Completion of the Deep Tunnel Sewerage System Phase 2 Tunnelling Works

SPEECH BY MS GRACE FU, MINISTER FOR SUSTAINABILITY AND THE ENVIRONMENT, AT THE EVENT TO MARK THE COMPLETION OF THE DEEP TUNNEL SEWERAGE SYSTEM PHASE 2 TUNNELLING WORKS ON 21 AUGUST 2023

Mr Chiang Chie Foo, Chairman, PUB,

Board members of PUB,

Goh Si Hou, CE PUB,

Distinguished guests,

Ladies and gentlemen,

1 Good morning. We are gathered here today to commemorate a significant achievement after a decades-long effort to transform Singapore’s used water management system.

2 In 2019, we commenced tunnelling for Phase 2 of the Deep Tunnel Sewerage System, or what we call DTSS2, at this very site. Four years and over 40 million man-hours later, we now celebrate the completion of this remarkable engineering feat. We constructed a 50km network of deep tunnels and link sewers, stretching from Keppel Road to Tuas. At its peak, over 5,000 workers contributed to this project. We would like to thank every single person who has worked on this project, including many who have persisted through the COVID years. Mr Thirumurugan, Mr Loganathan, and many like them. Thank you every single one of you for your hard work.

History of Singapore’s used water system

3 We have indeed come a long way. In the first 20 years of my life, my family’s sanitation involved an outhouse toilet with a night soil bucket system. Workers would come with a truck, commonly known as a 32-door truck, to collect human waste twice a week. In the 1980s, when we moved to a newer house, modern sanitation with sewage pipe and a flushing system was a vast improvement in hygiene. In the early years, our efforts focused mainly on tackling pollution in our waterways and improving public hygiene standards to prevent the spread of water-borne diseases.

4 But soon, we found ourselves at the crossroads. Singapore’s population and economy were growing rapidly, and our then-Sewage Treatment Works were nearing their maximum capacities. Faced with the challenge of collecting and treating the increasing volume of used water, we had two options.

5 We could continue to upgrade and expand the number of plants and network of pumping stations. And if we had not changed with the DTSS, with population growing, new towns sprouting up, you can imagine the number of plants needed all over the island, and the number of pumping stations that would be needed as well. This would have come at the cost of significant land take, which meant less land for other important uses such as housing, business and community spaces.

6 The alternative, transformational approach - out of the box, really using a white blank canvas to think about solutions was to challenge ourselves at a nationwide system level, by completely rethinking and redesigning our used water infrastructure to make better use of underground space to meet future challenges and support future developments.

Embarking on DTSS

7 We decided to take this transformative approach, and PUB undertook the bold step of constructing the DTSS. These tunnels located deep underground are on a scale similar to our MRT tunnels. They serve to collect and convey used water by gravity to water reclamation plants located at the eastern, northern, and western ends of Singapore.

8 Tunnelling deep underground in Singapore has many challenges. We are highly urbanised and built-up. Manoeuvring heavy machinery within confined and crowded spaces underground demanded careful planning and meticulous execution to account for varying ground conditions and existing services in crowded underground space.

9 As with many other construction projects, the onset of the Covid-19 pandemic resulted in widespread manpower shortages, supply chain disruptions and work stoppages causing delays in its construction. Despite these roadblocks, the DTSS team was undeterred, and I am glad that PUB and our contractors continued to make steady progress.

DTSS as Game-changer

10 In land-scarce Singapore, developing water infrastructure must be done sustainably. A key consideration lies in balancing competing land use demands as we constantly explore innovative solutions to enhance the resilience of our water supply.

11 The DTSS is a gamechanger because it allows us to progressively phase out the existing intermediate pumping stations and conventional water reclamation plants, freeing up land for other important purposes.

12 Phase 1 allowed us to phase out intermediate pumping stations as well as three water reclamation plants at Kim Chuan, Bedok and Seletar. The land freed up at Seletar is now part of Seletar Aerospace Park, a thriving aerospace cluster, enabling us to attract over $1.5 billion worth of investments and providing over 6,000 jobs. With the completion of Phase 2, we will similarly free up land from two water reclamation plants at Ulu Pandan and Jurong, and the rest of our 130 pumping stations across the island. When the entire DTSS is completed in 2026, we would have successfully halved the space used aboveground for used water infrastructure – saving 150 hectares of land, or nearly twice the size of the sprawling Singapore Botanic Gardens.

DTSS as Critical Investment

13 Our commitment to build the DTSS, both Phase 1 and Phase 2, will cost us $10 billion in total. This is a significant investment, but a necessary one to safeguard the resilience and long-term sustainability of Singapore’s water supply.

14 Today, our water demand is 440 million gallons per day, equivalent to 800 Olympic-sized swimming pools. This figure is projected to double by 2065. The amount of used water to be collected and treated will also increase correspondingly, hence the need to expand our used water infrastructure.

15 At the same time, used water is also precious to us for closing the water loop. We aim to collect, treat, reclaim and re-use every drop of used water to produce NEWater, and expand our water resources. The DTSS is central to this objective.

16 This is especially important with the effects of climate change. More extreme weather and prolonged droughts will adversely impact our weather-dependent sources. Hence, NEWater and desalination will become more important than ever in meeting the long-term water needs for Singapore. However, these sources are also more energy intensive and costly to produce.

17 Utilities around the world, including PUB, have grappled with rising cost pressures in the production and distribution of water due to higher inflation, energy prices and construction costs. A case in point – DTSS Phase 2 costs almost double of Phase 1 when it was built two decades ago. This is why we must right price water to ensure our water security by promoting conservation and continue investing in essential long-term water infrastructure, such as the DTSS, to support our national development.

Looking ahead – Strengthening our systems for managing used water

18 Despite our achievements in pursuing water security and sustainability, water demand will continue to grow with population and new economic opportunities.

19 We will continue to invest in our infrastructure to fortify our water resilience – PUB is currently expanding the Changi Water Reclamation Plant (WRP), constructing the new Tuas WRP and is embarking on the redevelopment of the Kranji WRP to complete our three-node DTSS. Together with the expanded NEWater capacity at each of these three nodes, we will bolster our used water treatment capabilities and NEWater production to meet the long-term water needs for Singapore.

From one generation to the next

20 This year marks the 60th anniversary of PUB. Over six decades, PUB has worked tirelessly to build a diversified and sustainable water supply through the four National Taps. We turned adversity into strength, advancing Singapore’s water security. Generations of PUB officers have made this possible, through bold vision, long-term planning and innovation. Some of our DTSS pioneers are here with us today – among them is Mr Chiang Kok Meng, whose contributions hark back not just to the DTSS, but the decade-long clean-up of the Singapore River.

21 The PUB story is the Singapore story. About how we are always looking forward long term. Not thinking just about our generation, but investing big sums, significant investments, for the long-term good of Singapore and Singaporeans.

22 When we talk about Forward Singapore, and talk about stewardship of our environment, stewardship of our financial resources, the DTSS illustrates so clearly what we have done three decades ago. That generation was setting aside money in the billions all ready to build for the future generations. And we are sitting on the fruits of their investment, of their labour.

23 Sustainable development must be the social compact that we continue going forward with, for Singapore to be successful. That we are not just looking at what short-term gain there are for us — for our generation, what we can get back from the system. But rather, what we can do to make this space a liveable, successful, prosperous and beautiful place to stay in.

24 We will continue to do that. Investing in the future, investing for the future, and investing for all Singaporeans.

25 Our water system clearly illustrates them. Our drains are now beautified - Active, Beautiful, and Clean water that Singaporeans can enjoy. I feel a deep sense of pride as a Singaporean. I also feel a deep sense of gratitude to the many generations before me that they were both far-sighted and they were prepared to put aside resources to invest in the future.

26 So let us continue to with that Singapore spirit of not just thinking about now, and me, but rather the future we — including those not yet born, so that when they are born, they have a place, a beautiful place they can call home.

Conclusion

27 Lastly, I want to thank many who have contributed to the DTSS journey – the pioneers who started the planning, not forgetting our many contractors, workers that really represent the can-do spirit in Singapore. Thank you all, for overcoming many challenges to achieve this landmark success for Singapore’s used-water management. Thank you very much, and congratulations!