By the sounds of it, it was sludge that somehow escaped the PD refinery battery limits into the local drainage system. This is the stuff that accumulates at the bottom of crude storage tanks, consisting of some heavy hydrocarbon and a whole lot of gunk.
The incident is being investigated, and hopefully measures will be put in place so that such occurrences don't happen again in the future.
Oil leak from refinery causes scare in PD
PORT DICKSON: Residents at the resort town here had a fright when unprocessed fuel from the Shell refinery leaked into nearby waterways while the plant was closed for maintenance work over the weekend.
It could not be immediately ascertained how much fuel had leaked from the refinery.
The residents saw scores of men in white overalls working round the clock to clean up the mess after the incident occurred at about 3pm on Saturday.
Workers from Shell and the Petroleum Industry Malaysia Mutual Aid Group helping to clear oil sludge from a monsoon drain in Port Dickson, Negri Sembilan on Monday. The unprocessed fuel from the Shell refinery leaked into nearby waterways while the plant was closed for maintenance work over the weekend. — UU BAN LEONG / The StarRead more at thestar.com.my