Pulau Semakau was home to a small fishing village, as was the nearby island of Pulau Sakeng (Chinese: 锡京岛) which was also known as Pulau Seking. Houses built on both islands were perched on stilts as most of the villagers were subsistence fishermen, making a living off the nearby coral reefs. Located on the southern part of Singapore.
In 1987, the Singapore government, after having acquired the land on both islands from the islanders, set about relocating the islanders to the mainland where they were resettled in the Bukit Merah and Telok Blangah housing estate areas by HDB. One of the oldest residents continued to live on the Pulau Sakeng despite his family having been resettled but he eventually moved out as well in 1991, as the island's jetty fell into a sorry state of disrepair. The Singapore SPCA was tasked to round up the few cats that were left behind after his departure.
Subsequently, Pulau Sakeng was subsumed by the land reclamation process of Pulau Semakau and the present day Semakau landfill receiving station was built directly on top of Pulau Sakeng after that process.
The Semakau Landfill is Singapore's first and only landfill situated offshore among the southern islands of Singapore. It covers a total area of 3.5 square kilometres and has a capacity of 63 million m³. To create the required landfill space, a 7 km perimeter rock bund was built to enclose a part of the sea between Pulau Semakau and Pulau Sakeng. As of August 2011 it was estimated that the landfill, which began operations on 1 Apr 1999, will last until 2045.
Semakau Landfill is filled mainly with ash produced by Singapore's four incineration plants, which incinerate the country's waste, shipped there in a covered barge (to prevent the ash from getting blown into the air) every night. Contrary to popular belief that Semakau Landfill would be another dirty and smelly landfill, the care put into the design and operational work at the landfill has ensured that the site is clean, free of smell and scenic. During construction, silt screens were installed to ensure that the corals were not affected during the reclamation works. The landfill is lined with an impermeable membrane, and clay and any leachateproduced is processed at a leachate treatment plant. Regular water testing is carried out to ensure the integrity of the impermeable liners.