SINGAPORE - National water agency PUB said on Friday (Dec 21) that it is not possible for worms to be present in tap water.

The agency's comments came after reports that a worm had dropped into a baby bottle along with the running water from a kitchen tap in Ang Mo Kio on Dec 6.

At the time, Chinese evening newspaper Shin Min Daily News also reported that a resident found a worm in a toilet bowl a few weeks prior.

On its Facebook on Friday, PUB said that it has a rigorous, multi-barrier water treatment process. It added that a comprehensive water quality monitoring programme also ensures that customers are delivered only "good and clean drinking water".

According to PUB, water supply is delivered to customers via pressurised mains. In the case of high-rise buildings, water is pumped into water tanks which are "fully enclosed and securely locked" before customers consume it.

"It is not likely for worms to make its way into these pressurised mains and enclosed systems, and be present in the tap water," said PUB.

Following the reports on the worm in the bottle, PUB and the Ang Mo Kio Town Council conducted checks on various areas including the water tank, the pump room and PUB's water supply main on Dec 7 and Dec 12.

On-site water quality testing was also carried out, and the water from the various water points was found to be clean and clear, with no sign of worms.

On Friday, in addition to re-emphasising the checks it had done, PUB added that it had checked the resident's tap and found that it was fitted with a constant flow regulator with tiny holes.

PUB said: "This meant that it would not have been possible for a worm, which is larger in diameter, to pass through the tiny holes of the flow regulator.

"We would like to assure the public that we maintain high standards for our drinking water."

Shin Min Daily earlier quoted the domestic worker who was washing the baby bottle as saying that the worm was a "4 to 5cm live worm".

At the time, PUB said that based on the photo of the worm provided by the resident, the worm was likely an earthworm, which could have come from the surrounding area.