In a statement, SPAN said failure to do so was an offence under the Water Services Industry Act.

“As a regulatory body we had to ensure that Air Selangor cut off the water supply immediately after discovering water pollution at two rivers.”

SPAN said if water continued to be supplied by the treatment plants it would have endangered the health of consumers.

Last night, the Federation of Malaysian Consumers Associations (Fomca) called for stringent action against Air Selangor following the unscheduled water disruptions in Kuala Lumpur and Selangor due to the water pollution.

Fomca president Marimuthu Nadason also slammed SPAN for not holding Air Selangor accountable, which he said led to its lack of caution and urgency.

SPAN must fine Air Selangor so that it would be more cautious, he said.

Marimuthu also claimed that SPAN lacked serious contingency plans, especially for hospitals and schools.

Odour pollution at Sungai Kundang and Sungai Sembah led to the temporary shutdown of four water treatment plants, resulting in unscheduled water disruptions in hundreds of areas across Kuala Lumpur and Selangor.

Air Selangor mobilised water tankers to the affected areas of Kuala Lumpur, Petaling, Klang, Shah Alam, Gombak, Hulu Selangor, and Kuala Selangor.

Today, SPAN said it had instructed all water operators to have contingency plans to provide treated water to consumers in the event of an unscheduled disruption, especially to “critical premises”.

“In the latest incident, Air Selangor has taken measures to mitigate the water disruptions, including mobilising water tankers to affected areas,” it said.