Air Selangor said work started at 9am and is expected to be completed by 11pm.

It said the water supply will resume in stages starting at 5pm tomorrow once the supply system has been stabilised.

Previously, Air Selangor had said the shutdown of the treatment plant was expected to affect water supply in 998 areas in the state from today to Oct 16.

The areas include the districts of Petaling, Klang, Shah Alam, Gombak, Kuala Lumpur, Hulu Selangor, Kuala Langat and Kuala Selangor.

“The duration of the water supply disruption and recovery in the affected areas would vary depending on the distance of the consumers’ premises and the water pressure at the distribution system,” Air Selangor said in a statement.

It said more information would be provided from time to time through its official social media accounts and its 15300 hotline number.

Any queries and complaints may be directed to the help centre at www.airselangor.com and through its app.