TRENCHLESS TECHNOLOGY
The City of Singapore (Credit: Darya Jum)
Deep tunnel sewerage systems:
SINGAPORE’S SUCCESS STORY
Singapore’s pioneering role in developing deep tunnel sewerage systems (DTSSs) serves as a prime example of what could be replicated by South African cities. Across the world, cities face similar challenges in terms of intensified urbanisation, poulation growth and the need to modernise decades-old wastewater infrastructure using best practice techniques. By Frank Stevens & Swen Weiner* 34
IMIESA April 2022
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ccording to the UN, 9.8 billion people will be living on the planet by 2050, with growth particularly coming from Africa and Asia. A total of 70% of that population will be urban, a 1.7-fold increase compared to 2015. Cities will have to invest massively in sewage handling capacity to ser ve this growing population, while climate change will further stress capacity. Additionally, extreme weather is confronting cities with high amounts of rainwater to be collected, discharged and – at least partly – treated within a short period. Diminishing sur faces for infiltration add to the problem by leaving fewer opportunities for rainwater to drain naturally. In addition, many cities want to reuse sewage instead of discharging it into
nearby rivers.In Singapore’s case, this sovereign island city-state has an area of 730 km2 and a population of 5.7 million people. In addition to having the second highest population density in the world, this countr y boasts the second highest GDP per capita globally and Singaporeans enjoy one Tunnel types in Singapore’s underground infrastructure system
