Syarikat Bekalan Air Selangor Sdn Bhd (Syabas) said its Sungai Selangor Phase 1, 2, 3 and Rantau Panjang treatment plants have resumed full operations after being suspended yesterday for pollution at the water source.
However, Syabas said it will take time for the water supply in Klang Valley to be fully restored.
"We are still in the process of raising and stabilising the reservoir levels and pressure in the distribution system for supply restoration process in stages.
"Based on the monitoring, as at 6am today, the restoration percentage of the total areas is still low at 19 percent and we are not able to provide water restoration estimates at the moment," it said in a statement.
Syabas added that an investigation, together with the authorities, has identified the source of the pollution.
"The investigations show that the high level of odour originates from Sungai Liam in Batang Kali, Hulu Selangor.
"Relevant enforcement agencies will make a public announcement with regards to the pollution from the area," he said.
Yesterday, Syabas said the pollution had affected a total of 1,133 areas in Kuala Lumpur, Petaling, Klang, Shah Alam, Kuala Selangor, Hulu Selangor, Gombak and Kuala Langat, affecting more than a million households.
This had also forced Syabas to suspend its schedule maintenance to the Sungai Selangor Phase 1 water treatment plant, which would have seen water disruption for up to three days.
Syabas said as the current unscheduled water disruption involves large-scale areas, it will have to prioritise critical premises and emergencies for supply via water tanker.
It advised customers who require water to visit one of its 16 local service centres and 17 public water taps for relief water supply.