Turning trash into treasure: NEA seeks to reuse landfill materials

A dump truck discharging incineration ash at Semakau Landfill.
A dump truck discharging incineration ash at Semakau Landfill.PHOTO: NATIONAL ENVIRONMENT AGENCY

SINGAPORE - The National Environment Agency (NEA) is looking to reuse landfill materials in an effort to turn trash into treasure.

This would not only extend the lifespan of ash and other wastes but also the life of Semakau Landfill, which is fast filling up.

Singapore's only landfill has been in operation since 1999. It is projected to run out of space by 2035 if no action is taken, NEA said in a statement on Friday (Sept 25).

To better understand how the lifespan of Semakau Landfill can be extended and how to avoid having to construct another offshore landfill while at the same time promoting a circular economy that will have zero waste, NEA has issued a proposal to study the technical feasibility of recovering mixed landfilled materials.

These mixed landfilled materials comprise incineration bottom ash (IBA) and incineration fly ash, which come from waste-to-energy plants, as well as non-incinerable waste from industries. IBA is the thicker and heavier component of incineration ash.

If successful, this initiative will mark the first step to truly close the waste loop for Singapore, going beyond what is being currently done: creating NEWSand, which is generated from IBA and municipal solid waste slag.

NEWSand has been used to make concrete benches, a footpath in Tampines town and the new concrete plaza in front of NEA's Environment Building in Scotts Road.

Through this proposal, NEA looks forward to exploring innovative and novel solutions for prolonging the lifespan of Semakau Landfill as well as spur Singapore's drive towards becoming a zero-waste nation, the agency said.

The proposal aims to understand the physical and chemical properties of the landfilled materials that have "aged" over time.

An aerial view of replanted mangroves at the southern plot of Semakau Landfill. NEA is looking to explore innovative and novel solutions for prolonging the lifespan of Semakau Landfill. PHOTO: NATIONAL ENVIRONMENT AGENCY 


By assessing the technical and economic feasibility of extracting the landfilled materials and applying them elsewhere, such as potentially using them as sand, the landfill space can be refreshed.

NEA chief executive officer Tan Meng Dui said: "NEA is spearheading research and development (R&D) efforts to go even further so as to truly close the waste loop for the range of end-of-life waste and residues ending up at Semakau Landfill. This R&D initiative seeks to develop safe and sustainable solutions to turn the trash dumped into a landfill, into treasure that will have new future uses."