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World Cities Summit Issue, Jun 2008
Waste Management and
Economic Growth
Lee Yuen Hee
THE SOLID WASTE CHALLENGE
With limited land area and high population density, it is not surprising that the disposal of municipal solid waste poses a major challenge to Singapore. The strong economic growth achieved in the last 40 years of development has resulted in a corresponding explosion in waste generated and, if not properly managed, would have caused degradation to Singapore’s environment. In 1970, about 1,300 tonnes of solid waste were disposed of daily; by 2000, this had increased six-fold to 7,600 tonnes per day (Figure 1). The problem was further compounded by Singapore’s warm and humid climate, which makes refuse extremely putrefiable. Refuse has to be removed and disposed of quickly, efficiently and safely before it gives rise to smell nuisance, infectious diseases and other public health hazards.
Furthermore, if the rate of waste disposal were to continue to grow as it did, scarce land resources would need to be set aside to build more expensive incinerators and landfills. This was clearly not sustainable.
SUSTAINABLE SOLID WASTE MANAGEMENT
The National Environment Agency (NEA) has, in close partnership with key stakeholders in the Private, Public and People (3P) sectors, adopted strategies and programmes to address this problem. These strategies are: Volume Reduction through Incineration; Waste Recycling and Reduction of Landfilled Waste; and Waste Minimisation.
These measures have increased the overall recycling rate from 40% in 2000 to 54% in 2007, putting the country in a good position to achieve its target of 60% as outlined in the SGP 2012.
Strategy 1: Volume Reduction
Before 1979, all waste was disposed of in landfills carved out of swampy areas on the main island of Singapore. The situation was becoming precarious—projections showed that space for landfills would run out very quickly as waste quantities grew in leaps and bounds. Studies indicated that waste-to-energy incineration plants were the way to go in our situation. Being able to reduce waste volume by a drastic 90% in a short time and in facilities requiring relatively small footprints was clearly an ideal solution to our resource-scarce situation. The first incineration plant was commissioned in 1979. Since then, three other bigger plants followed in quick succession—1986, 1992 and 2000—to meet the ever-increasing waste loads.
These four modern waste-to-energy incineration plants are fitted with advanced treatment systems to remove acidic gases, dust and other contaminants from the flue gas before it is released through the chimneys. The flue gas is closely monitored to comply with Singapore’s clean air emission standards. Energy is recovered to generate electricity; scrap iron is also recovered. The resulting incineration ash, which takes up only 10% of its original volume, is then landfilled.
Strategy 2: Waste Recycling
Even as incineration offered us an effective, though expensive, technical solution to our waste situation, projections showed that we would have still exhausted all our landfills on the main island by 1999. We therefore had to look beyond, to enclose a sea space eight kilometres south of the main island, and at great expense, to build our sole remaining landfill off the shores of Pulau Semakau island (see box story).
Moving up the waste hierarchy, the second strategy was therefore to promote waste recycling in the industrial/commercial sectors and in households, to reduce the waste disposed of at the incineration plants and landfill. This was done through a three-pronged approach of engaging the industry, community and schools.
Less than half of the waste disposed of in Singapore comes from the industrial and commercial sectors. Such waste includes metals, horticultural and wood waste, and paper waste. Recycling in the industrial and commercial sectors helps avoid the gate fees charged at the waste disposal facilities and thus contributes directly to the bottom line.
The NEA promotes waste recycling by conducting talks, running awareness programmes targeted at businesses, and providing recycling information and data. It also worked with the largest owner of industrial land and ready-built factories, JTC Corporation, to set up recycling facilities in all its 21 flatted-factory and nine terraced-workshop industrial estates.
The Singapore Land Authority also helped by allocating some 20 hectares of land at Sarimbun for recycling activities. Sitting on a closed landfill, the Sarimbun Recycling Park (SRP) is operated by NEA. To date, the SRP has been well utilised for various recycling activities, such as composting of horticultural waste and recycling of construction and demolition waste.
NEA administers the S$20 million “Innovation for Environmental Sustainability” (IES) Fund that was set up by the Government in 2001 to promote the adoption of innovative environmental technologies that contribute towards Singapore’s long-term environmental sustainability. In this regard, waste minimisation is one area targeted by the IES Fund. To date, 15 Singapore-based companies had tapped the IES Fund for funding of several waste management and recycling test-bedding projects. Some of these projects include the production of pre-cast concrete drainage channels using recycled aggregates; the conversion of horticultural waste into packaging materials; and the processing of ladle furnace slag, a by-product of the steel making process, into road construction materials.
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