Aerial View of Rasa Water Treatment Plant
Rasa and Bukit Badong water treatment plants are other key components of SSP3. The Rasa water treatment plant is equipped with a total treatment capacity of 250 Mld of water. This treatment plant serves the area in northern region of Selangor. Built over 2 phases, the first phase is able to supply 125 Mld and completed in November 2001. The second stage of another 125 Mld was completed in January 2004.
The other treatment plant is located in Bukit Badong and has the capacity to treat drinking water up to 800 Mld. This treatment plant serves the Klang Valley area. The first phase of Bukit Badong water treatment plant that is able to supply 400 Mld was completed in July 2003 and the second phase of another 400 Mld is targeted to complete by July 2005.
Note: Click the picture to enlarge
Intake
At the intake, there is a river gate consisting of motorised gates which control the river level. From the river, raw water is channeled to the floating boom and a coarse screen which traps floating debris. The water then flows through a rotating band screen which traps smaller debris and 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. The polymer enhances floc formation for easier removal in the clarification process.
Clarifiers
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 which are 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 the filtered water 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
From the clear water tank, treated water is pumped to the balancing reservoir for offtake by the state water supply distribution company.
Balancing reservoir
Treated water stored here is gravitated to smaller service reservoirs which 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 land fill at sludge depository.
