KUALA LUMPUR, Oct 19 — The pollution of Sungai Selangor behind the current Klang Valley supply disruption was caused by intentional dumping some time after midnight today, said Environment and Water Minister Datuk Seri Tuan Ibrahim Tuan Man, reports Astro Awani. 

Tuan Ibrahim said his ministry was investigating the incident that left millions in the region without water supply again.

According to Astro Awani, he said the culprits were suspected to have dumped the pollutants late at night during the weekend to avoid detection.

"Maybe during those times when people were not working, these irresponsible parties took the opportunity [to pollute the river],’’ he said during a press conference today. 

He also vowed that there will be no compromise with those found to be responsible for the latest incident.

Tuan Ibrahim said the pollution reached a threshold odour number (TON) of three at one point, but has since declined to one.

The TON measures the dilution factor of odour pollutants in drinking water.

"We hope it will end soon,” he said

"We will act decisively against those who pollute our water resources with the law and authority of the Ministry,” he said. 

Tuan Ibrahim also urged members of the public to come forward and provide information on the incident. 

He said such reports would allow authorities to act quickly.

"We are not able to control all industrial plants and places, so we encourage the public to help,” he said, adding that those who come forward with relevant information could stand to be rewarded. 

Earlier today, Pengurusan Air Selangor Sdn Bhd (Air Selangor) announced an unscheduled water cut affecting over a million accounts in Selangor and the Klang Valley today. 

This was due to contamination detected in the Sungai Selangor river at 2am today, which force a stop-work order on Phase 1, 2, 3 and Rantau Panjang water treatment plants 

This is the second time in as many months that water supply to the Klang Valley has been disrupted due to illegal dumping.