The discoloured tap water that appeared at the Basic Military Training (BMT) Centre on Pulau Tekong last November was due to "naturally occurring minerals", said Minister for the Environment and Water Resources Masagos Zulkifli yesterday.
He also said national water agency PUB will work with the centre to clean the water mains in the first half of this year.
The minister told Parliament that PUB officers went into action when the discoloured tap water at some parts of the centre was reported at 7.30am on Nov 20.
They looked into the cause, brought water wagons to provide temporary water supply to the servicemen and flushed the water supply network on Pulau Tekong.
PUB also did water sampling tests to ensure the water was safe to drink and within the drinking water quality standards of the Environmental Public Health Regulations 2019, and the World Health Organisation's guidelines.
Water supply was fully restored at 9.30pm the next day.
Mr Masagos said PUB's investigations found that the minerals in the centre's pipes were "churned up", affecting the appearance of the water.
The tap water became clear again after the flushing, he added.
As a preventive measure, PUB will clean the water mains in the first half of this year, when there is a break in the centre's training schedule, he said.