PUB, Singapore’s National Water Agency, has appointed Koh Brothers Building & Civil Engineering Contractor (Pte) Ltd and China Harbour (Singapore) Engineering Company Pte Ltd Joint Venture to construct the Influent Pumping Stations for the Tuas Water Reclamation Plant (WRP), which is a major part of the Deep Tunnel Sewerage System (DTSS) Phase 2 project.
The DTSS Phase 2 is a SGD 6.5 billion (USD 4.7 billion) infrastructure project that will enhance Singapore’s water sustainability by boosting PUB’s capability to reclaim and recycle water in an endless cycle. Phase 1 of the project, which channels used water from the eastern part of the island to Changi WRP, was completed in 2008.
This contract, valued at SGD 668.2 million (USD 482 million), was awarded following an open tender exercise in 4Q 2018. PUB received a total of 16 bids for the project. The project involves the construction of a total of five deep shafts, to house 26 large capacity pumps. The largest pump has a capacity of 195,000 cubic meters/day, which can fill 78 Olympic-sized swimming pools. The shafts will have diameters of up to 48 meters and will reach depths of up to 80m.
These will be PUB’s deepest pumping stations and they will be equipped to pump domestic and industrial used water from the deep sewerage tunnels to the plant separately for treatment. Domestic used water will be treated before being further purified to NEWater (NEWater is the name given to the process for recycling Singapore’s treated used water into ultra-clean, high-grade reclaimed water), while industrial used water will be treated and supplied to industries for reuse.
Construction work on the pumping stations, including ancillary facilities such as the electrical substations and an odor control facility, is expected to be completed by 2025. By then, a conveyance system, consisting of a 100 km network of deep tunnels and link sewers under the DTSS Phase 2 project, will also be ready. All used water from the western half of the island will be channeled via gravity to the Tuas WRP for treatment. Existing conventional WRPs in Ulu Pandan and Jurong, as well as intermediate pumping stations, will then be progressively phased out.
Tuas WRP will have an initial treatment capacity of 800,000 cubic meters per day – 650,000 cubic meters/day of domestic used water and 150,000 cubic meters/day of industrial used water. Once completed, it will be the largest membrane bioreactor facility in the world, with an overall 30% more compact footprint compared to conventional water reclamation plants. The plant, along with the National Environment Agency’s Integrated Waste Management Facility, will form the future Tuas Nexus, which will integrate used water and solid waste treatment processes.
(Sources: :PUB; Straits Times)