I decided against risking the chainsaw I mentioned a week or so ago and have
been hacking away at the roots of this big tree. Today I finally managed to
topple it (surprisingly easy - no roots going down, all were going outwards
maybe due to the high clay content of the ground?)

Anyway, there was a funny smell once I toppled it that I cant quite put my
finger on. Smells a bit like creosote (and a patch of the soil underneath
looks a bit oily), but there is something else I cant quite figure out. I
asked the guy in the garden behind (tree was next to the garden fence) if he
had spilt any oil/creosote but he said no. Apparently there is a sewer
running underneath the end of all the gardens on our row, but I have only
dug down about 18" and I havent come across any pipes (although I did find a
lot of water last week that kept filling up the hole within seconds!?).

Is this normal to get such a smell, or is there something more sinister
afoot???

cheers

da.