SINGAPORE - A contractor which tainted the water supply at Changi Airport Terminal 3 while carrying out pipe diversion works earlier this year has been fined $9,000, national water agency PUB said on Tuesday.

Sam Lain Equipment Services Pte Ltd was slapped with a composition fine of $5,000 for engaging five unlicensed workers to carry out water service works. PUB also issued each worker a warning letter, it said in a news release.

The $9,000 fine will be paid to the court, while the $5,000 composition fine will be paid to PUB.

The incident happened on Jan 29, when food and beverage retailers at Terminal 3 found light brown water flowing from their taps at about 3pm.

This resulted in a temporary shutdown of T3's water supply as the affected water tank was cleaned and workers flushed the internal service pipes.

Retailers also halted the sales of drinks and some food items such as soup for about two hours, while Changi Airport Group (CAG) distributed water to affected food outlets, employees and airport visitors.

The water supply at T3 returned to normal only on the following day.

Joint investigations by the CAG and PUB showed that a pipe diversion operation carried out by contractor Sam Lain Equipment Services Pte Ltd had failed to follow the PUB's procedures when carrying out pipe diversion operations, resulting in the water turning cloudy.