The National Environment Agency (NEA) is looking to reuse landfill materials in an effort to turn trash to 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 one and 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 yesterday.

To better understand how the lifespan of Semakau Landfill can be extended and how to avoid having to construct another offshore landfill, NEA has issued a proposal to study the technical feasibility of recovering mixed landfilled materials. This would also help promote a circular economy with zero waste.

These mixed landfilled materials comprise incineration bottom ash (IBA) and incineration fly ash, which comes 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 by creating NEWSand, which is generated from IBA and municipal solid waste slag. NEWSand has been used in the past to make concrete benches, a footpath in Tampines town and the new concrete plaza in front of NEA's Environment Building. 

Through this proposal, NEA seeks to explore 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 had "aged" over time. 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 could be refreshed. 

A key  waste reduction target in Singapore's Zero Waste Masterplan is to reduce by a third the ash and waste sent to Semakau Landfill each day by 2030. This initiative would complement current waste reduction efforts to save Semakau Landfill from being fully filled up. 

Mr Tan Meng Dui, chief executive of NEA, said: "NEA is spearheading research and development 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 futures uses."