First DTSS Contracts awarded in Singapore 14 Sep 2017

PUB, the Singapore National Water Agency, has appointed three contractors

• Ed Züblin AG
• Penta-Ocean/Koh Brothers JV, and
• Leighton Contractors

to design and build the first batch of 30km of deep tunnels and link sewers in the 40km of deep tunnels and 60km of link sewers of its Deep Tunnel Sewerage System (DTSS) Phase 2. Contracts for the remaining sections of Phase 2 are to be awarded from 2018.

Award of the first three construction contracts, with a combined total value of Sing$1.51 billion, are confirmed following a pre-qualification and tender exercise in mid-2016. During the next seven years, the contractors will develop the detailed designs and excavate the deep tunnels, link sewers and associated ancillary structures.

Fig 3. Tunnels of two phases of the DTSS strategy in Singapore

Lead Consultant for DTSS Phase 2 for PUB is the Black & Veatch + AECOM Joint Venture.

"The deep tunnels are an integral part of the strategy to facilitate large-scale water recycling in Singapore,” said Yong Wei Hin, Director for PUB of the DTSS Phase 2. “The goal is to convey every drop of used water for treatment and channel it for further reclamation at the NEWater Factory thereby increasing the overall water recycling rate in Singapore from a current 40% to up to 55% of total water demand in the long term. The network of 100km of deep tunnels and link sewers in Phase 2 will connect to the Tuas Water Reclamation Plant, which is expected to be completed in 2025. By then, and with the completed DTSS Phase 1, the whole of Singapore will be served by the DTSS network (Fig 3). Used water will then be conveyed by gravity to one of three water reclamation plants for treatment, before undergoing further purification to produce NEWater, or discharged into the sea.”