Deep Tunnel Sewerage System Phase 2 (DTSS Phase 2)

  • Location: Singapore
  • Location: Singapore
  • Client: PUB, Singapore’s National Water Agency
  • Project status: Ongoing

Project Overview 

The DTSS2 Project is the second phase of a nationwide program that completes Singapore’s long-term vision of a recycled water super-highway that further enhances its water security and achieves its ultimate objective of being self sufficient to meet the water demands of its growing population and industries. It comprises of a tunnel conveyance system of approximately 63km of Link Sewers of diameter 0.3-4m and 35km of tunnels of diameter 3-6m, adding resiliency to Phase 1 and adopting lessons learned, focusing on energy usage, operational efficiency and minimisation of land-take.

Our role

  • Aiding in the initial planning definition phase comprising:
    1. Feasibility study
    2. Preliminary design
  • Overall programme management for Phase 2 alongside PUB


  • Minimising land take whilst freeing up existing land through decommissioning of old parts
  • Maximising integration with existing infrastructure through cross connection and linkages
  • Minimising personnel and energy usage through use of sustainable energy and technology

Unique features and solutions

  • State-of-the-art practices and processes benchmarked against other local and international projects
  • Integration of the Tuas WRP with the co-located Integrated Waste Management Facility (IWMF) to fully utilise the water/energy nexus, resulting in lower overall operation costs
  • New South Tunnel and a state-of-the-art Water Reclamation Plant at Tuas to compliment infrastructure in Phase 1

Benefits and Achievements


Tuas Water Reclamation Plant (TWRP) is the world’s largest water reclamation facility at 1800 MLD

Environment Friendly

Return of about 100 hectares of very valuable land that can be redeployed for other use. Implementation of the entire DTSS will result in 50% reduction in land taken up by used water infrastructure once it is fully completed, from 300 hectares in the 1990s to 150 hectares in the long terms

Award Winning

PUB: Consultant Safety Recognition Award, 2020

Southern Resilience Scheme
View Project
Dovecliff Weir
View Project
River Thames Scheme
View Project
Feasibility Study on Underground Drainage and Reservoir System (UDRS)
View Project
Our City Our River: Derby flood risk management scheme
View Project
River Poddle Flood Alleviation Scheme
View Project
Burton Washlands Landscape Vision
View Project
Keadby terminal assisted outfall sustainment project
View Project