Chestnut Avenue Water Works upgrade project
Achieving greater treatment capacity and higher quality water with existing infrastructure
ClientSingapore's Public Utilities Board
Service Lines/Product Description
Singapore has a unique political driver to ensure that its water consumption becomes self-sufficient and not having to rely on sources from Malaysia. It has a population of 6 million people on an island with a land area of 700 km2. High population density and low land area means that it is considered to be a water-scarce country.
To secure greater domestic water supply, achieving greater treatment capacity from an existing water treatment infrastructure was identified as a cost effective way to achieve this goal. The Chestnut Avenue Water Works (CAWW) upgrade project, which began in 2002, was the extension of an existing conventional water treatment plant built in 1976. The objective of the project was to augment the plants existing operations to potentially treat a total capacity of 546 million litres per day and to incorporate a number of unit processes including the use of immersed ultrafiltration (UF) membranes for the removal of particulate matter.
A consortium between UGL and SembCorp Engineers and Constructors successfully completed the design and construction of a 273 million cubic litre per day immersed water treatment plant for the Singapore Public Utilities Board (PUB). At the time of project completion, the plant was the largest of its kind in the world using immersed membrane technology supplied by GE Water & Process Technologies.
For several years, the Singapore PUB has worked diligently to secure sufficient domestic water supplies for residents and industry. With a growing population, the PUB re-evaluated its drinking water infrastructure to ensure that it could continue to provide high quality water to meet the increasing demand.
CAWW was targeted for upgrade being the largest drinking water plant in the country which employed a conventional sand filtration system. CAWW also had difficulty in keeping up with the water quality standards imposed by the government.
UGL’s solution included the design of the overall plant process including the membrane system, the design of the chloramination plant, all plant chemical dosing including stabilisation, sludge treatment, a new SCADA system, and the design and construction of all civil elements including structures, pipelines and pumping stations plus power generation facilities.
Critical in achieving greater efficiencies at the CAWW was UGL’s integration of a leading control system. From a technical standpoint the solution introduced a hybrid design with a programmable logic supervisory control and data acquisition (PLC/SCADA) system in a hierarchical structure. The CAWW was also Singapore’s first water works to incorporate a large fieldbus network called Profibus which delivers cost and time savings compared to traditional PLC/SCADA setups. Profibus efficiently controls individual process trains and equipment that contain complex instrumentation and algorithms.
At the commissioning in December 2003, the CAWW plant was the largest operational ultrafiltration (UF) membrane-based drinking water plant in the world. The entire 273 million cubic litre per day plant was designed and commissioned in only 15 months and was placed in immediate service.
Key Outcomes and Benefits
By implementing a combination of engineering solutions with leading technologies, Singapore’s PUB was able to generate the quality and capacity of treated water required for future demands from the CAWW upgrade project. Through close liaison with the PUB, UGL’s engineering team consisting of experts from its Singapore, Malaysian and Australian offices were able to identify problem areas in the existing plant and assist the customer to enhance operational performance.
Key successes included:
- Greater treatment plant capacity for future requirements able to process up to 476,900 cubic metres per day, almost twice the current demand of only 272,520 cubic metres per day
- Capital and operating cost savings which will reduce the plants carbon footprint with UGL’s engineering process solutions and the use of leading membrane technology
- An upgraded water treatment system that provides quality, reliable drinking water which avoids costly maintenance downtime through UGL’s proven and robust engineering solutions
- An innovative SCADA system design solution made it possible to optimise water treatment plant automation strategies which delivered better process control and vastly improved chemical dosing control
- Designing a fit for purpose system that satisfied the customer’s requirements where operational performance exceeded expectations