Ladies and gentlemen,
am pleased to join you today to mark the commencement of tunnelling works for
Phase 2 of the Deep Tunnel Sewerage System, or DTSS. This is another key milestone
in one of Singapore’s most significant water infrastructure projects.
2. A total of 19 tunnel boring machines will
be deployed for this phase of the project. The machines will dig deep underground
to create a network of tunnels and link sewers to serve the western and
downtown parts of Singapore. Some $2.3 billion will be devoted to this endeavour.
That’s nearly a third of the $6.5 billion price tag for the entire DTSS Phase
2. This is a significant and necessary investment to meet our population’s long-term
water needs and enhance the sustainability of our water supply.
SUSTAINABLE SEWERAGE SYSTEM
3. For a highly urbanised and densely
populated city state like Singapore, a proper wastewater management system is important
to protect our environment, public health and water sources. The DTSS allows us
to transform our used water system to support Singapore’s growing water needs
and ensure an effective and efficient sewerage system for Singaporeans. This is
why PUB undertook the project.
4. Borne out of a bold vision conceived
some 25 years ago, the DTSS is a powerful example of how, by planning decades
ahead, and investing in innovative solutions, we can overcome challenges and
turn them into opportunities. The DTSS is also an example of how we have applied
circular economy strategies successfully in our water system. By conveying used
water entirely via gravity to centralised water reclamation plants for
treatment and recycling into NEWater, every drop of used water will be
continually reused, closing our water loop. The risk of cross-contamination
between Singapore’s water catchments and used water system will also be
5. DTSS Phase 1 was completed in 2008 to
serve the eastern part of Singapore. Under Phase 2, the DTSS will serve the western
and downtown areas, including upcoming developments such as the Jurong Lake
District, Tengah Town and the Greater Southern Waterfront. A 100km network –
comprising 40km of deep tunnels and 60km of link sewers – will be built. All
five deep tunnel contracts have been awarded, and six out of 13 contracts for
the link sewers have been awarded.
6. When construction of Phase 2 concludes by
2025, the whole of Singapore will be served by the DTSS, and it will be one of
the largest integrated underground sewerage system in the world. It took hard
work by many engineers to realise this vision. I am happy that some of the
pioneers of the DTSS project are here with us today. Please join me in thanking
them for their contributions.
7. The DTSS will bring tremendous economic
benefits for Singapore. Existing water
reclamation plants and pumping stations, as well as buffer land around the reclamation
plants, will be phased out when they reach the end of their economic lifespans,
freeing up space for higher value developments. Some 150 hectares of
land – about the size of 214 football fields – will be made available.
8. The deep tunnels and link sewers will
convey used water to the future Tuas Nexus. As an integrated used water
treatment and waste management facility, Tuas Nexus will harness synergies from
the water-energy-waste nexus by co-locating PUB’s Tuas Water Reclamation Plant
and NEA’s Integrated Waste Management Facility. When completed, the Tuas Nexus facility
will achieve high energy self-sufficiency, by co-digesting used water sludge
and food waste to improve biogas yield and energy efficiency in used water
SMART AND SAFE SEWERAGE SYSTEM
9. Besides being part of a sustainable
water system, DTSS Phase 2 will also be a smart and safe sewerage system.
10. During construction, the DTSS team will
be using a smart monitoring system to monitor and gather real-time information
on the construction progress, and location of the tunnel boring machines and
pipe jacking machines during the tunnelling works.
11. Once the tunnels are completed, the use
of Remotely Operated Vehicles and embedded fibre optic cables will allow for
remote monitoring. This minimises the need for officers and contractors to
enter the shafts, improving overall work safety. If maintenance is needed,
individual segments of the tunnel can be isolated to prevent any disruption to
water flow. This is also the first project to use a combination of air jumpers
and odour control facilities to prevent odorous air from escaping into the
12. These deep tunnels will have enhanced
resilience thanks to a special concrete mix that will offer better protection
against corrosion from sewage gases. Underwater sections of the deep tunnel at
Tuas Bay and Sentosa will have an additional waterproof membrane to ensure the
tunnel is water-tight.
DEEP EXPERTISE INVOLVED
13. The construction of DTSS Phase 2 is a challenging
project. We will have to navigate the different ground conditions in the Jurong
Formation and dig deep to tunnel beneath existing underground infrastructure.
But I am confident that our team of skilled engineers are up to the task. PUB’s
senior engineer Loh Siew Hui, who oversees the planning and construction of one
of the deep tunnel segments, is one of them. Siew Hui is an experienced hand
when it comes to tunnelling work, having also been involved in PUB's sewer and
NEWater pipeline projects. She is an excellent example of how our engineers
have acquired the knowledge and skills to take on larger, more complex and
14. Tunnelling works for DTSS Phase 2 will
commence shortly after today’s event. I wish the DTSS team every success, as we
work together to enhance the sustainability of our water resource, and write
the next chapter of our Singapore Water Story.