This caused serious injuries to staff on duty, Syarikat Bekalan Air Selangor (Syabas) said in a statement today.

Details of the injuries and what happened to the workers were not disclosed.

Water supply to large parts of Selangor was affected from this morning to enable repair works to be carried out on critical equipment at the Sungai Selangor Phase 3 Water Treatment Plant (SSP3).

Syabas customer relations and communication department head Abdul Raof Ahmad told Bernama in a statement that the repair work was completed ahead of time at 5pm today.

He said the unexpected incident occurred as the plant was about to resume operations.

He said officials of the National Water Services Commission (SPAN), with those from Water Management Sdn Bhd and Syarikat Pengeluar Air Selangor Sdn Bhd (Splash), were present at the scene during the incident.

Splash had then informed SPAN and the Department of Occupational Safety and Health (DOSH) regarding the incident, he said.

Raof said following the incident, the original schedule for the water supply restoration had been affected and it may take longer to restore water supply.

The shutdown affects areas in Petaling, Klang, Shah Alam, Gombak, Kuala Lumpur, Kuala Langat and Hulu Selangor.

The Petaling region is expected to see water supply disruption from 8am today to 9pm tomorrow.

Klang and Shah Alam will be affected from 8am today to 9am on Friday; Gombak till midnight on Thursday; Kuala Lumpur till 9pm on Thursday; Kuala Langat till 3pm tomorrow; and Hulu Selangor till 9pm tomorrow.

Rauf said Syabas would continue to send water tankers to the affected areas.

The one-stop service centre would be in operations for 24 hours until the water supply is fully restored, Rauf said.

He also urged for customers’ cooperation and understanding over the incident and assured that all necessary action was being taken to minimise the impact of the water supply disruption.