MIRI, June 9 -- Sarawak Water Sdn Bhd will begin preliminary testing on affected transmission pipelines at 10pm tonight to identify the source of a major leak here.

Sarawak Water acting chief executive officer Malseni Jamal said the assessment would involve temporarily shutting off a 750mm valve to establish whether the leak originates from the 750mm pipeline or the larger 1.1 metre pipeline.

"If the leak is traced to the 750mm pipeline, approximately 20,000 households, representing about 30 per cent of consumers in Miri could be affected when repair works commence on Wednesday (June 10), with valve closure scheduled for 5pm," she told a press conference.

Malseni said if the leak is traced to the 750mm pipeline, the areas affected woul...