PUB calls pre-qualification exercises for DTSS Phase 2 Tunnel and Tuas WRP

The first exercise will be called on 8 April 2016 to pre-qualify consultancy firms to provide professional engineering services for the design, and supervise the construction and commissioning of the Tuas Water Reclamation Plant (WRP). A highlight of DTSS Phase 2, Tuas WRP will treat 800,000 cubic metres of used water a day. The compact plant will also incorporate technologies to improve its energy efficiency, reduce waste, and will be highly automated to minimise manpower needs.

The second pre-qualification exercise will be called on 29 April 2016 for construction companies to design and construct some 50 kilometres of sewer tunnels* and their associated shafts and manholes. These sewer tunnels will extend the existing deep tunnel system to serve the western part of Singapore. 

“We are looking for industry partners with established track records to take us another step closer to the completion of DTSS Phase 2. This is an opportunity for the industry to participate in the delivery of one of the world’s most anticipated water infrastructure projects that will ensure Singapore’s water sustainability for generations to come,” said Mr Yong Wei Hin, Project Director, DTSS Phase 2, PUB.

The pre-qualification documents will be available on Government Electronic Business Portal (GeBiz) at

Background on DTSS

A superhighway for used water management, the DTSS is a core water infrastructure which provides a cost-effective and sustainable solution to support Singapore’s continued growth and meet its long-term needs for used water collection, treatment, reclamation and disposal. 

The DTSS uses deep tunnel sewers to convey used water entirely by gravity to centralised WRPs located at the coastal areas. The used water is then treated and further purified into ultra-clean, high-grade reclaimed water called NEWater, with excess treated effluent discharged to the sea through outfalls.

DTSS Phase 1, comprising the North and Spur Tunnels, the associated link sewers, the Changi WRP and outfall, was completed in 2008. A NEWater factory, located on the rooftop of the Changi WRP, was built in 2010 to facilitate large-scale water recycling.

Expected to complete by 2025, DTSS Phase 2 will extend the deep tunnel system to cover the western part of Singapore, including the downtown area and major upcoming developments such as Tengah Town. A NEWater factory to be integrated with the Tuas WRP will be built to facilitate water recycling, contributing to the goal of increasing the overall water recycling rate from 30% to up to 55% of total water demand in the long term.

Once Phase 2 is in place, the existing conventional WRPs at Ulu Pandan and Jurong, as well as intermediate pumping stations, will be progressively phased out and the land freed up for higher value development. The implementation of the entire DTSS will result in a 50% reduction in land taken up by used water infrastructure once it is fully completed. DTSS will also streamline the used water network with three centralised collection and treatment points: Changi WRP in the east, Kranji WRP in the north and Tuas WRP in the west.

The joint venture of Black & Veatch + AECOM was appointed as PUB’s Professional Engineering Consultants for the Programme Management Consultants for the DTSS Phase 2 in April 2014. They have since completed Feasibility Studies and Preliminary Design and will assist PUB in the delivery of the overall Programme of work through to completion.

*This consists of about 40km of deep tunnel sewers and 10km of link sewers to be constructed using tunnel boring machines.

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(Press release Singapore International Water Week, april 2016)