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Treatment and Water Quality Monitoring Process from Reservoir to Tap

The water treatment process at the plants is a multi-barrier one that treats raw
water coming from various sources to comply with the water quality standards
specified in the Schedule of the Environmental Public Health (Quality of Piped
Drinking Water) Regulations and international World Health Organisation (WHO)
Guidelines for drinking water quality.

Here’s how water is treated:
1. Coagulants and coagulant-aids are added to aggregate suspended
impurities in raw reservoir water.
2. The aggregates combine to become bigger and heavier, which settles
down readily to be removed in the sedimentation tank.
3. The water is then passed through rapid gravity filters or membranes to
remove the finer particles of suspended matter.
4. The filtered water, on its way to the clear water tank where it is
temporarily stored, is disinfected with chlorine to get rid of all harmful
bacteria and viruses.
5. The water is then pumped into the distribution system and service
reservoirs, ready for consumption.

Using on-line analyzers, the water quality at each stage of the treatment process
is monitored and controlled through the Supervisory Control and Data Acquisition
(SCADA) system. This is an automated system, and the readings of online
analyzers are verified with laboratory testing once every 8 hours.

PUB’s Water Research and Analytical Laboratories at Waterhub carries out a
comprehensive water sampling and analysis programme for more detailed
chemical, bacteriological and virological tests to verify the water quality from the
waterworks. This is in addition to the routine tests carried out by the waterworks.
These systems and programmes ensure the waterworks produces quality water that
consistently meets the regulatory standards and international guidelines.