Pulau Semakau is located to the south of the main island of Singapore, off the Straits of Singapore. The Semakau Landfill is located on the eastern side of the island, and was created by the amalgamation of the Pulau Sakeng (also known as Pulau Seking), and "anchored" to Pulau Semakau. The Semakau Landfill is Singapore's first offshore landfill and now the only remaining landfill in Singapore.
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 off between Pulau Semakau and Pulau Sakeng. It is currently estimated that the landfill, which began operations on 1 Apr 1999, will last till 2040. The Ministry of the Environment and Water Resources, along with the National Environment Agency which manages the landfill, hopes this deadline will be extended through various waste minimisation and resource conservation initiatives.
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 get 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 have 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 leachate produced is processed at a leachate treatment plant. Regular water testing is carried out to ensure the integrity of the impermeable liners.
The terrestrial flora and fauna of the (natural) island has not been fully surveyed.
Marine flora and fauna
The coral reefs around Pulau Semakau have been monitored since the late 1980s to 2001, by the National University of Singapore, and from 2003 to the present by the "Reef Friends" programme (a joint project between the National Parks Board and Blue Water Volunteers). Results of the surveys can be found at the 'Coral Reefs of Singapore' webpage and Blue Water Volunteers webpage.
The intertidal areas
A survey of the coastal and inter-tidal areas of the island in 2005 revealed four plants listed as endangered in Singapore
, including the Seashore Bat Lily (Tacca leontopetaloides) which so far has only been recorded in one area of Singapore: Pulau Semakau. Semakau also has vast stretches of Tape seagrass (Enhalus acoroides) which is considered rare and vulnerable in Singapore. Semakau is also the only known location in Singapore of the seagrass Syringodium isoetifolium. The seagrass meadow is being monitored by the recently set up 'Team Seagrass'
The mangroves
The construction of the perimeter bund of the Landfill affected mangroves on the eastern side of the island. The developers replanted two plots of mangroves totaling 136,000 square metres, just outside the perimeter bund. The two plots are doing well, indicating that there has been no seepage through the liners. Another design feature is the built-in channels that allow the flow of seawater into non-active cells, keeping the water fresh at all times.
Today, after years of operation, the replanted mangrove, and remaining natural habitats on the island are doing well. Even the closed cells, topped up with soil, are flourishing. Birds can be seen in the air and on the open landscape, fishes swim in and out of the lagoons, and marine life continues to thrive in the mangrove mudflats and the western shorelines of Pulau Semakau.
The National Environment Agency on 16 July 2005 officially opened Semakau Landfill to the public for selected recreational activities. It was launched by the Minister for the Environment and Water Resources, Dr Yaacob Ibrahim, with 40 families of the former residents of Pulau Sakeng, one of the small islands from which Semakau Landfill was built, invited back to their former home as guests of the event. The residents had left over 10 years ago. The opinions of various interest groups and organisations such as Nature Society of Singapore, Sport Fishing Association (Singapore) and Wild Singapore in using Semakau Landfill for recreational purposes were sought. Currently, members of the public who wish to visit the island are advised to contact the Nature Society, Sport Fishing Association, or the Raffles Museum of Biodiversity Research which conducts guided walks on the shores of Semakau for the public. All groups are led by a trained guide. This supervision is in place to protect the island's natural environment.
Further, facilities have been put in place, such as strategically-located shelters lightning arresters and lifebuoys, as well as directional signage and clear markings of no-access areas to keep visitors away from the operation areas.
Targeting interested groups in Singapore now have a unique recreational destination in the form of a huge open ash-filled landfill tucked away in the pristine waters of southern Singapore, coexisting with a mix of mangrove, grassland and shoreline habitats.