Singapore is exploring the possibility of repurposing incineration ash from Semakau, its sole landfill, for use in projects like the construction of Tuas Port. As Semakau is expected to reach full capacity by 2035, the government is considering recycling ash from the landfill.
The landfill, spanning 350 hectares and capable of accommodating 28 million cubic meters of waste, is divided into two phases. Phase 1 comprises 11 landfill cells segregated by internal bunds, while Phase 2 involves the conversion of 157 hectares of sea space into landfill area. Phase 1 is now at full capacity, leading to the disposal of waste in Phase 2. The island generates three main waste categories: incineration bottom ash, incineration fly ash, and non-incinerable waste like wastewater sludge. The National Environment Agency (NEA) and the Maritime and Port Authority of Singapore are considering repurposing these waste materials for use in Tuas Port Phase 3. Prime Minister Lee Hsien Loong announced at the National Day Rally in August 2022 that land reclamation for Tuas Port Phase 2 is ongoing, with Phase 3 planning in progress. This port expansion comprises four phases, with an estimated total cost of USD 20 billion.
Researchers are evaluating the quality and potential treatment methods for the mixed waste, which has been exposed to the elements for up to 20 years. This research aims to determine how the waste can be used, such as in the construction of caissons for the port, land reclamation, road construction, or in concrete blocks, while ensuring that contaminants do not leach into the environment. The study is expected to continue into 2024, with preliminary results anticipated by the end of 2023 or early 2024.
(Source: The Straits Times)