My Chief Instructor was teaching on the strats today, the word on the strait is that somone dumped their central heating oil (2 tonnes of) down an old drain pipe which runs in the straits in Y Felinheli (Port Denorwic).
The bbc website says it came from a disused sewage treatment plant and
"It was said to be made up of a number of industrial oils including diesel, generator fluid and heating oil."
