Rasa and Bukit Badong Water Treatment Plants
Malaysia (2000 - 2005)

Our expertise in the construction of water supply infrastructure is proven with the construction of two of the biggest water supply treatment plants in the state of Selangor, with a combined treated and supplied water capacity of 1,050 million liters per day (mld). These large water treatment plants were built as part of Sungai Selangor Water Supply Scheme Phase 3 (SSP3).

The masterplan for SSP3 came in the wake of a water-shortage crisis faced by the Selangor State Government in the year 1998. Due to massive industrial and commercial development as well as population growth, the state was unable to meet the water demands of its population and thriving commercial hubs.

Working in concert with the State Government, Gamuda proposed a sustainable solution for the state’s critical water needs, which gave rise to a regulating dam that harmonises the water flows of Sungai Selangor, while ensuring sufficient water supply to the Rasa and Bukit Badong Water Treatment Plants.

The Rasa Water Treatment Plant is equipped with a water treatment capacity of 250 mld of water, while the Bukit Badong Water Treatment Plant was constructed with a water treatment capacity of up to 800 mld.

Feature Highlights:

  • Intake

    A river gate at the intake consists of motorised gates that control the river level. Raw water from the river is channeled to the floating boom and a coarse screen that traps floating debris. The water then flows through a rotating band screen that traps smaller debris where sediments settle into sand hoppers built into the floor of the intake channel. Accumulated sediment is pumped out regularly with sand ejectors. The raw water then flows to the raw water pump sump.

  • Raw water pumps

    From here, the water is pumped to the treatment plant via a raw water pipe.

  • Aerator

    At the treatment plant, the raw water enters the aerator, which is designed to create sufficient turbulence to achieve a dissolved oxygen content of 80% saturation at ambient temperature. Pre-lime and a primary coagulant, poly aluminium chloride (PACI) are added.

  • Mixing chamber

    The raw water then flows to a flash mixing chamber where a flocculent aid (polyelectrolyte) is added to enhance floc formation for easier removal in the clarification process.

  • Clarifiers (shown above)

    Clarifiers perform the function of floc concentration, collection and discharge. Settled water overflows into collection channels for onward flow to the filters.

  • Filters

    Rapid gravity sand filters perform the task of removing fine particles that have not settled in the clarification process. Clarified water is filtered through a sand filter media to trap unsettled particles.

  • Fluoridation

    The filtered water is collected at the filtered water channel where sodium silicofluoride is added and then flows to a clear water tank.

  • Disinfection and pH correction

    In the clear water tank, chlorine is added for disinfection and tests are carried out to ensure the treated water is free from pathogenic organisms. Hydrated lime is added for pH correction.

  • The clear water tank

    The tank provides sufficient contact time for the disinfection and conditioning chemicals to work on the water as part of the treatment process.

  • Treated water pumps

    These are used to pump clean and treated water from the balancing reservoir or the clear water tank to the state water supply distribution company.

  • Balancing reservoir

    Treated water stored here is gravitated towards smaller service reservoirs that cater to the needs of the consumers. A custody transfer flowmeter records the volume of water supplied to the distribution company.

  • Water quality monitoring

    Treated water quality is tested in the plant laboratory to ensure that water passing through the plant is always clean and safe for consumption. An independent external testing laboratory is also engaged to ensure water quality compliance.

  • Supervisory Control and Data Acquisition (SCADA)

    The SCADA system allows all functions of the plant to be automated and monitored from the control room.

  • Sludge lagoons

    Sludge lagoons are provided for the storage and drying of sludge. The lagoons are used in rotation. As one lagoon is filled, it is isolated for drying and wet sludge is channeled into an adjacent lagoon. Dried sludge is removed for disposal as a landfillat sludge depository.