National water agency PUB said on July 23 that affected water that smells like pandan has since been isolated.

PUB announced this in a Facebook post, which said that "extra precaution" has been taken by flushing out the affected network pipes and water tanks, and replenishing them with water produced by local waterworks.

"Based on our investigations, the issue has been traced to water imported from Malaysia. PUB has since isolated the affected water," the agency said.

The pandan smell in water is detected after the water has been boiled.

This is due to trace amounts of the organic compound tetrahydrofuran (THF).

On-site tests

Local production of water was also "ramped up" mid-week.

PUB officers have conducted on-site tests and collected water samples from customers' tap points, as well as water mains for further analysis.

So far, results have shown that "every water quality parameter is within normal range", said PUB, even as new samples were still taken on Thursday for tests.

This indicates that there is no compromise to water safety, it added.

Highly soluble compound

"The amount of THF detected in the water supply is less than 10 parts per billion (10ppb) or equivalent to two tablespoons in an Olympic-sized pool," said PUB, adding that trace amounts of the highly soluble compound has no adverse impact on health.

"The water supply remains fully potable and safe for consumption straight from the tap."

Any smell still detected could be due to remnants of the affected water in the pipes.

"This can be resolved by running your taps for about five minutes to flush out the water," said the agency.

The agency reiterated on July 24 that water remains potable from taps and that the trace amounts of THF is "harmless" and would not have been detected by screening technologies currently available.

https://mothership.sg/2020/07/pandan-smell-tap-water/