For the second time in less than a week, the Croydon arm of the Wandle has suffered a worrying pollution incident.

Following last Thursday’s slug of coloured water, yesterday evening’s heavy rain appeared to wash a large volume of diesel through Croydon’s surface water drains – and from there into the Wandle.

Floating as a smelly, sheeny layer on the surface rather than affecting the whole water column, much of the spill now seems to have been contained in the lake at Beddington Park with Environment Agency booms (we’ve also got oily water samples from the river at Shepley Mill, from about 9.00am this morning).

However, a specialist cleanup operation will be necessary, and several swans have already been rescued by our friends at the nearby London Wildcare Hospital.

Once again, we owe a debt of gratitude to more than 20 local residents and Wandle Trust supporters who called the incident into the Environment Agency’s hotline.

As before, we’d also be very keen to discover any more about where this pollution started: surely someone must have noticed what one of our sources called “losing a large quantity of red diesel” in the last few days?