The company’s head of customer relations and communication, Abdul Raof Ahmad, said the Rantau Panjang WTP had to stop operations at 6pm yesterday, followed by the WTP SSP3 at 8pm and WTP SSP1 and WTP SSP2 at 8.15pm.

He said in a statement that the source of pollution was sand digging activities at the upper reaches of the river, and that the incident had been reported to the authorities.

“This is the second incident within three days involving the closure of all four major water treatment plants, causing large-scale water supply disruption to the customers,” said Raof, referring to similar action taken on Friday following odour pollution.

He said Air Selangor could not ascertain the time frame for recovery if similar pollution of raw water resources recurred.

On Friday, 1,133 areas involving 1,166,842 customer accounts in Kuala Lumpur and Selangor were affected by an unscheduled water supply disruption following odour pollution at the Sungai Selangor raw water source.

In a statement earlier yesterday, Air Selangor said it was targeting the full recovery of water supply in all affected areas by midnight on July 22 before it issued a separate statement on work stoppage at the four water treatment plants.