C&D Waste Management in Singapore: A Land-Scarce Challenge

Singapore is a fast-developing country with a population of 6,012,510 and 728.6 km² of land area. [1] It is a country that is built on land reclaimed from the sea and is intrinsically a land-scarce island nation. Despite this severe limitation, Singapore has maintained a record recycling rate for Construction and Demolition waste of 99% since 2013 (Fig.). *quite amazing, right?*

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This is why we feel densely-populated-land-scarce urban metropolises around that world can learn a lot from Singapore! In this article, we take a deep dive into understanding C&D waste management in Singapore and learnings that countries can apply to make their own C&D waste management systems more circular.

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C&D Waste Management in Singapore

Waste Management Governance: Major government organisations which look over waste management are National Environment Agency (NEA) and Building and Construction Authority (BCA). NEA is responsible for ensuring a clean and sustainable environment for Singapore and has 10 more related organisations which look over different aspects of a sustainable environment including waste management [2]. BCA champions the development and transformation of the built environment sector [3] and also overlooks the implementation and execution of the demolition codes.

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Demolition Standards: The existing codes for demolition is called “Code of Practice of Demolition (SS 557), 2010” [4], BCA also released a Demolition Protocol [5] in 2004 which is incorporated in the SS 557 Code. Hereon we will refer to the SS 557 Code of Practice of Demolition as “Code”.

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The Code mentions several methods of demolition, both manual and mechanical. The Code also mentions demolition guidelines for sensitive structures which include precast concrete building elements, bridges, jack arches, and chimneys.

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Demolition Procedures and Safety Guidelines: The Code is compliant with several acts and authorities in the domain of Public Health and Safety, Environment Protection and Management, Asbestos Factory Regulations, Land Transport Authority, Risk Management Guidelines, and Stability and Safety of adjacent buildings [4]. As per the Code each demolition project has a Professional Engineer (PE) who is responsible for submitting a demolition plan along with risk assessments, specifics for movement of licensed machinery on the site, and the sequence of demolition. The PE also maintains stability reports throughout the demolition process and submits them to the concerned authority which is BCA.

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Development of a Demolition Plan: Before the demolition begins, the original building plans and contractors are consulted in order to understand the building structure type and come up with a suitable demolition plan. Materials are quantified beforehand and an estimate of salvageable materials is submitted along with the demolition plan. A list of authorised recycling facilities for each type of waste is also submitted prior to the building demolition.

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Comparative Analysis with Delhi - A Crowded Urban Metropolis

NEA provides an open-source list of collectors, traders, and local recycling facilities for different kinds of waste. According to the latest list of 2022, Singapore has 302 such facilities for handling C&D waste which is listed on the bases of location pin codes. Back in 2013, Singapore successfully recycled 1.69 million tonnes of C&D waste, which was 99% of the total waste generated [6]. If we draw a comparison to Delhi, it currently has five C&D recycling plants till date, with a total annual recycling capacity of 1.54 million tonnes. While for India the recycling rate is estimated at 1% [7], for Delhi Malba Project estimates a recycling rate of 50%. Delhi has become land-scarce and the city is getting rebuilt since it has reached its saturation. Although Delhi is much denser than Singapore, with a population of 19,301,096 (estimated) [8] in a land area of 1483  km², we can still learn from the methods adopted by Singapore.

What can one learn from Singapore?

Singapore has been actively working on enforcing correct practices of demolition since 2002. Semakau (a floating landfill) [9] is the only landfill in Singapore. It came into function in 1999 and was designed to cater to incinerated ash and non-incinerable waste till 2035 and hopefully beyond. Semakau has an area of 350 hectares and charges a per-ton fee of $97 from the waste generator. In this situation, the country makes sure for it to recycle its C&D waste to the maximum because it cannot afford to send "recyclable waste" to a landfill which has a limited capacity. Not to forget a fun fact, Semakau is maintained in a manner that it also is an eco-park and hosts educational tours for students. [10]

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Here are some points where we think, Indian cities can learn from the case of Land-Scarce Singapore:

• Adopt a land-scarce mindset: Urban settlements like Delhi, Mumbai, Chennai need to adopt a land-scarce-island mindset and treat C&D waste management with the urgency that Singapore does in order to achieve higher recycling rates.
  
• Landfill as the last-resort: Landfills should be seen as a last-resort and not a standard practice. Even though Delhi has a much higher population density, it has far less infrastructure for landfill. All three landfills of Delhi have crossed their capacities long ago and thus are overloaded. Recyclable materials, especially C&D waste that are voluminous in nature should never be landfilled. Further, landfills must be “designed and maintained” to be sanitary, in a manner that does not create ill-living conditions around them.
  
• Health and Safety for all: The Demolition Code from Singapore teaches us that Development for tomorrow needn’t be a nuisance today. It specifically focuses on the health and safety of workers, neighbouring structures, and has formal measures to ensure compliance can ascertain that demolition does not disrupt life.
  
• Accountability in Execution: The Indian IS 4130 ‘Safety Code for Demolition of Buildings’ [11] is the Indian equivalent of the SS 557 ‘Code of Practice of Demolition’. It emphasises demolition planning, including a decision on the demolition sequence, however, it does not hold anyone accountable, and neither the Code asks for any documentation on material procurement or structural stability prior to nor during the demolition process. Moreover, in a country where much of the construction and demolition occurs without permits, it is tough to regulate the implementation of the Indian Codes.
  
• Worker Training Programs: Specially licensed and trained professional engineers are essential to ensure that best practices are followed. Having a training program for workers can also help in efficient training of a new set of workers for demolition. In the current system, there is no standardised knowledge available to the professionals and workers who are in the field.
  
• End-to-end Documentation: Specific guidelines and end-to-end documentation will increase the amount of materials salvaged, further, we can develop a database and create material passports [12] for the amount of materials that stay within the system and the amount of material that leaks out of the system. We can account for the contribution of the informal sector as well as the formal sector towards a circular economy.