The Sungai Semeyih water treatment plant resumed operations at 12.30pm yesterday, less than four hours after it was shut in response to a diesel odour pollution incident.

Selangor Tourism and Environment Committee chairperson Hee Loy Sian said after receiving information from Pengurusan Air Selangor Sdn Bhd regarding odour pollution at 8.45am, Lembaga Urus Air Selangor (Luas) investigated a factory doing maintenance work on heavy machinery.

Hee said the investigation found there was a...