Air Selangor said the Sungai Semenyih and Bukit Tampoi water treatment plants had to completely stop operations following pollution detected in Sungai Semenyih, the raw water source for these plants.

However, Selangor Menteri Besar Amirudin Shari said later this evening that the source of the pollution was detected 30km away from the Sungai Semenyih water treatment plant in Sungai Batang Benar, Negeri Sembilan.

“I have contacted the Negeri Sembilan menteri besar to solve this issue together,” Amirudin said.

Air Selangor said the suspension of the two treatment plants would affect 273 areas and 309,605 consumers. There would be unscheduled water supply disruptions across four districts: Petaling, Hulu Langat, Kuala Langat and Sepang.

“Air Selangor has reported this incident to the Selangor Water Management Authority (LUAS) and measures are being taken to identify the source of water pollution in and around Sungai Semenyih,” it said in a statement.

Air Selangor said it could not provide an expected time frame for when the water supply would resume as normal.

Nearly 1.2 million consumer accounts in the Klang Valley were affected by unscheduled water cuts in early September after four treatment plants ceased operations due to pollution from a factory.

A total of 1,292 areas in the Klang Valley, Petaling, Klang/Shah Alam, Kuala Selangor, Hulu Selangor, Gombak and Kuala Langat were affected.