blue sheen on tarmac after woodchipper used

[arbitration]

A neighbour had some work done on a horse chestnut tree and the woodchipper was parked on my drive. The chaps cleaned up pretty well but as the next morning's 1 cm on snow began to melt I noticed a blue sheen in the area under and around the woodchipper and by the random wood chips that had escaped but weren't cleaned up. It wasn't the thin film rainbow spectrum you get from engine oil and the like but more a pale royal blue sort of colour. Any ideas if this is from the horse chestnut's sap/oils or from some sort of biodegradable chipper or saw oil? Not complaining, just curious.

[nickos]

From the tree, common on Horse chestnut in the wet!

[Shane]

I saw exactly the same thing last week.

Reducing horse chestnut (in the rain) looked like oil had been leaking all over the place,

including a trail into the back garden. Looked like someone had removed the oil cap from a chainsaw then run around shaking it.

[bumble B]

I was using a JCB to push a load of Horse Chestnut up. The yard mechanic started going potty he thought I had smashed the sump because there was so much of what looked like engine oil all over the wet concrete.

[Gary Prentice]

Its simply a water soluble chemical from the trees, it shouldn't last and should wash away naturally. We see it often with some wood in wet weather, from beneath the chipper and even draining from the chip in the back of the pickup.

[Shane]

It certainly is worth being aware of it - in case customers think your poorly maintained machine has unloaded its lifeblood all over their driveway.

[arbitration]

thanks for all the replies - every day's a school day

 

the chippings also didn't give off the most pleasant of smells

[Joy Yeomans]

Horse chestnut and oak are packed with tannins that gives the blue colour especially on a metal blade like log splitter

[Tom D]

The blue colour is specific to HC and is a compound called aesculin I believe, its a sugar based compound not a tannin.

[AA Teccie (Paul)]

The blue colour is specific to HC and is a compound called aesculin I believe, its a sugar based compound not a tannin.

 

Need to be careful where there is a possibility of leaching into adjacent water courses as in a previous case the EA prosecuted a tree surgeon for (inadvertently) allowing so and killing some fish...or similar.

 

Cheers..

Paul