Engineers in the tiny island nation of Singapore have been constructing a state of the art new sewer system, know as the DTSS (Deep Tunnel Sewer System). Phase one of the project was completed in 2008 and phase two began in 2013.
It is a cost-effective and sustainable solution, offered by the Singapore Public Utilities Board, to meet the country’s long-term wastewater needs.
The main feature of this system is a network of deep tunnel gravity sewers leading into two major tunnels, many wastewater reclamation plants (WRPs) on the edges of the city, and a network of ocean outfall pipes.
Phase two extends the system to the southern and western parts of Singapore, linking to the already successful wastewater reclamation plant in Changi.
Trenchlessinternational.com with Project Director Young Wei Hin reflect upon the benefits of this highly advanced system:
“The DTSS optimizes land use for used water infrastructure. For a densely populated city-state with limited land, the DTSS is a more strategic and cost-effective solution than the conventional approach of renewing and expanding the existing used water infrastructure.”
The Tuas WRP will be able to treat two streams of wastewater separately, with a total treatment capacity of 800,000 m3. The facility will also be capable of recycling wastewater to produce NEWater. It will feature advanced technologies to enhance energy recovery from wastewater and improve water efficiency, using more biogas for power and consuming lesser energy than conventional plants. Tuas WRP will be located along the National Environment Agency’s Integrated Waste Management Facility (IWMF) to maximise energy and resource recovery. The two facilities will work in unison to efficiently break down food waste, in the process producing biogas that will power the IWMF’s incinerators.
Existing WRPs at Ulu Pandan and Jurong, as well as intermediate pumping stations, will be progressively phased out in the finals stages of DTSS, which is expected to be completed by 2025.”
The planning and implementing of this system is ongoing and requires meticulous care and attention from those working at all levels.
Effective infrastructure management requires the construction of the right assets, at the right time, to the right standards and cost.
So much of the total lifecycle cost of an asset is locked in at the time of construction – a poorly built asset will require a high level of operations and maintenance, and likely fail early, all of which costs more.
An asset built to the right standards with analysis of the total lifecycle cost and future operations and maintainability will produce an optimum lifecycle cost.
As seen in this example from Singapore, existing constraints can also be an opportunity to ‘think outside the box’ and produce solutions that are innovative and produce long-term benefits.