PUB, Singapore's national water agency and the National Environment Agency of Singapore (NEA), will be calling tenders from this year onwards for the Deep Tunnel Sewerage System (DTSS) Phase 2 and the Integrated Waste Management Facility (IWMF) to spearhead the implementation of Singapore's world-class used water and solid waste management solutions.

DTSS Phase 2, which includes enhanced deep tunnels with advanced sensing and maintenance features, associated link sewers, Tuas Water Reclamation Plant (TWRP) and integrated NEWater factory, is estimated to cost some S$6.5 billion. With a total treatment capacity of 800,000 cubic metres per day, TWRP will also be the largest membrane bioreactor facility in the world.

Currently at the detailed design milestone of the project, PUB will be calling for consultancy and construction tenders for the various project components in phases beginning from Q3 2016. These include professional engineering services for the detailed design of the TWRP and link sewers. Other tenders will cover the design and construction of deep tunnel sewers, associated shafts and manholes.

IWMF, equipped with state-of-the-art technologies, will be able to effectively process various waste streams which include incinerable waste, household recyclables collected under the National Recycling Programme (NRP), source-segregated food waste and dewatered sludge from the TWRP.

The IWMF will be designed with an incineration capacity of 5,800 tonnes per day and is estimated to cost S$3.0 billion. NEA will be calling tender to engage professional engineering services to assist in project management, supervision of the construction works and commissioning of the IWMF. Tenders will also be called to appoint Engineering, Procurement and Construction contractors to design and construct the IWMF.

Driving synergies through co-location to integrate used water and solid waste treatment processes.

One of the highlights of both projects, is the co-location of PUB's TWRP with NEA's IWMF, which marks Singapore's first initiative to integrate used water and solid waste treatment processes.

"As one of the world's most anticipated water infrastructure projects, DTSS Phase 2 continues to harness advanced technologies to enhance Singapore's used water management system and ensure its water sustainability for generations to come," said Yong Wei Hin, Director, DTSS Phase 2, PUB. "The co-location of TWRP and IWMF is also the first project of its kind in the world to be planned from ground-up, and is designed to bring about a multitude of synergies harnessing the Water-Energy-Waste Nexus while optimising Singapore's land-use".

Co-digestion of food waste with used water sludge at TWRP to increase the yield of biogas production

A good example of the synergies is the co-digestion of food waste with used water sludge at TWRP to increase the yield of biogas production. Biogas will be utilised at IWMF to improve steam quality and give rise to higher overall plant thermal efficiency. This will increase electricity production and enable IWMF to export more to the Grid while allowing both facilities to be energy self-sufficient.  

Joseph Boey, Project Director, IWMF, NEA commented:

"The co-location of the TWRP and IWMF marks a new chapter in the way used water and solid waste are managed in land-scarce Singapore. Leveraging the use of advanced technologies and project innovations, the two facilities will be able to maximise energy and resource recovery efficiencies while minimising their environmental and land footprint."

"The IWMF plays an integral part in meeting Singapore's future waste management needs, and ensuring long term environmental sustainability."