
Without knowing the exact amount of wastes generated, a proper planning and management of solid wastes is not possible. Waste Management System (WMS) is a central computerised system which links headquarters of EHD with various sites as waste landfills and incineration plants. The system provides update information on geographical origin ‘of waste vehicles arriving at these sites, and the amount of wastes carried by them.
Such information helps in planning of waste collection routes and deployment of refuse (waste) collection vehicles. The Control Room at the EHD office has the latest information on incineration plants and landfill site; daily deployment of vehicles and workers; vehicular maintenance, availability and breakdowns; and other emergencies. Such comprehensive organisation, minute work distribution, and provision of modern monitoring and control mechanisms have ensured a smooth functioning of solid waste management services to the-citizens of Singapore.
Singapore – Options and Strategy for Solid Waste Management:
Singapore’s prosperous economy, technological accessibility, and efficient administration and organisation allow it to go in for high technology based, high cost solid waste management options. However, choice of options, here, has been conditioned by an extremely limited land supply.
This scarcity of land led the government to decide on conserving the life of sanitary landfills or waste disposal sites through recourse to waste volume reduction strategies. Hence, the solid waste plan review in early 1970s was called for.
Various alternatives considered by it for reduction of solid waste volume were:
(a) High Pressure Compaction and Baling of Solid Wastes.
This process reduces the volume of disposable wastes by upto 30 per cent.
(b) Shredding/Milling.
Here, waste is converted into relatively odourless, incombustible, humus-like substance. The process reduces volume by half.
(a) Incineration:
It is the process of high-temperature oxidation, which reduces volume by about 90 per cent. It also helps in generation of electricity and recovery of scrap metal. This can help extend the life of landfills by almost 10 times.
(b) Pyrolysis:
It is the process of thermal decomposition of wastes in an inert atmosphere. The wastes are converted into various gases, tars, oils, organic compounds, inert solid residues and char. Conversion of wastes is proportionate to temperature attained during the process.
In this process organic solid wastes are converted into soil conditioner or manure by, for example, aerobic microbes in the presence of oxygen and high temperature. However, the demand for this product was not high in highly urbanised Singapore.
Sanitary landfills, or waste dumping grounds, as we know, need a lot of space and do not reduce the volume of the solid wastes.
This ought to be in environmentally safe area, by means of compacted bales, which must sink to bottom and must not break. It is also desirable to dispose of these solid wastes in a bounded area with provision to harvest and treat the leachates obtained from the wastes.
Based on the consideration of all the alternatives, incineration was, then, chosen as a cost effective strategy, which also had the additional advantage of maximum volume reduction of wastes amongst all the methods. Net calorific value of Singapore’s solid wastes was found to be between 4000-9000 kJ/kilogram, which can sustain its own combustion.
Singapore’s New Solid Waste Management Strategy:
However, due to various factors like growing amounts of solid wastes and rising incineration costs, difficulties of recruitment in waste collection and disposal, concern for limited land and resource conservation, the government decided to review its long-term strategy of solid waste management. As a result, it adopted a hierarchical waste management strategy in late 1980s, which has also been endorsed by United Nations Environment Programme.
The different levels of waste management hierarchy, with progressively decreasing preference and emphasis, are as follows:
(a) Waste Avoidance or Waste Reduction at Source:
This aim is to be achieved through use of lesser-raw materials-based technology in manufacturing, use of clean technologies, and extending the life-span of the products.
Where the production cannot be avoided, reuse of products has to be encouraged as the second-best resource conserving measure.
This strategy is to be adopted when even the reuse of products or ‘wastes’ is not possible. This process conserves both energy and materials and is less polluting than manufacturing from virgin materials.
When the first three options are not possible, incineration of wastes, accompanied with energy recovery, is to be chosen as the next best alternative.
This process has been given the least emphasis in this strategy, and is to be resorted to only when all other options of waste management have been exhausted.
Extremely limited land area of Singapore; together with its high rate of waste generation, coming from an affluent, urbanized society; creates a peculiar challenging situation. To face it successfully, Singapore has adopted a solid waste management strategy, i.e., Towards Zero Landfill and Towards Zero Waste, which can be summarized as – (i) Volume reduction through incineration (ii) Waste reuse and recycle, in order to reduce waste disposable at incineration plants and the landfill, and (iii) Waste minimization, to reduce the amount of generated waste.
Thus, theoretically; Singapore has adopted a very comprehensive solid waste management strategy, which has been adapted to the peculiar situation in which it is placed.
Solid Waste Management Practice in Singapore:
The highly prosperous society of Singapore generates a large amount of solid wastes. Its prosperity leads to a high level of consumption of goods which, in turn, results into production of an equally large quantity of wastes. In the year 2003, a total of 2.51 million tonnes was disposed of which was 4.9 per cent less than in 2002. In 2004, the quantity of disposed wastes further declined to 2.48 million tonnes, a decline of 1.20 per cent over the preceding year.
About 57.3 per cent of the wastes were generated in 2003 from residential premises, food centres and markets; and 42.7 per cent from commercial and industrial premises. The corresponding figures for 2004 were 56.4 and 43.1 per cent, respectively. Daily average disposal of wastes in 2003 was 6,863 tonnes, which registered a decline of 80 tonnes in 2004, at 6,783 tonnes. Average per capita domestic refuse generation was 0.94 kilogram day–1 in 2003, and 0.91 kilogram day–1 in 2004. This decline in average refuse disposal reflects the more aggressive perusal of Waste Minimisation and Recycling Programme (Table 34.1).
Solid wastes in private housing estates/trade premises are stored by the residents and shopkeepers in bags. This waste is collected by door-to-door service. In the markets, the owners are supposed to store their wastes, and then convey it to the waste centres (Bin Centres) personally, or through waste contractor. The owners of the food centres are also required to bag their wastes, and to bring them out only in the morning, in specified wheeled-bins for collection.
The public housing estates/condominiums have a different kind of waste storage system, which has three variants:
(a) Bulk Bin System:
In the Bulk Bin System, the multistorey public housing apartments and condominiums are, generally, provided with individual refuse (waste) chutes. The wastes are conveyed to the chutes from the kitchen. Below the chute, the refuse chamber contains bins, wherein the wastes get stored.
The refuse bins are daily emptied into bulk bins of 1 cubic metre capacity by the workers. These bulk bins are then pushed to the bin centre. Wherever possible, battery operated carts are used to carry bins, directly, from refuse chambers to bin centres, where these bins are emptied into bulk bins.
(b) Roll-Off Refuse Compactor System:
Under the Compactorisation Programme all large bin centres are being provided with roll-off refuse containers fitted with compactors. The bulk bins filled with wastes are directly emptied into the roll-off container by a mechanised system.
(c) Centralised Refuse Chute System:
This system was introduced in all new Housing and Development Board’s multistorey flats since 1991. In this system, a common chute is provided near the lift lobby of each floor, instead of the individual chutes in each flat. The chute ends in a refuse room at first floor which is large enough to store 3 days’ worth of wastes generated in the block.
The storage system in shopping complexes, commercial buildings and flatted factories consists of both the bulk bins and roll-off refuse containers. Here, refuse chutes are replaced by the service lifts, though.
Singapore needs daily collection of urban solid wastes, because high humidity and heat of the equatorial climate degenerates the organic wastes rapidly, causing bad odour. Since April 1, 1996 urban solid waste collection process has been corporatised in Singapore. Pre-qualified waste collection companies compete to provide collection services for the designated domestic and trade premises in the nine geographical sectors of Singapore. Tenders are awarded to serve different sectors for 5-7 years.
The waste collectors are also required to provide door-to-door collection services for recyclable materials from households under National Recycling Programme. Towards the end of 2005, three public waste collectors were providing collection services in the nine sectors of Singapore. The role of NEA now has been confined to the regulation of waste collection services in Singapore.
Its work now includes – safeguarding standards of environmental public health; safeguarding consumer interests regarding performance standards and reliability of waste collection services; and promotion of higher efficiency and productivity in solid waste collection. Licensed private waste contractors collect the wastes from industrial, commercial and shopping complexes, and construction sites. Wastes here, being mostly inorganic, the removal service may not be provided on daily basis.
Solid wastes are collected either by direct or indirect method. The direct collection refers to house-to-house collection of wastes by the waste collection crews. Such service is provided to private housing estates and shop houses. It is, however, a labour-intensive and time-consuming method and is, therefore, costly and inefficient.
In the indirect method, wastes are collected from common waste collection points or bin centres, where large amounts are stored in big containers or roll-off refuse compactors. The bulk-bins are carried by the refuse collection vehicles (RCVs), while the compactors are simply towed away.
Each bin centre is usually meant to serve a precinct, comprising high-rise apartment blocks and often, shopping and commercial complexes, markets and food centres. The wastes from high-rise blocks are collected by private sector or town councils’ employees, and are conveyed from refuse chambers to the bin centres.
This method is more efficient and productive than the direct method as wastes from many sources are collected from a single location. However, it involves double handling of wastes due to two sets of workers involved, which may also cause waste leakage.
However, compared to bulk bins, the transfer of wastes into roll-off compactors does not need extra two waste workers as the whole operation can be performed by the driver alone. Similarly, in the Centralised Refuse Chute System, the waste truck can collect wastes directly from the refuse room just by pushing a control knob. Waste collection system of Singapore seems all-set to go high-tech in the future. This futuristic system, currently undergoing experimental trials, is quite different from the conventional direct and indirect waste collection.
Known as Pneumatic Refuse Collection System, it consists of a central waste collection point connected via pipes to the refuse chutes of the apartments. It makes use of a vacuum to draw wastes to the collection centre. This potentially productive system could save time, avoid double handling of wastes, require lesser man-power, allow lesser waste leakage and prevent foul smells.
Singapore’s reputation for cleanliness is based upon a reliable, regular waste collection system as well as efficient cleaning of public areas. The Environmental Health Department of NEA ensures cleaning of Singapore’s streets, drains, beaches and sidewalks. To increase efficiency, much of this cleaning is mechanized. Public cleansing of manual type is carried out daily in congested areas inaccessible to mechanical sweepers.
Mechanised road sweeping services are now being carried out by the contracting agencies. Waste collection service in Singapore is provided on cost recovery basis. Amongst domestic premises, charges are higher for privately owned, richer landed properties. Similarly, for the trade premises, charges vary according to the volume of wastes collected from there.
All the wastes collected from residential, trade and institutional areas are transported by the public waste collectors to the incineration plants. The private contractors also bring other combustible wastes from industrial and commercial areas here.
As about 80-85 per cent of all wastes in Singapore is combustible, it is brought down for incineration. The remaining portion of the wastes generated is taken directly to the dumping site. In addition, the inert matter produced during incineration process is also sent, finally, to the disposal sites.
As Senoko and Tuas incineration plants are located in the extreme north and west of the island, a waste transfer station was built at Kim Chuan in the eastern part of the island to increase the efficiency of waste transportation. At Kim Chuan Transfer Station (KCTS) wastes from three to four refuse collection vehicles are transferred to the 20 tonnes capacity container-trailers after being compacted (Fig. 34.1). A waste disposal fee of Singapore Dollars (S.D.) 47 per tonne was levied for cumulative load above half a tonne per vehicle per day in 1997, with an additional charge of 11 S.D. per tonne for haulage.
Incineration residues and wastes from the main island are brought to the Tuas Marine Transfer Station (TMTS) on the south-south western coast. Incoming vehicles are weighed at the weighbridge before they enter the refuse reception hall, where the refuse is directly discharged into specially built high capacity marine barges via the 20 discharge bays. The hatch covers of the barges are closed before the 25 kilometres journey to the Semakau offshore landfill site begins. The barging operation is performed during night. There were six barges in 2005, each with a capacity of 3500 m3.
Collection and transportation of wastes is possible only with an efficient vehicular maintenance support structure. The well-equipped Vehicle Workshop at Eunos has 54 bays for repairing, servicing, painting and testing of vehicles. The individual care for every waste transport vehicle can be judged from the average maintenance cost of 31.20 S.D. per vehicle a day in 1995.
Waste Processing by Incineration:
In view of Singapore’s serious land constraint, the official policy has been to incinerate or burn all combustible wastes in order to conserve precious land. The three incineration plants of Ulu Pandan, Tuas and Senoko had a total incineration capacity of 6000 tonnes of wastes a day in 1997. This capacity was planned to be augmented to 9000 tonnes per day. Together, the three plants incinerated 68.5 per cent of the collected wastes in 1995.
They generated a total electricity of 582.81 mkWh, and also recovered 31,701 tonnes of scrap metal from the wastes in 1995. In 2004 these three plants, along with the fourth at Tuas South, incinerated 91.06 per cent of the wastes generated in Singapore (Table 34.2). During this year, 962 mkWh of electricity was generated as a byproduct of incineration, which formed 2-3% of Singapore’s total electricity.
Singapore is planning to build its fifth incineration plant in the private sector. The air pollution is strictly controlled in all the plants. Use of advanced pollution control equipment like dry lime reactors, electrostatic precipitators and catalytic bag filters ensures compliance with clean air standards. However, Singapore has to spend heavily on the operation of its incineration plants.
Though these plants earned a revenue of 38.30 million S.D. from the sale of electricity and scrap metals, as well as from waste disposal fees and disposal certificates, this earning only partially offset the operational costs. In 1995 alone, Singapore spent a total of 78.48 million S.D. on the operation of the three incineration plants. Thus, the country spent 21.98 S.D. on an average, just to incinerate every tonne of waste.
Refuse Disposal Fees is charged for disposal of wastes at different sites. For Tuas and Tuas South incineration plants it is $77 per tonne, for Senoko and Ulu Pandan it is $81 per tonne. During peak hours it is $87 per tonne for Ulu Pandan. A fees of $77 per tonne is charged for disposal at Tuas Marine Transfer Station/Semakau Landfill.
Waste Disposal by Dumping or Landfilling:
Waste dumping grounds, or sanitary landfills, as waste management option arc of secondary importance as per the official policy of Singapore. Only the wastes which cannot be reused, recycled or incinerated are supposed to be sent for landfilling. The residue left after incineration also goes to the landfill.
The landfilling has not been given the priority status because sanitary landfills occupy a large area and the filled-up landfills cannot sustain intensive industrial or housing development. Therefore, even though landfilling is a much cheaper option than incineration, the government has opted for the latter because of the very restricted land supply in Singapore.
Since early 1930s, Singapore had been resorting to the practice of dumping wastes in the swamplands. In the 1970s, however, it changed its strategy primarily towards incineration. Crude dumping of wastes had all along been carried out in all the earlier dumping grounds.
However, the last on-shore dumping site at Lorong Halus can only be called a ‘Sanitary Landfill’ in real sense of the term. The earlier dumping grounds led to bad odour, flies, and serious problem of water pollution in the swamps, and nearby streams, due to seepage of leachates.
The off-shore landfill site at Pulau Semakau was commissioned in April 1999, and is the only landfill site presently in Singapore. Covering an area of 350 hectares and with landfill capacity of 63 million m3, it is expected to last till 2045 AD. The landfill was created by constructing a 7 kilometre perimeter bund that encloses the sea between the island of Pulau Semakau and a small adjacent island of Pulau Sakeng. An impermeable high density polyethylene membrane has been provided at the base of the landfill, in order to prevent pollution of the surrounding sea due to seepage of the leachates generated in the landfill.
It also has a system to harvest the leachates that percolate down in the landfill. The leachates are treated at the on-site leachate treatment plant before being released into the sea as tested and non-pollutive water. The first phase of the landfill was completed in four years and it took $610 million to construct this environmentally-safe, offshore landfill site.
The barges carrying wastes from the Tuas Marine Transfer Station are berthed in an enclosed transfer building for unloading the wastes. Large excavators are used to unload the barges. A fully loaded barge takes about six hours to empty. Excavators either unload the wastes directly on to 35 tonnes capacity dump trucks, or on to the floor from where wheeled loaders load the wastes onto dump trucks. These trucks take the wastes to the tipping site.
Every truck at the site is weighed on the automated weighbridge before tipping the waste. After the disposal of the wastes at the landfill, they are disinfected and covered with earth in order to control bad odour, flies and other vectors. The Waste Management System (WMS) of the NEA consists of close circuit TV cameras, automated weighbridges and an integrated computer network which links the Semakau offshore landfill, the four incineration plants and waste transfer station with the NEA headquarters.
The weighbridges consist of overhead decoders, connected with the computers, which read the particulars of the vehicle from a card stuck near the front screen. The WMS enables NEA to monitor closely the amount of wastes collected and disposed in Singapore, and thereby helps in its scientific planning and management.
The landfill is expected to last till 2045 AD. In order to prolong its life, Singapore is resorting to the practice of 3 Rs—reduction, reuse and recycling of wastes. When it is filled up completely, a new recreational island will emerge in its place. The landfill area is clean, smell-free, scenic and thriving with birds, fishes and plants.
The western part of the landfill was opened to the public in 2005 AD for recreation, even while it continues to serve its primary purpose. This offshore landfill is symbol of Singapore’s struggle for a neat and clean environment in the face of a very tight land supply situation, and despite a heavy spending on this account.
Waste Minimisation, Reuse and Recycling:
As we saw above, waste minimization is a vital component of Singapore’s waste management strategy. A full-fledged Waste Minimisation Department (WMD) was established in February 1992 in order to minimise waste generation at source and to raise levels of waste recovery by its recycling and reuse. It sought to achieve these objectives by development, coordination, promotion and overseeing of waste minimisation and recycling programmes. Monitoring waste production and composition trends, formulating waste minimisation policies, and identifying environment-friendly products in order to encourage Green Consumerism have also been its aims.
In April 2001, the WMD was reconstituted under the Environmental Protection Division of the NEA. The WMD has now been assigned to the new Resource Conservation Department (RCD) of Environmental Protection Division as Waste Minimisation Section, which, along with Energy Conservation Section of the RCD, works on various broader issues pertaining to resource conservation. The RCD aims, inter alia, at formulation of holistic waste minimisation and energy efficiency policies, propulsion of public education, and encouragement of public participation in waste minimisation and recycling.
The kind of waste minimization and recycling operations performed by Waste Minimisation Section can be gauzed by looking at some of its activities which include – Setting Environmental Committees – Trade associations are encouraged to set up committees to minimize waste generation in hotels, hospitals and industry etc.
Waste Audit Programme – It was launched to help offices and industries to identify the quantity and types of wastes generated in their complexes and, thereafter, plan and implement a recycling scheme to minimize it. Promotion of Recycling Plants – The WMD inspires investors to set-up Recycling Plants for a number of waste materials.
It helps them by conducting studies and giving information on potential and viability of recycling various types of wastes. Minimal Packaging – The industries are convinced to use minimal packaging, and to use refill packs instead. The retailers are encouraged to use fewer plastic bags. Waste Exchanges – These are set up to enable exchange of waste materials for newer uses within and among industries. Waste Tracking – The Waste Minimisation Section keeps watch on waste generation, composition and trends by gathering data from disposal sites, by making surveys and sampling of wastes generated.
Recycling of wastes is being encouraged in different sections of the society (Table 34.3), and several recycling programmes have been introduced since 1990s. These include National Recycling Programme, Recycling Bins at Public Places, Recycling Programme for Schools, Recycling Programme for Condominiums, Recyling Programmes for Industrial and Commercial Premises etc.
Reuse and recycling of several non-incinerable wastes, which are usually sent to the landfills, is being encouraged under the programme Towards Zero Waste:
(i) Four construction and demolition wastes recycling facilities are working in order to sort-out, and process, such wastes into secondary aggregates and other products for the construction industry;
(ii) Three copper slag recycling units take in copper slag from the marine industry, which is processed and reused in grit blasting, and in manufacturing concrete-paving blocks and ready-mix concrete;
(iii) One unit processes steel slag, obtained from the scrap iron mill, in order to process road-building material;
(iv) A pilot project is going on in order to assess the feasibility of using bottom ash from incineration plants for making roads; and
(v) About 16,500 tonnes of scrap metal was recycled in the incineration plants and sold to a local’ steel mill for recycling into steel for the construction industry.
In the year 2004, about 90 per cent of the ferrous metals, 83 per cent of the non-ferrous metals, 49 per cent of scrap tyres, 46 per cent of paper and cardboard, 33 per cent of wood and timber, 56 per cent of horticultural waste, and only 11 per cent of the plastics were recycled in Singapore. The recycling set-up of Singapore thus retrieved about 48 per cent of all the wastes generated in 2004 in Singapore, which shows an overall progress of nine per cent over 1996 in a duration of eight years.
Legislation, Enforcement and Complaint Redressal Mechanism:
There is a separate and elaborate legislation on solid waste management in Singapore. No one is allowed to sweep, throw, deposit or even spit in any street or public place. No person can use the services of a waste collector unless the latter possesses a licence. All licensed waste collectors are required not to drop any waste during transportation, to keep their vehicles in good repair, and to keep proper records on waste collection service provided by them.
Fines and punishments in Singapore are very heavy for infringement of any provision of the aforesaid laws. For a first offence, a maximum fine of 150 Singapore Dollars (S.D.), for a second offence a maximum of 500 S.D., and for a third offence fine up to 1000 S.D. can be levied. These offences may be of various types like depositing wastes and spitting in public places and undesignated areas. Penalties for illegal waste dumping by licensed waste collectors have been increased heavily.
Now a maximum fine of 1000 S.D. or jail upto 12 months or both are possible. For second offence, a fine upto 2000 S.D. can be levied. In 1996, 78 offenders were booked for illegal dumpings of wastes. Due to continuing, or even rising, incidences of littering—by Singaporean standards that is—the Environmental Health Department (EHD) introduced the Corrective Work Order (CWO). This is a rather dramatic and alternative punishment to fines for serious, and repeat minor littering offences.
Under CWO punishment, offenders are required to perform cleansing for upto a maximum of 3 hours in a public area. The CWOs are, typically, widely publicised and offenders are made to wear a specific dress while at work. In 1996, 642 persons were given CWO, an increase of 259 over 1995. Litterbug Attack is an ongoing campaign directed against such erring persons.
The complaints received by NEA at its various offices are monitored from the control room at the Environmental Health Department (EHD) headquarters. All the field offices of EHD are connected with the head office through the computer network. This enables the EHD to effectively follow the public complaints.
Public Education and Awareness:
Creation of public awareness and environmentally-responsible behaviour through educational programmes and other activities has been another essential element in the success of Singapore’s waste management strategy. The Public Education Department (PED) has been actively associated with creation of environmental awareness among people since 1968. It was soon realised that without active cooperation of the people a clean environment can hardly be achieved.
Consequently, the first of the annual environmental campaigns in Singapore was organised on the theme ‘Keep Singapore Clean’ for one month in 1968. Before the campaign, the government improved the environmental infrastructure and the level of environmental health services, and brought into force more effective environmental legislation and enforcement of law.
This was done under a three-pronged strategy of environmental infrastructure, legislation and its enforcement, and public education. During the campaign period various talks, films and competitions were organised by the government offices, private organisations, schools, trade associations etc.
These campaigns proved successful in modifying the environmental behaviour of the people, and gained further momentum during 1970s with the launch of Keep Singapore Clean and Pollution Free. Environmental campaigns in 1980s became more specific, having their focus on proper disposal of waste in bags, avoidance of spitting and littering in public places etc. This decade also saw an emergence of non-governmental ‘green’ organizations.
In order to make Singapore a Model Green City by 2000, the aim during 1990s had been to make Singapore’s an ‘environmentally proactive society’. In 1990 the annual campaign called Clean and Green Week (CGW) was started with a specific theme every year. It has now assumed a festive outlook with exhibitions, tree-plantations, environmental carnivals and green markets. The decade also saw setting up of National Council on the Environment, which has become a major environmental NGO.
In the year 2000 campaigns for recycling of waste were launched. However, despite efficient infrastructure, strict enforcement and high environmental awareness complete eradication of problems like littering, dengue and illegal dumping has not taken place.
To deal with such problems, the Ministry of Environment and Water Resources plans to instill a sense of community identification through active involvement with improving one’s living environment; to encourage small core groups to serve as role models to lead environmental action in the community; and to encourage mass media to provide more environmental information.
Hence, NEA adopted the 3P (Private, Public, People) Approach in 2002. The objective is to rely more on the collaboration with, and among, these sectors than solely on government-led programmes. This approach puts greater responsibility on individuals, green organizations, schools and companies to carry environmental activities.
Some examples of this approach are:
(i) Singapore, Litter-Free initiative was launched in 2002, and aims at ensuring litter-free, large scale public events through participating peoples’ cooperation.
(ii) Recycling Corner Programme seeks to encourage recycling behaviour among school children.
(iii) Adopt-a-School Scheme encourages industries and their adopted schools to work together on environmental projects, and
(iv) The NGOs have got progressively more and more proactive in environmental matters.
Their role has evolved from consultation to cooperation and nowadays to co-leadership. Singapore Environment Council (SEC) is the leading environmental NGO in Singapore. It runs Singapore Green Labelling Scheme (to identify environment friendly products), Clean Rivers Education Programme, and also jointly oversees Fuel Economy Labelling Scheme (regarding awareness about fuel efficiency in the cars) with NEA, amongst others.
It is clear that waste and environmental management in Singapore, instead of being executed by the government alone, is getting more and more broad-based, with wider, active participation of different sections of the society. In fact, this is a pre-requisite for the success of any waste management system.
Singapore’s Performance in Solid Waste Management:
Singapore is a highly neat and clean city, even by European standards. An extensive, technology- based infrastructure, created and sustained with the help of a very strong economy; solid waste management structure marked by detailed, well-thought organization and effective control mechanism; a very strict legislation and its meticulous implementation; and severe land constraint have decided the direction of urban solid waste management in Singapore.
It has been instrumental in the selection of a strategy which is directed towards saving the precious land from the land-devouring option of dumping of wastes, and for putting greater emphasis on incineration, and now also on reduction and recycling of wastes.
Waste storage, collection and transportation in Singapore is oriented more and more towards automation, avoidance of double handling of wastes, and efficiency. The last is reflected in the safe and bulk transportation of wastes without spilling its bad odour in the atmosphere, or the waste itself on the roads. The bulk transportation enabled by compactization saves on transportation costs and is, therefore, more economically efficient.
The waste processing by incineration is a physical imperative because of limited land supply in the island. The latter is the reason why waste dumping has been given secondary importance in Singapore. Singapore has set high environmental standards which are also reflected in its solid waste management strategy. The possible land pollution from waste dumping, or the air pollution from incineration, have been suitably checked by strict control of possibly polluting processes.
This has been made possible by heavy spending and use of advanced technology at waste dumping and incineration sites. The increasing waste generation and rising cost of incineration have made the administration to adopt a more comprehensive, hierarchical waste management strategy.
This strategy lays greater emphasis on waste reduction/avoidance, reuse and recycling, than on incineration or dumping. No strategy or planning can be a real success unless the unconditional, unstinted cooperation of the masses is rendered voluntarily.
Realising this, Singapore embarked on sustained public awareness campaigns quite a long time back. It is now moving towards engendering public responsibility through mass participation in environmental programmes. Provision of sufficient infrastructure and waste removal services, mass awareness, and enactment of environmental legislation and its strict enforcement can be said to be the three vital aspects of solid waste management system in Singapore.