Singapore’s efforts towards sustainable waste management-
Singapore’s squeaky-clean surroundings are achieved at a substantial price tag that is escalating rapidly. The early strategy of the 1970s that focused on reducing waste volumes largely through incineration has given way to a stronger focus on waste minimisation since the turn of the century. This strategy is critical in a land-scarce island nation whose population has grown by nearly two and a half times since 1970. Even more alarmingly, the total quantity of waste for disposal, despite a 60 per cent rate of recycling, has grown by over a whopping six and a half times.
Though Singapore has a target of achieving 70 per cent recycling rate by 2030 as part of its sustainable development plan, achieving this is imperative from a financial standpoint.The costs of incineration and landfills are rising rapidly. Thus far, the government has steered away from legal mandates; instead, it has relied on public awareness campaigns and set voluntary goals to encourage industries to minimise waste.
Growing challenges
One of the biggest challenges for the city is the acceleration of its waste generation and the amount of waste disposed of. While total waste generation grew by just over 3 per cent annually (compounded) between 2000 and 2008, it has climbed up to 5 per cent during the four years 2008 to 2012. While waste headed for disposal shrank by 0.8 per cent during the earlier period, it rose from 2008 to 2012 averaging 2.6 per cent annually (compounded).
The strategy that the city has so far utilised includes stringently enforced standards, fee-for-service refuse collection and recycling, as well as voluntary agreements (with industry associations) for waste reduction at the source.
The most successful example of the voluntary approach is an agreement jointly developed by the government, NGOs, and industries. The First Singapore Package Agreement that was signed in 2007 aims to reduce package waste at the source. This five-year agreement that ended in 2012 helped to eliminate packaging waste of over 10,000 tonnes cumulatively over this period and produced savings of nearly $22 million for the participants. A second agreement is now in place: it is targeted at an annual reduction of 6,500 tonnes of packaging waste for 2015. The number of signatories has gone up from 126 (for the first agreement) to the current 315.
Overall, approximately 72 per cent of commercial and industrial waste is recycled on average, though the range is large (refer to Table 2 for details). For components (such as traditional commodities) that have a high resale value, recycling success has been outstanding. For instance, 99 per cent of construction and demolition waste, 97 per cent of used slag, and 96 per cent of ferrous metas are being recycled at present.
However, the reduction, recycling, and reuse of certain categories of waste, including food, textile/leather, plastics, and sludge, have remained disappointingly low. Though this waste cumulatively accounts for a little less than a quarter of the total waste generated, it constitutes over 67 per cent of the waste disposed of.
Among the most troubling waste categories is the 703,200 tonnes of food waste (approximately 133 tonnes per person) generated, of which 88 per cent is disposed of. Part of the problem is that food waste is currently lumped together with all waste for collection before it is sorted for recycling and reuse. Given the large size of the food and beverage industry in Singapore, a targeted partnership with this industry segment to promote waste minimisation or voluntary participation in food donation programmes will not only reduce the burden on the incineration plants (IPs), but also improve their performance.
For the other categories characterised by low recycling levels, such as plastics or textile/leather, the potential for reuse is high. Improved information campaigns, along with infrastructure for storage, recycling, and reuse, may go a long way in addressing this challenge.
Waste management infrastructure: Hi-tech and high costs
Waste collection and recycling services were privatised in 2001. Government-licensed/contracted waste collection agencies are responsible for the collection of all waste for sorting, recycling, and disposal. While government-nominated public waste collectors are deployed to collect solid waste from domestic and trade premises, industrial and commercial waste generators are required to engage their own waste collectors.
The city is currently divided into nine public waste collection sectors, each catering to roughly 100,000 households. They are in the process of being consolidated into six sectors (refer to Fig. 1). In preparation for the consolidation, all sectors other than Sectors 7 and 8 will not have the following uniform fees: S$7 per household per month for housing development board apartments and S$23.19 per landed house per month. The other sectors will move to the uniform fee structure by January 2015 by which time the current uniform fee for all sectors will be up for a review.
Unlike the past when contracts were awarded for a fixed fee throughout the contract period (six to seven years), all new contracts will have their fees reviewed biannually.
Every day, all the city’s waste ends up at the sophisticated collection and recycling centres, almost all of which are located in the Tuas area (a region bordering Malaysia in the western part of the city). Some of these waste collectors have deployed innovative technologies for automatic sorting, processing, and recycling of waste.
These collectors get to keep the earnings that stem from their trading of recycled materials. However, they have to pay S$77–81 for each tonne of waste they bring for disposal at the IPs. This approach is designed to give waste collection companies a significant incentive to increase their recycling rates. The country targets a recycling rate of 65 per cent and 70 per cent by 2020 and 2030, respectively.
Other than sludge and slag, which cannot be incinerated, the rest, 1,779 tonnes of waste, is delivered to the four IPs that have the capacity to generate approximately 130 MW of power of which 80 per cent is sold to the grid. Together, these plants meet 2 per cent of the country’s power consumption.
The National Environment Agency (NEA) runs the Tuas South IP (TSIP) and the Tuas IP, while the other two privately owned IPs operate under a service contract model with a fee and incentive. The fee from power generation goes directly to the government.
Designed by international consultants and the NEA, these plants adhere to the highest environmental standards, but that comes at a price. For instance, according to C.K. On, General Manger, TSIP, the plant that was installed at a cost of S$890 million has an annual operating cost of S$30 million. All plants feature a modular design, thus allowing them to be in operation 24×7 with enough redundancy in capacity to cater for seasonal upswings in waste disposal requirements.
Reduced to 10 per cent of the volume that arrives at the IP, the bottom ash is transported to the Semakau landfill. Spanning 350 hectares, this picturesque “island” in the sea was built in April 1999 at a cost of S$610 million. As per the given current estimates of waste headed for landfill and the new guidelines by the Urban Redevelopment Authority, it is expected to reach its maximum capacity by 2035.
Whither now?
Without a doubt, Singapore boasts of one of the world’s best infrastructure for solid waste management. Moreover, it has shown great innovation and adopted proactive strategies to ensure that its infrastructure is able to keep pace with the country’s growing waste management needs.
However, it may be time to focus on some beginning-of-the-pipe solutions to reduce its waste generation at source, as well as increase separation and treatment for reuse before collection, to complement its current strategy. Given that the country’s population will increase to 7 million by 2030, the current trend of waste generation and disposal is unsustainable.
Fortunately, the government is aware of the challenges. However, given its reluctance to mandate further waste reduction or recycling through regulations, it will really need to identify some innovative partnership strategies in order to maintain its high standards of waste disposal.
